%0 journal article %@ 2213-9567 %A Wang, S.,Huang, Y.,Yang, L.,Zeng, Y.,Hu, Y.,Zhang, X.,Sun, Q.,Shi, S.,Meng, G.,Hort, N. %D 2023 %J Journal of Magnesium and Alloys %N 1 %P 259-269 %R doi:10.1016/j.jma.2021.04.002 %T Microstructure and mechanical properties of Mg-3Sn-1Ca reinforced with AlN nano-particles %U https://doi.org/10.1016/j.jma.2021.04.002 1 %X Microstructural evolution and strengthening mechanisms of Mg-3Sn-1Ca based alloys with additions of different amounts of AlN nano-particles were investigated. It was found that with increasing the amount of AlN nano-particles the grain size decreases obviously. The existence of AlN nano-particles could refine the primary crystal phases CaMgSn, which provided more heterogeneous nucleation sites for the formation of magnesium. Moreover, such nano-particles could also restrict the grain growth during solidification. After adding AlN nano-particles, both the tensile properties at room temperature and high temperature 250 °C and the hardness are largely improved. The improvement of strength is attributed to grain refinement and second phase refinement. %0 journal article %@ 2213-9567 %A Xu, Y.,Huang, Y.,Wang, Y.,Gan, W.,Wang, S.,Maawad, E.,Schell, N.,Hort, N. %D 2023 %J Journal of Magnesium and Alloys %N 2 %P 607-613 %R doi:10.1016/j.jma.2021.06.011 %T Investigations on the tensile deformation of pure Mg and Mg–15Gd alloy by in-situ X-ray synchrotron radiation and visco-plastic self-consistent modeling %U https://doi.org/10.1016/j.jma.2021.06.011 2 %X In this study, the texture evolutions of two Mg materials during tension are explored. In-situ X-ray synchrotron and Visco-Plastic Self-Consistent (VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg–15Gd (wt.%) alloy. These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation. The basal (a) slip has the highest contribution to the initial stage of plastic deformation for pure Mg. During the subsequent plastic deformation, the prismatic slip is dominant due to the strong ED // (100) fiber texture. In contrast, the deformation behavior of Mg–15Gd alloy is more complex. Twinning and basal slip are dominant at the early stage of plastic deformation, but further deformation results in the increased activation of prismatic and pyramidal slips. In comparison to pure Mg, the ratios of the critical resolved shear stress (CRSS) between non-basal slip and basal slip of the Mg–15Gd alloy are much lower. %0 journal article %@ 2213-9567 %A Yang, L.,Huang, Y.,Hou. Z.,Xiao, L.,Xu, Y.,Dong, X.,Li, F.,Kurz, G.,Sun, B.,Li, Z.,Hort, N. %D 2023 %J Journal of Magnesium and Alloys %N 8 %P 2763-2775 %R doi:10.1016/j.jma.2021.08.010 %T Microstructure, mechanical properties and fracture behaviors of large-scale sand-cast Mg-3Y-2Gd-1Nd-0.4Zr alloy %U https://doi.org/10.1016/j.jma.2021.08.010 8 %X In order to improve the ductility of commercial WE43 alloy and reduce its cost, a Mg-3Y-2Gd-1Nd-0.4Zr alloy with a low amount of rare earths was developed and prepared by sand casting with a differential pressure casting system. Its microstructure, mechanical properties and fracture behaviors in the as-cast, solution-treated and as-aged states were evaluated. It is found that the aged alloy exhibited excellent comprehensive mechanical properties owing to the fine dense plate-shaped β' precipitates formed on prismatic habits during aging at 200 °C for 192 hrs after solution-treated at 500 °C for 24 hrs. Its ultimate tensile strength, yield strength, and elongation at ambient temperature reach to 319 ± 10 MPa, 202 ± 2 MPa and 8.7 ± 0.3% as well as 230 ± 4 MPa, 155 ± 1 MPa and 16.0 ± 0.5% at 250 °C. The fracture mode of as-aged alloy was transferred from cleavage at room temperature to quasi-cleavage and ductile fracture at the test temperature 300 °C. The properties of large-scale components fabricated using the developed Mg-3Y-2Gd-1Nd-0.4Zr alloy are better than those of commercial WE43 alloy, suggesting that the new developed alloy is a good candidate to fabricate the large complex thin-walled components. %0 journal article %@ 2213-9567 %A Jia, G.,Zhou, M.,Huang, Y.,Chen, C.,Jin, L.,Wu, Q.,Weng, J.,Yu, F.,Xiong, A.,Yuan, G.,Feyerabend, F.,Zeng, H. %D 2023 %J Journal of Magnesium and Alloys %N 6 %P 2054-2060 %R doi:10.1016/j.jma.2021.10.011 %T Effects of dynamic flow rates on degradation deposition behavior of Mg scaffold %U https://doi.org/10.1016/j.jma.2021.10.011 6 %X Degradability of bone tissue engineering scaffold that matching the regeneration rate could allow a complete replacement of host tissue. However, the porous structure of biodegradable Mg scaffolds certainly generated high specific surface area, and the three-dimensional interconnected pores provided fast pervasive invasion entrance for the corrosive medium, rising concern of the structural integrity during the degradation. To clarify the structural evolution of the three-dimensional (3D) porous structure, semi-static immersion tests were carried out to evaluate the degradation performance in our previous study. Nevertheless, dynamic immersion tests mimicking the in vivo circulatory fluid through the interconnected porous structure have yet been investigated. Moreover, the effects of dynamic flow rates on the degradation deposition behavior of 3D porous Mg scaffolds were rarely reported. In this study, Mg scaffolds degraded at three flow rates exhibited different degradation rates and deposition process. A flow rate of 0.5 mL/min introduced maximum drop of porosity by accumulated deposition products. The deposition products provided limited protection against the degradation process at a flow rate of 1.0 mL/min. The three-dimensional interconnected porous structure of Mg scaffold degraded at 2.0 mL/min well retained after 14 days showing the best interconnectivity resistance to the degradation deposition process. The dynamic immersion tests disclosed the reason for the different degradation rates on account of flow rates, which may bring insight into understanding of varied in vivo degradation rates related to implantation sites. %0 journal article %@ 0169-4332 %A Yao, X.,Tang, J.,Zhou, Y.,Huang, Z.,Xu, J.,Long, Y.,Tan, L.,Wiese, B.,Ebel, T.,Yan, M. %D 2022 %J Applied Surface Science %N %P 152229 %R doi:10.1016/j.apsusc.2021.152229 %T Selective laser melting of an Mg/Metallic Glass hybrid for significantly improving chemical and mechanical performances %U https://doi.org/10.1016/j.apsusc.2021.152229 %X Pure magnesium (Mg) is widely used as biomedical material, but its degradation rate is often too high and problematic to clinic applications. In this study, selective laser melting (SLM) was used to prepare an Fe-based metallic glass surface on a pure Mg substrate, forming a hybrid material to explore the advantage associated with such designed structure. It was found that the corrosion resistance was significantly improved with the hybrid material (from 0.89 ± 0.1 mm/a to 0.11 ± 0.03 mm/a in simulated body fluid), along with much increased hardness from 0.46 GPa to 14.3 GPa. The metallic glass surface was shown to retain its amorphous nature after the SLM processing. The molten pool formed by the applied laser beam resulted in a good mechanically interlocked bonding between the metallic glass layer and the Mg matrix. It was further revealed that the metallic glass surface had better wetting property than the Mg substrate, explaining why the MG-63 cells had good adhesion to it. The cell toxicity test was followed under the in vitro condition, indicating no toxicity in the metallic glass part. The results provide a feasible way to develop advanced Mg materials for biomedical applications via the capable SLM technology and via the suggested hybrid material. %0 journal article %@ 2452-199X %A Krüger, D.,Galli, S.,Zeller-Plumhoff, B.,Wieland, F.,Peruzzi, N.,Wiese, B.,Heuser, P.,Mossmann, J.,Wennerberg, A.,Willumeit-Römer, R. %D 2022 %J Bioactive Materials %N %P 37-52 %R doi:10.1016/j.bioactmat.2021.10.041 %T High-resolution ex vivo analysis of the degradation and osseointegration of Mg-xGd implant screws in 3D %U https://doi.org/10.1016/j.bioactmat.2021.10.041 %X Biodegradable magnesium (Mg) alloys can revolutionize osteosynthesis, because they have mechanical properties similar to those of the bone, and degrade over time, avoiding the need of removal surgery. However, they are not yet routinely applied because their degradation behavior is not fully understood.,In this study we have investigated and quantified the degradation and osseointegration behavior of two biodegradable Mg alloys based on gadolinium (Gd) at high resolution.,Mg-5Gd and Mg-10Gd screws were inserted in rat tibia for 4, 8 and 12 weeks. Afterward, the degradation rate and degradation homogeneity, as well as bone-to-implant interface, were studied with synchrotron radiation micro computed tomography and histology. Titanium (Ti) and polyether ether ketone (PEEK) were used as controls material to evaluate osseointegration.,Our results showed that Mg-5Gd degraded faster and less homogeneously than Mg-10Gd. Both alloys gradually form a stable degradation layer at the interface and were surrounded by new bone tissue. The results were correlated to in vitro data obtained from the same material and shape. The average bone-to-implant contact of the Mg-xGd implants was comparable to that of Ti and higher than for PEEK. The results suggest that both Mg-xGd alloys are suitable as materials for bone implants. %0 conference paper %@ %A Hort, N.,Maier, P. %D 2022 %J Magnesium Technology 2022 %N %P 165-168 %R doi:10.1007/978-3-030-92533-8_28 %T To Fail or Not to Fail %U https://doi.org/10.1007/978-3-030-92533-8_28 %X When new research topics appear, theoretical approaches are developed, predictions are made, and expectations are raised. However, experiments, modelling and simulations often show results that do not fit the expectations and the theories that were used to design the models and experiments appear to be incomplete or even wrong, or better to say unexpected. These results are often regarded as “bad” results and the conclusion of a failure is drawn! This leads often to the fact that these theories and results are not published. We think that this is the wrong approach as any result is a “good” result. It is a useful result, which can be used for further decisions, adaption of models and experiments. Therefore, we would like to raise attention on this issue and encourage everybody to publish even “bad” results, providing their discussion. These results could be helpful in the design of research strategies or in the identification of new research areas. %0 journal article %@ 1438-1656 %A You, S.,Huang, Y.,Dieringa, H.,Maawad, E.,Gan, W.,Zhang, Y.,Kainer, K.,Willumeit-Römer, R.,Hort, N. %D 2022 %J Advanced Engineering Materials %N 4 %P 2101033 %R doi:10.1002/adem.202101033 %T Effects of Y Additions on the Microstructures and Mechanical Behaviours of as Cast Mg–xY–0.5Zr Alloys %U https://doi.org/10.1002/adem.202101033 4 %X Previous investigations demonstrated that rare-earth elements (REs) could improve their creep properties effectively. Herein, the influence of Y content on the creep properties of magnesium is investigated systematically with different amount of Y additions. The mechanisms responsible for creep deformation are clarified by the analysis of stress exponent and microstructural characterizations. It is found that the addition of Y in Mg can improve both the ambient strength and high temperature strength owing to its effective solid solution strengthening. At room temperature, the yield strength of Mg–Y alloys has a linear relation with the content of Y. When tested at high temperatures, the yield strength reduces. Compared with pure magnesium, Mg–Y alloys exhibit a high thermal stability even above 200 °C. Small amount of Y addition can improve the creep resistance of Mg largely. With further increasing its content, its contribution to the improvement of creep resistance is weakened for Mg. Under the applied stresses 60–100 MPa and at temperatures of 200–250 °C, the responsible creep mechanism is dislocation controlled. During creep deformation, the Y segregation regions play an important role in hindering the movement of dislocations. %0 journal article %@ 0921-5093 %A Yang, H.,Jiang, B.,Huang, G.,Huang, Y.,Jin, Y.,Gavras, S.,Dieringa, H. %D 2022 %J Materials Science and Engineering: A %N %P 142358 %R doi:10.1016/j.msea.2021.142358 %T Revealing the role of Al in the microstructural evolution and creep properties of Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn alloy %U https://doi.org/10.1016/j.msea.2021.142358 %X The influence of Al (0.5 wt%, 1 wt%, 2 wt%) on the microstructural evolution and creep resistance of Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn (El21) alloy was systematically investigated. The creep results revealed that the additions of 0.5 wt% and 1 wt% Al significantly decreased the creep rate of El21 by more than an order of magnitude, whereas 2 wt% Al in El21 led to the reduction of creep properties. Microstructural analyses indicated that the additions of 0.5 wt% and 1 wt% Al led to significant grain coarsening due to the consumption of Zr via the formation of Al2Zr3 and Al2Zr phases. In contrast, the addition of 2 wt% Al caused distinct grain refinement, resulting from the additional formation of lumpy Al2RE in the centre of α-Mg grains. Additionally, the increase of Al content in the El21 gradually led to the disappearance of the Mg3RE phase and left Al2RE as the only dominant phase. The main Al–Zr phase was also changed from Al2Zr3+Al2Zr to Al2Zr phase. Creep data analysis showed that the dominant creep mechanism was dislocation creep for all alloys, which was in agreement with the EBSD and TEM characterizations. The enhanced creep resistance via the addition of 0.5 wt% and 1 wt% Al was ascribed to the high area fraction of intermetallic phases and the additional formation of the thermally stable Al2RE phase. El21 + 0.5Al has better creep resistance than El21+1Al, which was attributed to its stronger dynamic precipitation strengthening from γ precipitates. The deteriorated creep properties caused by adding 2 wt% Al in El21 alloy arose from the bimodal inhomogeneous distribution of grains and the laminar Al2RE phase. Such microstructure might cause significant stress concentrations and could not effectively impede dislocation motion or reinforce the grain/dendritic boundaries during creep, thus deteriorating the creep properties of El21+2Al. %0 journal article %@ 1005-0302 %A Liu, Q.,Song, J.,Huang, Y.,Jiang, B.,Xiao, B.,Pan, F. %D 2022 %J Journal of Materials Science & Technology %N %P 24-35 %R doi:10.1016/j.jmst.2021.09.033 %T Comparison of edge cracking and tensile cracking in in-situ deformation at 150°C of Mg-2Zn-1.5Mn alloy sheet %U https://doi.org/10.1016/j.jmst.2021.09.033 %X The Mg-2Zn-1.5Mn alloy (ZM21) sheets were hot-rolled in a single pass at 150 °C with different reductions through on-line heating rolling. Microstructures and edge cracking behavior of the rolled sheets were investigated. The in-situ tensile tests at 150 °C were also carried out, the crack initiation and propagation were compared with the edge cracking behavior of ZM21 sheets prepared by on-line heating rolling. The results reveal that the edge cracks are most likely to originate in the rolling direction and normal direction (RD-ND) plane due to the secondary tensile stress along RD. Edge cracking becomes more severe with an increasing reduction. The edge cracks mainly initiate and propagate in the fine recrystallized grain areas and the junction of recrystallized grains and sub-grains with hard orientation. The in-situ tensile test indicates that micro-cracks mainly initiate at the triple junction of grain boundaries where grains have hard orientation with low basal Schmid factor (SF). Meanwhile, those cracks are more likely to propagate along the grain boundaries with maximum difference in basal Schmid factor. Besides, the crack initiation and propagation during the in-situ tensile deformation at 150 °C are found not to be associated with the recrystallization. %0 journal article %@ 2238-7854 %A Zhao, D.,Zhao, C.,Chen, X.,Huang, Y.,Hort, N.,Gavras, S.,Pan, F. %D 2022 %J Journal of Materials Research and Technology : JMRT %N %P 944-959 %R doi:10.1016/j.jmrt.2021.12.053 %T Compressive deformation of as-extruded LPSO-containing Mg alloys at different temperatures %U https://doi.org/10.1016/j.jmrt.2021.12.053 %X This work investigates the compressive deformation behavior of as-extruded Mg-6Gd-1.6Y–1Zn-0.4Zr (VZ61) and Mg-6Gd-4.8Y–3Zn-0.4Zr (VZ63) alloys via uniaxial compressive tests at various deformation temperatures. At room temperature, compared with the VZ61 alloy, the compressive yield strength of the VZ63 alloy were obviously enhanced due to its increased amount of LPSO phase. Both alloys exhibited a three-stage strain hardening feature. The strain hardening rate first sharply decreases (stage I), then continues to increase at a slower rate (stage II) and finally decreases (stage III). At stage III, a larger number of dislocation accumulation around the kinked LPSO phase resulted in a higher strain hardening rate for VZ63 alloy than that for VZ61 alloy. During high temperature compression, the true stress–strain curves showed that the flow stress gradually reduced with increasing temperature and also the reducing of strain rate, and the VZ63 alloy displayed a higher peak stress than VZ61 alloy. Constitutive equations were constructed based on the true stress–strain to better understand the relation among flow tress (σ), strain rate () and deformation temperature (T) in VZ alloys during hot deformation. The results showed that the VZ63 alloy had a lower deformation activation energy (Q = 255.6 kJ/mol) than VZ61 alloy (Q = 395.5 kJ/mol). The DRX kinetic models of the VZ61 and VZ63 alloys were also established, indicating that the VZ63 alloy was more prone to DRX with a higher volume fraction of dynamically recrystallized grains (XDRX) at the same deformation conditions. %0 journal article %@ 2047-4849 %A Sun, Y.,Helmholz, H.,Will, O.,Damm, T.,Wiese, B.,Luczak, M.,Peschke, E.,Luthringer-Feyerabend, B.,Ebel, T.,Hövener, J.,Glüer, C.,Willumeit-Römer, R. %D 2022 %J Biomaterials Science %N 6 %P 1532-1543 %R doi:10.1039/D2BM00051B %T Dynamic in vivo monitoring of fracture healing process in response to magnesium implant with multimodal imaging: Pilot longitudinal study in a rat external fixation model %U https://doi.org/10.1039/D2BM00051B 6 %X Rodent models are commonly used in pre-clinical research of magnesium (Mg) -based and other types of biomaterials for fracture treatment. Most studies selected unstable fixation methods, and there is a lack of multimodal longitudinal in vivo monitoring of bone healing. The purpose of this study is to develop a rat femoral fracture model stabilized by external fixation with intra-medullary Mg implant, and to investigate the dynamic bone union process with several imaging techniques offering complementing insights into the process. Pure Mg pins were prepared, followed by in vitro degradation test. Male Sprague-Dawley rats in the experimental group underwent femoral osteotomy stabilized by external fixators with intra-medullary implantation of Mg pins, and the control group underwent external fixation without intra-medullary implants. Post-operative radiograph, micro-CT and B-mode ultrasonography were acquired directly after surgery, and re-examined at week 4, 8 and 12. Bone tissue volume, in vivo implant degradation, histological staining and MRI images were analyzed using ex vivo samples. Both groups achieved fracture union at week 12, and the dynamic healing process was illustrated by in vivo radiograph, micro-CT and ultrasonography. Bilateral whole femur ex vivo analysis further demonstrated increased ratio of bone tissue volume in the surgical femur with Mg implants, and in vivo degradation of Mg pins was slower than in vitro results. Titanium screws rather than intra-medullary Mg pins were the source of artifact in MRI. This pilot study showed the rat fracture model with external fixation and intra-medullary Mg implantation, to be an effective method for dynamic in vivo monitoring of the bone healing process. Future application of the animal model may facilitate pre-clinical translational research of biodegradable orthopaedic implant materials for fracture treatment. %0 journal article %@ 1438-1656 %A Li, X.,Hofmann, M.,Landesberger, M.,Reiberg, M.,Zhang, X.,Huang, Y.,Wang, L.,Werner, E.,Gan, W. %D 2021 %J Advanced Engineering Materials %N 11 %P 2100163 %R doi:10.1002/adem.202100163 %T A Unique Quenching and Deformation Dilatometer for Combined In Situ Neutron Diffraction Analysis of Engineering Materials %U https://doi.org/10.1002/adem.202100163 11 %X A modified quenching and deformation dilatometer (TA instruments DIL 805A/D/T) is now in operation at the Heinz Maier‐Leibnitz Zentrum (MLZ, Germany) neutron center. It is customized for running neutron scattering measurements during the temperature/deformation treatment of the sample, in particular neutron diffraction (phase, texture, lattice strain) and neutron small angle scattering. The bulk length change of dilatometer specimens is successfully combined with in‐situ neutron diffraction patterns for analyzing dynamic processes in metallic materials. A detailed introduction to the unique dilatometer is given and examples of recent experiments highlight the use of the added insight provided by combining diffraction and dilatometry. %0 journal article %@ 2213-9567 %A Yang, L.,He, S.,Yang, C.,Zhou, X.,Lu, X.,Huang, Y.,Qin, G.,Zhang, E. %D 2021 %J Journal of Magnesium and Alloys %N 2 %P 676-685 %R doi:10.1016/j.jma.2020.09.015 %T Mechanism of Mn on inhibiting Fe-caused magnesium corrosion %U https://doi.org/10.1016/j.jma.2020.09.015 2 %X In the present study, to understand the mechanism of Mn on inhibiting Fe-caused Mg corrosion, the corrosion behaviour of commercial pure Mg and Mg-6Mn alloy in 0.6 M NaCl solution is investigated. It is found that in Mg-6Mn alloy, Fe impurity is incorporated into Mn to form Mn (Fe) phase with Fe as solid solute. The initial galvanic corrosion cannot be reduced through converting Fe-rich phase to Mn (Fe) phase, since Mn (Fe) phase also has relatively strong cathodic activity and has much larger volume fraction than Fe-rich phase. However, the cathodic activation behaviour of pure Mg is inhibited. The cathodic activity even decreases for Mg-Mn alloy with increased exposure time, due to the reduced cathodic HER at the Mn (Fe) particles. Mn can be oxidized at the OCP of Mg-6Mn alloy, resulting in relatively dense Mn-rich corrosion film on particle surface, which separates the particle from the electrolyte and, consequently, inhibits HER. %0 journal article %@ 1438-1656 %A Zeller-Plumhoff, B.,Tolnai, D.,Wolff, M.,Greving, I.,Hort, N.,Willumeit-Römer, R. %D 2021 %J Advanced Engineering Materials %N 11 %P 2100197 %R doi:10.1002/adem.202100197 %T Utilizing Synchrotron Radiation for the Characterization of Biodegradable Magnesium Alloys—From Alloy Development to the Application as Implant Material %U https://doi.org/10.1002/adem.202100197 11 %X Magnesium alloys are highly attractive for their application as structural materials as well as medical implants. A range of alloying systems exists which are investigated e.g. in terms of alloy microstructure changes, in particular during different processing steps or mechanical testing, and in terms of the associated corrosion performance of the material. Synchrotron radiation and in particular synchrotron radiation micro computed tomography and nanotomography yield a unique opportunity to investigate such changes and processes in 3D at high resolution and in situ, thus significantly broadening our knowledge base. In this review we demonstrate the benefits of using synchrotron radiation for the investigation of magnesium alloys with particular respect to its application as a biodegradable implant. We review advances in experimental environments for in situ testing, and cover all stages of materials testing in which synchrotron radiation has been used, i.e. from developing and processing of the material, to corrosion testing and assessing implant integration and stability ex vivo. This review incorporates advances both in micro- and nanotomographic imaging regimes and further includes complementary techniques, such as X-ray diffraction, small angle X-ray scattering, X-ray fluorescence and diffraction tomography. Finally, we provide an outlook into future developments. %0 journal article %@ 2296-8016 %A Höche, D.,Weber, W.,Gazenbiller, E.,Gavras, S.,Hort, N.,Dieringa, H. %D 2021 %J Frontiers in Materials %N %P 575530 %R doi:10.3389/fmats.2021.575530 %T Novel Magnesium Based Materials: Are They Reliable Drone Construction Materials? A Mini Review %U https://doi.org/10.3389/fmats.2021.575530 %X Novel magnesium-based materials are ideal candidates for use in future aviation vehicles because they are extremely light and can therefore significantly increase the range of these vehicles. They show very good castability, are easy to machine and can be shaped into profiles or forgings to be used as components for next generation aerial vehicle construction. In the case of a large number of identical components, high-pressure die casting of magnesium alloys is clearly superior to high-pressure die casting of aluminum alloys. This is due to the lower solubility of iron in magnesium and thus tool/casting life is significantly longer. In addition, the die filling times for magnesium high-pressure die casting are approximately 30% shorter. This is due to the lower density: aluminum alloys are approximately 50% heavier than magnesium alloys, which is a significant disadvantage for aluminum alloys especially in the aerospace industry. There are cost-effective novel die casting alloys, besides AZ91 or AM50/60 such as DieMag633 or MRI230D, which show very good specific strength at room and elevated temperatures. In the case of magnesium-based wrought alloys, the choice is smaller, a typical representative of these materials is AZ31, but some new alloys based on Mg-Zn-Ca are currently being developed which show improved formability. However, magnesium alloys are susceptible to environmental influences, which can be eliminated by suitable coatings. Novel corrosion protection concepts for classical aerial vehicles currently under development might suitable but may need adaption to the construction constraints or to vehicle dependent exposure scenarios. Within this mini-review a paradigm change due to utilization of new magnesium materials as drone construction material is briefly introduced and future fields of applications within next-generation aerial vehicles, manned or unmanned, are discussed. Possible research topics will be addressed. %0 editorial %@ 2073-4352 %A Tolnai, D. %D 2021 %J Crystals %N 2 %P 96 %R doi:10.3390/cryst11020096 %T Processing and Characterization of Magnesium-Based Materials %U https://doi.org/10.3390/cryst11020096 2 %X %0 journal article %@ 0925-8388 %A Zhang, Y.,Du, C.,Liu, Y.,Wen, S.,Liu, S.,Huang, Y.,Hort, N.,Du, Y. %D 2021 %J Journal of Alloys and Compounds %N %P 159517 %R doi:10.1016/j.jallcom.2021.159517 %T Interdiffusion and atomic mobility in hcp Mg–Al–Sn alloys %U https://doi.org/10.1016/j.jallcom.2021.159517 %X For the purpose of studying the diffusion behavior of hcp Mg–Al–Sn alloys, several Mg–Al, Mg–Sn and Mg–Al–Sn alloys were prepared and assembled into ten diffusion couples annealed at 723, 773, 823 K separately. With the aid of the electron probe microanalyzer technique and efficient CALTPP (CALculation of ThermoPhysical Properties) software, the composition dependent interdiffusivities at various temperatures were calculated. After that, the atomic mobilities were evaluated according to the obtained diffusivities in conjunction with available thermodynamic descriptions of the system in literature. Extensive comparisons between the model-predicted and experimental data on diffusion behaviors indicate the reliability of the presently obtained kinetic parameters. It worth noting that the measured composition profiles and diffusion paths can be logically predicted merely with two ternary interaction parameters. The currently obtained atomic mobilities will serve the high-throughput computation design for multi-component Mg alloys. %0 journal article %@ 0010-938X %A Zeller-Plumhoff, B.,Gile, M.,Priebe, M.,Slominska, H.,Boll, B.,Wiese, B.,Würger, T.,Willumeit-Römer, R.,Meißner, R. %D 2021 %J Corrosion Science %N %P 109272 %R doi:10.1016/j.corsci.2021.109272 %T Exploring key ionic interactions for magnesium degradation in simulated body fluid – A data-driven approach %U https://doi.org/10.1016/j.corsci.2021.109272 %X We have studied the degradation of pure magnesium wire in simulated body fluid and its subsets under physiological conditions to enable the prediction of the degradation rate based on the medium's ionic composition. To this end, micro-computed tomography and scanning electron microscopy with energy-dispersive X-ray spectroscopy were used, followed by a tree regression analysis. A non-linear relationship was found between degradation rate and the precipitation of calcium salts. The mean absolute error for predicting the degradation rate was 1.35 mm/yr. This comparatively high value indicates that ionic interactions were exceedingly complex or that an unknown parameter determining the degradation may exist. %0 journal article %@ 0079-6425 %A Meng, X.,Huang, Y.,Cao, J.,Shen, J.,Dos Santos, J. %D 2021 %J Progress in Materials Science %N %P 100706 %R doi:10.1016/j.pmatsci.2020.100706 %T Recent progress on control strategies for inherent issues in friction stir welding %U https://doi.org/10.1016/j.pmatsci.2020.100706 %X Friction stir welding (FSW), a mature solid-state joining method, has become a revolutionary welding technique over the past two decades because of its energy efficiency, environmental friendliness and high-quality joints. FSW is highly efficient in the joining of Al alloys, Mg alloys, Ti alloys, polymers and other dissimilar materials. Recently, FSW has gained considerable scientific and technological attention in several fields, including aerospace, railway, renewable energy and automobile. To broaden the adoption of FSW in manufacturing fields, three inherent issues—back support, weld thinning and keyhole defects—must be addressed to ensure the structural integrity, safety and service life of the manufactured products. This review covers the recent progress on the control strategies for these inherent issues, which are basically divided into self-supported FSW, non-weld-thinning FSW and friction stir-based remanufacturing. Herein, the aim is to focus on the corresponding technical development, process parameters, metallurgical features and mechanical properties. Additionally, the challenges and future outlooks are emphasized systematically. %0 journal article %@ 2213-9567 %A Nidadavolu, E.,Krüger, D.,Zeller-Plumhoff, B.,Tolnai, D.,Wiese, B.,Feyerabend, F.,Ebel, T.,Willumeit-Römer, R. %D 2021 %J Journal of Magnesium and Alloys %N 2 %P 686-703 %R doi:10.1016/j.jma.2020.05.006 %T Pore characterization of PM Mg–0.6Ca alloy and its degradation behavior under physiological conditions %U https://doi.org/10.1016/j.jma.2020.05.006 2 %X Several material parameters affect degradation characteristics of Mg and its alloys under physiological conditions. Porous Mg materials are interesting for their simultaneous degradation and drug delivery capabilities. However, an increase in pore surface area is detrimental to both degradation resistance and subsequent mechanical properties. The present work aims at determining the threshold porosity value in Mg–0.6Ca specimens produced by powder metallurgy (PM) below which low degradation rates persist with acceptable mechanical properties. Seven different porous Mg–0.6Ca specimens containing both closed and open pore structures were fabricated with porosities ranging from 3% to 21%. Degradation profiles were obtained via a semi static immersion test over 16 days under physiological conditions using Dulbecco's modified Eagle's medium with Glutamax and 10% fetal bovine serum as supplements. The results are related to morphological pore parameters like pore size distribution, pore interconnectivity and pore curvatures that were quantified using an ex situ µCT analysis. In general, with decreasing porosity a decrease in pore interconnectivity is seen followed by rounding of the pores. Low degradation rates (MDR < 0.3 mm/year) are observed in specimens until 10% porosity, however, the upper bound for reproducible degradation is observed to be in specimens until 12% porosity. This porosity level also marks the transition from closed to open pore nature with a simultaneous change in pore interconnectivity from less than 10% to greater than 95%, below and above this porosity level, respectively. The tensile strength and elongation to failure recorded for specimens with 10% porosity were 70 MPa and 2%, respectively displaying positive traits of both homogenous degradation and mechanical properties. The results suggest that high pore interconnectivity is the dominant factor controlling degradation and mechanical properties in porous Mg-0.6Ca specimens. The results also indicate a good sintering response of Mg-0.6Ca specimens providing further material development towards biomaterial applications. %0 journal article %@ 2213-9567 %A Wiese, B.,Willumeit-Römer, R.,Letzig, D.,Bohlen, J. %D 2021 %J Journal of Magnesium and Alloys %N 1 %P 112-122 %R doi:10.1016/j.jma.2020.08.001 %T Alloying effect of silver in magnesium on the development of microstructure and mechanical properties by indirect extrusion %U https://doi.org/10.1016/j.jma.2020.08.001 1 %X The effect of Ag in solid solution on the microstructure, texture and the deformation behaviour of indirectly extruded Mg was investigated. Ag as a solid solution strengthener affects the behaviour during extrusion, resulting in enhanced deformation related heating and corresponding coarser grained microstructures. No substantial effect on the texture development is revealed. The mechanical properties simultaneously increase in stress and strain levels with increasing Ag content, especially in tension as a result of the changing impact of the slip modes which can be associated with a decrease of the lattice parameters as well as the c/a ratio of the hcp lattice structure. In compression tests with twin dominated flow, the impact is much smaller on the compressive yield stress but higher with respect to the twinning related strain hardening rate. Solid solution strength functions for Fleischer and Labusch were determined, also confirming the anisotropic behaviour of the extruded Mg alloys. %0 journal article %@ 2213-9567 %A Yao, X.,Tang, J.,Zhou, Y.,Atrens, A.,Dargusch, M.,Wiese, B.,Ebel, T.,Yan, M. %D 2021 %J Journal of Magnesium and Alloys %N 6 %P 2155-2168 %R doi:10.1016/j.jma.2020.08.011 %T Surface modification of biomedical Mg-Ca and Mg-Zn-Ca alloys using selective laser melting: Corrosion behaviour, microhardness and biocompatibility %U https://doi.org/10.1016/j.jma.2020.08.011 6 %X Magnesium alloys such as Mg–Ca and Mg–Zn–Ca are good orthopaedic materials; however their tendency to corrode is high. Herein we utilize selective laser melting (SLM) to modify the surface of these Mg alloys to simultaneously improve the corrosion behaviour and microhardness. The corrosion rate decreased from 2.1 ± 0.2 mm/y to 1.0 ± 0.1 mm/y for the laser-processed Mg–0.6Ca, and from 1.6 ± 0.1 mm/y to 0.7 ± 0.2 mm/y for laser-processed Mg–0.5Zn–0.3Ca. The microhardness increased from 46 ± 1 HV to 56 ± 1 HV for Mg–0.6Ca, and from 47 ± 3 HV to 55 ± 3 HV for Mg–0.5Zn–0.3Ca. In addition, good biocompatibility remained in the laser processed Mg alloys. The improved properties are attributed to laser-induced grain refinement, confined impurity elements, residual stress, and modified surface chemistry. The results demonstrated the potential of SLM as a surface engineering approach for developing advanced biomedical Mg alloys. %0 journal article %@ 1742-7061 %A Zhang, Y.,Huang, Y.,Feyerabend, F.,Blawert, C.,Gan, W.,Maawad, E.,You, S.,Gavras, S.,Scharnagl, N.,Bode, J.,Vogt, C.,Zander, D.,Willumeit-Römer, R.,Kainer, K.,Hort, N. %D 2021 %J Acta Biomaterialia %N %P 695-712 %R doi:10.1016/j.actbio.2020.11.050 %T Influence of the amount of intermetallics on the degradation of Mg-Nd alloys under physiological conditions %U https://doi.org/10.1016/j.actbio.2020.11.050 %X The influence of amount of intermetallics on the degradation of as-extruded Mg-Nd alloys with different contents of Nd was investigated via immersion testing in DMEM+10% FBS under cell culture conditions and subsequent microstructural characterizations. It is found that the presence of intermetallic particles Mg41Nd5 affects the corrosion of Mg-Nd alloys in two conflicting ways. One is their negative role that their existence enhances the micro-galvanic corrosion. Another is their positive role. Their existence favours the formation of a continuous and compact corrosion layer. At the early stage of immersion, their negative role predominated. The degradation rate of Mg-Nd alloys monotonously increases with increasing the amount of intermetallics. Mg-5Nd alloy with maximum amount of intermetallics suffered from the most severe corrosion. With the immersion proceeding (≥7 days), then the positive role of these intermetallic particles Mg41Nd5 could not be neglected. Owing to the interaction between their positive and negative roles, at the later stage of immersion the corrosion rate of Mg-Nd alloys first increases with increasing the content of Nd, then reaches to the maximum at 2 wt. % Nd. With a further increase of Nd content, a decrease in corrosion rate occurs. The main corrosion products on the surfaces of Mg-Nd alloys include carbonates, calcium-phosphate, neodymium oxide and/or neodymium hydroxide. They are amorphous at the early stage of immersion. With the immersion proceeding, they are transformed to crystalline. The existence of undegradable Mg41Nd5 particles in the corrosion layer can enhance the crystallization of such amorphous corrosion products. %0 book part %@ %A Yang, H.,Gavras, S.,Dieringa, H. %D 2021 %J Encyclopedia of Materials: Composites %N %P 375-388 %R doi:10.1016/B978-0-12-803581-8.11822-3 %T Creep Characteristics of Metal Matrix Composites %U https://doi.org/10.1016/B978-0-12-803581-8.11822-3 %X Creep is the slow, plastic deformation of materials at elevated temperatures and a constant applied stress or load. Metals creep faster as the temperature or stress increases. This creep is the consequence of various deformation mechanisms, which in turn are the result of different microstructures. The deformation behavior is influenced, for example, by the presence of solute atoms, intermetallic precipitates, grain sizes, twins in the microstructure, different dislocation densities as a result of deformation processes or different thermal expansions, or dispersoids introduced into the metal matrix by different processes. These dispersoids, in turn, can influence the factors mentioned above which influence creep deformation. Thus, the creep resistance of metals can be altered with reinforcing components. The minimum creep rate is often used as a measure of the creep resistance of metallic materials. It corresponds to the minimum of the first derivative of the creep curve, which is located in the secondary area of this curve. The lower the minimum creep rate, the more resistant is the material against creep. This is usually correct, but not always. This article describes the influence of reinforcing components on the microstructure and thus on the creep properties of metal matrix composites. Examples are given for fiber- and particle-reinforced composites whose reinforcing components are arranged in different concentrations, sizes, and orientations in the composite material and influence the creep resistance of the composite material. %0 journal article %@ 1005-0302 %A Jin, Y.,Blawert, C.,Hang, H.,Wiese, B.,Bohlen, J.,Mei, D.,Deng, M.,Feyerabend, F.,Willumeit, R. %D 2021 %J Journal of Materials Science & Technology %N %P 214-224 %R doi:10.1016/j.jmst.2021.04.005 %T Deteriorated corrosion performance of micro-alloyed Mg-Zn alloy after heat treatment and mechanical processing %U https://doi.org/10.1016/j.jmst.2021.04.005 %X The corrosion performances of the as-cast and solution-treated Mg-0.5Zn samples were investigated in 0.9% NaCl solution and compared. From the electrochemical measurement results and corrosion morphology observations, it is found that the corrosion resistance of Mg-0.5Zn deteriorated with the extension of solution treatment duration. The main reason was the formation of Fe-Si precipitates with higher Fe concentrations during heat treatment. The Fe-Si precipitates, especially the ones with high Fe contents influenced the corrosion initiation and propagation significantly. In regard of corrosion performance, the solution-treated and then extruded sample was also performing not as good as the cast and then directly extruded sample. %0 conference paper %@ 2367-1181 %A Yang, H.,Huang, Y.,Kainer, K.,Dieringa, H. %D 2021 %J Magnesium 2021 : Proceedings of the 12th International Conference on Magnesium Alloys and their Applications %N %P 57-69 %R doi:10.1007/978-3-030-72432-0_7 %T Improving the Creep Resistance of Elektron21 by Adding AlN/Al Nanoparticles Using the High Shear Dispersion Technique %U https://doi.org/10.1007/978-3-030-72432-0_7 %X A novel high shear dispersion technique (HSDT) was used for the first time to effectively distribute AlN/Al nanoparticles (NPs) in Elektron21 (El21) Mg alloys. Different high shearing speeds were adopted to investigate the optimum shearing speed for optimum deagglomeration of NPs and enhancing the creep resistance of AlN/Al NPs reinforced El21 alloy. The results showed that the creep resistance of El21 + 0.5% AlN/Al nanocomposite increased with the increasing speed of HSDT. The individual/synergistic roles of AlN and Al were also systematically identified by comparing the microstructural evolutions and creep properties of El21, El21 + 0.25% Al, El21 + 0.75% AlN, and El21 + 1% AlN/Al. The creep results showed that the mixture additions of AlN and Al NPs gave a synergistic improvement on the creep resistance of El21 alloy compared to the single addition of Al or AlN NPs. %0 conference lecture %@ %A Reifenrath, J.,Willumeit-Römer, R.,Windhagen, H.,Wiese, B.,Mavila, B.,Helmholz, H.,Scheper, V.,Angrisani, N. %D 2021 %J 13th Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Implantation of pure magnesium beads in the subchondral bone plate to influence bone quality in osteoarthritic rabbits %U %X %0 book part %@ %A Yang, H.,Gavras, S.,Dieringa, H. %D 2021 %J Encyclopedia of Materials: Composites %N %P 375-388 %R doi:10.1016/B978-0-12-803581-8.11822-3 %T Creep Characteristics of Metal Matrix Composites %U https://doi.org/10.1016/B978-0-12-803581-8.11822-3 %X Creep is the slow, plastic deformation of materials at elevated temperatures and a constant applied stress or load. Metals creep faster as the temperature or stress increases. This creep is the consequence of various deformation mechanisms, which in turn are the result of different microstructures. The deformation behavior is influenced, for example, by the presence of solute atoms, intermetallic precipitates, grain sizes, twins in the microstructure, different dislocation densities as a result of deformation processes or different thermal expansions, or dispersoids introduced into the metal matrix by different processes. These dispersoids, in turn, can influence the factors mentioned above which influence creep deformation. Thus, the creep resistance of metals can be altered with reinforcing components. The minimum creep rate is often used as a measure of the creep resistance of metallic materials. It corresponds to the minimum of the first derivative of the creep curve, which is located in the secondary area of this curve. The lower the minimum creep rate, the more resistant is the material against creep. This is usually correct, but not always. This article describes the influence of reinforcing components on the microstructure and thus on the creep properties of metal matrix composites. Examples are given for fiber- and particle-reinforced composites whose reinforcing components are arranged in different concentrations, sizes, and orientations in the composite material and influence the creep resistance of the composite material. %0 journal article %@ 2213-9567 %A Kandemir, S.,Gavras, S.,Dieringa, H. %D 2021 %J Journal of Magnesium and Alloys %N 5 %P 1753-1767 %R doi:10.1016/j.jma.2021.03.029 %T High temperature tensile, compression and creep behavior of recycled short carbon fibre reinforced AZ91 magnesium alloy fabricated by a high shearing dispersion technique %U https://doi.org/10.1016/j.jma.2021.03.029 5 %X The present study seeks the feasibility of using short carbon fibres recycled from polymer matrix composites as alternative to virgin carbon fibres in the reinforcement of magnesium alloys. The microstructures, high temperature mechanical and creep properties of AZ91 alloy and its composites with various recycled carbon fibre contents (2.5 and 5 wt.%) and lengths (100 and 500 μm) were investigated in the temperature range of 25–200 °C. The microstructural characterization showed that the high shear dispersion technique provided the cast composites with finer grains and relatively homogenous distribution of fibres. The materials tested displayed different behaviour depending on the type of loading. In general, while enhancements in the mechanical properties of composites is attributed to the load bearing and grain refinement effects of fibres, the fluctuations in the properties were discussed on the basis of porosity formation, relatively high reinforcement content leading to fibre clustering and interlayer found between the matrix and reinforcement compared to those of AZ91 alloy. The compressive creep tests revealed similar or higher minimum creep rates in the recycled carbon fibre reinforced AZ91 in comparison to the unreinforced AZ91. %0 journal article %@ 2405-4615 %A Yang, H.,Patel, J.,Yang, X.,Gavras, S.,Dieringa, H. %D 2021 %J Current Nanomaterials %N 2 %P 106-118 %R doi:10.2174/2405461506666210420133620 %T Properties of Mg-based Metal Matrix Nanocomposites Processed by High Shear Dispersion Technique (HSDT) - A Review %U https://doi.org/10.2174/2405461506666210420133620 2 %X Metal Matrix Nanocomposites (MMNCs) often show excellent properties as compared to their non-reinforced alloys due to either the achieved grain refinement or Orowan strengthening. Especially in light metals such as aluminium and magnesium as the matrix has the potential to be significantly improved in relation to mechanical properties. Functionalisation can also be achieved in some cases. However, the challenge lies in the homogeneous distribution of the ceramic nanoparticles in the melt if MMNCs have been processed via melt metallurgical processes. The large surface area of the nanoparticles generates large van der Waals forces, which need to be overcome. Furthermore, the wettability of the particles with molten metal is difficult. Additional forces can be applied by ultrasound, electromagnetic stirring, or even high-shearing. In this paper, properties of MMNCs with a light metal matrix, which have been produced with the High-Shearing Dispersion Technique are discussed. First, the process with its different characteristics and the underlying theory is presented, and then property improvements are discussed by comparing MMNCs to their matrix materials. %0 conference lecture %@ %A Wiese, B. %D 2021 %J IMA-Webinar: Magnesium Medical Applications — End-Product Focus %N %P %T Magnesium - More than a load-bearing implant %U %X %0 journal article %@ 2075-4701 %A Meyer, S.,Wolf, A.,Sanders, D.,Iskhakova, K.,Ćwieka, H.,Bruns, S.,Flenner, S.,Greving, I.,Hagemann, J.,Willumeit-Römer, R.,Wiese, B.,Zeller-Plumhoff, B. %D 2021 %J Metals %N 9 %P 1422 %R doi:10.3390/met11091422 %T Degradation Analysis of Thin Mg-xAg Wires Using X-ray Near-Field Holotomography %U https://doi.org/10.3390/met11091422 9 %X Magnesium–silver alloys are of high interest for the use as temporary bone implants due to their antibacterial properties in addition to biocompatibility and biodegradability. Thin wires in particular can be used for scaffolding, but the determination of their degradation rate and homogeneity using traditional methods is difficult. Therefore, we have employed 3D imaging using X-ray near-field holotomography with sub-micrometer resolution to study the degradation of thin (250 μm diameter) Mg-2Ag and Mg-6Ag wires. The wires were studied in two states, recrystallized and solution annealed to assess the influence of Ag content and precipitates on the degradation. Imaging was employed after degradation in Dulbecco’s modified Eagle’s medium and 10% fetal bovine serum after 1 to 7 days. At 3 days of immersion the degradation rates of both alloys in both states were similar, but at 7 days higher silver content and solution annealing lead to decreased degradation rates. The opposite was observed for the pitting factor. Overall, the standard deviation of the determined parameters was high, owing to the relatively small field of view during imaging and high degradation inhomogeneity of the samples. Nevertheless, Mg-6Ag in the solution annealed state emerges as a potential material for thin wire manufacturing for implants. %0 conference lecture %@ %A Meyer, S.,Wiese, B.,Ebel, T.,Willumeit-Römer, R. %D 2021 %J 13th Biometal 2021 %N %P %T Grain refinement in cold drawn Mg-xAg wires %U %X %0 conference lecture %@ %A Wiese, B.,Meyer, S.,Sanders, D.,Ebel, T.,Willumeit-Römer, R. %D 2021 %J 13th Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Mechanical properties of Mg-Ag wires with 2; 4 and 6 wt.% Ag %U %X %0 journal article %@ 2213-9567 %A Krüger, D.,Zeller-Plumhoff, B.,Wiese, B.,Yi, S.,Zuber, M.,Wieland, F.,Moosmann, J.,Willumeit-Römer, R. %D 2021 %J Journal of Magnesium and Alloys %N 6 %P 2207-2222 %R doi:10.1016/j.jma.2021.07.029 %T Assessing the microstructure and in vitro degradation behavior of Mg-xGd screw implants using µCT %U https://doi.org/10.1016/j.jma.2021.07.029 6 %X Biodegradable implants are taking an increasingly important role in the area of orthopedic implants with the aim to replace permanent implants for temporary bone healing applications. During the implant preparation process, the material's surface and microstructure are being changed by stresses induced by machining. Hence degradable metal implants need to be fully characterized in terms of the influence of machining on the resulting microstructure and corrosion performance.,In this study, micro-computed tomography (µCT) is used for the quantification of the degradation rate of biodegradable implants. To our best knowledge, for the first time quantitative measures are introduced to describe the degradation homogeneity in 3D. This information enables a prediction in terms of implant stability during the degradation in the body.,Two magnesium gadolinium alloys, Mg-5Gd and Mg-10Gd (all alloy compositions are given in weight% unless otherwise stated), in the shape of M2 headless screws have been investigated for their microstructure and their degradation performance up to 56 days. During the microstructure investigations particular attention was paid to the localized deformation of the alloys, due to the machining process. In vitro immersion testing was performed to assess the degradation performance quantified by subsequent weight loss and volume loss (using µCT) measurements.,Although differences were observed in the degree of screw's near surface microstructure being influenced from machining, the degradation rates of both materials appeared to be suitable for application in orthopedic implants. From the degradation homogeneity point of view no obvious contrast was detected between both alloys. However, the higher degradation depth ratios between the crests and roots of Mg-5Gd ratios may indicated a less homogeneous degradation of the screws of these alloys on contract to the ones made of Mg-10Gd alloys. Due to its lower degradation rates, its more homogeneous microstructure, its weaker texture and better degradation performance extruded Mg-10Gd emerged more suitable as implant material than Mg-5Gd. %0 journal article %@ 1473-2262 %A Angrisani, N.,Willumeit-Römer, R.,Windhagen, H.,Mavila Chathoth, B.,Scheper, V.,Wiese, B.,Helmholz, H.,Reifenrath, J. %D 2021 %J European Cells & Materials %N %P 179-195 %R doi:10.22203/eCM.v042a14 %T Small-sized magnesium cylinders influence subchondral bone quality in osteoarthritic rabbits - an in vivo pilot study %U https://doi.org/10.22203/eCM.v042a14 %X No optimal therapy exists to stop or cure chondral degeneration in osteoarthritis (OA). While the pathogenesis is unclear, there is consensus on the etiological involvement of both articular cartilage and subchondral bone. Compared to original bone, the substance of sclerotic bone is mechanically less solid. The osteoproliferative effect of Mg has been shown repeatedly during development of Mg-based osteosynthesis implants. The aim of the present study was to examine the influence of implanted high-purity Mg cylinders on subchondral bone quality in a rabbit OA model. 10 New Zealand White rabbits received into the knee either 20 empty drill holes or 20 drill holes, which were additionally filled with one Mg cylinder each. Follow-up was at 8 weeks. Micro-computed tomography (µCT) was performed. After euthanasia, cartilage condition was determined, bone samples were collected and processed for histological evaluation and elemental imaging by micro-X-ray fluorescence spectrometry (µXRF). Articular cartilage collected post-mortem showed different stages of lesions, from mild alterations up to exposed subchondral bone, which tended to be slightly lower in animals with implanted Mg cylinders. µCT showed significantly increased bone volume in the Mg group. Also, histological evaluation revealed distinct differences. While right, operated limbs did not show any significant difference, left, non-operated controls showed significantly less changes in articular cartilage in the Mg group. A distinct influence of implanted cylinders of pure Mg on subchondral bone of osteoarthritic rabbits was shown. Subsequent evaluations, including other time points and alternative alloys, will show if this could alter OA progression. %0 journal article %@ 1438-1656 %A Tolnai, D.,Gavras, S.,Wilde, F.,Hammel, J.,Bruns, S. %D 2021 %J Advanced Engineering Materials %N 11 %P 2100383 %R doi:10.1002/adem.202100383 %T In Situ Synchrotron Tomography of the Solidification of an Elektron 21 Mg Alloy %U https://doi.org/10.1002/adem.202100383 11 %X The directional solidification of an Elektron 21 magnesium alloy is investigated by in situ synchrotron radiation tomography. To visualize the solidification process, samples of Elektron 21 are first heated to 800 °C, and the melt is held at this temperature for 5 min, to ensure temperature homogeneity. Subsequently, the samples are cooled with a cooling rate of 10 K min−1, while for every 35 s, one full tomogram is acquired. The evolution of the microstructure can be followed in 3D on the reconstructed tomograms. The contrast between rare-earth metals and Mg enables to quantitatively analyze the changes in the morphology of the dendritic structure during solidification. At the onset of the detection, the growth of secondary dendrite arms occurs, which ends at the dendritic coherency point. From this temperature on, only the coarsening and coalescence of existing dendrite arms occurs. %0 journal article %@ 1002-0071 %A Xu, Y.,Wang, S.,Wang, Y.,Chen, L.,Yang, L.,Xiao, L.,Hort, N. %D 2021 %J Progress in Natural Science: Materials International %N 4 %P 591-598 %R doi:10.1016/j.pnsc.2021.06.005 %T Mechanical behaviors of extruded Mg alloys with high Gd and Nd content %U https://doi.org/10.1016/j.pnsc.2021.06.005 4 %X The influence of alloying elements and heat treatment on the microstructure and mechanical behaviors of extruded Mg–Gd–Nd ternary alloys was investigated in this study. The grain sizes dramatically decreased after extrusion, and the particles which distributed in Mg matrix had great effect on the grain size. The grain sizes of extruded alloys decreased from 26 to 5 ​μm with the alloying content increasing. The mechanical test results show that both Gd and Nd had positive effect on the hardness, yield strength and Young's modulus. The ultimate tensile strength (UTS) was enhanced by Gd content, decreased with Nd content. The elongation of alloys was lower with higher alloying elements. Those extruded alloys were aged for 200 ​h in 200 ​°C. The Young's moduli were decreased by ageing treatment. Combined with microstructure study, the part of the reinforcement which identified as Mg5(Gd/Nd) was dissolved in Mg matrix. Nd element obviously has influence on the solubility of Gd in Mg alloys. %0 journal article %@ 1996-1944 %A Maier, P.,Clausius, B.,Richter, A.,Bittner, B.,Hort, N.,Menze, R. %D 2021 %J Materials %N 13 %P 3686 %R doi:10.3390/ma14133686 %T Crack Propagation in As-Extruded and Heat-Treated Mg-Dy-Nd-Zn-Zr Alloy Explained by the Effect of LPSO Structures and Their Micro- and Nanohardness %U https://doi.org/10.3390/ma14133686 13 %X The investigation of the crack propagation in as-extruded and heat-treated Mg-Dy-Nd-Zn-Zr alloy with a focus on the interaction of long-period stacking-ordered (LPSO) structures is the aim of this study. Solution heat treatment on a hot extruded Mg-Dy-Nd-Zn-Zr (RESOLOY®) was done to change the initial fine-grained microstructure, consisting of grain boundary blocky LPSO and lamellar LPSO structures within the matrix, into coarser grains of less lamellar and blocky LPSO phases. C-ring compression tests in Ringer solution were used to cause a fracture. Crack initiation and propagation is influenced by twin boundaries and LPSO lamellae. The blocky LPSO phases also clearly hinder crack growth, by increasing the energy to pass either through the phase or along its interface. The microstructural features were characterized by micro- and nanohardness as well as the amount and location of LPSO phases in dependence on the heat treatment condition. By applying nanoindentation, blocky LPSO phases show a higher hardness than the grains with or without lamellar LPSO phases and their hardness decreases with heat treatment time. On the other hand, the matrix increases in hardness by solid solution strengthening. The microstructure consisting of a good balance of grain size, matrix and blocky LPSO phases and twins shows the highest fracture energy. %0 conference lecture %@ %A Bilal, M.,Hort, N. %D 2020 %J International Conference on Modelling of Casting; Welding and Advanced Solidification Processes (MCWASP XV) %N %P %T Predicting the interfacial heat transfer coefficient of cast Mg-Al alloys using Beck's inverse analysis %U %X %0 conference paper %@ 1757-8981 %A Bilal, M.,Hort, N. %D 2020 %J IOP Conference Series: Materials Science and Engineering %N 1 %P 012027 %R doi:10.1088/1757-899X/861/1/012027 %T Predicting the interfacial heat transfer coefficient of cast Mg-Al alloys using Beck's inverse analysis %U https://doi.org/10.1088/1757-899X/861/1/012027 1 %X Apart from many governing parameters, the interfacial heat transfer coefficient (IHTC) has prime importance for the numerical simulation of casting as it quantifies the heat flux between casting and mold (or chill). Most Mg alloys are based on the Mg-Al system and casting is the commonly used production process. The experimental configuration makes it challenging to measure flux and surface temperatures required to evaluate the IHTC. In this study, the IHTC was predicted for a variety of Mg-Al compositions which were cast using a permanent cylindrical mold. Unidirectional heat flow was ensured in order to replicate the experimental conditions for solving the one-dimensional transient heat equation. The numerically determined mold and surface temperatures, using Beck's inverse methodology, were in good agreement with the experiments and analytical solution, respectively. Moreover, the heat transfer behavior across the interface depicted in the form of IHTC was analyzed, also various empirical and numerical aspects of the method are discussed. %0 conference lecture %@ %A Meyer, S.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Römer, R. %D 2020 %J Updates in Bioabsorbable Metals 2020 %N %P %T The grain refinement effect of gadolinium in magnesium at modified extrusion ratio %U %X %0 conference paper %@ 2367-1181 %A Gavras, S.,Bilal, M.,Tolnai, D.,Hort, N. %D 2020 %J Magnesium Technology 2020 %N %P 281-287 %R doi:10.1007/978-3-030-36647-6_42 %T Investigation and Modelling of the Influence of Cooling Rates on the Microstructure of AZ91 Alloys %U https://doi.org/10.1007/978-3-030-36647-6_42 %X An increasingly important tool in modern experimental investigations is the ability to accurately produce a digital model or “digital twin” of samples and their properties. This goes hand-in-hand with the primary tenant of Industry 4.0 which is to provide advanced manufacturing solutions through the use of cyber-physical systems. A comparison of various quenching media, namely liquid nitrogen, water at 5 ℃, water at 20 ℃ and in the air on the microstructure of permanent mould cast AZ91 alloys was investigated. Particular emphasis was centred on the changes in microstructural features such as grain size and dendrite arm spacing. Phase-field method was used to produce a digital twin and qualitative analysis of the investigated cooling rates on AZ91. The combination of practical microstructural investigations and the simulated microstructures will advance the knowledge of cooling rate influences on AZ91 and their ability to be accurately simulated to assist with property and microstructural predictions. %0 journal article %@ 0921-5093 %A Yang, H.,Zander, D.,Jiang, B.,Huang, Y.,Gavras, S.,Kainer, K.,Dieringa, H. %D 2020 %J Materials Science and Engineering A %N %P 139669 %R doi:10.1016/j.msea.2020.139669 %T Effects of heat treatment on the microstructural evolution and creep resistance of Elektron21 alloy and its nanocomposite %U https://doi.org/10.1016/j.msea.2020.139669 %X In previously published research, creep resistance of commercial alloy Elektron21 (El21) and El21 + 1% AlN/Al nanocomposite were predominantly investigated in as-cast condition, little work focused on creep resistance following heat treatment. In this work, El21 and its nanocomposite with and without T6 treatment (520 °C for 8 h and 200 °C for 16 h) were prepared to reveal the influence of heat treatment on their microstructural evolutions and creep properties. Different intermetallic particles and precipitates that formed in El21 and El21 + 1% AlN/Al with different states were characterized using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Creep tests were performed over a stress range of 80–140 MPa at 240 °C. Creep results showed that the application of T6 treatment could improve the creep resistance of El21, but deteriorate that of El21 + 1% AlN/Al. This is attributed to the reduced amount of γ'' and β′ precipitates in El21 + 1% AlN/Al (T6) after ageing, resulting from the formation of plate-like Al2(Nd, Gd) (Al2RE) precipitates. It is also found that after T6 heat treatment, El21 (T6) had a lower minimum creep rate with a shorter duration of secondary creep stage than El21 + 1% AlN/Al (T6) at high creep temperatures due to the overageing of precipitates and the thermal stability of the Al2RE particles. El21 + 1% AlN/Al nanocomposites, either in the as-cast or T6 condition, show a much longer duration of secondary creep than NP-free El21. The responsible mechanism was attributed to the addition of AlN NPs and the formation of particulate/plate Al2RE phase. %0 journal article %@ 1742-7061 %A Zeller-Plumhoff, B.,Malich, C.,Krueger, D.,Campbell, G.,Wiese, B.,Galli, S.,Wennerberg, A.,Willumeit-Römer, R.,Wieland, D.C.F. %D 2020 %J Acta Biomaterialia %N %P 637-645 %R doi:10.1016/j.actbio.2019.11.030 %T Analysis of the bone ultrastructure around biodegradable Mg–xGd implants using small angle X-ray scattering and X-ray diffraction %U https://doi.org/10.1016/j.actbio.2019.11.030 %X Magnesium alloys are increasingly researched as temporary biodegradable metal implants in bone applications due to their mechanical properties which are more similar to bone than conventional implant metals and the fact that Magnesium occurs naturally within the body. However, the degradation processes in vivo and in particular the interaction of the bone with the degrading material need to be further investigated. In this study we are presenting the first quantitative comparison of the bone ultrastructure formed at the interface of biodegradable Mg–5Gd and Mg–10Gd implants and titanium and PEEK implants after 4, 8 and 12 weeks healing time using two-dimensional small angle X-ray scattering and X-ray diffraction. Differences in mineralization, orientation and thickness of the hydroxyapatite are assessed. We find statistically significant (p < 0.05) differences for the lattice spacing of the (310)-reflex of hydroxyapatite between titanium and Mg–xGd materials, as well as for the (310) crystal size between titanium and Mg–5Gd, indicating a possible deposition of Mg within the bone matrix. The (310) lattice spacing and crystallite size further differ significantly between implant degradation layer and surrounding bone (p < 0.001 for Mg–10Gd), suggesting apatite formation with significant amounts of Gd and Mg within the degradation layer. %0 journal article %@ 0921-5093 %A Mo, N.,McCarroll, I.,Tan, Q.,Ceguerra, A.,Cairney, J.,Dieringa, H.,Huang, Y.,Jiang, B.,Pan, F.,Bermingham, M.,Zhang, M.-X. %D 2020 %J Materials Science and Engineering A %N %P 139152 %R doi:10.1016/j.msea.2020.139152 %T Roles of Nd and Mn in a new creep-resistant magnesium alloy %U https://doi.org/10.1016/j.msea.2020.139152 %X Modification of the recently developed creep-resistant Mg-3Gd-2Ca (wt.%) magnesium alloy using Nd and Mn remarkably improved the creep resistance at both 180 and 210 . The modified Mg-2Gd-1Nd-2Ca-0.5Mn alloy after solid solution treatment exhibited outstanding creep resistance that is superior to the commercial creep-resistant Mg alloy, EV31, but contained less RE addition. The microstructural observations revealed that partial replacement of Gd with 1 wt% Nd did not enhance the effect of dynamic precipitates significantly. But further analysis by atom probe tomography verified the stronger co-segregation between Nd solute atoms and other solute atoms than that of Gd and Ca in the Mg solid solutions, leading to a higher solid solution strengthening effect on the creep resistance. The addition of 0.5 wt% Mn led to the formation of polygonal-shape α-Mn precipitates, which served as heterogeneous nucleants for dynamic precipitates, refining their size and increasing the number densities. As a result, the creep properties of newly developed Mg alloys were strengthened by a combination of improved solid solution strengthening by Nd and increased precipitation hardening by Mn addition. %0 journal article %@ 0925-8388 %A Lyu, S.,Xiao, W.,Li, G.,Xia, D.,Huang, Y.,Gavras, S.,Hort, N.,Zheng, R.,Ma, C. %D 2020 %J Journal of Alloys and Compounds %N %P 153477 %R doi:10.1016/j.jallcom.2019.153477 %T Formation mechanism of the abnormal texture during extrusion in Mg-Y-Sm-Zn-Zr alloy %U https://doi.org/10.1016/j.jallcom.2019.153477 %X An abnormal texture with c axis of the grains parallel to extrusion direction (ED) was found in extruded Mg–Y-Sm-Zn-Zr alloy. The mechanisms for the formation of this abnormal texture were investigated based on the dynamic recrystallization (DRX) mechanisms and deformation modes during extrusion using electron backscatter diffraction (EBSD) and a viscoplastic self-consistent (VPSC) model. The microstructure evolution during extrusion indicated that the abnormal <0001>//ED texture was dominated by DRX grains. With the strain increasing, the intensity of this texture enhanced. Based on the EBSD results analysis, discontinuous dynamic recrystallization (DDRX) played the dominated role in nucleation of the new grains at the initial stage and then continuous dynamic recrystallization (CDRX) was activated at high strain. The formation of abnormal <0001>//ED texture was attributed to the activation of slips and it could promote the rotation of c-axis of grains to ED, which contributed to the formation of <0001>//ED texture. The simulated texture predicated that the CRSS of basal slip was higher than that of pyramidal slip, which played an important role in contributing the formation of the <0001>//ED texture component. %0 journal article %@ 0925-8388 %A Canelo-Yubero, D.,Kovács, Z.,Simonet Fotso, J.,Tolnai, D.,Schell, N.,Groma, I.,Poletti, C. %D 2020 %J Journal of Alloys and Compounds %N %P 153282 %R doi:10.1016/j.jallcom.2019.153282 %T In-situ characterization of continuous dynamic recrystallization during hot torsion of an Al–Si–Mg alloy %U https://doi.org/10.1016/j.jallcom.2019.153282 %X An extruded Al–Si–Mg alloy was deformed by torsion at 400 °C during in-situ high energy synchrotron radiation diffraction. This technique is used to prove, by analysing texture changes and the coherently scattering domain size evolution, that dynamic recovery followed by continuous dynamic recrystallization are the main restoration mechanisms. Moreover, the dislocation density types corresponding to each stage of deformation are discussed and the recrystallization grade is calculated. %0 journal article %@ 0264-1275 %A Jin, Y.,Blawert, C.,Yang, H.,Wiese, B.,Feyerabend, F.,Bohlen, J.,Mei, D.,Deng, M.,Silva Campos, M.,Scharnagl, N.,Strecker, K.,Bode, J.,Vogt, C.,Willumeit-Römer, R. %D 2020 %J Materials and Design %N %P 108980 %R doi:10.1016/j.matdes.2020.108980 %T Microstructure-corrosion behaviour relationship of micro-alloyed Mg-0.5Zn alloy with the addition of Ca, Sr, Ag, In and Cu %U https://doi.org/10.1016/j.matdes.2020.108980 %X The effects of micro-addition (0.2 wt.%) of Ca, Sr, Ag, In and Cu on the microstructure and corrosion properties of the as-cast Mg-0.5Zn alloy were systematically studied. It is found that the grain refinement efficiency and intermetallics forming ability differed greatly among these elements. Si impurity also played a vital role in the precipitates formation in all systems. It is generally observed that Mg-Zn-Ca possessed the highest corrosion resistance due to the refined grain size, limited intermetallics and uniform corrosion, whereas Mg-Zn-Cu showed the highest corrosion rate due to the coarse grains, intermetallics activity and severe pitting corrosion. With the exception of Mg-Zn-Cu, the corrosion performances of Mg-0.5Zn(-0.2X) alloys were comparable with the higher concentrated systems from literature, indicating the feasibility of these micro-alloying systems for biomedical applications. %0 journal article %@ 1005-0302 %A Wang, K.,Wang, J.,Dou, X.,Huang, Y.,Hort, N.,Gavras, S.,Liu, S.,Cai, Y.,Pan, F. %D 2020 %J Journal of Materials Science and Technology %N %P 72-82 %R doi:10.1016/j.jmst.2020.04.013 %T Microstructure and mechanical properties of large-scale Mg-Gd-Y-Zn-Mn alloys prepared through semi-continuous casting %U https://doi.org/10.1016/j.jmst.2020.04.013 %X Large-scale Mg-8Gd-4Y-1Zn-Mn (wt.%) alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting. Chemical composition, microstructure and mechanical properties at different locations of the samples with as-cast, T4 and T6 heat-treated states, respectively, were investigated. No obvious macro segregation has been detected in the high-quality alloy ingot. The main eutectic structures at all different locations are composed of α-Mg, Mg3RE-type, Mg5RE-type and LPSO phases. At the edge of ingot, the unusual casting twins including extension twins and compression twins were observed due to the intensive internal stress. In T4 heat-treated alloy, the micro segregation was eliminated. The remained phases were α-Mg and LPSO phase. Combined with the remarkable age-hardening response, T6 samples exhibits improved mechanical properties at ambient temperature, which derives from the dense prismatic β' precipitates and profuse basal γ' precipitates. %0 journal article %@ 0921-5093 %A Yang, H.,Zander, D.,Huang, Y.,Kainer, K.,Dieringa, H. %D 2020 %J Materials Science and Engineering A %N %P 139072 %R doi:10.1016/j.msea.2020.139072 %T Individual/synergistic effects of Al and AlN on the microstructural evolution and creep resistance of Elektron21 alloy %U https://doi.org/10.1016/j.msea.2020.139072 %X The creep properties of Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn (El21) alloys with additions of 0.25 wt% Al, 0.75 wt% AlN and 1 wt% AlN/Al nanoparticles (NPs) were studied over a stress range from 80 to 140 MPa at 240 °C, respectively. The individual/synergistic roles of Al and AlN in the El21 alloy were investigated systematically to reveal their creep strengthening mechanisms. Creep results show that individually all three additions of 0.25 wt% Al, 0.75 wt% AlN and 1 wt% AlN/Al could increase the creep resistance of El21 alloy apparently. However, the addition of mixed 1 wt% AlN/Al NPs shows the best strengthening effect on creep properties in El21 alloy. Microstructural characterizations reveal that the additions of Al and AlN increased the area fraction of intermetallic particles obviously. Blocky Al2Zr, Al2Zr3 particles and Al2(Nd, Gd) (Al2RE) particulates were observed in both El21 + 0.25% Al and El21 + 0.75%AlN. Nevertheless, when Al and AlN were simultaneously added into El21 alloy the formation of these blocky phases Al2Zr/Al2Zr3 was suppressed, and a larger amount of Al2RE phase was observed. This is attributed to the preferential reaction between AlN and Zr, which restricted the formation of Al–Zr phase and subsequently promoted the reaction of Al-RE phase. The dominant mechanism during creep at 240 °C was calculated to be viscous glide of dislocation. The simultaneous additions of Al and AlN NPs could lead to a more homogeneous distribution of intermetallic particles and increase the amount of Al2RE phase. Such kind of microstructures is beneficial for hindering the dislocation movement, transfer the load from matrix and alleviate the local stress concentration. Consequently, El21 + 1% AlN/Al exhibits the best creep properties among four alloys. %0 journal article %@ 0921-5093 %A Xu, Y.,Huang, Y.,Zhong, Z.,You, S.,Gan, W.,Xiao, B.,Maawad, E.,Schell, N.,Gensch, F.,Pan, F.,Hort, N. %D 2020 %J Materials Science and Engineering A %N %P 138938 %R doi:10.1016/j.msea.2020.138938 %T In situ compressive investigations on the effects of solid solution Gd on the texture and lattice strain evolution of Mg %U https://doi.org/10.1016/j.msea.2020.138938 %X The present work studies the effects of solid solution Gd on the texture and lattice strain evolution of an extruded Mg15Gd alloy under uniaxial compression. In situ experiments were carried out using high energy X-ray diffraction on samples of the investigated materials with three different orientations. The original textures of the pure Mg and the Mg15Gd alloy exhibit basal planes that are preferentially parallel and perpendicular to the extrusion direction (ED), respectively. The c/a ratio of the Mg15Gd alloy decreases with increasing Gd content in the solid solution, leading to a different deformation behavior compared with pure Mg under the compressive load. The addition of Gd enhances the slip and twinning modes. However, prismatic slip is activated earlier in the Mg15Gd alloy due to the lower c/a ratio. %0 journal article %@ 1862-5282 %A Tolnai, D.,Sosro, T.,Gavras, S.,Buzolin, R.,Hort, N. %D 2020 %J International Journal of Materials Research %N 1 %P 4-10 %R doi:10.3139/146.111786 %T In-situ synchrotron investigation of the phases- and their morphology-development in Mg–Nd–Zn alloys %U https://doi.org/10.3139/146.111786 1 %X The addition of Zn to the Mg–Nd system improves the yield strength and creep resistance, however its influence on the intermetallic phases in the ternary system is not yet fully understood. Understanding the sequence of phase-formation and phase-evolution during solidification and processing is essential to microstructure design. The solidification was investigated with in-situ synchrotron radiation-diffraction and tomography during cooling from the molten state to 200°C to investigate the phase-formation and transformation characteristics. The solidification starts with α-Mg followed by two distinct intermetallic phases T2 and T3. The results suggest that Zn stabilizes the Mg3Nd phase and accelerates precipitate formation. The dendritic morphology changes during solidification towards coarser shapes, thus impedes feeding and promotes hot tearing. %0 journal article %@ 1996-1944 %A Bohlen, J.,Meyer, S.,Wiese, B.,Luthringer-Feyerabend, B.J.C.,Willumeit-Römer, R.,Letzig, D. %D 2020 %J Materials %N 2 %P 391 %R doi:10.3390/ma13020391 %T Alloying and Processing Effects on the Microstructure, Mechanical Properties, and Degradation Behavior of Extruded Magnesium Alloys Containing Calcium, Cerium, or Silver %U https://doi.org/10.3390/ma13020391 2 %X Magnesium alloys attract attention as degradable implant materials due to their adjustable corrosion properties and biocompatibility. In the last few decades, especially wrought magnesium alloys with enhanced mechanical properties have been developed, with the main aim of increasing ductility and formability. Alloying and processing studies allowed demonstrating the relationship between the processing and the microstructure development for many new magnesium alloys. Based on this experience, magnesium alloy compositions need adjustment to elements improving mechanical properties while being suitable for biomaterial applications. In this work, magnesium alloys from two Mg-Zn series with Ce (ZE) or Ca (ZX) as additional elements and a series of alloys with Ag and Ca (QX) as alloying elements are suggested. The microstructure development was studied after the extrusion of round bars with varied processing parameters and was related to the mechanical properties and the degradation behavior of the alloys. Grain refinement and texture weakening mechanisms could be improved based on the alloy composition for enhancing the mechanical properties. Degradation rates largely depended on the nature of second phase particles rather than on the grain size, but remained suitable for biological applications. Furthermore, all alloy compositions exhibited promising cytocompatibility. %0 journal article %@ 1073-5623 %A Zhang, Y.,Huang, Y.,Feyerabend, F.,Gavras, S.,Xu, Y.,Willumeit-Römer, R.,Ulrich Kainer, K.,Hort, N. %D 2020 %J Metallurgical and Materials Transactions A %N %P 5498-5515 %R doi:10.1007/s11661-020-05926-7 %T Effects of Intermetallic Microstructure on Degradation of Mg-5Nd Alloy %U https://doi.org/10.1007/s11661-020-05926-7 %X The influence of intermetallic microstructure on the degradation of Mg-5Nd alloy with different heat treatments was investigated via immersion testing in DMEM + 10 pct FBS under cell culture conditions and subsequent microstructural characterizations. It was found that T4 heat-treated sample had the poorest corrosion resistance due to the lack of finely dispersed precipitates inside grains, continuous lamellar particles along grain boundaries and outer Ca-P layer, and to the formation of a loose corrosion product layer. In contrast, the aged samples exhibited a better corrosion resistance due to their presence and to the formation of a compact corrosion layer. Their degradation behavior largely depended on the intermetallic microstructure. Corrosion was initiated in the matrix around stable globular particles Mg41Nd5 at grain boundaries. In the sample aged at high temperature 245 °C, the coexistence of lamellar Mg41Nd5 particles and their nearby Nd-poor regions enhanced the corrosion. The corrosion first started in such regions. It was shown that those finely dispersed precipitates formed during aging had no influence on the corrosion initiation. However, they indeed affected the subsequent corrosion propagation with the immersion proceeding. They supplied barriers for corrosion propagation and hence were beneficial for improving the corrosion resistance. The continuously distributed lamellar Mg41Nd5 precipitates formed at grain boundaries during aging at 245 °C supplied an additional effective obstacle to corrosion propagation. This was especially beneficial for hindering the corrosion propagation at the later stage of corrosion. %0 journal article %@ 0947-5117 %A Buzolin, R.,Volovitch, P.,Maltseva, A.,Lamaka, S.,Blawert, C.,Mendis, C.,Lohmüller, A.,Kainer, K.,Hort, N. %D 2020 %J Materials and Corrosion %N 3 %P 339-351 %R doi:10.1002/maco.201911327 %T Thixomolded AZ91D and MRI153M magnesium alloys and their enhanced corrosion resistance %U https://doi.org/10.1002/maco.201911327 3 %X AZ91D and MRI153M alloys were produced by thixomolding. Their corrosion resistance is significantly higher than that of similar materials produced by ingot or die‐casting. A corrosion rate smaller than 0.2 mm/year in 5 wt% NaCl solution is measured for the thixomolded AZ91D alloy. The corrosion behaviour was evaluated using immersion tests, electrochemical impedance spectroscopy, hydrogen evolution, glow discharge optical emission spectroscopy, and atomic emission spectroelectrochemistry. A bimodal microstructure is observed for both alloys, with the presence of coarse primary α‐Mg grains, fine secondary α‐Mg grains, β‐phase, and other phases with a minor volume fraction. The amount of coarse primary α‐Mg is significantly higher for the AZ91D compared with the MRI153M. The network of β‐phase around the fine secondary α‐Mg grains is better established in the thixomolded AZ91D alloy. A combination of several factors such as the ratio of primary to secondary α‐Mg grains, localised corrosion or barrier effect due to other phases, as well as regions of preferential dissolution of the α‐Mg due to chemical segregation, are thought to be responsible for the high corrosion resistance exhibited by the thixomolded AZ91D and MRI153M. %0 journal article %@ 2213-9567 %A Horváth Fekete, K.,Drozdenko, D.,Čapek, J.,Máthis, K.,Tolnai, D.,Stark, A.,Garcés, G.,Dobroň, P. %D 2020 %J Journal of Magnesium and Alloys %N 1 %P 199-209 %R doi:10.1016/j.jma.2019.11.009 %T Hot deformation of Mg-Y-Zn alloy with a low content of the LPSO phase studied by in-situ synchrotron radiation diffraction %U https://doi.org/10.1016/j.jma.2019.11.009 1 %X The compressive deformation behavior of the extruded WZ42 (Mg98.5Y1Zn0.5 in at.%) magnesium alloy containing a low amount of long-period stacking ordered (LPSO) phase was studied by in-situ synchrotron radiation diffraction technique. Tests were conducted at temperatures between room temperature and 350 °C. Detailed microstructure investigation was provided by scanning electron microscopy, particularly the backscattered electron imaging and electron backscatter diffraction technique. The results show that twinning lost its dominance and kinking of the LPSO phase became more pronounced with increasing deformation temperature. No cracks of the LPSO phase and no debonding r at the interface between the LPSO phase and the Mg matrix were observed at temperatures above 200 °C. At 350 °C, the LPSO phase lost its strengthening effect and the deformation of the alloy was mainly realized by the dynamic recrystallization of the Mg matrix. %0 journal article %@ 1742-7061 %A Tie, D.,Liu, H.,Guan, R.,Holt-Torres, P.,Liu, Y.,Wang, Y.,Hort, N. %D 2020 %J Acta Biomaterialia %N %P 415-425 %R doi:10.1016/j.actbio.2020.09.023 %T In vivo assessment of biodegradable magnesium alloy ureteral stents in a pig model %U https://doi.org/10.1016/j.actbio.2020.09.023 %X Today, ureteral stent technology is making progress towards the reduction of complications and patient discomfort. Therefore, magnesium alloys have become excellent candidate materials for manufacturing ureteral stents due to their biodegradability and antibacterial activity. Built on our previous work on biodegradable magnesium alloys, this article reports a semisolid rheo-formed magnesium implant that displays degradability and biocompatibility in vivo, and feasibility as ureteral stents in a pig model. Refined non-dendritic microstructure was observed in the rheo-formed alloy, whose grain size and shape factor were ca. 25.2 μm and ca. 1.56 respectively. Neither post-interventional inflammation nor pathological changes were observed in the urinary system during the implantation period of 14 weeks, and the degradation profile (14 weeks) meets the common requirement for the indwelling time of ureteral stents (8 to 16 weeks). Furthermore, histopathological observation and urinalysis results confirmed that the alloy had significantly higher antibacterial activity than the medical-grade stainless steel control. To our knowledge, this is the first in vivo study of biodegradable magnesium alloy as urinary implants in large animal models. Our results demonstrate that magnesium alloys may be a reasonable option for manufacturing biodegradable ureteral stents. %0 journal article %@ 0925-8388 %A Fu, Y.,Huang, Y.,Liu, Z.,Guo, R.,Li, S. %D 2020 %J Journal of Alloys and Compounds %N %P 155993 %R doi:10.1016/j.jallcom.2020.155993 %T Mechanical behaviors of novel multiple principal elements CuAl10Fe5Ni5Mn1.2 wt% with micro-nano structures %U https://doi.org/10.1016/j.jallcom.2020.155993 %X A multiple principal elements CuAl10Fe5Ni5Mn1.2 alloy is widely used in the bearing bracket of high speed railway, nuclear power and marine engineering. In traditional metal materials, the evolution of strength and elongation are mutually inconsistent. The multiple principal elements CuAl10Fe5Ni5Mn1.2(wt%) alloy shows the simultaneous improvement of strength and toughness. The present work has systematically studied the strengthening and plasticity behaviors of CuAl10Fe5Ni5Mn1.2(wt%) alloy under complex stirring. The mechanisms responsible for both increasing its strength and plasticity were clarified. It is found that the properties of novel Al10Fe5Ni5Mn1.2 (wt%) alloy are better than other aluminum bronze alloys. Its Rm is 729 MPa, A5.65 is 16% and yield strength (Rp0.2) is 382 MPa. K phases with nano structures distribute in the grains boundaries complete boundaries strengthening. Schmid factor for the basal slip system is from 0.3 to 0.5, which could largely contribute to grain boundary migration and grain rotation. Twinning deformation is initiated and it can open the low angle grain boundaries (LAGBs) and media angle grain boundaries (MAGBs), so the proper combination of strain hardening and plastic deformation enables CuAl10Fe5Ni5Mn1.2 wt% to undergo uniform deformation with micro-nano structures, result in increasing the toughness. The solid solution forms atom scale strengthening. Nano-structures and micron K phase form nano-micro scale strengthening, respectively. Multi-scales strengthening and twinning deformation opening the LAGBs and MAGBs, resulting in increasing both strength and plasticity on the novel CuAl10Fe5Ni5Mn1.2 wt% alloy. %0 conference paper %@ 2367-1181 %A Tolnai, D.,Sarkis, G.,Barriobero-Vila, P.,Stark, A.,Schell, N. %D 2020 %J Magnesium Technology 2020 %N %P 37-42 %R doi:10.1007/978-3-030-36647-6_8 %T Effect of Gd and Nd Additions on the Thermo-Mechanical Response of a MgMn Alloy %U https://doi.org/10.1007/978-3-030-36647-6_8 %X Alloying Mg with Mn improves the strength and corrosion resistance. The addition of rare-earth elements weakens the texture and improves the age hardening response. Nd and Gd are ideal elements to investigate the effect of low and high solid soluble rare-earth elements in Mg on the thermo-mechanical behavior of MgMn alloy. For this purpose, a Mg alloy with 1 wt% Mn and 1 wt% Nd was produced and then modified with the addition of 1 wt% Gd. In situ high-energy synchrotron X-ray diffraction was performed during compression to analyse the deformation behavior of the material. The compression experiments have been performed at room temperature and 350 °C up to a deformation of 0.3 with a deformation rate of 10−3 s−1. The compressed samples were subsequently subjected to electron-backscattered diffraction to investigate the post-mortem microstructure. %0 journal article %@ 0928-4931 %A Luo, J.,Huang, Y.,Xu, J.,Sun, J.,Dargusch, M.,Hou, C.,Ren, L.,Wang, R.,Ebel, T.,Yan, M. %D 2020 %J Materials Science and Engineering C %N %P 110903 %R doi:10.1016/j.msec.2020.110903 %T Additively manufactured biomedical Ti-Nb-Ta-Zr lattices with tunable Young's modulus: Mechanical property, biocompatibility, and proteomics analysis %U https://doi.org/10.1016/j.msec.2020.110903 %X Some β-Ti alloys, such as Ti-Nb-Ta-Zr (TNTZ) alloys, exhibit a low Young's modulus and excellent biocompatibility. These alloys are promising new generation biomedical implant materials. Selective laser melting (SLM) can further enable customer-specific manufacturing of β-Ti alloys to satisfy the ever-increasing need for enhanced biomedical products. In this study, we quantitatively determined the relationships between porosity, yield strength, and Young's modulus of SLM-prepared TNTZ lattices. The study constitutes a critical step toward understanding the behavior of the lattice and eventually enables tuning the Young's modulus to match that of human bones. Fatigue properties were also investigated on as-printed lattices in terms of the stress limit. The biocompatibility study included a routine evaluation of the relative cell growth rate and a proteomics analysis using a common mouse fibroblast cell line, L929. The results indicated that the as-printed TNTZ samples exhibited evidence of protein proliferation of the L929 cells, particularly P06733, and that those proteins are responsible for biological processes and molecular functions. They in turn may have promoted cell regeneration, cell motility, and protein binding, which at least partially explains the good biocompatibility of the as-printed TNTZ at the protein level. The study highlights the promising applications of additively manufactured TNTZ as a bone-replacing material from mechanical and biocompatibility perspectives. %0 conference lecture %@ %A Xu, Y.,Yang, L.,Liu, W.,Sun, J.,Xiao, L.,Jiang, X.,Hort, N. %D 2020 %J TMS Annual Meeting 2020 %N %P %T Investigation on the Microstructure and Mechanical Properties of Mg–Gd–Nd Ternary Alloys %U %X %0 journal article %@ 1047-4838 %A Xu, Y.,Gavras, S.,Gensch, F.,Kainer, K.,Hort, N. %D 2020 %J JOM: The Journal of the Minerals, Metals and Materials Society %N 1 %P 517-522 %R doi:10.1007/s11837-019-03877-y %T Effect of Nd Additions on the Mechanical Properties of Mg Binary Alloys %U https://doi.org/10.1007/s11837-019-03877-y 1 %X The influence of Nd contents and particles on the microstructure and mechanical properties of extruded Mg alloys are discussed. Pure Mg and binary Mg-xNd (x = 0.2 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.%, 5 wt.%) alloys were cast and extruded. Hardness and tensile/compression tests were measured on those alloys. The results show that the addition of Nd to Mg leads to improvements in hardness, tensile/compression yield strengths and elongation. However, the Nd has little effect on ultimate strengths and compressibility of Mg alloys. The contributions of strengthening mechanisms to the tensile/compressive yield strength of extruded Mg-Nd alloys are investigated. Mg41Nd5 phase was distributed in Mg-2Nd and Mg-5Nd alloys after extrusion, which is the main reason that decreased the grain size of Mg-Nd. The tension-compressing yield asymmetry is decreased from 1.8 to 1 with the increased additions Nd in extruded alloys. %0 journal article %@ 2213-9567 %A Pulido-Gonzáles, N.,Torres, B.,Rodrigo, P.,Hort, N.,Rams, J. %D 2020 %J Journal of Magnesium and Alloys %N 2 %P 510-522 %R doi:10.1016/j.jma.2020.02.007 %T Microstructural, mechanical and corrosion characterization of an as-cast Mg–3Zn–0.4Ca alloy for biomedical applications %U https://doi.org/10.1016/j.jma.2020.02.007 2 %X The as-cast Mg–3Zn–0.4Ca alloy shows a great potential to be used in biomedical applications due to its composition, mechanical properties and biodegradability. Zn and Ca appear naturally in the organism accomplishing vital functions. The alloy consists of an α-Mg matrix and a eutectic composed of α-Mg + Ca2Mg6Zn3. The eutectic product enhances the mechanical properties of the studied alloy, causing strengthening and providing superior hardness values. In this alloy, cracks initiate at the intermetallic compounds and progress through the matrix because of the open network formed by the eutectics. Attending to the corrosion results, the eutectic product presents a noble potential compared to the α-Mg phase. For this reason, the corrosion progresses preferentially through the matrix, avoiding the (α-Mg + Ca2Mg6Zn3) eutectic product, when the alloy is in direct contact to Hank's solution. %0 conference paper %@ 2367-1181 %A Xu, Y.,Yang, L.,Liu, W.,Sun, J.,Xiao, L.,Jiang, X.,Hort, N. %D 2020 %J Magnesium Technology 2020 %N %P 79-85 %R doi:10.1007/978-3-030-36647-6_14 %T Investigation on the Microstructure and Mechanical Properties of Mg–Gd–Nd Ternary Alloys %U https://doi.org/10.1007/978-3-030-36647-6_14 %X The present work deals with microstructure and mechanical properties of Mg–xGd–yNd (x = 10, 15; y = 2, 5) ternary alloys. Hardness, tensile, and compressive properties are measured on the as-cast alloys and the alloys after solid solution treatment (T4 state). The hardness, tensile yield stress (TYS), and ultimate tensile stress (UTS) are increased with increasing amount of alloying elements for both as-cast and T4 state. The elongation (El) of alloys is lower with higher Nd content. The compressive properties of all studied alloys are increased by T4 treatment. With increasing of alloy concentration, both compressive yield stress (CYS) and ultimate compressive stress (UCS) of alloys are enhanced, but the compressibility is decreased. Intermetallic compounds which appear along the grain boundary are reduced after T4 treatment for alloys with 2% Nd. However, large amount of intermetallic compounds with high Nd concentrations remains on the grain boundary of Mg–xGd–5Nd alloys. %0 journal article %@ 1047-4838 %A Maier, P.,Steinacker, A.,Clausius, B.,Hort, N. %D 2020 %J JOM: The Journal of the Minerals, Metals and Materials Society %N %P 1870-1879 %R doi:10.1007/s11837-020-04077-9 %T Influence of Solution Heat Treatment on the Microstructure, Hardness and Stress Corrosion Behavior of Extruded Resoloy® %U https://doi.org/10.1007/s11837-020-04077-9 %X The microstructural changes and corrosion response of Resoloy®, a resorbable Mg-Dy-based alloy, are the focus of this study. Hardness, tensile and compressive, and bending tests are used to monitor the changes in the mechanical properties of this material. The corrosion behavior is investigated by stress corrosion of C-rings. Hot-extruded tubes are solution heat-treated at different temperatures and times. The as-extruded condition shows a homogeneous fine-grained microstructure with matrix long-period stacking-ordered (LPSO) structures. Heat treatment at low temperatures and for short times does not significantly change the microstructure but reduces the hardness. Solution heat treatment at relatively high annealing temperatures and long annealing times causes grain growth, resulting in reduced hardness. The microstructure becomes inhomogeneous, medium-sized grains grow, the matrix LPSO structures dissolve, and small bulk LPSO phases develop. The matrix LPSO structures have a positive effect on the corrosion behavior. In particular, the short-term annealing condition shows the most uniform corrosion morphology. Resoloy® is not free of pitting corrosion, but none of the samples fails by cracking. %0 journal article %@ 2073-4352 %A Buzolin, R.,Guimaraes, L.,Díaz, J.,da Silva, E.,Tolnai, D.,Mendis, C.,Hort, N.,Pinto, H. %D 2020 %J Crystals %N 12 %P 1140 %R doi:10.3390/cryst10121140 %T Restoration Mechanisms at Moderate Temperatures for As-Cast ZK40 Magnesium Alloys Modified with Individual Ca and Gd Additions %U https://doi.org/10.3390/cryst10121140 12 %X The deformation behaviour of as-cast ZK40 alloys modified with individual additions of Ca and Gd is investigated at 250 °C and 300 °C. Compression tests were carried out at 0.0001 s−1 and 0.001 s−1 using a modified Gleeble system during in-situ synchrotron radiation diffraction experiments. The deformation mechanisms are corroborated by post-mortem investigations using scanning electron microscopy combined with electron backscattered diffraction measurements. The restoration mechanisms in α-Mg are listed as follows: the formation of misorientation spread within α-Mg, the formation of low angle grain boundaries via dynamic recovery, twinning, as well as dynamic recrystallisation. The Gd and Ca additions increase the flow stress of the ZK40, which is more evident at 0.001 s−1 and 300 °C. Dynamic recovery is the predominant restoration mechanism in all alloys. Continuous dynamic recrystallisation only occurs in the ZK40 at 250 °C, competing with discontinuous dynamic recrystallisation. Discontinuous dynamic recrystallisation occurs for the ZK40 and ZK40-Gd. The Ca addition hinders discontinuous dynamic recrystallisation for the investigated temperatures and up to the local achieved strain. Gd addition forms a semi-continuous network of intermetallic compounds along the grain boundaries that withstand the load until their fragmentation, retarding discontinuous dynamic recrystallisation. %0 editorial %@ 2075-4701 %A Maier, P.,Hort, N. %D 2020 %J Metals %N 10 %P 1328 %R doi:10.3390/met10101328 %T Magnesium Alloys for Biomedical Applications %U https://doi.org/10.3390/met10101328 10 %X %0 journal article %@ 2213-9567 %A Yu, J.,Song, B.,Xia, D.,Zeng, X.,Huang, Y.,Hort, N.,Mao, P.,Liu, Z. %D 2020 %J Journal of Magnesium and Alloys %N 3 %P 849-859 %R doi:10.1016/j.jma.2020.02.013 %T Dynamic tensile properties and microstructural evolution of extruded EW75 magnesium alloy at high strain rates %U https://doi.org/10.1016/j.jma.2020.02.013 3 %X The dynamic tensile properties and microstructural evolution of an extruded EW75 magnesium alloy deformed at ambient temperature and different high strain rates (from 1000 to 3000 s-1) along extrusion direction (ED) were investigated by Split Hopkinson Tension Bar (SHTB). The corresponding deformation mechanisms, texture evolution and microstructure changes were analyzed by optical microscope (OM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The results show that the extruded EW75 magnesium alloy along ED exhibits a conventional positive strain rate sensitivity that the dynamic flow stresses increase with increasing strain rate. Texture measurements show that after dynamic tension, the initial weak texture of extruded EW75 magnesium alloy tansforms to a relatively strong <10-10>//ED texture with increasing strain rates. The microstructural analysis demonstrates that dislocation motion are main deformatin mode to accommodate dynamic tensile deformation at high strain rates. In addition, the interactions of dislocation-dislocation and dislocation-second phase lead to the increase of flow stress and strain hardening with increasing strain rate. %0 journal article %@ 0921-5093 %A Xia, D.,Zhang, J.,Chen, X.,Huang, G.,Jiang, B.,Tang, A.,Gavras, S.,Huang, Y.,Hort, N.,Pan, F. %D 2020 %J Materials Science and Engineering: A %N %P 139599 %R doi:10.1016/j.msea.2020.139599 %T Effect of biaxial compressive stress state on the microstructure evolution and deformation compatibility of rolled sheet Mg alloy AZ31 at room temperature %U https://doi.org/10.1016/j.msea.2020.139599 %X Mg alloys usually deform under complex biaxial compressive stress states (e.g. during drawing, forging and extrusion). In order to better understand how the biaxial compressive stress state influences the evolution of the microstructure and the deformation compatibility, the uniaxial and biaxial compression tests of AZ31 rolled sheets were performed at room temperature. The new self-developed biaxial compression devices offered a possibility to obtain the evolution of the microstructures by in situ measurements via electron backscatter diffraction. The analysis of geometrically necessary dislocation and the simulation based on the visco-plastic self-consistent method were used to examine the microscopic behaviors in the sheets during the uniaxial and biaxial compression tests. The results indicated that the reorientation of the texture during the biaxial compression was different from that during the uniaxial compression. The simulated results based on the visco-plastic self-consistent model suggested that the equivalent yield strength under a biaxial compressive stress state was lower than that under a uniaxial stress state. This was due to the higher relative activity of extension twins under biaxial compressive stress state. This also led to a lower geometrically necessary dislocation density in the biaxial compressed sample. The geometrically necessary dislocations were also more homogeneously distributed with a biaxial compressive stress state. The analysis of the activation of all the deformation mechanisms proved that the appearance of extension twinning variants limited the activation of prismatic slip during the uniaxial compression while promoting prismatic slip during the biaxial compression. This changeable interaction between extension twinning and prismatic slip combining with the lower geometrically necessary dislocations, the lower flow stress inferred that the application of the biaxial compressive stress state during processing at room temperature was a way to improve the deformability of Mg alloys. %0 journal article %@ 0921-5093 %A Wang, K.,Dou, X.,Wang, J.,Huang, Y.,Gavras, S.,Hort, N.,Liu, S.,Hu, H.,Wang, J.,Pan, F. %D 2020 %J Materials Science and Engineering: A %N %P 139635 %R doi:10.1016/j.msea.2020.139635 %T Achieving enhanced mechanical properties in Mg-Gd-Y-Zn-Mn alloy by altering dynamic recrystallization behavior via pre-ageing treatment %U https://doi.org/10.1016/j.msea.2020.139635 %X The effects of pre-ageing treatment on the microstructure and mechanical properties of the Mg-9.2Gd-4.4Y-1.0Zn-0.8Mn (wt.%) alloy were investigated. Microstructural analysis indicated that the ageing treatment before extrusion led to the formation of dense prismatic β′ and basal γ′ precipitates in heat treated alloys. The presence of these precipitates and their solution obstructed the dynamic recrystallization process during hot extrusion. The lamellar long-period stacking ordered (LPSO) phases restrained the recrystallization through forming the kink band and releasing the stress concentration, and the fine β-Mg5(Gd, Y) particles suppressed the recrystallization by the particle pinning effect. The block-shaped LPSO phases and coarse β-Mg5(Gd, Y) particles promoted the recrystallization following the particle stimulated nucleation (PSN) mechanism. The combined effects led to the formation of the bimodal microstructure, which shows fine recrystallized grains with random grain orientation and deformed grains with strong fiber texture. The bimodal microstructure with lower recrystallization fraction provides the alloy higher strength and lower ductility. With solid-solution and pre-ageing treatments, the as-extruded alloy shows the best strength-ductility balance with an ultimate tensile strength (UTS) of 455 MPa, tensile yield strength (TYS) of 382 MPa and elongation to failure (EL) of 11.0%. The outstanding mechanical properties are mainly attributed to the bimodal microstructure, strong fiber texture, β-Mg5(Gd, Y) particles, lamellar and block-shaped LPSO phases. %0 journal article %@ 2075-4701 %A Maier, P.,Clausius, B.,Wicke, J.,Hort, N. %D 2020 %J Metals %N 5 %P 584 %R doi:10.3390/met10050584 %T Characterization of an Extruded Mg-Dy-Nd Alloy during Stress Corrosion with C-Ring Tests %U https://doi.org/10.3390/met10050584 5 %X This study focuses on the characterization of the failure behavior of an extruded Mg10Dy1Nd alloy during stress corrosion. The microstructure, hardness, strength and corrosion behavior of binary alloys Mg10Dy and Mg1Nd are compared to those of the ternary alloy system. The ternary alloy Mg-Dy-Nd that is not fully recrystallized has the highest hardness but lacks ductility. The investigated alloys twin during plastic deformation. Static C-ring tests in Ringer solution were used to evaluate the stress corrosion properties, and stress corrosion could not be found. None of the alloys failed by fracturing, but corrosion pits formed to various extents. These corrosion pits were elliptical in shape and located below the surface. Some of the pits reduced the remaining wall thickness significantly, but the stress increased by the notch effect did not lead to crack initiation. Furthermore, the C-ring specimen was subjected to compressive loading until fracture. Whereas the Mg1Nd alloy showed ductile behavior, the alloys containing Dy fractured on the tensile side. The crack initiation and growth were mainly influenced by the twin boundaries. The Mg10Dy1Nd alloy had an inhomogeneous microstructure and low ductility, which resulted in a lower fracture toughness than that of the Mg10Dy alloy. There were features that indicate hydrogen-assisted fracture. Although adding Nd decreased the fracture toughness, it reduced the grain size and had a positive influence on the corrosion rate during immersion testing. %0 journal article %@ 1047-4838 %A You, S.,Huang, Y.,Dieringa, H.,Maawad, E.,Gan, W.,kainer, K.U.,Hort, N. %D 2019 %J JOM: Journal of the Minerals, Metals and Materials Society %N 7 %P 2227-2234 %R doi:10.1007/s11837-019-03515-7 %T The Role of Second Phases on the Creep Behavior of As-Cast and Hot-Extruded Mg-Ca-Zr Alloys %U https://doi.org/10.1007/s11837-019-03515-7 7 %X The effect of second phases on the creep behavior of Mg-Ca-Zr alloys was investigated. Casting and hot-extrusion processes were performed to prepare Mg-xCa-0.5Zr (x = 0 wt.%, 0.3 wt.% and 0.6 wt.%) alloys with different morphologies and distributions of second phases. The as-cast microstructures of Mg-Ca-Zr alloys consisted of an Mg matrix and coarse Mg2Ca intermetallic compounds distributed at the grain boundaries. The hot-extruded microstructures exhibited finer Mg2Ca spherical particles and precipitates distributed homogeneously inside the matrix and along the grain boundaries. The results of creep tests suggested that the viscous glide of dislocation and dislocation climb were the dominant creep mechanisms of Mg-Ca-Zr alloys crept at 200°C. The creep property was strongly related to the morphology and distribution of the Mg2Ca phases. The finer and more homogeneously distributed particles showed a better strengthening effect than the coarser intermetallic compounds distributed along the grain boundaries. %0 journal article %@ 1047-4838 %A Maier, P.,Lauth, N.,Mendis, C.L.,Bechly, M.,Hort, N. %D 2019 %J JOM: Journal of the Minerals, Metals and Materials Society %N 4 %P 1426-1435 %R doi:10.1007/s11837-019-03359-1 %T Mechanical and Corrosion Properties of Two Precipitation-Hardened Mg-Y-Nd-Gd-Dy Alloys with Small Changes in Chemical Composition %U https://doi.org/10.1007/s11837-019-03359-1 4 %X Precipitation hardening in Mg-Y-Nd alloys (WE-type) is based on finely dispersed particles offering an effective strengthening mechanism to achieve high strength at moderate ductility. However, these particles often affect corrosion by being more noble than the matrix. Biodegradable implant materials should show a corrosion rate fit to its application but should be free of pitting corrosion. Especially deep and narrow pits act as notches and cause increased mechanical stress leading into early failure. WE43 has already shown to have an acceptable biological response. In this study, two Mg-Y-Nd-Gd-Dy alloys, WE32 and WE33, in extruded, solution and precipitation heat-treated conditions have been investigated. The difference in alloy composition is not very high. Solution heat treatment (T4) causes grain growth and strength loss. The ageing response to peak hardness depends on the temperature. A rather short ageing response was observed for 250°C, and highest hardness has been found for 200°C at longer ageing time but higher hardness compared to 250°C. Grain growth during ageing is not significant. The higher alloyed alloy WE33 shows better mechanical strength, but less ductility. Corrosion was evaluated with immersion and potentiodynamic polarization in Ringer Acetate solution. The corrosion rate strongly depends on the alloy and heat-treatment condition as well as on the test method. The highest corrosion rate is observed in the solution-treated condition. The peak aged alloy shows the lowest corrosion rate, but non-uniform corrosion and has been evaluated by the pitting factor. %0 book part %@ %A Rao, K.P.,Chalasani, D.,Suresh, K.,Prasad, Y.V.R.K.,Dieringa, H.,Hort, N. %D 2019 %J Material and Process Design for Lightweight Structures %N %P 90-103 %R doi:10.3390/books978-3-03897-959-3 %T Connected Process Design for Hot Working of a Creep-Resistant Mg–4Al–2Ba–2Ca Alloy (ABaX422) %U https://doi.org/10.3390/books978-3-03897-959-3 %X With a view to design connected processing steps for the manufacturing of components, the hot working behavior of the ABaX422 alloy has been characterized for the as-cast and extruded conditions. In the as-cast condition, the alloy has a limited workability, due to the presence of a large volume of intermetallic phases at the grain boundaries, and is not suitable to process at high speeds. A connected processing step has been designed on the basis of the results of the processing map for the as-cast alloy, and this step involves the extrusion of the cast billet to obtain a 12 mm diameter rod product at a billet temperature of 390◦C and at a ram speed of 1 mm s−1. The microstructure of the extruded rod has a finer grain size, with redistributed fine particles of the intermetallic phases. The processing map of the extruded rod exhibited two new domains, and the one in the temperature range 360–420◦C and strain rate range 0.2–10 s−1 is useful for manufacturing at high speeds, while the lower temperature develops a finer grain size in the product to improve the room temperature strength and ductility. The area of the flow instability is also reduced by the extrusion step, widening the workability window. %0 journal article %@ 1359-6462 %A Xia, D.,Chen, X.,Huang, G.,Jiang, B.,Tang, A.,Yanh, H.,Gavras, S.,Huang, Y.,Hort, N.,Pan, F. %D 2019 %J Scripta Materialia %N %P 31-35 %R doi:10.1016/j.scriptamat.2019.06.014 %T Calculation of Schmid factor in Mg alloys: Influence of stress state %U https://doi.org/10.1016/j.scriptamat.2019.06.014 %X A modified global Schmid factor under different stress states was developed by introducing the stress intensity to normalize the stress tensor. The new method offers an efficient way to compare the activation of one deformation mode under different stress states. The distributions of global Schmid factors for deformation modes in Mg alloys were also studied using this new method. The results indicated that stress state dominated the distributions of global Schmid factors for different deformation modes in a similar way. Additionally, the deformation compatibilities among deformation modes were also influenced by the stress state, especially under a biaxial stress state. %0 journal article %@ 1047-4838 %A Yang, H.,Huang, Y.,Gavras, S.,Kainer, K.U.,Hort, N.,Dieringa, H. %D 2019 %J JOM: Journal of the Minerals, Metals and Materials Society %N 7 %P 2245-2252 %R doi:10.1007/s11837-019-03499-4 %T Influences of AlN/Al Nanoparticles on the Creep Properties of Elektron21 Prepared by High Shear Dispersion Technology %U https://doi.org/10.1007/s11837-019-03499-4 7 %X Elektron21 (E21) and its composites with additions of 0.25 wt.%, 0.5 wt.%, and 1 wt.% AlN/Al nanoparticles (NPs) were fabricated by a high shear dispersion technology. Their creep properties were investigated over a stress range between 80 MPa and 140 MPa at 240°C. The grain size exhibits an obvious increase with the addition of AlN/Al NPs compared with the monolithic E21 alloy. Increasing the content of AlN/Al NPs leads to a pronounced improvement of creep resistance. Microstructural analysis shows that, with the addition of 1% AlN/Al NPs in E21, the distribution of the intermetallics Mg3RE becomes much more homogeneous and their size is reduced. Such Mg3RE particles can prevent the dislocation slip more efficiently during creep. Besides these Mg3RE particles, the additional formation of Al2RE and Al2Zr3 phases, which results from the reactions of AlN/Al NPs and the alloying elements Zr and REs, could act as thermal stable particles to improve the creep resistance. Finally, the remained AlN NPs without reactions are beneficial for the improvement of the creep resistance to some extent due to Orowan strengthening. %0 journal article %@ 0925-8388 %A Meng, F.,Lv, S.,Yang, Q.,Qin, P.,Zhang, J.,Guan, K.,Huang, Y.,Hort, N.,Li, B.,Liu, X.,Meng, J. %D 2019 %J Journal of Alloys and Compounds %N %P 436-445 %R doi:10.1016/j.jallcom.2019.04.346 %T Developing a die casting magnesium alloy with excellent mechanical performance by controlling intermetallic phase %U https://doi.org/10.1016/j.jallcom.2019.04.346 %X Although Mg−Al−RE (RE: rare earth) alloys have significant weight saving potential in automotive industries, their applications were interrupted due to their unsatisfactory mechanical performance. Intermetallic phases in structural magnesium (Mg) alloys are of practical significance for being able to optimize their microstructures for specific applications. Here we report a new alloy design concept that can develop an alloy for a given system with out-standing mechanical performance and low cost. Such designed alloy exhibits even more excellent strength-ductility balance and cost creep-performance than the commercial/experimental die casting Mg alloys and A380 aluminum alloy. The alloy design concept used in this work is based on strictly controlling intermetallic phase components according to modifying alloy's compositions. Such developed alloy has huge potential to be widely applied in automotive powertrain components acted as the alternative of Mg alloys and even aluminum alloys. %0 journal article %@ 1047-4838 %A Zhang, X.,Huang, Y.,Li, X.,Gan, W.,Kainer, K.U.,Hort, N. %D 2019 %J JOM: Journal of the Minerals, Metals and Materials Society %N 8 %P 2906-2912 %R doi:10.1007/s11837-019-03516-6 %T Unexpected Expansion Behavior of Mg-Al Alloys During Isothermal Ageing %U https://doi.org/10.1007/s11837-019-03516-6 8 %X The precipitation behavior of Mg-Al alloys during isothermal ageing has been investigated by dilatometry. Only continuous precipitation was observed in Mg-5.5Al during ageing at 175°C, 200°C, or 225°C, while both discontinuous and continuous precipitation occurred in Mg-8.9Al at the same ageing temperatures. Dilatometry curves showed that Mg-8.9Al expanded when aged at 225°C or 250°C. These results demonstrate that high content of Al is beneficial for discontinuous precipitation in binary Mg-Al alloys. Additional analyses indicated that the expansion of Mg-8.9Al during isothermal ageing can be attributed to the increment of the Mg cell lattice parameters. Moreover, continuous precipitation could suppress the discontinuous precipitation by reducing the driving force for growth of discontinuous precipitates. %0 conference lecture %@ %A Huang, Y.,Gu, J.,You, S.,Kainer, K.U.,Hort, N. %D 2019 %J 5th International Conference on Advances in Solidification Processes, ICASP-5 - 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining, CSSCR-5 %N %P %T Grain refinements of magnesium alloys inoculated by additions of external SiC particles %U %X %0 journal article %@ 1757-8981 %A Huang, Y.,Gu, J.,You, S.,Kainer, K.U.,Hort, N. %D 2019 %J IOP Conference Series: Materials Science and Engineering %N 1 %P 012049 %R doi:10.1088/1757-899X/529/1/012049 %T Grain refinements of magnesium alloys inoculated by additions of external SiC particles %U https://doi.org/10.1088/1757-899X/529/1/012049 1 %X A homogeneous microstructure of as-cast magnesium alloys is desired to improve the formability during their subsequent thermomechanical processing. Owing to its similar crystal structure to Mg, the part of Zr formed by peritectic reaction during solidification was considered to be the most effective nucleants for alpha-Mg. However, regarding the Al-containing magnesium alloys, up to now no suitable and effective external nucleants were found for them. Recently, it was demonstrated that the additions of SiC worked in refining both the Mg-Al and Mg-Zn alloys. The SiC particles acted as nucleants in magnesium alloys are attracting more attentions. The present work investigated and compared the effects of external SiC particle additions on the grain refinements of Mg-Al and Al-free Mg-Zn (Mn) alloys. Their microstructures were characterized using XRD, SEM and TEM. It was found that the additions of SiC particles could refine the grains of both Mg-Al and Mg-Zn alloys. The SiC particles cannot act as a direct heterogeneous nucleant for the nucleation of alpha-Mg in both Mg-Al and Mg-Zn (Mn) alloys. The responsible mechanisms for their grain refinements are different. Regarding for Mg-Al alloys, the grain refinement caused by the addition of SiC particles is attributed to the formation of a ternary intermetallics Al2MgC2, which has a very similar crystal structure to that of Mg. As for Mg-Zn (Mn) alloys, the grain refinement is attributed to the formation of a (Mn, Si)-enriched intermetallics by the interactions between SiC and impurity Mn in alloys. %0 conference paper %@ %A Wang, W.,Gao, M.,Huang, Y.,Tan, L.,Yang, K.,Hort, N. %D 2019 %J Magnesium Technology 2019, 148th Annual Meeting & Exhibition, TMS 2019 %N %P 151-157 %R doi:10.1007/978-3-030-05789-3_23 %T Microstructures, Corrosion and Mechanical Properties of Mg–Si Alloys as Biodegradable Implant Materials %U https://doi.org/10.1007/978-3-030-05789-3_23 %X Magnesium alloys attracted more and more attentions as biodegradable implant materials because of their properties similar to cortical bone. From the perspective of element biosafety and dietetics, the ideal alloying elements suitable for biodegradable applications should be those essential to or naturally presented in the human body. This study presents a novel aluminum-free magnesium alloy system with Si selected as a major alloying element, due to its superior biocompatibility in biological environment, especially in bone regeneration and repairment. Mg–Si binary alloys with different Si contents were prepared in a permanent mould via gravity casting and direct-chill casting. The microstructures, corrosion properties and mechanical properties were inves- tigated as a function of alloy composition. %0 journal article %@ 1005-0302 %A Guan, K.,Meng, F.,Qin, P.,Yang, Q.,Zhang, D.,Li, B.,Sun, W.,Lv, S.,Huang, Y.,Hort, N.,Meng, J. %D 2019 %J Journal of Materials Science and Technology %N 7 %P 1368-1377 %R doi:10.1016/j.jmst.2019.01.019 %T Effects of samarium content on microstructure and mechanical properties of Mg–0.5Zn–0.5Zr alloy %U https://doi.org/10.1016/j.jmst.2019.01.019 7 %X Effects of samarium (Sm) content (0, 2.0, 3.5, 5.0, 6.5 wt%) on microstructure and mechanical properties of Mg–0.5Zn–0.5 Zr alloy under as-cast and as-extruded states were thoroughly investigated. Results indicate that grains of the as-cast alloys are gradually refined as Sm content increases. The dominant intermetallic phase changes from Mg3Sm to Mg41Sm5 till Sm content exceeds 5.0 wt%. The dynamically precipitated intermetallic phase during hot-extrusion in all Sm-containing alloys is Mg3Sm. The intermetallic particles induced by Sm addition could act as heterogeneous nucleation sites for dynamic recrystallization during hot extrusion. They promoted dynamic recrystallization via the particle stimulated nucleation mechanism, and resulted in weakening the basal texture in the as-extruded alloys. Sm addition can significantly enhance the strength of the as-extruded Mg–0.5Zn–0.5 Zr alloy at room temperature, with the optimal dosage of 3.5 wt%. The optimal yield strength (YS) and ultimate tensile strength (UTS) are 368 MPa and 383 MPa, which were enhanced by approximately 23.1% and 20.8% compared with the Sm-free alloy, respectively. Based on microstructural analysis, the dominant strengthening mechanisms are revealed to be grain boundary strengthening and dispersion strengthening. %0 conference paper %@ %A Hort, N.,Floss, V.,Gavras, S.,Wiese, G.,Tolnai, D. %D 2019 %J Magnesium Technology 2019, 148th Annual Meeting & Exhibition, TMS 2019 %N %P 267-276 %R doi:10.1007/978-3-030-05789-3_40 %T Metallography of Mg Alloys %U https://doi.org/10.1007/978-3-030-05789-3_40 %X Processing and composition determine microstructural properties. To reveal the microstructure, the metallographic investigation is a commonly used method, and therefore, it is a crucial part in the characterization of metals and alloys. Choosing incorrect preparation steps will lead to artefacts and misleading conclusions due to the compositional analysis and processing steps influencing the microstructure. However, in the published literature, it is obvious that not all reported microstructures are in fact true microstructures of investigated material. Especially in the case of magnesium and its alloys, special care is necessary to obtain micrographs with a true representation. What quite often is presented are surfaces that show artefacts rather than microstructures. Examples of this will be shown as well as their counterpart real microstructures. %0 conference lecture %@ %A Wang, W.,Gao, M.,Huang, Y.,Tan, L.,Yang, K.,Hort, N. %D 2019 %J 148th Annual Meeting & Exhibition, TMS 2019 %N %P %T Microstructures, corrosion and mechanical properties of Mg-Si alloys as biodegradable implant materials %U %X %0 conference paper %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Dharmendra, C.,Hort, N. %D 2019 %J Magnesium Technology 2019, 148th Annual Meeting & Exhibition, TMS 2019 %N %P 313-318 %R doi:10.1007/978-3-030-05789-3_46 %T Forging of Mg–3Sn–2Ca–0.4Al Alloy Assisted by Its Processing Map and Validation Through Analytical Modeling %U https://doi.org/10.1007/978-3-030-05789-3_46 %X The processing map for hot working of cast Mg–3Sn–2Ca–0.4Al (TXA320) alloy has been validated using forging experiments to form a rib–web (cup) shaped component. Finite-element (FE) simulation has also been conducted to obtain the strain and strain rate variations in the components as well as the load–stroke curves. TXA320 has been successfully forged under optimum processing conditions (450 °C at press speeds of 1 and 0.1 mm s−1) predicted by the processing map, where dynamic recrystallization (DRX) occurs. The microstructure obtained on these components revealed fully DRX grains and the average grain size has increased with increase in temperature. The load–stroke curves predicted by FE simulation of the forging process correlate well with experimental curves, although the simulated curves are slightly lower. Forging done in the flow instability regime of the processing map resulted in specimen fracture and the microstructure exhibited cracks at flow localization bands. %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Dharmendra, C.,Hort, N. %D 2019 %J 148th Annual Meeting & Exhibition, TMS 2019 %N %P %T Forging of Mg-3Sn-2Ca-0.4Al alloy assisted by its processing map and validation through analytical modelling %U %X %0 conference paper %@ %A Huang, Y.,Gu, J.,You, S.,Kainer, K.U.,Hort, N. %D 2019 %J Magnesium Technology 2019, 148th Annual Meeting & Exhibition, TMS 2019 %N %P 331-338 %R doi:10.1007/978-3-030-05789-3_49 %T Influences of SiC Particle Additions on the Grain Refinement of Mg–Zn Alloys %U https://doi.org/10.1007/978-3-030-05789-3_49 %X A homogeneous microstructure of as-cast magnesium alloys is desired to improve their mechanical properties when achieving lightweighting. Recently, it was demonstrated that the addition of SiC refines both Mg–Al and Mg–Zn alloys. The present work investigates the effect of SiC particle additions on the grain refinement of Mg–Zn alloys, including their addition amount, particle size, addition temperature and holding time. The microstructures were characterized using XRD, SEM and EDS. It was found that the addition of SiC particles refines the grains of Mg–Zn alloys. With increasing their amount and reducing the addition temperature and holding time, the grain size decreases. The optimal SiC particle size for nucleation of alpha-Mg was found to be around 2 µm. The responsible refinement mechanism is attributed to the formation of (Mn, Si)-enriched intermetallics by the interactions between SiC and impurity Mn in alloys. %0 conference lecture %@ %A Huang, Y.,Gu, J.,You, S.,Kainer, K.U.,Hort, N. %D 2019 %J 148th Annual Meeting & Exhibition, TMS 2019 %N %P %T Influences of SiC particle additions on the grain refinement of Mg-Zn alloys %U %X %0 journal article %@ 0921-5093 %A Yang, H.,Huang, Y.,Tolnai, D.,Kainer, K.U.,Dieringa, H. %D 2019 %J Materials Science and Engineering A %N %P 138215 %R doi:10.1016/j.msea.2019.138215 %T Influences of Al and high shearing dispersion technique on the microstructure and creep resistance of Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn alloy %U https://doi.org/10.1016/j.msea.2019.138215 %X Effects of 0.25% Al addition and the high shearing dispersion technique (HSDT) on the microstructure and creep resistance of Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn (Elektron21, El21) alloy were investigated. Compressive creep testes were performed at 240 °C over a stress range between 80 and 140 MPa. The results indicate that the creep resistance of El21 was significantly improved by about one order of magnitude with the addition of 0.25% Al and HSDT than that of El21 without Al and HSDT. Microstructural characterizations show that the grains were coarsened from 80.1 ± 5.0 to 167.0 ± 5.7 μm due to the loss of grain refiner Zr by the chemical reaction of Al with Zr. With the addition of 0.25% Al to El21, the grain morphology was changed from equiaxed to typical dendrite. The morphology of intermetallic Mg3RE was modified from network to a pronounced dendritic structure. Owing to the employment of HSDT, the dendrite arm spacing of primary α-Mg was refined from 74.0 ± 6.4 to 56.2 ± 1.6 μm in Al-containing El21 alloy, the dominant Al–Zr compound changed from Al2Zr3 to Al2Zr phase. A small amount of Al2Nd phase was formed. Creep data analysis indicates that the dominant controlling mechanism for H-El21A alloy is dislocation climb during creep deformation. Its superior creep resistance was mainly attributed to the pronounced and dense dendritic structure of Mg3RE intermetallic in the α-Mg hindering the grain boundary sliding and dislocation movement. In addition, the relative homogeneous dispersion of Al2Zr phase and Al2Nd phase with a high melting point can also act as efficient reinforcements to inhibit the dislocation movement and benefit the creep properties. %0 conference lecture %@ %A Hort, N.,Floss, V.,Gavras, S.,Wiese, G.,Tolnai, D. %D 2019 %J 148th Annual Meeting & Exhibition, TMS 2019 %N %P %T Metallography of Mg Alloys %U %X %0 conference paper %@ %A Wadsoe, L.,Hort, N.,Orlov, D. %D 2019 %J Magnesium Technology 2019, 148th Annual Meeting & Exhibition, TMS 2019 %N %P 121-126 %R doi:10.1007/978-3-030-05789-3_19 %T Effect of Alloying with Rare-Earth Metals on the Degradation of Magnesium Alloys Studied Using a Combination of Isothermal Calorimetry and Pressure Measurements %U https://doi.org/10.1007/978-3-030-05789-3_19 %X With all the versatility in structural performance and recent progress in developing magnesium alloys, their Achilles heel remains to be degradation or corrosion property. While applications in mobility demand corrosion protection by all means, bio-medical applications of Mg alloys require well-controlled degradation rates. Meeting these requirements is only possible through the understanding of phenomena on surface–environment interfaces and the characteristics of Mg alloys affecting them. In this study, in situ monitoring during immersion testing along with 3D-optical and scanning-electron microscopy were used for assessing structure-performance characteristics. The effect of alloying with rare-earth metals on the degradation of magnesium has been studied in three model alloys Mg–0.8Nd, Mg–0.2Zr and Mg–2.0Gd using a combination of isothermal calorimetry and pressure measurements. The combination appears to be a powerful method to study corrosion of magnesium. The degradation of the Gd-containing alloy is approximately 100 times that of the other two alloys studied and is associated with the release of heat and hydrogen gas in large quantities. Differences in the morphology of corrosion products on Mg–0.8Nd and Mg–0.2Zr alloy surfaces can be associated with minute variations in the degradation process detected by the developed method. %0 conference lecture %@ %A Wadsoe, L.,Hort, N.,Orlov, D. %D 2019 %J 148th Annual Meeting & Exhibition, TMS 2019 %N %P %T Effect of alloying with rare-earth metals on the degradation of magnesium alloys studied using a combination of isothermal calorimetry and pressure measurements %U %X %0 journal article %@ 0921-5093 %A Yang, H.,Huang, Y.,Song, B.,Kainer, K.U.,Dieringa, H. %D 2019 %J Materials Science and Engineering A %N %P 18-27 %R doi:10.1016/j.msea.2019.03.131 %T Enhancing the creep resistance of AlN/Al nanoparticles reinforced Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn alloy by a high shear dispersion technique %U https://doi.org/10.1016/j.msea.2019.03.131 %X A high shearing dispersion technique (HSDT) was utilized for the first time to incorporate AlN/Al nanoparticles in Mg-2.85Nd-0.92Gd-0.41Zr-0.29Zn (Elektron21) alloy. Compressive creep tests of unreinforced and reinforced Elektron21 alloys were performed at 240 °C with an applied stress of between 70-140 MPa. The results show that HSDT is an effective way to incorporate the nanoparticles and therefore to improve the creep resistance of El21 alloy by about one order of magnitude with 0.5% AlN/Al nanoparticles (NPs) compared with unreinforced alloy. The calculation of true creep stress exponent indicates that the viscous glide of dislocation and dislocation climbing are the rate controlling mechanisms during creep deformation. The microstructural observations show that the grains changed from equiaxed to dendritic grains with the addition of NPs by HSDT. Grain refiner Zr in Elektron21 alloy was partly consumed by Al atoms from the nano-powder mixture to form stable compound leading to grain coarsening. After high shearing, AlN NPs are effectively dispersed without any discernible clusters. The eutectic phases of El21 + 0.5AlN/Al composite become less continuous, much thinner, and are more homogeneously distributed in the alloy, which helps to pin the grain boundary sliding and hinder the dislocation movement inside the grain. The existence of AlN NPs is helpful for modifying the morphologies of α-Mg dendrites during solidification and thus resulting in obtaining thinner and hyper-branched eutectic phases in the nanocomposite. As a result, the creep resistance of reinforced alloy is additionally improved. %0 journal article %@ 2075-4701 %A Gawlik, M.M.,Wiese, B.,Welle, A.,Gonzalez, J.,Desharnais, V.,Harmuth, J.,Ebel, T.,Willumeit-Roemer, R. %D 2019 %J Metals %N 2 %P 117 %R doi:10.3390/met9020117 %T Acetic Acid Etching of Mg-xGd Alloys %U https://doi.org/10.3390/met9020117 2 %X Mg-xGd alloys show potential to be used for degradable implants. As rare earth containing alloys, they are also of special interest for wrought products. All applications from medical to engineering uses require a low and controlled degradation or corrosion rate without pitting. Impurities from fabrication or machining, like Fe inclusions, encourage pitting, which inhibits uniform material degradation. This work investigates a suitable etching method to remove surface contamination and to understand the influence of etching on surface morphology. Acetic acid (HAc) etching as chemical surface treatment has been used to remove contamination from the surface. Extruded Mg-xGd (x = 2, 5 and 10) discs were etched with 250 g/L HAc solution in a volume of 5 mL or 10 mL for different times. The microstructure in the near surface region was characterized. Surface characterization was done by SEM, EDS, interferometry, and ToF-SIMS (time-of-flight secondary ion mass spectrometry) analysis. Different etching kinetics were observed due to microstructure and the volume of etching solution. Gd rich particles and higher etching temperatures due to smaller etchant volumes promote the formation of pits. Removal of 2–9 µm of material from the surface was sufficient to remove surface Fe contamination and to result in a plain surface morphology. %0 journal article %@ 0925-8388 %A Li, B.,Guan, K.,Yang, Q.,Niu, X.,Zhang, D.,Lv, S.,Meng, F.,Huang, Y.,Hort, N.,Meng, J. %D 2019 %J Journal of Alloys and Compounds %N %P 666-678 %R doi:10.1016/j.jallcom.2018.10.322 %T Microstructures and mechanical properties of a hot-extruded Mg−8Gd−3Yb−1.2Zn−0.5Zr (wt%) alloy %U https://doi.org/10.1016/j.jallcom.2018.10.322 %X Microstructures and mechanical properties of a Mg−8Gd−3Yb−1.2Zn−0.5Zr (wt%) alloy have been investigated. The dominant intermetallic phases in the as-cast sample are Mg5RE (RE = Gd,Yb) phase, 14H-type long-period stacking ordered (LPSO) phase, and Mg2Zn2RE (W) phase and ordered Mg12RE phase. Furthermore, the ordered Mg12RE phase generally coexists with the W phase following an orientation relationship as [01¯1]w//[2¯30]Mg12RE, and (1¯11)w//(001)Mg12RE. After extrusion, the microstructure is consisted of un-recrystallized regions along with a small part of fine dynamically recrystallized (DRXed) regions. Simultaneously, the coarse Mg5RE, W and Mg12RE particles were disintegrated and mainly distribute at extrusion stringers while the fine LPSO plates mainly distribute in un-recrystallized regions. Moreover, amounts of nanoscale Mg5RE particles were dynamically precipitated in DXRed regions. Then, the as-extruded Mg−8Gd−3Yb−1.2Zn−0.5Zr alloy exhibits clearly higher strength than the classic rare-earth-containing magnesium alloys with comparative or even much higher rare earth content at both room temperature and high temperatures. The dominant strengthening mechanism was finally revealed as precipitation/dispersion strengthening. %0 journal article %@ 0010-938X %A Jin, Y.,Blawert, C.,Feyerabend, F.,Bohlen, J.,Silva Campos, M.,Gavras, S.,Wiese, B.,Mei, D.,Deng, M.,Yang, H.,Willumeit-Roemer, R. %D 2019 %J Corrosion Science %N %P 108096 %R doi:10.1016/j.corsci.2019.108096 %T Time-sequential corrosion behaviour observation of micro-alloyed Mg-0.5Zn-0.2Ca alloy via a quasi-in situ approach %U https://doi.org/10.1016/j.corsci.2019.108096 %X The corrosion behaviour of as-cast and solution-annealed Mg-0.5Zn-0.2Ca alloy containing 150 ppm Si was investigated in 0.9% NaCl solution. The main secondary phases in the as-cast state are isolated MgCaSi and a coexisting intermetallic particle which consists of Mg2Ca and Ca2Mg6Zn3. A quasi-in situ approach is applied to investigate the corrosion initiation and development. It is proved that Mg2Ca phase is anodic and preferentially corrodes within the first hour of immersion. Whereas, Ca2Mg6Zn3 and MgCaSi phases continuously act as cathodes until 24 h. After solution annealing, the more homogeneous microstructure and reduced galvanic corrosion result in a higher corrosion resistance. %0 journal article %@ 0921-5093 %A Lyu, S.,Zheng, R.,Xiao, W.,Huang, Y.,Gavras, S.,Hort, N.,Li, G.,Ma, C. %D 2019 %J Materials Science and Engineering A %N %P 426-430 %R doi:10.1016/j.msea.2019.06.029 %T Abnormal extrusion texture and reversed yield asymmetry in a Mg–Y-Sm-Zn-Zr alloy %U https://doi.org/10.1016/j.msea.2019.06.029 %X An extruded Mg–Y-Sm-Zn-Zr alloy exhibited an abnormal texture component, that is, the c-axis of most grains was aligned parallel to the extrusion direction. The reversed yield asymmetry with a tension/compression of 0.94 was attributed to the activation of extension twinning under tensile strain. %0 conference poster %@ %A Gawlik, M.M.,Ebel, T.,Willumeit-Roemer, R.,Wiese, B. %D 2019 %J 11th Symposium on Biodegradable Metals, Biometal 2019 %N %P %T Impact of etching on the degradation of Mg-Gd alloys %U %X %0 journal article %@ 1359-6454 %A Mo, N.,McCarroll, I.,Tan, Q.,Ceguerra, A.,Liu, Y.,Cairney, J.,Dieringa, H.,Huang, Y.,Jiang, B.,Pan, F.,Bermingham, M.,Zhang, M.-X. %D 2019 %J Acta Materialia %N %P 185-199 %R doi:10.1016/j.actamat.2019.09.058 %T Understanding solid solution strengthening at elevated temperatures in a creep-resistant Mg–Gd–Ca alloy %U https://doi.org/10.1016/j.actamat.2019.09.058 %X The present work studies the strengthening mechanisms of a creep-resistant Mg-0.5Gd-1.2Ca (at.%) alloy at both room and elevated temperatures. Although peak-ageing (T6) at 180 °C for 32 h led to a significant increase in room temperature strength due to the precipitation strengthening by three types of precipitates (Mg2Ca, Mg5Gd on prismatic planes and a new type of Mg–Gd–Ca intermetallic compound on the basal plane), the as-solid solution treated (T4) alloy exhibited better resistance to temperature softening during compression and to stress relaxation at 180 °C and better creep resistance at 210 °C/100 MPa. The Gd–Ca co-clusters with short-range order in the Mg solid solution, which was verified, at the first time, by atom probe tomography (APT) analysis and atomic-resolution high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), were responsible for the solid solution hardening, offering a more effective strengthening effect through local order-strengthening. Such solid solution strengthening increased the thermal stability of the alloy structure at elevated temperatures, at least at early stage of the creep. Subsequently, dynamic precipitation started contributing to the creep resistance due to the formation of higher density of precipitates. However, in the T6 alloy, creep testing at elevated temperatures, particularly at 210 °C that was higher than the ageing temperature, led to coarsening of the precipitates, which acted as over ageing. As a result of such over ageing, the resistance of the T6 alloy to heat-induced softening was weakened, leading to lower creep resistance than the T4 alloy. %0 journal article %@ 0921-5093 %A Xia, D.,Huang, G.,Liu, S.,Tang, A.,Gavras, S.,Huang, Y.,Hort, N.,Jiang, B.,Pan, F. %D 2019 %J Materials Science and Engineering: A %N %P 1-10 %R doi:10.1016/j.msea.2019.04.029 %T Microscopic deformation compatibility during biaxial tension in AZ31 Mg alloy rolled sheet at room temperature %U https://doi.org/10.1016/j.msea.2019.04.029 %X In this paper, in situ electron back scattered diffraction combined with scanning electron microscopy and digital image processing techniques were used to study the microscopic deformation compatibility of AZ31 Mg alloy rolled sheets with strong basal texture during biaxial tension at room temperature. The results firstly quantitatively showed that the distribution of microscopic strain in AZ31 rolled sheet was inhomogeneous during formation. Strain concentrations happened in some regions even at early stage of deformation. Short distorted bands also appeared in these regions and extended to connect each other with increasing macroscopic strain. The appearance of distorted bands play an important role in strain compatibility since the materials lack easy deformation modes at room temperature. Besides slips and twins, the grain distortion should also be an indispensable mechanism in accommodating plastic deformation in some parts in distorted bands. According to the analysis from the Schmid factor, the geometric compatibility factors and slip trace identification, the comprehensive effect of strong basal texture and biaxial tensile stress state not only led to the quite low SFs for prismatic, pyramidal slips and tensile twinning, but limited the compatibility between slip systems and tensile twins. This mechanism was the main reason for the lack of easy deformation modes and the appearance of distorted bands, which further led to the inhomogeneous strain distribution at room temperature. Therefore, the formability of Mg alloys rolled sheets with strong basal texture was weakened at room temperature. %0 conference object %@ %A Gawlik, M.M.,Ebel, T.,Willumeit-Roemer, R.,Wiese, B. %D 2019 %J Abstract Book, 11th Symposium on Biodegradable Metals, Biometal 2019 %N %P Cor-17 %T Impact of etching on the degradation of Mg-Gd alloys %U %X %0 conference paper %@ 1742-6588 %A Poletti, C.,Simonet-Fotso, T.,Halici, D.,Canelo Yubero, D.,Montheillet, F.,Piot, D.,Kovacs, Z.,Schell, N.,Tolnai, D. %D 2019 %J Journal of Physics: Conference Series %N 1 %P 012049 %R doi:10.1088/1742-6596/1270/1/012049 %T Continuous dynamic recrystallization during hot torsion of an aluminum alloy %U https://doi.org/10.1088/1742-6596/1270/1/012049 1 %X Most commercial aluminum alloys are characterized by dynamic recrystallization at very large deformations in a continuous manner. The present study deals with the characterization and modeling of the evolution of the microstructure of an aluminum wrought alloy at large plastic deformations. Hot torsion tests of the AA6082 aluminum alloy are carried out using the thermomechanical simulator Gleeble®3800 in a wide range of temperatures and strain rates. The use of water quenching immediately after deformation avoids any static restoration during cooling. Microstructural investigations are carried out by means of electron back scattered diffraction using a scanning electron microscope to determine the grain and subgrain structures, as well as the misorientation distributions. In-situ synchrotron radiation tests during hot torsion are used to confirm the continuous dynamic recrystallization (CDRX) by the evidence of the conversion of low angle boundaries (LAGBs) into high-angle boundaries (HAGBs) and the formation of new texture. Experimental investigations show that CDRX starts with the formation of LAGBs at low strains (center of the sample). By subsequent straining (close to the surface of the sample), the accumulation of dislocations at the LAGBs causes an increase in their misorientation until a critical value is reached and LAGBs transforms into HAGBs. The developed model consists of a microstructural model, equation rates and constitutive equations. The microstructure is described by three internal variables. Their rates are evaluated using the Kocks-Mecking model. The modelled and experimental flow stresses show softening due to the consumption of dislocations and the continuous formation of new HAGBs. %0 journal article %@ 1996-1944 %A Tolnai, D.,Dupont, M.-A.,Gavras, S.,Fekete-Horváth, K.,Stark, A.,Schell, N.,Máthis, K. %D 2019 %J Materials %N 23 %P 3935 %R doi:10.3390/ma12233935 %T In situ synchrotron diffraction analysis of Zn additions on the compression properties of NK30 %U https://doi.org/10.3390/ma12233935 23 %X In situ synchrotron radiation diffraction was performed during the compression of as-cast Mg–3Nd–Zn alloys with different amounts (0, 0.5, 1, and 2 wt %) of Zn addition at room temperature. During the tests, the acoustic emission signals of the samples were recorded. The results show that the addition of Zn decreased the strength of the alloys but, at the same time, increased their ductility. In the earlier stages of deformation, twin formation and basal slip were the dominant deformation mechanisms. The twins tended to grow during the entire compression stage; however, the formation of new twins dominated only at the beginning of the plastic deformation. In order to accommodate the strain levels, the alloys containing Zn underwent nonbasal slip in the later stages of deformation. This can be attributed to the presence of precipitates containing Zn in the microstructure, inhibiting twin growth. %0 conference paper %@ 2367-1181 %A Tolnai, D.,Dupont, M.,Gavras, S.,Mathis, K.,Klaudia, H.,Stark, A.,Schell, N. %D 2019 %J Magnesium Technology 2019 %N %P 297-303 %R doi:10.1007/978-3-030-05789-3_44 %T Thermo-mechanical Processing of EZK Alloys in a Synchrotron Radiation Beam %U https://doi.org/10.1007/978-3-030-05789-3_44 %X Nd, a rare earth element with low solid solubility in Mg, is an ideal alloying element to improve elevated temperature yield strength and creep resistance cost effectively. The addition of Zn leads to further improvement in the elevated temperature properties; therefore, Mg–Nd–Zn alloys are prospective materials for structural and medical applications. In situ synchrotron radiation diffraction was performed during compression at 200 and 350 ℃ for Mg3NdxZn (x = 0, 0.5, 1, 2 wt%) alloys up to a deformation of 0.3 with a deformation rate of 10−3 s−1. The compressed samples were subsequently subjected to electron backscattered diffraction. The results show that at 200 ℃ the addition of Zn increased the ductility. At the beginning of plastic deformation twinning was the dominant deformation mechanism complemented by sub-grain formation at a later stage. At 350 ℃, the compression strength was increased with the addition of Zn and the microstructure of the samples underwent partial dynamic recrystallization during compression. %0 conference lecture %@ %A Wiese, B.,Ebel, T.,Willumeit-Römer, R. %D 2019 %J 37. Arbeitskreis Magnesium %N %P %T Medizinisches Magnesium: Ein aktueller Überblick %U %X %0 conference lecture %@ %A Dieringa, H.,Yang, H.,Huang, Y.,Tolnai, T.,Kainer, K. %D 2019 %J LightMAT2019 %N %P %T Influence of Al on the microstructural evolution and creep properties of Elektron21 processed by high shearing dispersion technique %U %X %0 journal article %@ 1996-1944 %A Estrin, Y.,Martynenko, N.,Anisimova, N.,Temralieva, D.,Kiselevskiy, M.,Serebryany, V.,Raab, G.,Straumal, B.,Wiese, B.,Willumeit-Römer, R.,Dobatkin, S. %D 2019 %J Materials %N 23 %P 3832 %R doi:10.3390/ma12233832 %T The Effect of Equal-Channel Angular Pressing on the Microstructure, the Mechanical and Corrosion Properties and the Anti-Tumor Activity of Magnesium Alloyed with Silver %U https://doi.org/10.3390/ma12233832 23 %X The effect of equal-channel angular pressing (ECAP) on the microstructure, texture, mechanical properties, corrosion resistance and cytotoxicity of two magnesium-silver alloys, Mg-2.0%Ag and Mg-4.0%Ag, was studied. Their average grain size was found to be reduced to 3.2 ± 1.4 μm and 2.8 ± 1.3 μm, respectively. Despite the substantial grain refinement, a drop in the strength characteristics of the alloys was observed, which can be attributed to the formation of inclined basal texture. On a positive side, an increase in tensile ductility to ~34% for Mg-2.0%Ag and ~27% for Mg-4.0%Ag was observed. This effect can be associated with the activity of basal and prismatic slip induced by ECAP. One of the ECAP regimes tested gave rise to a drop in the corrosion resistance of both alloys. An interesting observation was a cytotoxic effect both alloys had on tumor cells in vitro. This effect was accompanied with the release of lactate dehydrogenase, an increase in oxidative stress, coupled with the induction of NO-ions and an increase in the content of such markers of apoptosis as Annexin V and Caspase 3/7. Differences in the chemical composition and the processing history-dependent microstructure of the alloys did not have any significant effect on the magnitude of their antiproliferative effect. %0 journal article %@ 1005-0302 %A Xue, P.,Pauly, S.,Gan, W.,Jiang, S.,Fan, H.,Ning, Z.,Huang, Y.,Sun, J. %D 2019 %J Journal of Materials Science & Technology %N 10 %P 2221-2226 %R doi:10.1016/j.jmst.2019.06.003 %T Enhanced tensile plasticity of a CuZr-based bulk metallic glass composite induced by ion irradiation %U https://doi.org/10.1016/j.jmst.2019.06.003 10 %X N+ ion irradiation is utilized to tune the structure and mechanical properties of a Cu48Zr47.2Al4Nb0.8 bulk metallic glass composite (BMGC). Ion irradiation increases the disorder near the surface, as probed by neutron diffraction, and, moreover, causes the phase transformation from B2 CuZr to B19’ CuZr martensitic phase in the studied BMGC. The tensile plasticity of the BMGC is dramatically improved after ion irradiation, which results from multiple shear banding on the surface and the martensitic transformation of the B2 to B19’ CuZr martensitic phase. The experimental results are strongly corroborated by complementary molecular dynamic simulations. %0 conference lecture %@ %A Dieringa, H.,Yang, H.,Huang, Y.,Tolnai, D.,Kainer, K.U. %D 2019 %J 3rd International Conference on Light Materials - Science and Technology, LightMAT 2019 %N %P %T Influence of Al on the microstructural evolution and creep properties of Elektron21 processed by high shearing dispersion technique %U %X %0 journal article %@ 2296-8016 %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Römer, R. %D 2019 %J Frontiers in Materials %N %P 201 %R doi:10.3389/fmats.2019.00201 %T Wide Range Mechanical Customization of Mg-Gd Alloys With Low Degradation Rates by Extrusion %U https://doi.org/10.3389/fmats.2019.00201 %X Currently, only a few magnesium alloys have been approved for implant applications. For biomedical purposes, the choice of the alloying elements is a critical parameter and rare earth elements have been proven to be mechanically suitable and biologically tolerable. In this comprehensive study, tailoring the mechanical properties of binary Mg-Gd alloys by indirect extrusion is shown to obtain a property profile that is applicable to different biomedical applications. Mg-2Gd, Mg-5Gd, and Mg-10Gd were solid solution treated before extrusion. For each alloy various combinations of extrusion temperature and speed were applied. Resulting effects of alloy composition and processing on microstructure development, texture evolution, mechanical properties, and degradation behavior were investigated. Grain sizes and corresponding textures were adjusted by the extrusion parameters. Despite changes in the texture, grain boundary strengthening effects were confirmed for all alloys in accordance with the Hall-Petch relationship. The alloy composition contributed to the mechanical properties by solid solution strengthening and a combination of texture changes and slip activities. Consequently, mechanical properties can be tailored within a wide range resulting in tensile yield strengths of 90 to 200 MPa (ultimate tensile strengths 180–280 MPa) and compressive yield strengths of 80 to 220 MPa (ultimate compressive strengths 300–450 MPa) with elongations of 10–45%. Low degradation rates in the range of 0.2 mm/year were determined for all alloys. Degradation was only slightly influenced by the alloy composition but not affected by processing. Overall, the properties of Mg-Gd determined in this work appear to be suitable to future implant applications. %0 journal article %@ 1059-9495 %A Song, B.,Liu, T.,Xin, R.,Yang, H.,Guo, N.,Chai, L.,Huang, Y.,Hort, N. %D 2019 %J Journal of Materials Engineering and Performance %N 7 %P 4403-4414 %R doi:10.1007/s11665-019-04152-6 %T Influence of Torsion on Precipitation and Hardening Effects during Aging of an Extruded AZ91 Alloy %U https://doi.org/10.1007/s11665-019-04152-6 7 %X The effect of torsional deformation by various routes prior to artificial aging treatment on the microstructure of extruded AZ91 rods was investigated. The tension and compression properties along the extruded direction were tested to evaluate the hardening effect. The results showed that torsional deformation can largely enhance the subsequent age-hardening effect. A detailed microstructural characterization revealed that torsional deformation produced a high density of dislocations and {10-12} twins, which can promote continuous precipitation and increase the number density of the Mg17Al12 phase. In addition, part of dislocations and the {10-12} twins were retained after aging treatment. The combination of the increased precipitation hardening by Mg17Al12, dislocation strengthening and refinement strengthening contributed to the high hardening effect. Moreover, the hardening effect can be further increased by tailoring the torsion route. The torsion route exhibited little influence on the age-hardening effect, while it remarkably affected the texture of the twisted AZ91 rods. Reciprocating torsion had little influence on the texture. In contrast, unidirectional torsion caused the c-axis of the texture to rotate toward the extrusion direction, resulting in a texture softening effect. Therefore, combining reciprocating torsion and aging caused a higher hardening effect than combining unidirectional torsion and aging. The detailed strengthening mechanism was analyzed and is discussed. %0 journal article %@ 2296-8016 %A Gavras, S.,Zhu, S.,Easton, M.A.,Gibson, M.A.,Dieringa, H. %D 2019 %J Frontiers in Materials %N %P 262 %R doi:10.3389/fmats.2019.00262 %T Compressive creep behaviour of high-pressure die-cast aluminium-containing magnesium alloys developed for elevated temperature applications %U https://doi.org/10.3389/fmats.2019.00262 %X In addition to AZ- and AM-series magnesium alloys, which are mainly used at ambient temperature, there are also die-cast magnesium alloys developed for use at elevated temperatures. This paper examines the compressive creep resistance of several aluminum-containing magnesium high-pressure die-cast alloys, including the commercially available AE42, AE44-2, AE44-4, MRI230D alloys and newly developed DieMag series, i.e., DieMag211, DieMag422, and DieMag633. Compressive creep is the common load case for automotive powertrain components such as transmission housings, engine blocks or oil pans, which are typically mounted with steel or aluminum bolts that have lower thermal expansion than magnesium alloys. When the components heat up, there is a compressive load in the area around the bolt. The compressive creep experiments are accompanied by microstructure investigations. It is shown that MRI230D and the two high-concentrated DieMag alloys have the best creep resistance at 200°C. Similar results are also observed in the tensile tests at room temperature and 150°C, with DieMag633 showing outstanding strength. %0 conference lecture %@ %A Dieringa, H.,Gavras, S. %D 2019 %J Werkstoffwoche 2019 %N %P %T Druckkriechverhalten moderner aluminiumhaltiger Magnesiumlegierungen fuer den Druckguss %U %X %0 journal article %@ 0925-8388 %A Mingo, B.,Mohedano, M.,Blawert, C.,del Olmo, R.,Hort, N.,Arrabal, R. %D 2019 %J Journal of Alloys and Compounds %N %P 151992 %R doi:10.1016/j.jallcom.2019.151992 %T Role of Ca on the corrosion resistance of Mg–9Al and Mg–9Al–0.5Mn alloys %U https://doi.org/10.1016/j.jallcom.2019.151992 %X The effect of Ca additions on the microstructure and corrosion resistance of Mg–9Al and Mg–9Al-0.5Mn alloys is investigated. Model alloys were used instead of a commercial AZ91 alloy in order to avoid masking effects from other alloying elements. Grain size and secondary phases were characterised with special interest in their Volta potential. Corrosion performance was evaluated by hydrogen evolution and electrochemical methods. A synergetic effect was found when Ca and Mn were added in small amounts (0.5 wt%), reaching corrosion rates up to two orders of magnitude lower than the model Mg–9Al alloy. Such improvement was associated with Ca decreasing the Volta potential of the β-phase and with Ca and Mn decreasing the galvanic activity of Fe-rich intermetallics. Precipitation of Al2Ca decreased the amount of β-phase and had a negative impact on the corrosion resistance due to its cathodic behaviour. %0 conference object %@ %A Bilal, M.U.,Hort, N. %D 2019 %J Proceedings of Liquid Metal Processing & Casting Conference 2019 %N %P 267-274 %T Numerical Prediction of the Interfacial Heat Transfer Coefficient for Permanent Mold Casting of Mg-Al Alloys %U %X %0 conference lecture %@ %A Bilal, M.U.,Hort, N. %D 2019 %J Liquid Metal Processing & Casting Conference 2019 %N %P %T Numerical Prediction of the Interfacial Heat Transfer Coefficient for Permanent Mold Casting of Mg-Al Alloys %U %X %0 conference object %@ %A Jin, Y.,Feyerabend, F.,Blawert, C.,Bohlen, J.,Wiese, B.,Willumeit-Roemer, R. %D 2019 %J Abstract Book, 11th Symposium on Biodegradable Metals, Biometal 2019 %N %P Cor-7 %T Microstructure of a Si contaminated Mg-Zn-Ca alloy and the corrosion behaviour observation via an in-situ approach %U %X %0 journal article %@ 0924-0136 %A Schaper, J.G.,Wolff, M.,Wiese, B.,Ebel, T.,Willumeit-Römer, R. %D 2019 %J Journal of Materials Processing Technology %N %P 241-246 %R doi:10.1016/j.jmatprotec.2018.12.015 %T Powder metal injection moulding and heat treatment of AZ81 Mg alloy %U https://doi.org/10.1016/j.jmatprotec.2018.12.015 %X Ongoing research has proven that Mg alloys can be introduced into the metal injection moulding process for the production of small parts in high quantities and of complex shape for medical as well as lightweight applications. Previously, development studies have been conducted using Mg and Mg-Ca alloys intended for medical application. However, progress towards the implementation of a process for technical and lightweight applications alloys with higher strength is needed. Therefore, in this study processing of conventional AZ81 alloy by MIM was successfully developed. Using this alloy, a yield strength of approximately 120 MPa and an ultimate tensile strength of approximately 255 MPa with elongation at fracture of approximately 7% was achieved. T4 heat treatment at 420 °C for 10 h does not reveal a positive influence on the mechanical properties this could be caused by an observed grain growth effect. This is in contrast to conventional material for example as cast, where T4 heat treatment is known to improve the mechanical properties especially elongation at fracture. %0 conference poster %@ %A Jin, Y.,Feyerabend, F.,Blawert, C.,Bohlen, J.,Wiese, B.,Willumeit-Roemer, R. %D 2019 %J 11th Symposium on Biodegradable Metals, Biometal 2019 %N %P %T Microstructure of a Si contaminated Mg-Zn-Ca alloy and the corrosion behaviour observation via an in-situ approach %U %X %0 journal article %@ 1003-6326 %A Buzolin, R.H.,Mohedano, M.,Mendis, C.L.,Mingo, B.,Tolnai, D.,Blawert, C.,Kainer, K.U.,Pinto, H.,Hort, N. %D 2018 %J Transactions of Nonferrous Metals Society of China %N 3 %P 427-439 %R doi:10.1016/S1003-6326(18)64676-X %T Corrosion behaviour of as-cast ZK40 with CaO and Y additions %U https://doi.org/10.1016/S1003-6326(18)64676-X 3 %X The microstructures of as-cast ZK40, ZK40 with 2% (mass fraction) CaO and ZK40 with 1% (mass fraction) Y were investigated, and the intermetallic phase morphology and the distribution were characterised. By having discrete intermetallic particles at the grain boundaries for the ZK40, the microstructure was modified to a semi-continuous network of intermetallic compounds along the grain boundaries for the ZK40 with CaO or Y additions. The CaO was not found in the microstructure. However, Ca was present in Ca2Mg6Zn3 intermetallic compounds which were formed during casting. Hydrogen evolution and electrochemical impedance spectroscopy tests revealed that the addition of CaO slightly enhanced the corrosion resistance whereas Y had a negative effect on the corrosion resistance of ZK40. Immersion tests showed that severe localised corrosion as well as corrosion along the intermetallic compounds played an important role in the corrosion process of ZK40–Y whereas the localised corrosion was not pronounced for ZK40 or ZK40–CaO alloys. Micro-segregation in the α-Mg matrix was notably higher for the ZK40 alloy compared with the modified alloys. The combination of this effect with a possible formation of a more stable corrosion layer for the ZK40–CaO was attributed as the main reason for an improved corrosion resistance for the ZK40–CaO alloy. %0 journal article %@ 1996-1944 %A Gavras, S.,Buzolin, R.H.,Subroto, T.,Stark, A.,Tolnai, D. %D 2018 %J Materials %N 7 %P 1103 %R doi:10.3390/ma11071103 %T The Effect of Zn Content on the Mechanical Properties of Mg-4Nd-xZn Alloys (x = 0, 3, 5 and 8 wt.%) %U https://doi.org/10.3390/ma11071103 7 %X The mechanical properties of as-cast Mg-4Nd-xZn (x = 0, 3, 5 or 8 wt.%) alloys were investigated both in situ and ex situ in as-cast and solution-treated conditions. The additions of 3 or 5 wt.% Zn in the base Mg-4Nd alloy did not improve yield strength in comparison to the binary Mg-4Nd alloy. Mechanical properties were shown to improve only with the relatively high concentration of 8 wt.% Zn to Mg-4Nd. The change in intermetallic morphology from a continuous intermetallic to a lamella-like intermetallic was the primary reason for the decreased mechanical properties in Mg-4Nd-3Zn and Mg-4Nd-5Zn compared with Mg-4Nd and Mg-4Nd-8Zn. The dissolution of intermetallic at grain boundaries following heat treatment further indicated the importance of grain boundary reinforcement as shown in both in situ and ex situ compression testing. Azimuthal angle-time plots indicated little grain rotation most noticeably in Mg-4Nd, which also indicated the influence of a strong intermetallic network along the grain boundaries. %0 conference paper %@ %A Dieringa, H.,Hort, N. %D 2018 %J Supplemental Proceedings, 147th Annual Meeting & Exhibition, TMS 2018 - Symposium on Functional Nanomaterials: Discovery and Integration of Nanomaterials %N %P 679-691 %R doi:10.1007/978-3-319-72526-0_64 %T Magnesium-Based Metal Matrix Nanocomposites - Processing and Properties %U https://doi.org/10.1007/978-3-319-72526-0_64 %X It is well known that magnesium alloys reinforced with ceramic particles of micro-scale sizes give increased hardness and wear resistance. However, such particles need to be smaller to improve the strength, ductility and creep resistance of alloys. The optimum size of particles for Orowan strengthening is a diameter less than 100 nm. Not only the size of particles, but also their chemical composition and the composition of the alloy are important for the beneficial effect of nanoparticles. The mechanical properties can be tailored with much fewer nanoparticles compared to microparticles, because the interparticle spacing is much smaller. However, with large surface areas compared to their weight and low wettability, any deagglomeration of the nanoparticles in a magnesium melt is difficult to achieve and so requires additional processing, such as by electromagnetic or ultrasound-assisted stirring. This paper presents a short review and some original work on ceramic nanoparticle reinforced magnesium alloys and their properties. %0 journal article %@ 2075-4701 %A Dharmendra, C.,Rao, K.P.,Suresh, K.,Hort, N. %D 2018 %J Metals %N 4 %P 216 %R doi:10.3390/met8040216 %T Hot Deformation Behavior and Processing Map of Mg-3Sn-2Ca-0.4Al-0.4Zn Alloy %U https://doi.org/10.3390/met8040216 4 %X Among newly developed TX (Mg-Sn-Ca) alloys, TX32 alloy strikes a good balance between ductility, corrosion, and creep properties. This study reports the influence of aluminum and zinc additions (0.4 wt % each) to TX32 alloy on its strength and deformation behavior. Uniaxial compression tests were performed under various strain rates and temperature conditions in the ranges of 0.0003–10 s−1 and 300–500 °C, respectively. A processing map was developed for TXAZ3200 alloy, and it exhibits three domains that enable good hot workability in the ranges (1) 300–340 °C/0.0003–0.001 s−1; (2) 400–480 °C/0.01–1 s−1; and (3) 350–500 °C/0.0003–0.01 s−1. The occurrence of dynamic recrystallization in these domains was confirmed from the microstructural observations. The estimated apparent activation energy in Domains 2 and 3 (219 and 245 kJ/mole) is higher than the value of self-diffusion in magnesium. This is due to the formation of intermetallic phases in the matrix that generates back stress. The strength of TXAZ3200 alloy improved up to 150 °C as compared to TX32 alloy, suggesting solid solution strengthening due to Al and Zn. Also, the hot deformation behavior of TXAZ3200 alloy was compared in the form of processing maps with TX32, TX32-0.4Al, TX32-0.4Zn, and TX32-1Al-1Zn alloys. %0 journal article %@ 1073-5623 %A Imandoust, A.,Barrett, C.D.,Al-Samman, T.,Tschopp, M.A.,Essadiqi, E.,Hort, N.,El Kadiri, H. %D 2018 %J Metallurgical and Materials Transactions A %N 5 %P 1809-1829 %R doi:10.1007/s11661-018-4520-8 %T Unraveling Recrystallization Mechanisms Governing Texture Development from Rare-Earth Element Additions to Magnesium %U https://doi.org/10.1007/s11661-018-4520-8 5 %X The origin of texture components often associated with rare-earth element (REE) additions in wrought magnesium alloys is a long-standing problem in magnesium technology. While their influence on the texture is unquestionable, it is not yet clear why certain texture components, such as ⟨112 ¯ 1⟩||extrusiondirection, ⟨112¯1⟩||extrusiondirection, are favored over other components typically observed in traditional magnesium alloys. The objective of this research is to identify the mechanisms accountable for these RE textures during early stages of recrystallization. Electron backscattered diffraction and transmission electron microscopy analyses reveal that REEs in zinc-containing magnesium alloys corroborate discontinuous dynamic recrystallization. REEs promote isotropic growth for all nuclei generated through the bulging mechanism. During nucleation, the effect of REEs on orientation selection was explained by the diversified activity of both ⟨101 ¯ 0⟩ ⟨101¯0⟩ and [0001] Taylor axes in the same grain with a marked preference for [0001] rotations to occur first. During nuclei growth, no growth preference was observed when sufficient REEs are added in the zinc-containing magnesium alloys, instead isotropic nuclei growth across all grain orientations occurs. This phenomenon is attributed to REEs segregating to grain boundaries (GBs), in agreement with prior computational and theoretical results (Barrett et al., Scripta Mater 146:46–50, 2018) that show a more isotropic GB energy and mobility after segregation. %0 journal article %@ 2452-199X %A Wolff, M.,Luczak, M.,Schaper, J.G.,Wiese, B.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R.,Klassen, T. %D 2018 %J Bioactive Materials %N 3 %P 213-217 %R doi:10.1016/j.bioactmat.2018.03.002 %T In vitro biodegradation testing of Mg-alloy EZK400 and manufacturing of implant prototypes using PM (powder metallurgy) methods %U https://doi.org/10.1016/j.bioactmat.2018.03.002 3 %X The study is focussing towards Metal Injection Moulding (MIM) of Mg-alloys for biomedical implant applications. Especially the influence of the sintering processing necessary for the consolidation of the finished part is in focus of this study. In doing so, the chosen high strength EZK400 Mg-alloy powder material was sintered using different sintering support bottom plate materials to evaluate the possibility of iron impurity pick up during sintering. It can be shown that iron pick up took place from the steel bottom plate into the specimen. Despite the fact that a separating boron nitrite (BN) barrier layer was used and the Mg-Fe phase diagram is not predicting any significant solubility to each other. As a result of this study a new bottom plate material not harming the sintering and the biodegradation performance of the as sintered material, namely a carbon plate material, was found. %0 journal article %@ 0032-678X %A Buzolin, R.H.,Mendis, C.L.,Tolnai, D.,Pereira da Silva, E.,Kainer, K.U.,Hort, N.,Cavalcanti Pinto, H. %D 2018 %J Practical Metallography - Praktische Metallographie %N 5 %P 268-287 %R doi:10.3139/147.110518 %T Zum Einfluss des Loesungsgluehens und Aushaertens auf die Mikrostruktur von ZK40-Legierungen, modifiziert durch Zugaben von Ca, Gd, Nd und Y - On the Influence of Solution and Ageing Treatments on the Microstructure of ZK40 Alloys Modified with Ca, Gd, Nd and Y %U https://doi.org/10.3139/147.110518 5 %X ZK40-Legierungen im Gusszustand, modifiziert durch Zugaben von CaO, Gd, Nd und Y, wurden untersucht. Diese Legierungen wurden auf Grundlage der Ergebnisse der Differenz-Thermoanalyse lösungsgeglüht. Die unmodifizierte ZK40-Legierung zeigte eine Mikrostruktur, die nahezu keine intermetallischen Verbindungen, jedoch Ausscheidungen enthielt, die sich während des Lösungsglühens gebildet hatten. Die modifizierten ZK40-Legierungen zeigten ein halb-aufgelöstes Netzwerk von intermetallischen Verbindungen entlang der Korngrenzen sowie Zonen mit intermetallischen Verbindungen innerhalb der Körner. Interessanterweise wurden keine Ausscheidungen direkt neben den Korngrenzen beobachtet. Die Linienscans der energiedispersiven Röntgenspektroskopie zeigten eine Anreicherung von Zn und Zr in den Bereichen, in denen die Ausscheidungen beobachtet wurden, was nahelegt, dass es sich um Zn-Zr-Ausscheidungen handelt. Das Alterungsverhalten der Werkstoffe im Gusszustand und das der lösungsgeglühten Werkstoffe wurden verglichen. Es stellte sich heraus, dass, abgesehen von ZK40-Gd, ZK40-Nd und ZK40-Y, die nach dem Lösungsglühen bei 200 °C alterten, keine deutliche Alterungsreaktion bei den untersuchten Legierungen zu beobachten war. %0 journal article %@ 1059-9495 %A Suresh, K.,Rao, K.P.,Chalasani, D.,Krishna, P.Y.V.R.,Hort, N.,Dieringa, H. %D 2018 %J Journal of Materials Engineering and Performance %N 3 %P 1440-1449 %R doi:10.1007/s11665-018-3219-8 %T Deformation Mechanisms and Formability Window for As-Cast Mg-6Al-2Ca-1Sn-0.3Sr Alloy (MRI 230D) %U https://doi.org/10.1007/s11665-018-3219-8 3 %X The hot deformation characteristics of MRI 230D alloy have been evaluated in the temperature range 260-500 °C and strain rate range 0.0003-10 s−1, on the basis of processing map. The processing map exhibited two domains in the ranges: (1) 300-370 °C and 0.0003-0.001 s−1 and (2) 370-480 °C and 0.0003-0.1 s−1. Dynamic recrystallization occurs in the both domains with basal slip dominating in the first domain along with climb as recovery process and second-order pyramidal slip dominating in the second with the recovery by cross-slip. In Domains (1) and (2), the apparent activation energy values estimated using the kinetic rate equation are 143 and 206 kJ/mole, respectively, the first one being close to that for lattice self-diffusion confirming climb. It is recommended that the alloy is best processed at 450 °C and strain rates less than 0.1 s−1, where non-basal slip and cross-slip occur extensively to impart excellent workability. The alloy exhibits flow instability in the form of adiabatic shear band formation and flow localization at lower temperatures and higher strain rates. Forging of a cup-shaped component was performed under various conditions, and the results validated the predictions of the processing map on the workability domains as well as the instability regimes. %0 journal article %@ 1438-1656 %A Rao, K.P.,Prasad, Y.V.R.K.,Dharmendra, C.,Suresh, K.,Hort, N.,Dieringa, H. %D 2018 %J Advanced Engineering Materials %N 9 %P 1701102 %R doi:10.1002/adem.201701102 %T Review on Hot Working Behavior and Strength of Calcium-Containing Magnesium Alloys %U https://doi.org/10.1002/adem.201701102 9 %X In recent years, calcium has been a chosen alloying element as an alternative to rare‐earth elements for developing creep‐resistant magnesium alloys, which find promising applications for components in automobile and aerospace industries, and as bio‐implants. In this paper, the research covering the influence of Ca additions to several magnesium alloy systems on their strength, microstructure, and hot workability is reviewed. During mechanical processing, the formation of basal texture is considerably weakened by Ca addition. Ca‐containing alloys have limited workability and can be processed only by choosing the right combination of temperature and strain rate that corresponds to the occurrence of dynamic recrystallization (DRX). This can be done without trial‐and‐error through the use of processing maps. The processing maps for hot working of low‐Ca containing alloys typically exhibit three DRX domains while the maps for high‐Ca alloys typically exhibit only two DRX domains. In particular, the high‐Ca alloys have to be processed at lower strain rates and higher temperatures since the high volume content of intermetallic particles prevents DRX at high strain rates. Flow instabilities occur rampantly in Ca‐containing alloys, particularly in high‐Ca alloys, at lower temperatures and higher strain rates that have to be avoided during their thermo‐mechanical processing. %0 journal article %@ 0042-207X %A Liu, L.,Pan, F.,Chen, X.,Huang, Y.,Song, B.,Yang, H.,Hort, N. %D 2018 %J Vacuum %N %P 445-455 %R doi:10.1016/j.vacuum.2018.06.048 %T The effect of Y addition on recrystallization and mechanical properties of Mg–6Zn–xY–0.5Ce–0.4Zr alloys %U https://doi.org/10.1016/j.vacuum.2018.06.048 %X Microstructure and mechanical properties of extruded Mg–6Zn–xY–0.5Ce–0.4Zr sheets were systematically investigated. Mg–Zn–Ce, I-phase (Mg3Zn6Y) and W-phase (Mg3Zn3Y2) with different morphologies were observed in as-cast and extruded conditions. Numerous nano-precipitates were found along grain boundaries and inside grains in both dynamically recrystallized (DRXed) and unDRXed regions after hot extrusion. The area fraction of DRXed regions increases with Y additions mainly due to particle stimulated nucleation (PSN). An extruded fiber texture was observed after hot extrusion. The texture is strengthened firstly and then weakened. The extruded alloys with 0.5–1 wt% Y and 0.5 wt% Ce exhibit much better mechanical properties compared with other Mg alloys such as Mg–5Zn–1Y–1Zr (wt.%) and Mg–6Zn–1Ce–0.5Zr (wt.%) alloys under the same extrusion ratio. The extruded alloy with 0.2 wt% Y and 0.5 wt% Ce has the yield strength of 322 MPa, ultimate tensile strength of 378 MPa and elongation of 8.6%, which is the highest value among the studied alloys. Grain boundary strengthening and precipitation strengthening are the two most important factors for improving yield strength of Mg–6Zn–xY–0.5Ce–0.4Zr alloys. The addition of Y is an effective way in significantly improving the mechanical properties of Mg–6Zn–xY–0.5Ce–0.4Zr alloys. %0 journal article %@ 2075-4701 %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Gupta, M. %D 2018 %J Metals %N 6 %P 437 %R doi:10.3390/met8060437 %T Enhancement of Strength and Hot Workability of AZX312 Magnesium Alloy by Disintegrated Melt Deposition (DMD) Processing in Contrast to Permanent Mold Casting %U https://doi.org/10.3390/met8060437 6 %X AZX312 (AZ31-2Ca) magnesium alloy, with starting conditions of as-cast (AC), cast-homogenized (CH), and disintegrated melt deposition (DMD), is examined in terms of its compressive strength and hot working behavior to establish the relative merits and limitations of these processing routes. Processing maps are developed in the temperature range of 300–500 °C and strain rate range of 0.0003–10 s−1, and mechanisms of hot deformation are established based on microstructures, tensile ductility, and activation parameters. The alloy in AC and CH conditions has a large grain size with intermetallic phases at the grain boundaries and in the matrix. In DMD processed alloy, the grain size is very small and the phases are refined and distributed uniformly. The compressive strength is significantly improved by DMD processing, which is attributed to the grain refinement. The processing maps for AC and CH conditions are similar, exhibiting only a single workability domain, while the DMD processed alloy exhibited three domains that enhanced workability. The additional workability domain at higher strain rates is an advantage in designing forming processes that facilitates faster production, while the fine grain size produced by a finishing operation in the lower temperature domain will improve the mechanical properties of the product. %0 journal article %@ 0261-3069 %A Mo, N.,Tan, Q.,Bermingham, M.,Huang, Y.,Dieringa, H.,Hort, N.,Zhang, M.-X. %D 2018 %J Materials and Design %N %P 422-442 %R doi:10.1016/j.matdes.2018.06.032 %T Current development of creep-resistant magnesium cast alloys: A review %U https://doi.org/10.1016/j.matdes.2018.06.032 %X The low creep resistance has been one of the major issues of Mg alloys, which limited their wider industrial applications in the past decades. It has been reported that the inherent creep resistance of Mg should be higher than that Al. Hence, it is highly likely that the low creep resistance of Mg alloys was attributed to the effects of alloying elements rather than Mg itself. In order to systematically understand the effects of alloying elements on the creep behaviours of cast Mg alloys and therefore to develop new alloys with higher creep resistance, the present work reviews the major creep-resistant Mg systems that were developed and successfully commercialized for applications at different temperatures. Because the majority of commercial Mg alloys are used as cast, this review focuses on cast alloys. %0 journal article %@ 2075-4701 %A Rao, K.P.,Chalasani, D.,Suresh, K.,Prasad, Y.V.R.K.,Dieringa, H.,Hort, N. %D 2018 %J Metals %N 6 %P 463 %R doi:10.3390/met8060463 %T Connected Process Design for Hot Working of a Creep-Resistant Mg–4Al–2Ba–2Ca Alloy (ABaX422) %U https://doi.org/10.3390/met8060463 6 %X With a view to design connected processing steps for the manufacturing of components, the hot working behavior of the ABaX422 alloy has been characterized for the as-cast and extruded conditions. In the as-cast condition, the alloy has a limited workability, due to the presence of a large volume of intermetallic phases at the grain boundaries, and is not suitable to process at high speeds. A connected processing step has been designed on the basis of the results of the processing map for the as-cast alloy, and this step involves the extrusion of the cast billet to obtain a 12 mm diameter rod product at a billet temperature of 390 °C and at a ram speed of 1 mm s−1. The microstructure of the extruded rod has a finer grain size, with redistributed fine particles of the intermetallic phases. The processing map of the extruded rod exhibited two new domains, and the one in the temperature range 360–420 °C and strain rate range 0.2–10 s−1 is useful for manufacturing at high speeds, while the lower temperature develops a finer grain size in the product to improve the room temperature strength and ductility. The area of the flow instability is also reduced by the extrusion step, widening the workability window. %0 conference lecture %@ %A Dieringa, H.,Hort, N. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018, Symposium on Functional Nanomaterials: Discovery and Integration of Nanomaterials %N %P %T Magnesium-Based Metal Matrix Nanocomposites - Processing and Properties %U %X %0 journal article %@ 1939-5981 %A Gavras, S.,Subroto, T.,Buzolin, R.H.,Hort, N.,Tolnai, D. %D 2018 %J International Journal of Metalcasting %N 3 %P 428-433 %R doi:10.1007/s40962-017-0174-3 %T The Role of Zn Additions on the Microstructure and Mechanical Properties of Mg–Nd–Zn Alloys %U https://doi.org/10.1007/s40962-017-0174-3 3 %X Mg-rare earth alloys have improved yield strength and creep resistance compared to commercial alloys such as AZ91, AM60 or AS21. The influence of Zn additions in Mg–Nd alloys on intermetallic phases and the resulting changes in the macroscopic mechanical behaviour of the materials are not yet fully understood. The aim of this work is to identify the effect of Zn additions on the nature of the intermetallic phases and on the mechanical properties in a Mg–4Nd (wt%) alloy. The addition of 8 wt% Zn to a base Mg–4Nd wt% alloy marginally improved the tensile and compression properties at room temperature or at 200 °C with the exception of the 0.2% proof stress of Mg–4Nd–8Zn alloys when tensile- or compression-tested at 200 °C. Two intermetallic phases, a quasi-binary Mg3(Zn, Nd) and ternary Mg50Nd8Zn42, have been identified by the means of electron microscopy and synchrotron diffraction. These results indicate that there are some discrepancies in the current thermodynamic calculations, suggesting an update to the databases may be required. %0 conference paper %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2018 %J Conference Proceedings, Magnesium Technology 2018, TMS 2018 %N %P 349-353 %R doi:10.1007/978-3-319-72332-7_53 %T Magnesium Pistons in Engines: Fiction or Fact? %U https://doi.org/10.1007/978-3-319-72332-7_53 %X Magnesium alloys are already widely used in numerous applications in transportation and consumer products. Ways have been found to improve corrosion and creep resistance, formability in general, and processing routes have been optimized. But would Mg alloys also be suitable for use in an environment where friction, corrosion, thermal fatigue and creep resistance at elevated temperatures are issues? Due to lightweighting benefits, pistons would be an ideal application for Mg based materials. It is much more efficient to accelerate and to decelerate a lightweight material compared to a heavier one. Al alloy pistons are already fairly well established. But Mg could provide further benefits compared with Al due to its specific strength and mass. We will report the state of the art in Mg pistons, with our own and others approaches to improve properties and the challenges that Mg pistons have to face. %0 conference lecture %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018 - Symposium Magnesium Technology 2018 %N %P %T Magnesium Pistons in Engines: Fiction or Fact? %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Letzig, D.,Bohlen, J.,Hoeche, D.,Blawert, C.,Zheludkevich, M.,Kainer, K.U. %D 2018 %J Conference Proceedings, Magnesium Technology 2018, TMS 2018 %N %P 3-14 %R doi:10.1007/978-3-319-72332-7_1 %T Mg Alloys: Challenges and Achievements in Controlling Performance, and Future Application Perspectives %U https://doi.org/10.1007/978-3-319-72332-7_1 %X In recent years, Mg alloys have made inroads into applications for transport industries. The favorable property profile of Mg promotes increased usage. Despite magnesium alloys being used for years, there is still a lack of knowledge about the potential of Mg alloys. New or optimized alloys and processes are creating new ideas for substituting traditional materials. High-pressure die-casting (HPDC) is the predominant technology, while other casting and wrought processes are of secondary importance. Developments in the last decade have led to an improvement of the property profile and effectiveness of magnesium wrought alloys. Additive manufacturing has opened new opportunities for tailoring of the property profile and functionality. In addition, Mg as material for battery anodes adds a new field of application in the energy sector. This presentation will provide an overview of the status of modern process and alloy development, and discuss the challenges to extending the use of magnesium alloys in various applications. %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Letzig, D.,Bohlen, J.,Hoeche, D.,Blawert, C.,Zheludkevich, M.,Kainer, K.U. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018 - Symposium Magnesium Technology 2018 %N %P %T Mg Alloys: Challenges and Achievements in Controlling Performance, and Future Application Perspectives %U %X %0 conference paper %@ %A Rao, K.P.,Dharmendra, C.,Prasad, Y.V.R.K.,Dieringa, H.,Hort, N. %D 2018 %J Conference Proceedings, Magnesium Technology 2018, TMS 2018 %N %P 289-296 %R doi:10.1007/978-3-319-72332-7_45 %T Hot Forging Behavior of Mg−8Al−4Ba−4Ca (ABaX844) Alloy and Validation of Processing Map %U https://doi.org/10.1007/978-3-319-72332-7_45 %X Newly developed die-cast alloys based on Mg–Al−Ba–Ca (ABaX) system show promise for high temperature creep resistance. ABaX844 alloy is one of them and it has limited workability due to high alloy content. To identify the optimum processing conditions, processing map for this alloy was developed earlier, which exhibited two workability domains in the temperature and strain rate ranges: (1) 340–410 °C and 0.0003–0.005 s−1, and (2) 425–500 °C and 0.0003–0.1 s−1. Dynamic recrystallization (DRX) occurs in these domains. The map also exhibited extensive flow instability mainly at strain rates > 0.01 s−1 up to a temperature of 400 °C and at strain rates >0.1 s−1 beyond 400 °C. The aim of the present study is to validate the findings of processing map by performing forging tests in the temperature range 300–500 °C (at an interval of 40 °C) and forging speeds of 0.01, 0.1, 1 and 10 mm s−1 to produce a rib-web (cup) shape component. Finite-element (FE) simulations were performed for obtaining the variations of strain and strain rate in the components during forging. The microstructures of forged specimens deformed under optimum process conditions derived from the processing map revealed the formation of dynamically recrystallized grains. The alloy specimens forged under the conditions of flow instability have fractured and/or exhibited flow localization. The results validated the predictions of the processing map and the load-stroke curves obtained by FE simulation correlated well with the experimental curves. %0 conference lecture %@ %A Rao, K.P.,Dharmendra, C.,Prasad, Y.V.R.K.,Dieringa, H.,Hort, N. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018 - Symposium Magnesium Technology 2018 %N %P %T Hot Forging Behavior of Mg−8Al−4Ba−4Ca (ABaX844) Alloy and Validation of Processing Map %U %X %0 conference lecture %@ %A Kainer, K.U.,Hort, N. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018 - Symposium Energy and Transportation from a European Materials Perspective %N %P %T Magnesium Alloys in Transportation: Hidden Champions? %U %X %0 conference paper %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2018 %J TMS 2018, 147th Annual Meeting & Exhibition, Supplemental Proceedings %N %P 253-262 %R doi:10.1007/978-3-319-72526-0_23 %T Microstructure and Mechanical Properties of Mg-Gd Alloys as Biodegradable Implant Materials %U https://doi.org/10.1007/978-3-319-72526-0_23 %X Mg alloys attract more and more attentions for biomedical applications. Mg-Gd alloys were designed as biodegradable implant materials which combine favorable mechanical and corrosion properties. In this work, the microstructure and mechanical properties of binary Mg-2Gd, ternary Mg-2Gd-(Ag, Ca) and quaternary Mg-2Gd-2Ag-0.4Ca alloys were investigated. The alloys were prepared by permanent mould casting. The results show that the additions of Ag and Ca had significant influences on the microstructure and mechanical properties of Mg-2Gd alloy. Ag and Ca additions affect the formation of second phases. A quaternary Mg-Gd-Ag-Ca second phase was found in the quaternary alloy. Both the hardness and tensile yield strength were improved by adding Ag and Ca to 2 wt% Gd-containing alloys due to grain refinement and formation of different intermetallic phases (IMPs). Furthermore, the addition of Ag and Ca can apparently enhance the age hardening of Mg-2Gd alloy. %0 journal article %@ 0947-5117 %A Maier, P.,Zimmermann, F.,Rinne, M.,Szakacs, G.,Hort, N.,Vogt, C. %D 2018 %J Materials and Corrosion %N 2 %P 178-190 %R doi:10.1002/maco.201709502 %T Solid solution treatment on strength and corrosion of biodegradable Mg6Ag wires %U https://doi.org/10.1002/maco.201709502 2 %X A warm-drawn Mg6Ag wire with a diameter of 1.6 mm is investigated by immersion tests in Ringer solution in two conditions: as-drawn and solution heat-treated wire. The initial as-drawn condition showed higher strength in comparison to the solution heat-treated one. As-drawn wire has heavily twinned grains. Heat treatment causes slight grain growth, but less microgalvanic corrosion due to dissolved second phases and a significantly reduction of twin boundaries. The mean corrosion rate decreases by more than half by the heat treatment resulting in higher remaining mechanical properties. The mean corrosion rate also decreases with corrosion time, slightly more for the heat-treated condition. Pitting corrosion was still present after solution heat treatment, although the pit shape is less harmful. The corroded wires and corrosion products were analysed qualitatively and quantitatively by SEM imaging and ICP-OES with focus on the exposure time. Mg6Ag wires corrode under forming Mg(OH)2, CaCO3 and AgCl, SEM imaging proves higher corrosion resistance of heat-treated Mg6Ag. Chemical analysis of wires, corrosion products and corrosion media offer to describe the time-dependent mechanism. %0 conference lecture %@ %A Maier, P.,Gavras, S.,Freese, M.,Schott, G.,Hort, N. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T Microstructural Changes of an Extruded WE33 Alloy during Precipitation Hardening %U %X %0 journal article %@ 0947-5117 %A Bartosch, M.,Peters, H.,Koerner, A.,Schmitt, B.,Berger, F.,Hort, N.,Witte, F. %D 2018 %J Materials and Corrosion %N 2 %P 156-166 %R doi:10.1002/maco.201709521 %T New methods for in vivo degradation testing of future stent materials %U https://doi.org/10.1002/maco.201709521 2 %X Selection of a degradable material for cardiovascular stent application is a difficult task. Beside various alloys, different processing routes, annealing and surface treatment options, and coatings are available. Unfortunately, the in vivo properties of materials cannot be reliably predicted in vitro. In order to narrow down the selection there is a great need for an easy and fast in vivo pre-selection method for possible stent materials. In this study we tested an approach presented by another group. It was compared to our new approach, the Carrier Stent. Here, several material samples are sewn on an inert, polymeric stent. It can be implanted in virtually every vessel of an animal model. It enables testing of different materials at the same location. Mg10Gd was chosen as an example for a degradable alloy for future stent applications. Wires were produced by drawing, annealed, etched, and analyzed. Due to the short wire lengths, a new clamping method for tensile tests was developed. Different heat treatments and etching processes were evaluated prior to the implantations. Both direct wire implantation and carrier stent implantation were performed and compared. %0 conference paper %@ %A Willumeit-Roemer, R.,Moosmann, J.,Zeller-Plumhoff, B.,Wieland, D.C.F.,Krueger, D.,Wiese, B.,Wennerberg, A.,Peruzzi, N.,Galli, S.,Beckmann, F.,Hammel, J.U. %D 2018 %J TMS 2018, 147th Annual Meeting & Exhibition, Supplemental Proceedings %N %P 275-284 %R doi:10.1007/978-3-319-72526-0_25 %T Visualization of Implant Failure by Synchrotron Tomography %U https://doi.org/10.1007/978-3-319-72526-0_25 %X Magnesium (Mg) and its alloys degrade under physiological conditions.,But how strong is the connection between the implant, the corrosion layer and the surrounding tissue, namely bone? Biomechanical tests like push-out tests have shown that a degraded Mg-pin is surprisingly well integrated with the bone “as,reported by Castellani et al. (Acta Biomater 7(1):432–440, 2011) [1]”.,High-resolution synchrotron tomography offers a deep look into the microstructure of the material as well as of the bone during deformation until fracture happens.,Here we present first data from an in situ tomography experiment of a biodegradable Mg-based implant under compressive load showing how Mg implants are incorporated into bone. %0 conference lecture %@ %A Willumeit-Roemer, R.,Moosmann, J.,Zeller-Plumhoff, B.,Wieland, D.C.F.,Krueger, D.,Wiese, B.,Wennerberg, A.,Peruzzi, N.,Galli, S.,Beckmann, F.,Hammel, J.U. %D 2018 %J 147th Annual Meeting & Exhibition, TMS 2018 %N %P %T Visualization of Implant Failure by Synchrotron Tomography %U %X %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T Microstructure and degradation properties of Mg-Gd-Ag-Ca alloys as biodegradable implant materials %U %X %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2018 %J 147th Annual Meeting & Exhibition, Magnesium Technology 2018 %N %P %T Microstructure and Mechanical Properties of Mg-Gd Alloys as Biodegradable Implant Materials %U %X %0 conference paper %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2018 %J Magnesium 2018, Proceedings of the 11th International Conference on Magnesium Alloys and Their Applications %N %P 396-401 %T Microstructure and degradation properties of Mg-Gd-Ag-Ca alloys as biodegradable implant materials %U %X %0 conference object %@ 2522-235X %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J eCells and Materials - eCM Conferences %N %P 2 %T Suitability of as extruded Mg-Gd-0.5Mn for biomedical applications %U %X No abstract %0 conference paper %@ %A Maier, P.,Gavras, S.,Freese, M.,Schott, G.,Hort, N. %D 2018 %J Magnesium 2018, Proceedings of the 11th International Conference on Magnesium Alloys and Their Applications %N %P 251-258 %T Microstructural Changes of an Extruded WE33 Alloy during Precipitation Hardening %U %X %0 journal article %@ 1996-1944 %A Tolnai, D.,Subroto, T.,Gavras, S.,Buzolin, R.,Stark, A.,Schell, N.,Hort, N. %D 2018 %J Materials %N 9 %P 1637 %R doi:10.3390/ma11091637 %T Phase Formation during Solidification of Mg-Nd-Zn Alloys: An In Situ Synchrotron Radiation Diffraction Study %U https://doi.org/10.3390/ma11091637 9 %X Mg-4Nd base alloys with Zn additions of 3, 5 and 8 wt % were investigated with in situ synchrotron radiation diffraction during solidification. This method enabled the investigation of phase formation and transformation in the alloys. The diffraction results were supported with TEM observations on the as-solidified samples. The results show the effect of increased Zn addition on stabilizing the Mg3RE phase (RE—rare earth). The experimental results agree only partially with the theoretical calculations indicating the need to improve the existing thermodynamic database on the alloy system. %0 conference lecture %@ %A Tolnai, D.,Sosro, T.,Gavras, S.,Buzolin, R.,Hort, N. %D 2018 %J MSE 2018 - Tomographic and Radiographic Imaging with Synchrotron X-rays and Neutrons %N %P %T In-situ synchrotron investigation of the phases- and their morphology development in Mg-Nd-Zn allyos %U %X The addition of Zn to the Mg–Nd system improves the yield strength and creep resistance, however its influence on the intermetallic phases in the ternary system is not yet fully understood. Understanding the sequence of phase–formation and phase–evolution during solidification and processing is essential to microstructure design. The solidification was investigated with in situ synchrotron radiation–diffraction and tomography during cooling from the molten state to 200 °C to investigate the phase–formation and transformation characteristics. The solidification starts with α–Mg followed by two distinct intermetallic phases T2 and T3. The results suggest that Zn stabilizes the Mg3Nd phase and accelerates precipitate formation. The dendritic morphology changes during solidification towards coarser shapes, thus impedes feeding and promotes hot tearing. %0 conference object %@ 2522-235X %A Jin, Y.,Wiese, B.,Feyerabend, F.,Blawert, C.,Bohlen, J.,Willumeit-Roemer, R. %D 2018 %J eCells and Materials - eCM Conferences %N %P 10 %T Micro-alloying of Mg-Zn based alloys-Influence on corrosion behaviour %U %X No abstract %0 conference object %@ %A Jin, Y.,Wiese, B.,Feyerabend, F.,Blawert, C.,Bohlen, J.,Willumeit-Roemer, R. %D 2018 %J Abstract Book of 10th Symposium on Biodegradable Metals for Biomedical Applications, BIOMETAL 2018 %N %P Met-10 %T Micro-alloying of Mg-Zn based alloys-Influence on corrosion behaviour %U %X %0 conference poster %@ %A Jin, Y.,Wiese, B.,Feyerabend, F.,Blawert, C.,Bohlen, J.,Willumeit-Roemer, R. %D 2018 %J 10th Symposium on Biodegradable Metals for Biomedical Applications, BIOMETAL 2018 %N %P %T Micro-alloying of Mg-Zn based alloys-Influence on corrosion behaviour %U %X %0 conference paper %@ %A Rafiei, S.,Habibollahzadeh, A.,Wiese, B. %D 2018 %J Proceedings of 7th International Conference on Materials Engineering and Metallurgy, IMAT 2018 %N %P IMES12_010 %T An Insight into Environment-Conscious (ECO) Magnesium: A Review %U %X Magnesium (Mg) is the lightest metallic structural material and the urge to reduce the weight of vehicles and improving fuel efficiency has inevitably resulted in the long-time exposure of Mg alloys to elevated temperatures (above 200 ℃). Calcium (Ca) addition has been considered as cheap and practical solution to overcome high reactivity and ignition risks of Mg and its alloys. Besides, Ca-bearing Mg alloys are capable of air casting. The recently-developed Environment-conscious (ECO) manufacturing route is novel method of Ca addition, which utilizes CaO to produce Ca-containing Mg alloys and it is thermodynamically proved that this reaction is possible. Elemental calcium is very reactive and needs special requirements in terms of handling. On the other hand, CaO is much cheaper than Ca and can be handled safely due to its good stability. It is also proved that CaO-added Mg has higher melt fluidity than its Ca-added counterpart. The retarded oxidation and ignition of Ca-bearing Mg are reported to be the outcome of dense oxide film made up of CaO and MgO. This report provides comprehensive review of the current literature regarding high-temperature oxidation of Ca-bearing Mg and its alloys. Because commercial Mg casting alloys are mostly based on the Mg-Al system the effect of Aluminum (Al) on ignition and oxidation has also been reviewed. %0 journal article %@ 0010-938X %A Lu, X.,Blawert, C.,Tolnai, D.,Subroto, T.,Kainer, K.U.,Zhang, T.,Wang, F.,Zheludkevich, M.L. %D 2018 %J Corrosion Science %N %P 395-402 %R doi:10.1016/j.corsci.2018.05.019 %T 3D reconstruction of plasma electrolytic oxidation coatings on Mg alloy via synchrotron radiation tomography %U https://doi.org/10.1016/j.corsci.2018.05.019 %X Plasma electrolytic oxidation (PEO) is a well-known surface treatment for Mg alloys, while high porosity is an issue to achieve long-term corrosion protection. Nevertheless, the presence of inherent porosity can be turned into advantage while used as nano/micro-structured reservoir of corrosion inhibitors or functional agents next to Mg surface providing an active corrosion protection and multi-functionality. For the first time, we report here the 3D internal architecture of PEO coated Mg via synchrotron-based microtomography. The pore characteristics have been qualitatively and quantitatively investigated to unveil the formation of the coating porosity and potential incorporation of functional elements in the pores. %0 conference object %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J Abstract Book of 10th Symposium on Biodegradable Metals for Biomedical Applications, BIOMETAL 2018 %N %P Met-2 %T Suitability of as extruded Mg-Gd-0.5Mn for biomedical applications %U %X %0 conference lecture %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J 10th Symposium on Biodegradable Metals for Biomedical Applications, BIOMETAL 2018 %N %P %T Suitability of as extruded Mg-Gd-0.5Mn for biomedical applications %U %X %0 conference paper %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J Magnesium 2018, Proceedings of the 11th International Conference on Magnesium Alloys and Their Applications %N %P 376-381 %T Tailoring of material properties of Mg-Gd alloys for biomedical applications %U %X %0 conference poster %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T Tailoring of material properties of Mg-Gd alloys for biomedical applications %U %X %0 journal article %@ 1002-0071 %A Xu, Y.,Gensch, F.,Ren, Z.,Kainer, K.U.,Hort, N. %D 2018 %J Progress in Natural Science: Materials International %N 6 %P 724-730 %R doi:10.1016/j.pnsc.2018.10.002 %T Effects of Gd solutes on hardness and yield strength of Mg alloys %U https://doi.org/10.1016/j.pnsc.2018.10.002 6 %X Relative contribution of individual strengthening mechanisms to the yield strength of Mg–0–15 wt% Gd alloys were investigated. Alloys with different grain size were prepared by adding Zr and hot extrusion. Hardness and tensile/compression yield strength were tested on the alloys after solid solution treatment and extrusion. Hall-Petch constants were calculated with hardness and tensile/compressive data. The results showed that the hardness of Mg–Gd alloys with similar Gd content and different grain size were almost the same, which indicates that grain size had little effect on hardness. The hardness linearly increased with rising Gd content (dHv/dc ≈ 25 kg mm−2/at%Gd). The tensile and compressive yield strengths enhanced with the increase of Gd content for all alloys in different conditions. In addition, the tensile/compressive (t/c) yield asymmetry of extruded alloys decreased with increasing Gd content. Large t/c yield asymmetry ratio (1.77) was observed for pure Mg, and with increasing Gd content this value decreased to 1. With the increasing of tensile strength, the stress intensity factor, ky, decreased from 0.27 MPa m1/2 for Mg–2 wt% Gd alloy to 0.19 MPa m1/2 for Mg–5 wt% Gd alloy, then increased to 0.29 MPa m1/2 for Mg–15 wt% Gd alloy. However, ky increased linearly form 0.16–0.31 MPa for compression test. The influence of grain size strengthening was eliminated, and the yield strength of tension and compression both linearly increased with cn, where c is the atom concentration of Gd, and n = 1/2 or 2/3. %0 journal article %@ 1996-1944 %A Gawlik, M.M.,Wiese, B.,Desharnais, V.,Ebel, T.,Willumeit-Roemer, R. %D 2018 %J Materials %N 12 %P 2561 %R doi:10.3390/ma11122561 %T The Effect of Surface Treatments on the Degradation of Biomedical Mg Alloys - A Review Paper %U https://doi.org/10.3390/ma11122561 12 %X This report reviews the effects of chemical, physical, and mechanical surface treatments on the degradation behavior of Mg alloys via their influence on the roughness and surface morphology. Many studies have been focused on technically-used AZ alloys and a few investigations regarding the surface treatment of biodegradable and Al-free Mg alloys, especially under physiological conditions. These treatments tailor the surface roughness, homogenize the morphology, and decrease the degradation rate of the alloys. Conversely, there have also been reports which showed that rough surfaces lead to less pitting and good cell adherence. Besides roughness, there are many other parameters which are much more important than roughness when regarding the degradation behavior of an alloy. These studies, which indicate the relationship between surface treatments, roughness and degradation, require further elaboration, particularly for biomedical Mg alloy applications. %0 journal article %@ 1003-6326 %A Suresh, K.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Dieringa, H. %D 2018 %J Transactions of Nonferrous Metals Society of China %N 8 %P 1495-1503 %R doi:10.1016/S1003-6326(18)64790-9 %T Hot forging of Mg-4Al-2Ba-2Ca (ABaX422) alloy and validation of processing map %U https://doi.org/10.1016/S1003-6326(18)64790-9 8 %X A cup-shaped component of Mg-4Al-2Ba-2Ca (ABaX422) alloy was forged in the temperature range of 300–500 °C and at speeds in the range of 0.01–10 mm/s with a view to validate the processing map and study the microstructural development. The process was simulated through finite-element method to estimate the local and average strain rate ranges in the forging envelope. The processing map exhibited two domains in the following ranges: (1) 300–390 °C and 0.0003–0.001 s−1, and (2) 400–500 °C and 0.0003–0.3 s−1 and both represented dynamic recrystallization (DRX). The map revealed a wide flow instability regime at higher strain rates and temperatures lower than 400 °C, in which flow localization occurred. Forgings produced under conditions of the above two domains were sound and symmetrical, and had finer grain sizes when being forged in the first domain. However, when being forged in the flow instability regimes, the alloy fractured before the final shape was reached. The experimental load–stroke curves for the conditions within the domains correlated well with the simulated ones, whereas the curves obtained in the instability regime were uneven. %0 conference poster %@ %A Rafiei, S.,Habibollahzadeh, A.,Wiese, B. %D 2018 %J 7th International Conference on Materials Engineering and Metallurgy, iMat 2018 %N %P %T An Insight into Environment-Conscious (ECO) Magnesium: A Review %U %X %0 journal article %@ 1438-1656 %A Xu,Y.,Wang, L.,Huang, M.,Gensch, F.,Kainer, K.U.,Hort, N. %D 2018 %J Advanced Engineering Materials %N 10 %P 1800271 %R doi:10.1002/adem.201800271 %T The Effect of Solid Solute and Precipitate Phase on Young's Modulus of Binary Mg–RE Alloys %U https://doi.org/10.1002/adem.201800271 10 %X The Young's modulus for a series of binary Mg–Gd and Mg–Nd alloys are studied in the present work. Fine and homogeneous grain structures are prepared by using hot extrusion. The results demonstrate that the Young's modulus of Mg–Gd alloys increase linearly by the increase of Gd in solid solution. Aging treatments are applied to the Mg–0.79–2.43 at% Gd alloys. A needle‐like orthorhombic structure β′ phase is formed in Mg matrix. Due to a higher Young's modulus of the intermetallic β′ phase which is estimated to be 80 GPa, the Young's modulus of Mg–Gd alloys are enhanced by aging. The results for Mg–Nd alloys indicate that Young's modulus firstly decreases and reaches 42.53 GPa for Mg–0.18 at% Nd which is attributed to the solid solution of Nd in Mg. The Mg41Nd5 particles appear in Mg matrix when Nd content is higher than 0.18 at%, and Young's modulus of the particles is tested as 57.0 GPa. Thus, the Young's modulus increases to 43.42 GPa for Mg–0.63 at% Nd. The Young's modulus of Mg alloys are affected by altering the crystal cell parameters with solid solutes, and/or the formation of precipitate phases with varying amounts. %0 conference lecture %@ %A Xu, Y.,Gan, W.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T Effect of Nd Content on Tension-compression Yield Asymmetry of Mg–Nd Alloys %U %X %0 conference lecture %@ %A Maier, P.,Bechly, M.,Mendis, C.L.,Hort, N. %D 2018 %J 2nd International Conference on Light Materials, Science and Technology, LightMAT 2017 %N %P %T Precipitation Hardening on Mechanical and Corrosion Properties of Extruded Mg10Gd Modified with Nd and La %U %X %0 conference lecture %@ %A Xu, Y.,Gan, W.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2018 %J Magnesium 2018, Proceedings of the 11th International Conference on Magnesium Alloys and Their Applications %N %P 147-153 %T Effect of Nd Content on Tension-compression Yield Asymmetry of Mg–Nd Alloys %U %X %0 conference lecture %@ %A Yang, H.,Huang, Y.,Song, B.,Kainer, K.U.,Hort, N.,Dieringa, H. %D 2018 %J Magnesium 2018, Proceedings of the 11th International Conference on Magnesium Alloys and Their Applications %N %P 128-135 %T Microstructure, Mechanical and Creep Properties of Elektron21 Reinforced with AlN Nanoparticles by Intensive Melt Shearing %U %X %0 conference lecture (invited) %@ %A Letzig, D.,Bohlen, J.,Wiese, B.,Wolff, M.,Willumeit-Roemer, R. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T From simple to very complex Mg implants: different processing routes for Ca containing Mg-alloys %U %X %0 conference lecture (invited) %@ %A Willumeit-Roemer, R.,Moosmann, J.,Zeller-Plumhoff, B.,Wieland, D.C.F.,Krueger, D.,Wiese, B.,Wennerberg, A.,Peruzzi, N.,Galli, S.,Beckmann, F.,Hammel, J.U. %D 2018 %J 10th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2018 %N %P %T Magnesium as biodegradable implant materials: how does the interface react to load? %U %X %0 conference lecture %@ %A Yang, H.,Huang, Y.,Song, B.,Kainer, K.U.,Hort, N.,Dieringa, H. %D 2018 %J 11th International Conference on Magnesium Alloys and Their Applications, Mg 2018 %N %P %T Microstructure, Mechanical and Creep Properties of Elektron21 Reinforced with AlN Nanoparticles by Intensive Melt Shearing %U %X %0 journal article %@ 2075-4701 %A Maier, P.,Bechly, M.,Mendis, C.L.,Hort, N. %D 2018 %J Metals %N 8 %P 640 %R doi:10.3390/met8080640 %T Precipitation Hardening on Mechanical and Corrosion Properties of Extruded Mg10Gd Modified with Nd and La %U https://doi.org/10.3390/met8080640 8 %X To improve the mechanical and corrosion properties of Mg10Gd, Nd and La are added, and from that, the influence of precipitation hardening was studied. An increase in strength, by decreasing grain size and increasing the volume fraction of Rare Earth-rich precipitates, has been found when increasing the amount of alloying elements. Alloys containing La appear less ductile. Where crack propagation is studied using 3-point bending on Mg10Gd and Mg10Gd1Nd, the failure is mostly driven by twinning; the alloys with La show suppressed twinning, but crack initiation and propagation is caused by brittle and coarse precipitates. Precipitation hardening did not improve fracture toughness and was mostly based on strong grain growth and low solubility of La in Mg. With added alloying elements, the grain size was found to be slightly smaller in the T6 condition—precipitates seem to pin grain boundaries and therefore limit grain boundary mobility. Alloys containing Nd showed the best precipitation hardening response. Corrosion behavior, investigated by voltammetry and immersion, showed the best behavior in the precipitation-hardened condition. Corrosion rates and surface morphology are used to discuss corrosion properties. %0 journal article %@ 0925-8388 %A Davis, T.A.,Bichler, L.,D`Elia, F.,Hort, N. %D 2018 %J Journal of Alloys and Compounds %N %P 70-79 %R doi:10.1016/j.jallcom.2018.05.129 %T Effect of TiBor on the grain refinement and hot tearing susceptibility of AZ91D magnesium alloy %U https://doi.org/10.1016/j.jallcom.2018.05.129 %X Hot tearing during solidification is frequently observed while casting alloys with a long freezing range (such as the AZ91D magnesium alloy) into molds with complex geometries and varying section thicknesses. Typically, hot tearing may be reduced or eliminated by manipulating the cooling rate, alloy composition or the mold geometry. These parameters directly influence the grain structure and interdendritic regions during the critical stage of an alloy's solidification when hot tears are prone to nucleate.,In this work, the effect of a novel TiBor grain refiner on the hot tearing behavior of the AZ91D magnesium alloy was quantitatively studied. The relationship between the grain refinement level, the alloy's cooling rate and the in-situ force evolution during casting solidification was investigated. The results revealed that for the AZ91D alloy, the force evolution rate and the microstructure were the critical determinants of the hot tearing severity. With the addition of the TiBor grain refiner, the grain size of the AZ91D alloy reduced by ∼70%, and the force and force-rate evolution significantly reduced as well, suggesting a homogenization of the internal stresses experienced by the solidifying alloy's microstructure, leading to a nearly complete elimination of hot tearing. %0 conference lecture %@ %A Gawlik, M.M.,Wiese, B.,Steiner, M.,Lamaka, S.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R.,Welle, A. %D 2017 %J 3rd EURO Intelligent Materials 2017 %N %P %T The influence of surface treatments on the degradation behaviour of Mg-5Gd %U %X %0 conference lecture %@ %A Hort, N.,Dieringa, H. %D 2017 %J Leichtbau grenzenlos, 8. Landshuter Leichtbau-Colloquium %N %P %T Magnesium Druckguss – Technologien, Legierungen und Schutzgase %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Tolnai, D.,Huang, Y.,Buzolin, R.,Hort, D. %D 2017 %J Open Seminar Materials Engineering, Lund University %N %P %T The Role of Synchrotron and Neutron Methods in the Development of Mg Based Alloys %U %X %0 journal article %@ 2366-9136 %A Gawlik, M.M.,Steiner, M.,Wiese, B.,Gonzalez, J.,Feyerabend, F.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R. %D 2017 %J Journal of Medical Materials and Technologies %N 2 %P 22-25 %R doi:10.24354/medmat.v1i2.17 %T The Effects of HAc Etching on the Degradation Behavior of Mg-5Gd %U https://doi.org/10.24354/medmat.v1i2.17 2 %X The effects of different acetic acid (HAc) etching procedures were investigated using Mg-5Gd samples in as-extruded and T4 conditions in order to achieve defined surfaces and homogenous degradation behavior. Samples were dipped into HAc solution with five different concentrations for three durations. In total, fifteen different etching conditions were tested with regard to the degradation resistance in physiological solution. The cell culture medium consisted of Dulbecco's Modified Eagle Medium (DMEM), Glutamax, 10 Vol.-% fetal bovine serum (FBS) and 1 Vol.-% Streptomycin/Penicillin solution. A screening test was performed to select the etching combinations with the lowest initial mean degradation depth. The most promising etching procedures were chosen for further long term degradation tests lasting up to 30 days in cell culture medium. The surfaces of the etched samples and for selected samples after degradation were characterized by interferometry, OM, SEM, and XRD to correlate the influence of morphology, roughness and microstructure on the degradation rate. Etching with 250 g/L HAc and 150 s leads to the most uniform degradation with low degradation rate compared to non-etched Mg-5Gd. %0 conference lecture %@ %A Marek, R.,Wohlfender, F.,Wiese, B.,de Wild, M. %D 2017 %J 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P %T Customizing the microstructure in three-dimensional Mg structures %U %X %0 journal article %@ 0261-3069 %A Mingo, B.,Arrabal, R.,Mohedano, M.,Mendis, C.L.,del Olmo, R.,Matykina, E.,Hort, N.,Merino, M.C.,Pardo, A. %D 2017 %J Materials and Design %N %P 48-58 %R doi:10.1016/j.matdes.2017.05.048 %T Corrosion of Mg-9Al alloy with minor alloying elements (Mn, Nd, Ca, Y and Sn) %U https://doi.org/10.1016/j.matdes.2017.05.048 %X Microstructure and corrosion behaviour of a Mg-9Al alloy with minor alloying additions (Mn, Y, Nd, Ca and Sn) are evaluated. All of the additions form Al-rich intermetallics with varying amounts of Fe, while Ca and Sn are also incorporated into the eutectic β-phase (β-Mg17Al12). Special attention is given to the surface potential values of the microconstituents, which are related to the formation of microgalvanic couples. Scanning Kelvin Probe Force Microscopy (SKPFM) measurements revealed that all the alloying elements, except Sn, reduced the potential difference between the secondary phases and the matrix, which is the main reason for the improvement of the corrosion resistance of Mn-, Y- and Nd-modified alloys. The beneficial effect of Ca is additionally related to the microstructure refinement and an increased area fraction of the β-phase. %0 journal article %@ 1942-0900 %A Liu, Z.,Schade, R.,Luthringer, B.,Hort, N.,Rothe, H.,Mueller, S.,Liefeith, K.,Willumeit-Roemer, R.,Feyerabend, F. %D 2017 %J Oxidative Medicine and Cellular Longevity %N %P 8091265 %R doi:10.1155/2017/8091265 %T Influence of the microstructure and silver content on degradation, cytocompatibility and antibacterial properties of magnesium-silver alloys in vitro %U https://doi.org/10.1155/2017/8091265 %X Implantation is a frequent procedure in orthopedic surgery, particularly in the aging population. However, it possesses the risk of infection and biofilm formation at the surgical site. This can cause unnecessary suffering to patients and burden on the healthcare system. Pure Mg, as a promising metal for biodegradable orthopedic implants, exhibits some antibacterial effects due to the alkaline pH produced during degradation. However, this antibacterial effect may not be sufficient in a dynamic environment, for example, the human body. The aim of this study was to increase the antibacterial properties under harsh and dynamic conditions by alloying silver metal with pure Mg as much as possible. Meanwhile, the Mg-Ag alloys should not show obvious cytotoxicity to human primary osteoblasts. Therefore, we studied the influence of the microstructure and the silver content on the degradation behavior, cytocompatibility, and antibacterial properties of Mg-Ag alloys in vitro. The results indicated that a higher silver content can increase the degradation rate of Mg-Ag alloys. However, the degradation rate could be reduced by eliminating the precipitates in the Mg-Ag alloys via T4 treatment. By controlling the microstructure and increasing the silver content, Mg-Ag alloys obtained good antibacterial properties in harsh and dynamic conditions but had almost equivalent cytocompatibility to human primary osteoblasts as pure Mg. %0 conference poster %@ %A Gawlik, M.M.,Steiner, M.,Wiese, B.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R. %D 2017 %J European Symposium and Exhibition on Biomaterials and Related Areas, EuroBioMat 2017 %N %P %T The effect of HAc etching on the degradation behaviour of Mg-5Gd %U %X %0 journal article %@ 1044-5803 %A Garces, G.,Onorbe, E.,gan, W.,Mathis, K.,Tolnai, D.,Horvath, K.,Perez, P.,Adeva, P. %D 2017 %J Materials Characterization %N %P 116-124 %R doi:10.1016/j.matchar.2017.02.017 %T Evolution of twinning in extruded AZ31 alloy with bimodal grain structure %U https://doi.org/10.1016/j.matchar.2017.02.017 %X Twinning in extruded AZ31 alloy with a bimodal grain structure is studied under compression along the extrusion direction. This study has combined in-situ measurements during the compression tests by Synchrotron Radiation Diffraction and Acoustic Emission techniques and the evaluation of the microstructure and texture in post-mortem compression samples deformed at different strains. The microstructure of the alloy is characterized by the coexistence of large areas of fine dynamic recrystallized grains and coarse non-recrystallized grains elongated along extrusion direction. Twinning occurs initially in large elongated grains before the macroscopic yield stress which is controlled by the twinning in equiaxed dynamically recrystallized grains. %0 conference object %@ %A Marek, R.,Wohlfender, F.,Wiese, B.,de Wild, M. %D 2017 %J Abstract Book, 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P Met-4 %T Customizing the microstructure in three-dimensional Mg structures %U %X %0 conference lecture %@ %A Sosro, T.,Gavras, S.,Buzolin, R.,Hort, N.,Kainer, K.U.,Tolnai, D. %D 2017 %J 6th Decennial International Conference on Solidification Processing %N %P %T A Combination of In Situ Synchrotron Diffraction and In Situ Synchrotron Tomography Techniques to Study the Solidification Behaviour of Mg-5Nd-5Zn Alloy %U %X %0 conference lecture %@ %A Davies, T.,Bichler, L.,D´Elia, F.,Hort, N. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T The Effect of Grain Refinement on Hot Tearing in AZ91D Magnesium Alloy %U %X %0 conference paper %@ %A Gu, J.,Huang, Y.,Zhang, M.,Kainer, K.U.,Hort, N. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 191-198 %R doi:10.1007/978-3-319-52392-7_29 %T Effects of Mn and Zn Solutes on Grain Refinement of Commercial Pure Magnesium %U https://doi.org/10.1007/978-3-319-52392-7_29 %X The effects of Mn (peritectic system) and Zn (eutectic system) on the grain refinement of commercial pure Mg were investigated. Interdependence model and solute paradigm theory were applied to evaluate the grain nucleation and growth for these two alloy systems. Both Mn and Zn can refine the grain of pure Mg. Compared to Mg–Zn, the nucleant particles in Mg–Mn alloys are more potent, but the relatively activated number of nucleation sites is much fewer. Zn with relatively high value of growth restriction factor increases the initial rate of development of the constitutional supercooling (CS) zone at the earliest stage of grain growth, which plays a key role in determining the final grain size. Moreover, heavy segregation of Zn during solidification provides a driving-force to activate further nucleation in the CS zone, which may trigger some unknown native nucleation particles to sever as nuclei. %0 conference paper %@ %A Subroto, T.,Mendis, C.L.,D`Elia, F.,Szakacs, G.,Fife, J.L.,Hort, N.,Kainer, K.U.,Tolnai, D. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 605-612 %R doi:10.1007/978-3-319-52392-7_83 %T 3D Microstructural Evolution on Solidifying Mg–5Nd–5Zn Alloy Observed via In Situ Synchrotron Tomography %U https://doi.org/10.1007/978-3-319-52392-7_83 %X In situ synchrotron tomography is a unique technique to study 3D microstructure evolution during solidification due to the high brilliance of the beam and the short acquisition time of the detector systems. In this work, in situ synchrotron tomographic observations were performed during the solidification of Mg–5Nd–5Zn (wt%) alloy with a cooling rate of 5 °C/min. The experiment was performed at the TOMCAT beamline of the Swiss Light Source (Paul Scherrer Institute (PSI), Villigen, Switzerland). The sample was melted using a laser-based heating system and then cooled until completely solidified. 3D tomograms were acquired during solidification. The microstructural analysis starts after the coherency point until the end of solidification. A differential thermal analysis (DTA) experiment was performed to estimate the liquidus and solidus temperature of the alloy. These values were used to correct the measured temperature from the in situ solidification experiment. Different microstructural parameters such as the volume fractions of the phases, i.e. α-Mg dendrites, interdendritics and pores, as well as the interconnectivity and skeletonization results are discussed. %0 conference lecture %@ %A Subroto, T.,Mendis, C.L.,D`Elia, F.,Szakacs, G.,Fife, J.L.,Hort, N.,Kainer, K.U.,Tolnai, D. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T 3D Microstructural Evolution on Solidifying Mg–5Nd–5Zn Alloy Observed via In Situ Synchrotron Tomography %U %X %0 conference paper %@ %A Tolnai, D.,Kaercher, T.,Buzolin, R.,Sosro, T.,Elia, F.,Gavras, S.,Stark, A.,Schell, N.,Hort, N.,Kainer, K.U. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 675-681 %R doi:10.1007/978-3-319-52392-7_93 %T Effect of the Zn Content on the Compression Behaviour of Mg5Nd(Zn): An In Situ Synchrotron Radiation Diffraction Study %U https://doi.org/10.1007/978-3-319-52392-7_93 %X The properties of commercially viable Mg alloys are not sufficient for many of the envisaged applications. The combination of Zn and rare earth metals is one of the most effective ways to enhance the mechanical properties of Mg alloys. In situ synchrotron radiation diffraction is a unique method to investigate the dynamic microstructural processes occurring during deformation . Azimuthal angle–time plots give information on grain structure changes that can be correlated with grain rotation, twinning, recovery and recrystallization. As-cast Mg5Nd, Mg5Nd3Zn, Mg5Nd5Zn and Mg5Nd7Zn alloys were investigated during compression at room temperature, at 200 °C and at 350 °C with a strain rate of 10−3 s−1 until 10% deformation. The results and post mortem metallography were compared. At high temperatures grain rotation and sub-grain formation are active to obtain the final texture, while at room temperature twinning is the dominant deformation mechanism. %0 conference lecture %@ %A Gu, J.,Huang, Y.,Zhang, M.,Kainer, K.U.,Hort, N. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T Effects of Mn and Zn Solutes on Grain Refinement of Commercial Pure Magnesium %U %X %0 journal article %@ 0928-4931 %A Yang, L.,Ma, L.,Huang, Y.,Feyerabend, F.,Blawert, C.,Hoeche, D.,Willumeit-Roemer, R.,Zhang, E.,Kainer, K.U.,Hort, N. %D 2017 %J Materials Science and Engineering C %N %P 1351-1358 %R doi:10.1016/j.msec.2017.03.010 %T Influence of Dy in solid solution on the degradation behavior of binary Mg-Dy alloys in cell culture medium %U https://doi.org/10.1016/j.msec.2017.03.010 %X Rare earth element Dy is one of the promising alloying elements for magnesium alloy as biodegradable implants. To understand the effect of Dy in solid solution on the degradation of Mg-Dy alloys in simulated physiological conditions, the present work studied the microstructure and degradation behavior of Mg-Dy alloys in cell culture medium. It is found the corrosion resistance enhances with the increase of Dy content in solid solution in Mg. This can be attributed to the formation of a relatively more corrosion resistant Dy-enriched film which decreases the anodic dissolution of Mg. %0 conference paper %@ %A Rao, K.P.,Suresh, K.,Dieringa, H.,Hort, N. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 449-461 %R doi:10.1007/978-3-319-52392-7_62 %T A Comparative Study on the Microstructure, Mechanical Properties, and Hot Deformation of Magnesium Alloys Containing Zinc, Calcium and Yttrium %U https://doi.org/10.1007/978-3-319-52392-7_62 %X Some magnesium alloys are considered as biocompatible materials because they are biodegradable or bioabsorbable in body fluids without causing health hazards. Zinc (Zn) and calcium (Ca) are essential micronutrients in the body and their bio-absorption is beneficial when an orthopedic implant made of magnesium alloy corrodes in a controlled manner. Yttrium (Y) in small quantity can be added to improve the mechanical properties. Cast alloys are hot worked to obtain wrought microstructures so as to develop components of superior and consistent properties. In this study, the microstructure, mechanical properties, and hot deformation behavior of four cast magnesium alloys containing zinc, calcium and yttrium in different combinations are compared. It is found that calcium is an excellent grain refiner whereas yttrium enormously increases the grain size. While all these elements provide strengthening, calcium is found to be the most effective one in combination with zinc and yttrium or zinc alone. The hot working behaviors of these alloys over broad ranges of temperature and strain rate are compared using processing maps. Mg–1Zn–1Y alloy exhibits higher level of workability compared to the other alloys and over entire strain rate range of 0.0003–10 s−1 and 460–540 °C, although the initial grain size of the cast alloy is extremely large. %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Dieringa, H.,Hort, N. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T A Comparative Study on the Microstructure, Mechanical Properties, and Hot Deformation of Magnesium Alloys Containing Zinc, Calcium and Yttrium %U %X %0 conference paper %@ %A Buzolin, R.,Dieringa, H.,Blawert, C.,Frank, H.,Mendis, C.L.,Lohmueller, A.,Kainer, K.U.,Hort, N. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 381-389 %R doi:10.1007/978-3-319-52392-7_54 %T Corrosion and Creep Resistance of Thixomolded® Magnesium Alloys %U https://doi.org/10.1007/978-3-319-52392-7_54 %X Process optimization is one pathway to maximizing strength of a given alloy. Thixomolding® is a semi-solid casting process that combines pores reduction with a typical bimodal grain size distribution that can lead to enhanced strength. AZ91D and AZX911 were processed via Thixomolding® using two different processing conditions to change fraction solid of primary particles at the point of injection into the mould. The tensile properties, creep resistance and corrosion behaviour of the alloys were investigated. The creep resistance was measured in the range of 135–150 °C for stresses of 50–85 MPa. The corrosion behaviour was measured via hydrogen evolution for the two alloys and was smaller than that for die-cast AZ91. The AZX911 alloy showed improved creep resistance compared to the AZ91D. The differences in the property profile of the chosen alloys are correlated with their chemical compositions as well as with different microstructures obtained through the different processing conditions. %0 conference paper %@ %A Sosro, T.,Gavras, S.,Buzolin, R.,Hort, N.,Kainer, K.U.,Tolnai, D. %D 2017 %J Solidification Processing 2017: Proceedings of the 6th Decennial International Conference on Solidification Processing %N %P 230-234 %T A Combination of In Situ Synchrotron Diffraction and In Situ Synchrotron Tomography Techniques to Study the Solidification Behaviour of Mg-5Nd-5Zn Alloy %U %X In this work, a combination of in situ experiments; synchrotron diffraction and synchrotron,tomography were used to study the solidification behaviour of Mg-5Nd-5Zn (wt. %). The,samples were cooled with a cooling rate of 100 °C/min and 5 °C/min in the in situ synchrotron,diffraction experiment and in situ synchrotron tomography experiments respectively. The,results from synchrotron diffraction experiments provided information regarding phase,formation temperature and phase identification. From these results, two intermetallic phases,,Mg3(Nd,Zn) and Mg50Nd8Zn42 were identified. The phases identified by the synchrotron,diffraction technique were verified with the results from transmission electron microscopy,(TEM) observations. Synchrotron tomography results showed that the volume fraction of α-,Mg increased and interdendritics decreased as solidification progressed, and pores formed at,the end of solidification. From synchrotron tomography, it was also found that interdendritic,interconnectivity decreased as the end of solidification approached. The α-Mg,interconnectivity was constantly at unity value throughout solidification. The grain coherency,temperature was estimated by both techniques – it was estimated to be approximately 535 °C,and 540 °C by synchrotron diffraction and tomography respectively. %0 conference paper %@ %A Davies, T.,Bichler, L.,D´Elia, F.,Hort, N. %D 2017 %J Magnesium Technology 2017, 146th Annual Meeting and Exhibition, TMS 2017 %N %P 653-660 %R doi:10.1007/978-3-319-52392-7_90 %T The Effect of Grain Refinement on Hot Tearing in AZ91D Magnesium Alloy %U https://doi.org/10.1007/978-3-319-52392-7_90 %X The AZ91D magnesium alloy is a popular casting alloy used for diverse automotive applications, despite its high susceptibility to hot tearing during casting solidification. In the metalcasting industry, hot tearing is manipulated via cooling rate, alloy composition or mold design optimization. In this work, the effect of grain refinement on hot tearing was quantitatively studied and the relationship between the alloy’s cooling rate and in situ force evolution during casting solidification was related to the severity of hot tears. The results suggest that the load evolution rate and microstructure were critical determinants of the hot tear severity for both unrefined and grain-refined alloys. The grain refiners were seen to significantly reduce the overall force and force-rate evolution, which contributed to the elimination of hot tearing in the AZ91D alloy under standard casting conditions. %0 journal article %@ 1013-9826 %A Rao, K.P.,Bagheripoor, M.,Dieringa, H.,Hort, N. %D 2017 %J Key Engineering Materials, Advances in Engineering Plasticity and its Application XIII %N %P 232-237 %R doi:10.4028/www.scientific.net/KEM.725.232 %T High Temperature Deformation of Cast ZW11 Magnesium Alloy with Very Large Grain Size %U https://doi.org/10.4028/www.scientific.net/KEM.725.232 %X Magnesium (Mg) alloys are considered for biomedical applications due to their matching,bone density and biodegradable/abioabsorable nature. Mg-1% Zinc-1% Yttrium (ZW11) alloy was cast using a direct chill slow cooling process to obtain dense ingot with uniform composition.,However, the resultant alloy developed a very coarse grained microstructure with a grain size in the range of 2,600 to 4,000 μm (2.6-4.0 mm). The hot working behavior of ZW11 alloy has been,investigated using compression tests in the temperature and strain rate ranges of 340-540 oC and,0.0003 – 10 s-1 to evaluate the optimum processing parameters. A processing map has been developed on the basis of the flow stress data. The processing map reveals a window of workability in the temperature and strain rate ranges of 460-540 °C and 0.0003-10 s-1 and regimes of flow,instability. The microstructures of the deformed alloy provided support to the processing map. %0 journal article %@ 0925-8388 %A Gil-Santos, A.,Szakacs, G.,Moelans, N.,Hort, N.,Biest, O.van der %D 2017 %J Journal of Alloys and Compounds %N %P 767-776 %R doi:10.1016/j.jallcom.2016.10.059 %T Microstructure and mechanical characterization of cast Mg-Ca-Si alloys %U https://doi.org/10.1016/j.jallcom.2016.10.059 %X Three different phase fields are predicted and experimentally detected in the Mg rich corner of the Mg-Ca-Si ternary diagram. The present phases are Mg + MgCaSi + Mg2Si in phase field 1, Mg + MgCaSi in phase field 2 and Mg + Mg2Ca + MgCaSi in phase field 3. The focus of this study is on the formation and evolution of the intermetallic phases. The final microstructures have been related with their solidification process and with the alloys mechanical properties. A clear influence of the observed intermetallic phases on the mechanical performance was found. A bigger size and higher amounts of the MgCaSi intermetallic phase increase the alloys strength and make them brittle, while in its fine morphology MgCaSi reduces the strengthening effect and slightly decreases the ductility compared to pure Mg. Mg2Si phase in its needle-like small size morphology contributes to an increase of the hardness and compressive strength. Its presence reduces the alloys ductility making them brittle. Finally, the highest values for compressive strength and hardness are related to the Mg2Ca presence. %0 journal article %@ 1996-1944 %A Vlcek, M.,Lukac, F.,Kudrnova, H.,Smola, B.,Stulikova, I.,Luczak, M.,Szakacs, G.,Hort, N.,Willumeit-Roemer, R. %D 2017 %J Materials %N 1 %P 55 %R doi:10.3390/ma10010055 %T Microhardness and In Vitro Corrosion of Heat-Treated Mg–Y–Ag Biodegradable Alloy %U https://doi.org/10.3390/ma10010055 1 %X Magnesium alloys are promising candidates for biodegradable medical implants which reduce the necessity of second surgery to remove the implants. Yttrium in solid solution is an attractive alloying element because it improves mechanical properties and exhibits suitable corrosion properties. Silver was shown to have an antibacterial effect and can also enhance the mechanical properties of magnesium alloys. Measurements of microhardness and electrical resistivity were used to study the response of Mg–4Y and Mg–4Y–1Ag alloys to isochronal or isothermal heat treatments. Hardening response and electrical resistivity annealing curves in these alloys were compared in order to investigate the effect of silver addition. Procedures for solid solution annealing and artificial aging of the Mg–4Y–1Ag alloy were developed. The corrosion rate of the as-cast and heat-treated Mg–4Y–1Ag alloy was measured by the mass loss method. It was found out that solid solution heat treatment, as well artificial aging to peak hardness, lead to substantial improvement in the corrosion properties of the Mg–4Y–1Ag alloy. %0 conference lecture %@ %A Tolnai, D.,Kaercher, T.,Buzolin, R.,Sosro, T.,Elia, F.,Gavras, S.,Stark, A.,Schell, N.,Hort, N.,Kainer, K.U. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T Effect of the Zn Content on the Compression Behaviour of Mg5Nd(Zn): An In Situ Synchrotron Radiation Diffraction Study %U %X %0 conference lecture %@ %A Buzolin, R.,Dieringa, H.,Blawert, C.,Frank, H.,Mendis, C.L.,Lohmueller, A.,Kainer, K.U.,Hort, N. %D 2017 %J 146th Annual Meeting and Exhibition, TMS 2017 %N %P %T Corrosion and Creep Resistance of Thixomolded® Magnesium Alloys %U %X %0 conference object %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2017 %J Abstract Book, 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P Met-5 %T Influence of extrusion parameters on Mg-10Gd %U %X %0 conference poster %@ %A Harmuth, J.,Wiese, B.,Bohlen, J.,Ebel, T.,Willumeit-Roemer, R. %D 2017 %J 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P %T Influence of extrusion parameters on Mg-10Gd %U %X %0 conference lecture %@ %A You, S.,Yuanding, H.,Mendis, C.,Kainer, K.U.,Hort, N. %D 2017 %J 23. International Symposium Research - Education - Technology, RET %N %P %T The effect of yttrium addition on microstructure and mechanical properties of Mg-Ca alloys %U %X %0 journal article %@ 0921-5093 %A Buzolin, R.H.,Mohedano, M.,Mendis, C.L.,Mingo, B.,Tolnai, D.,Blawert, C.,Kainer, K.U.,Pinto, H.,Hort, N. %D 2017 %J Materials Science and Engineering A %N %P 238-247 %R doi:10.1016/j.msea.2016.11.022 %T As cast microstructures on the mechanical and corrosion behaviour of ZK40 modified with Gd and Nd additions %U https://doi.org/10.1016/j.msea.2016.11.022 %X The microstructure of ZK40, ZK40 with 2 wt% of Nd and Gd (ZK40-2Nd and ZK40-2Gd, respectively) were investigated with optical, scanning and transmission electron microscopy, X-ray diffraction and Scanning Kelvin Probe Force Microscopy. The mechanical properties and the corrosion behaviour were correlated with the microstructure. The 2 wt% Gd addition enhanced the ductility, while the Nd addition resulted in deterioration in mechanical properties. The corrosion behaviour was also enhanced with the addition of Gd. %0 conference lecture %@ %A You, S.,Huang, Y.,Dieringa, H.,Kainer, K.U.,Hort, N. %D 2017 %J 2nd International Conference on Light Materials, Science and Technology, LightMAT 2017 %N %P %T Microstructure and mechanical properties of as-cast and heat treated Mg-Ca-Y-Zr alloys %U %X %0 conference paper %@ %A Moosmann, J.,Zeller-Plumhoff, B.,Wieland, D.C.F.,Galli, S.,Krueger, D.,Dose, T.,Burmester, H.,Wilde, F.,Bech, M.,Peruzzi, N.,Wiese, B.,Hipp, A.,Beckmann, F.,Hammel, J.,Willumeit-Roemer, R. %D 2017 %J Proceedings of SPIE, Developments in X-Ray Tomography XI %N %P 1039100 %R doi:10.1117/12.2275121 %T Biodegradable magnesium-based implants in bone studied by synchrotron radiation microtomography %U https://doi.org/10.1117/12.2275121 %X Permanent implants made of titanium or its alloys are the gold standard in many orthopedic and traumatological applications due to their good biocompatibility and mechanical properties. However, a second surgical intervention is required for this kind of implants as they have to be removed in the case of children that are still growing or on patient’s demand. Therefore, magnesium-based implants are considered for medical applications as they are degraded under physiological conditions. The major challenge is tailoring the degradation in a manner that is suitable for a biological environment and such that stabilization of the bone is provided for a controlled period. In order to understand failure mechanisms of magnesium-based implants in orthopedic applications and, further, to better understand the osseointegration, screw implants in bone are studied under mechanical load by means of a push-out device installed at the imaging beamline P05 of PETRA III at DESY. Conventional absorption contrast microtomography and phasecontrast techniques are applied in order to monitor the bone-to-implant interface under increasing load conditions. In this proof-of-concept study, first results from an in situ push-out experiment are presented. %0 journal article %@ 2075-4701 %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Dharmendra, C.,Hort, N.,Dieringa, H. %D 2017 %J Metals %N 10 %P 405 %R doi:10.3390/met7100405 %T High Temperature Strength and Hot Working Technology for As-Cast Mg–1Zn–1Ca (ZX11) Alloy %U https://doi.org/10.3390/met7100405 10 %X Cast Mg–1Zn–1Ca alloy (ZX11) has been tested to evaluate its compressive strength between 25 °C and 250 °C, and workability in the range of 260–500 °C. The ultimate compressive strength of this alloy is about 30% higher than that of creep-resistant alloy Mg–3Sn–2Ca (TX32) between 25 °C and 200 °C, and exhibits a plateau between 100 °C and 175 °C, similar to TX32. This is attributed to Mg2Ca particles present at grain boundaries that reduce their sliding. The processing map, developed between 260 and 420 °C in the strain rate limits of 0.0003 s−1 to 1 s−1, exhibited two domains in the ranges: (1) 280–330 °C and 0.0003–0.01 s−1 and (2) 330–400 °C and 0.0003–0.1 s−1. In these domains, dynamic recrystallization occurs, with basal slip dominating in the first domain and prismatic slip in the second, while the recovery mechanism being climb of edge dislocations in both. The activation energy estimated using standard kinetic rate equation is 191 kJ/mol, which is higher than the value for lattice self-diffusion in magnesium indicating that a large back stress is created by the presence of Ca2Mg6Zn3 intermetallic particles in the matrix. It is recommended that the alloy be best processed at 380 °C and 0.1 s−1 at which prismatic slip is favored due to Zn addition. At higher strain rates, the alloy exhibits flow instability and adiabatic shear band formation at <340 °C while flow localization and cracking at grain boundaries occurs at temperatures >400 °C. %0 conference lecture %@ %A Wolff, M.,Luczak, M.,Schaper, J.,Wiese, B.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R.,Klassen, T. %D 2017 %J 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P %T Manufacturing and Assessment of high strength Mg-Nd-Gd-Zr-Zn alloy implant prototypes and test specimen, using PM (Powder Metallurgy) methods %U %X %0 conference object %@ %A Lu, Y.,Zhidan, L.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Schade, R.,Liefeit, K.,Kainer, K.U.,Hort, N. %D 2017 %J Abstract Book, 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P Invit-13 %T Mg-Ag-Gd alloys as biodegradable implant materials %U %X %0 conference poster %@ %A Lu, Y.,Zhidan, L.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Schade, R.,Liefeit, K.,Kainer, K.U.,Hort, N. %D 2017 %J 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P %T Mg-Ag-Gd alloys as biodegradable implant materials %U %X %0 journal article %@ 0167-577X %A Huang, Y.,Lv, Z.,Wan, L.,Shen, J.,dos Santos, J.F. %D 2017 %J Materials Letters %N %P 172-175 %R doi:10.1016/j.matlet.2017.07.081 %T A new method of hybrid friction stir welding assisted by friction surfacing for joining dissimilar Ti/Al alloy %U https://doi.org/10.1016/j.matlet.2017.07.081 %X A new method of friction surfacing assisted hybrid friction stir welding (FS-HFSW) technique was developed to improve the joint efficiency and avoid the pin abrasion for joining of dissimilar Ti/Al joints. The FSW tool with enlarged head and concave end-face was designed to broaden the lap width and promote material flow. The maximum tensile load reached 12.2 kN, representing 85.3% of the parent Al alloy, with a ductile fracture locating at the heat affected zone of base Al. The excellent bonding of Ti and Al was based on the combined effects of nanoscale TiAl3 IMCs layer and complex mechanical inter-locking. %0 journal article %@ 2075-4701 %A Suresh, K.,Rao, K.P.,Prasad, Y.V.R.K.,Wu, C.-M.,Hort, N.,Dieringa, H. %D 2017 %J Metals %N 12 %P 539 %R doi:10.3390/met7120539 %T Mechanism of Dynamic Recrystallization and Evolution of Texture in the Hot Working Domains of the Processing Map for Mg-4Al-2Ba-2Ca Alloy %U https://doi.org/10.3390/met7120539 12 %X The occurrence of dynamic recrystallization (DRX) and its effect on the evolution of texture during uniaxial compression of a creep-resistant cast Mg-4Al-2Ba-2Ca alloy in the temperature range of 260–500 °C and strain rate range of 0.0003–10 s−1 has been studied using transmission electron microscopy and electron backscatter diffraction techniques with a view to understand its mechanism. For this purpose, a processing map has been developed for this alloy, which revealed two domains of DRX in the temperature and strain rate ranges of: (1) 300–390 °C/0.0003–0.001 s−1 and (2) 400–500 °C/0.0003–0.5 s−1. In Domain 1, DRX occurs by basal slip and recovery by dislocation climb, as indicated by the presence of planar slip bands and high dislocation density leading to tilt boundary formation and a low-intensity basal texture. On the other hand, DRX in Domain 2 occurs by second order pyramidal slip and recovery by cross-slip since the microstructure revealed tangled dislocation structure with twist boundaries and randomized texture. The high volume content of intermetallic phases Mg21Al3Ba2 and (Al,Mg)2Ca eutectic phase is considered to be responsible for the observed hot deformation behavior. %0 journal article %@ 0928-4931 %A Gil-Santos, A.,Marco, I.,Moelans, N.,Hort, N.,Biest, O.van der %D 2017 %J Materials Science and Engineering C %N %P 25-34 %R doi:10.1016/j.msec.2016.09.056 %T Microstructure and degradation performance of biodegradable Mg-Si-Sr implant alloys %U https://doi.org/10.1016/j.msec.2016.09.056 %X In this work the microstructure and degradation behavior of several as-cast alloy compositions belonging to the Mg rich corner of the Mg-Si-Sr system are presented and related. The intermetallic phases are identified and analyzed describing the microstructure evolution during solidification. It is intended in this work to obtain insight in the behavior of the ternary alloys in in vitro tests and to analyze the degradation behavior of the alloys under physiologically relevant conditions. The as-cast specimens have been exposed to immersion tests, both mass loss (ML) and potentiodynamic polarization (PDP). The degradation rate (DR) have been assessed and correlated to microstructure features, impurity levels and alloy composition. The initial reactions resulted to be more severe while the degradation stabilizes with time. A higher DR is related with a high content of the Mg17Sr2 phase and with the presence of coarse particles of the intermetallics Mg2Si, MgSiSr and MgSi2Sr. Specimens with a higher DR typically have higher levels of impurities and alloy contents. %0 journal article %@ 2075-4701 %A Rao, K.P.,Dharmendra, C.,Prasad, Y.V.R.K.,Hort, N.,Dieringa, H. %D 2017 %J Metals %N 11 %P 513 %R doi:10.3390/met7110513 %T Optimization of Thermo-Mechanical Processing for Forging of Newly Developed Creep-Resistant Magnesium Alloy ABaX633 %U https://doi.org/10.3390/met7110513 11 %X The compressive strength and creep resistance of cast Mg-6Al-3Ba-3Ca (ABaX633) alloy has been measured in the temperature range of 25 to 250 °C, and compared with that of its predecessor ABaX422. The alloy is stronger and more creep-resistant than ABaX422, and exhibits only a small decrease of yield stress with temperature. The higher strength of ABaX633 is attributed to a larger volume fraction of intermetallic particles (Al, Mg)2Ca and Mg21Al3Ba2 in its microstructure. Hot deformation mechanisms in ABaX633 have been characterized by developing a processing map in the temperature and strain rate ranges of 300 to 500 °C and 0.0003 to 10 s−1. The processing map exhibits two workability domains in the temperature and strain rate ranges of: (1) 380 to 475 °C and 0.0003 to 0.003 s−1, and (2) 480–500 °C and 0.003 to 0.5 s−1. The apparent activation energy values estimated in the above two domains (204 and 216 kJ/mol) are higher than that for lattice self-diffusion of Mg, which is attributed to the large back-stress that is caused by the intermetallic particles. Optimum condition for bulk working is 500 °C and 0.01 s−1 at which hot workability will be maximum. Flow instability is exhibited at lower temperatures and higher strain rates, as well as at higher temperatures and higher strain rates. The predictions of the processing map on the workability domains, as well as the instability regimes are fully validated by the forging of a rib-web (cup) shaped component under optimized conditions. %0 journal article %@ 2213-9567 %A You, S.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2017 %J Journal of Magnesium and Alloys %N 3 %P 239-253 %R doi:10.1016/j.jma.2017.09.001 %T Recent research and developments on wrought magnesium alloys %U https://doi.org/10.1016/j.jma.2017.09.001 3 %X Wrought magnesium alloys attract special interests as lightweight structural material due to their homogeneous microstructure and enhanced mechanical properties compared to as-cast alloys. In this contribution, recent research and developments on wrought magnesium alloys are reviewed from the viewpoint of the alloy design, focusing on Mg-Al, Mg-Zn and Mg-rare earth (RE) systems. The effects of different alloying elements on the microstructure and mechanical properties are described considering their strengthening mechanisms, e.g. grain refinement, precipitation and texture hardening effect. Finally, the new alloy design and also the future research of wrought magnesium alloys to improve their mechanical properties are discussed. %0 journal article %@ 0022-2461 %A Yu, Z.,Huang, Y.,Gan, W.,Zhong, Z.,Hort, N.,Meng, J. %D 2017 %J Journal of Materials Science %N 11 %P 6670-6686 %R doi:10.1007/s10853-017-0902-3 %T Effects of extrusion ratio and annealing treatment on the mechanical properties and microstructure of a Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy %U https://doi.org/10.1007/s10853-017-0902-3 11 %X This study investigates the effects of the extrusion ratio and annealing treatment on the microstructure, texture and mechanical properties of an as-extruded Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy. A high extrusion ratio (30:1) results in a homogeneous microstructure with fine dynamic recrystallized (DRXed) grains, while a low extrusion ratio (6:1) leads to a bimodal microstructure with un-DRXed regions and DRXed grains. The bimodal microstructure can be removed by subsequent annealing. This alloy contains several long-period stacking ordered (LPSO) and Mg5RE phases (RE: rare earth). The extrusion ratio and annealing process have negligible effects on the volume fraction of the LPSO phase but have significant effects on the Mg5RE phase. The volume fraction of the Mg5RE phase decreases as the extrusion ratio and annealing time increase. Cuboid precipitates form in the alloy extruded at low extrusion ratios after annealing. The alloy exhibits a bimodal texture with <0001> and <101 ¯ ¯ ¯ 0 101¯0> components. The presence of the <0001> component is determined by a critical grain size. The texture evolution (such as the degree of grain growth) is not influenced by the extrusion ratio, but it is affected by the annealing time, which is related to the Mg5RE phase rather than the LPSO phase. The grain refinement, the Mg5RE and LPSO phases, and the texture contribute to the alloy strengthening. Finally, a high-strength extruded Mg bar with a diameter of 32 mm (an extrusion ratio of 6:1) was successfully produced. %0 conference lecture (invited) %@ %A Tolnai, D.,Gavras, S.,Sosro, T.,Buzolin, R.,Hort, N. %D 2017 %J Seminar of School of Engineering, RMIT %N %P %T Structure-property relations in Mg-Nd-Zn alloys %U %X %0 conference lecture (invited) %@ %A Tolnai, D.,Gavras, S.,Sosro, T.,Buzolin, R.,Hort, N. %D 2017 %J Seminar of CSIC, CENIM %N %P %T Structure-property relations in Mg-Nd-Zn alloys %U %X %0 conference paper %@ 0255-5476 %A Gan, W.,Hofmann, M.,Ventzke, V.,Randau, C.,Huang, Y.,Kriele, A.,Brokmeier, H.-G.,Müller, M. %D 2017 %J Materials Science Forum %N %P 572-577 %R doi:10.4028/www.scientific.net/MSF.879.572 %T Microstructure and Residual Stress in Rotary Friction Welded Dissimilar Metals of AA7020 Aluminium Alloy with 316L Steel %U https://doi.org/10.4028/www.scientific.net/MSF.879.572 %X Rotary friction welding (RFW) was used in the current study to join the dissimilar metals AA7020-T6 aluminium alloy and 316L steel. Neutron diffraction was performed to investigate the texture gradient around the weld line and to map the residual stress over the whole specimen. The texture analysis showed a weak shear component near the bond line of AA7020-T6-T6 side which indicated a plastic deformation of AA7020-T6 during welding. The shear bands were also observed in optical microstructures. Relatively high tensile residual stresses were observed near the bond line on the AA7020-T6 side, which were in-homogeneously distributed from the perimeter to the rod centre, while high compressive residual stresses were found in the sample centre at the bond line in the 316L steel. %0 conference paper %@ 0255-5476 %A Gan, W.,Huang, Y.,Xu, Y.,Hofmann, M.,Kainer, K.,Hort, N. %D 2017 %J Materials Science Forum %N %P 779-783 %R doi:10.4028/www.scientific.net/MSF.879.779 %T In Situ Tensile Texture Analysis of a New Mg-RE Alloy %U https://doi.org/10.4028/www.scientific.net/MSF.879.779 %X A new Mg-RE (rare earth) alloy was previously developed by micro-alloying method (RE< 0.4 wt.%), which achieves a high ductility and good corrosion resistance. In-situ tensile test via neutron and synchrotron diffraction were performed to investigate first the deformation behaviour; and second the texture evolution which can be related to the deformation mechanism, and finally to understand why the as-cast Mg-RE alloys show such a high tensile ductility.Preliminary results showed that a dominated basal fibre texture was gradually developed with the increase of tensile strain. However, before the sample was broken a (10.0) fibre texture showed a similar intensity to that in (00.2), which means more activations of the non-basal slip planes during tensile deformation. This could also contribute to a relatively high elongation of this new Mg-RE alloy at room temperature. Further discussion will be showed together with the microstructures. %0 conference object %@ %A Wolff, M.,Luczak, M.,Schaper, J.,Wiese, B.,Dahms, M.,Ebel, T.,Willumeit-Roemer, R.,Klassen, T. %D 2017 %J Abstract Book, 9th Symposium on Biodegradable Metals, Biometall 2017 %N %P Met-8 %T Manufacturing and Assessment of high strength Mg-Nd-Gd-Zr-Zn alloy implant prototypes and test specimen, using PM (Powder Metallurgy) methods %U %X %0 conference lecture %@ %A Moosmann, J.,Zeller-Plumhoff, B.,Wieland, D.C.F.,Galli, S.,Krueger, D.,Dose, T.,Burmester, H.,Wilde, F.,Bech, M.,Peruzzi, N.,Wiese, B.,Hipp, A.,Beckmann, F.,Hammel, J.,Willumeit-Roemer, R. %D 2017 %J Developments in X-Ray Tomography XI, SPIE Optics and Photonics Conference 2017 %N %P %R doi:10.1117/12.2275121 %T Biodegradable magnesium-based implants in bone studied by synchrotron radiation microtomography %U https://doi.org/10.1117/12.2275121 %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Letzig, D.,Hort, N. %D 2016 %J 2nd Annual World Congress of Smart Material 2016 %N %P %T Magnesium alloys - Smart Materials for Dual Use - Aerospace Applications and Degradable Metallic Biomaterials %U %X %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 347-351 %R doi:10.1002/9781119274803.ch67 %T In vitro corrosion and cytocompatibility of Mg-2Gd-x(Ag, Ca) alloys %U https://doi.org/10.1002/9781119274803.ch67 %X The effects of solution treatment (T4) on the in vitro corrosion properties were investigated for Mg-2Gd-xAg (x=1, 2 wt. %), Mg-2Gd-xCa (x=0.4, 0.8 wt. %) alloys. The cytocompatibility of pure Mg, Mg-2Gd, Mg-2Gd-2Ag and Mg-2Gd-0.8Ca alloy was studied as well. All alloys were prepared by permanent mould casting. T4 heat treatment was carried out at 510 °C for 48 h under Ar atmosphere and specimens were quenched in water at room temperature. Corrosion experiments were performed in cell culture medium under cell culture conditions. Cytocompatibility was evaluated by direct cell adhesion and live/dead staining tests. After T4 heat treatment, the amount of intermetallic phases is significantly decreased, which leads to significant improvement of corrosion properties by a very high factor (5-30). The results of live/dead staining reveal that the cells are mostly in viable state and homogenously distributed over the surface. The corrosion layer shows no cytotoxicity to primary human osteoblasts. %0 conference lecture %@ %A D´Elia, F.,Tolnai, D.,Mendis, C.L.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T Hot Tearing Susceptibility of Mg-5Nd-xZn Alloys %U %X %0 conference lecture %@ %A D´Elia, F.,Tolnai, D.,Mendis, C.L.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 129-134 %R doi:10.1002/9781119274803.ch26 %T Hot Tearing Susceptibility of Mg-5Nd-xZn Alloys %U https://doi.org/10.1002/9781119274803.ch26 %X Magnesium-neodynium-zinc (Mg-Nd-Zn) alloys are promising candidates as creep resistant alloys. Further, Nd is a rare earth (RE) addition with lower solid solubility and a relatively lower cost. Hence, the use of such alloys may result in a feasible and cost effective alternative for enhancing Mg alloy use in high temperature applications. Nevertheless, studies on the castability of Mg-Nd-Zn alloys are lacking. As such, the aim of this research was to investigate the hot tearing susceptibility of Mg-5Nd-xZn (x = 0, 3, 5, 7 wt%) alloys during permanent mold casting. Specifically, a constrained-rod casting mold equipped with a load cell was used to characterize hot tearing severity and determine the onset temperature of hot tearing. The onset solid fraction of hot tearing was subsequently determined via thermodynamic software. The results suggest that hot tearing severity increased initially with addition of Zn (up to 5 wt%), but then decreased with further addition to 7 wt%. This was likely attributed to both the low onset solid fraction of hot tearing (i.e. 0.5) recorded for this alloy, which enabled enhanced feeding and opportunity to heal developing hot tears, as well as the divorced eutectic structure observed which may have facilitated late stage feeding of eutectic liquid and hence limit the alloy's susceptibility to hot tearing. %0 journal article %@ 1047-4838 %A Maier, P.,Peters, R.,Mendis, C.L.,Mueller, S.,Hort, N. %D 2016 %J JOM: Journal of the Minerals, Metals and Materials Society %N 4 %P 1183-1190 %R doi:10.1007/s11837-015-1762-4 %T Influence of Precipitation Hardening in Mg-Y-Nd on Mechanical and Corrosion Properties %U https://doi.org/10.1007/s11837-015-1762-4 4 %X Precipitation hardening is an effective strengthening mechanism to achieve high strength at moderate ductility in Mg-RE alloys. However, improved mechanical properties by precipitates that strengthen the alloy can affect corrosion rates as the finely dispersed particles are often more noble than the matrix. Biodegradable implant material should show a certain corrosion rate, but should be free of pitting, because wide and deep pits are notches that can cause higher stress concentration. WE43 has generally shown an acceptable biological response. In this study, a Mg-Y-Nd-Gd-Dy (WE32) alloy in extruded, solution and precipitation heat-treated conditions has been investigated. Solution heat treatment causes grain growth and strength loss. A rather short ageing response to peak hardness was observed, where peak hardening causes hardness values to exceed that of the initial extruded condition. Grain growth during ageing is not significant. Corrosion was evaluated with potentiodynamic polarization in Ringer Acetate solution. The highest corrosion rate was observed in the T4 condition. The peak aged alloy showed the most homogenous form of corrosion. %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T In vitro corrosion and cytocompatibility of Mg-2Gd-x(Ag, Ca) alloys %U %X %0 journal article %@ 0921-5093 %A Buzolin, R.H.,Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Pinto, H.,Kainer, K.U.,Hort, N. %D 2016 %J Materials Science and Engineering A %N %P 2-9 %R doi:10.1016/j.msea.2016.03.121 %T In situ synchrotron radiation diffraction investigation of the compression behaviour at 350 °C of ZK40 alloys with addition of CaO and Y %U https://doi.org/10.1016/j.msea.2016.03.121 %X The evolution of the microstructure during compression is investigated with in situ synchrotron radiation diffraction in as-cast ZK40, ZK40-2CaO and ZK40-1Y Mg alloys. The specimens were compressed at 350 °C with a strain rate of 10−3 s−1 until 30% deformation. The Y containing alloy showed the highest 0.2% proof strength in compression of 35 MPa at 350 °C which is double that of the ZK40 alloy, while the CaO added alloy shows a moderate increment at 23 MPa. The Y containing alloy shows some work hardening, while the CaO modified and the ZK40 alloys do not show work hardening after yield. Synchrotron radiation diffraction timelines show that continuous and discontinuous dynamic recrystallization occurs during deformation of the ZK40 alloy while a small amount of dynamic recrystallization was observed in the ZK40-1Y alloy. However, dynamic recrystallization was not present in the ZK40-2CaO alloy. SEM-EBSD analysis conducted on the deformed samples shows a significantly high volume fraction of twins in the Y and CaO containing alloys which was absent in the ZK40 alloy. The modified deformation behaviours observed in the CaO and Y containing alloys were attributed to the presence of intermetallic particles found at the grain boundaries and to the role of Ca and Y in stabilising twinning. %0 journal article %@ 0026-0843 %A Hort, N.,Wiese, B.,Dieringa, H.,Kainer, K.U. %D 2016 %J Metallurgia Italiana %N 6 %P 105-108 %T Protecting molten Magnesium and its alloys %U 6 %X Magnesium is having a high affinity to oxygen in the molten state and unlike other metals it is not forming a stable protecting film on the surface of melts. To avoid burning it is therefore necessary to protect molten Mg and its alloys. To achieve this, nowadays mostly SF6 is used in combination with carrier gases like dry air, N2, CO2, or even Ar. However, SF6 has been identified as a highly potent greenhouse gas with a global warming potential > 23,000 more than CO2. Moreover, SF6 is cracked at temperatures higher than 750 °C and toxic fluorine is set free. Fortunately fluorine immediately reacts with Mg vapour and forms stable MgF2. Due to the different threats caused by SF6 the European Union (EU) will ban the use of SF6 for high pressure die casting of magnesium alloys as of January 1st, 2018. Alternatives are already available. But most of them are,fluorinated hydrocarbons or other fluorinated chemicals. They are also under discussion in the EU due to the,risk that comes with fluorine. SO2 is already recommended as a possible SF6 replacement but is also having,its own restrictions with maximum working space concentrations. It might be necessary to reuse again fluxes, but they also have limitations. If magnesium and its alloys shall be further used and processed in the EU, alternative ways of magnesium melt protection need to be established within the near future. This contribution will discuss available methods to protect molten Mg and their consequences. %0 journal article %@ 1742-7061 %A Jaehn, K.,Saito, H.,Taipaleenmaeki, H.,Gasser, A.,Hort, N.,Feyerabend, F.,Schlueter, H.,Rueger, J.M.,Lehmann, W.,Willumeit-Roemer, R.,Hesse, E. %D 2016 %J Acta Biomaterialia %N %P 350-360 %R doi:10.1016/j.actbio.2016.03.041 %T Intramedullary Mg2Ag nails augment callus formation during fracture healing in mice %U https://doi.org/10.1016/j.actbio.2016.03.041 %X Intramedullary stabilization is frequently used to treat long bone fractures. Implants usually remain unless complications arise. Since implant removal can become technically very challenging with the potential to cause further tissue damage, biodegradable materials are emerging as alternative options. Magnesium (Mg)-based biodegradable implants have a controllable degradation rate and good tissue compatibility, which makes them attractive for musculoskeletal research. Here we report for the first time the implantation of intramedullary nails made of an Mg alloy containing 2% silver (Mg2Ag) into intact and fractured femora of mice. Prior in vitro analyses revealed an inhibitory effect of Mg2Ag degradation products on osteoclast differentiation and function with no impair of osteoblast function. In vivo, Mg2Ag implants degraded under non-fracture and fracture conditions within 210 days and 133 days, respectively. During fracture repair, osteoblast function and subsequent bone formation were enhanced, while osteoclast activity and bone resorption were decreased, leading to an augmented callus formation. We observed a widening of the femoral shaft under steady state and regenerating conditions, which was at least in part due to an uncoupled bone remodeling. However, Mg2Ag implants did not cause any systemic adverse effects. These data suggest that Mg2Ag implants might be promising for intramedullary fixation of long bone fractures, a novel concept that has to be further investigated in future studies. %0 conference poster %@ %A Wohlfender, F.,Saxer, S.,Wiese, B.,Rueegg, J.,Dietschy, A.,Schumacher, R.,de Wild, M. %D 2016 %J [MEET THE EXPERT] Implants, Innovation – from Idea to Patient Benefit %N %P %T Preliminary microstructural investigation of Mg cubes produced by SLM %U %X %0 journal article %@ 0921-5093 %A Srinivasan, A.,Dieringa, H.,Mendis, C.L.,Huang, Y.,Rajesh Kumar, R.,Kainer, K.U.,Hort, N. %D 2016 %J Materials Science and Engineering A %N %P 158-167 %R doi:10.1016/j.msea.2015.09.113 %T Creep behavior of Mg–10Gd–xZn (x=2 and 6wt%) alloys %U https://doi.org/10.1016/j.msea.2015.09.113 %X Creep behavior of Mg–10Gd–xZn alloys was investigated with two Zn contents, 2 and 6 wt%. The as cast microstructure of alloys contained (Mg, Zn)3Gd phase at the interdendritic regions and long period stacking ordered (LPSO) phase in the matrix. Increase in the Zn content from 2% to 6%, increased the volume fraction and morphology of second phase [(Mg,Zn)3Gd]. Creep testing at 250 and 300 °C with stress levels between 50 and 120 MPa indicated that increase in Zn content or temperature reduced the creep performance of the Mg–10Gd–xZn alloys. The minimum creep rate of Mg–10Gd–2Zn was one order less that of Mg–10Gd–6Zn. Dynamic precipitation was found in both the alloys during creep deformation at 250 °C and strengthened the alloys: prismatic platelets (Mg5Gd) were observed perpendicular to the LPSO phase in Mg–10Gd–2Zn alloy whereas basal oval precipitates (ternary composition) parallel to the LPSO occurred in Mg–10Gd–6Zn alloy. The dynamic precipitates were not observed in alloys during creep at 300 °C. Ternary bulk precipitates at the LPSO phase was observed in both alloys and at all testing conditions which facilitated the cracking during deformation. More continuous second phase at the interdendritic boundaries facilitated easy cracking in Mg–10Gd–6Zn alloy and hence reduced the creep performance. %0 conference lecture %@ %A Hort, N.,Wiese, B.,Dieringa, H.,Kainer, K.U. %D 2016 %J High Tech Die Casting, HTDC 2016 %N %P %T Protecting molten Magnesium and its alloys %U %X %0 conference lecture %@ %A Maier, P.,Gonzalez, J.,Peters, R.,Feyerabend, F.,Ebel, T.,Hort, N. %D 2016 %J 8th Symposium on Biodegradable Metals for Biomedical Applications, Biometal 2016 %N %P %T Degradation morphology and pitting factor compared to degradation rate %U %X %0 conference lecture %@ %A Szakacs, G.,Mendis, C.,Tolnai, D.,Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Wolff, M.,Schmidt-Fetzer, R.,Schell, N.,Kainer, K.U.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T As solidified microstructure investigation of Mg15Y and MgxYyGd (x+y=15 wt.%) ternary alloys %U %X %0 conference lecture %@ %A Schmid-Fetzer, R.,Kozlov, A.,Wiese, B.,Mendis, C.L.,Tolnai, D.,Kainer, K.U.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 67-72 %R doi:10.1002/9781119274803.ch15 %T Thermodynamic Description of Reactions between Mg and CaO %U https://doi.org/10.1002/9781119274803.ch15 %X CaO is considered as possible replacement for cover gases such as SF6 during melting and casting of Mg alloys. Such CaO additions to molten Mg increase the ignition resistance by forming a protective oxide layer. The actual reactions between liquid Mg and CaO are not well understood. An approach based on chemical reaction equations cannot capture the "CaO dissolution" process. This work presents the development of a consistent thermodynamic description of the ternary Mg-Ca-O alloy system. To that end a revision of the thermodynamic data of key oxides, CaO and MgO, has been performed based on original experimental work so far not considered in thermodynamic databases or tabulations. The formation of a liquid Mg-Ca-[O] alloy during the reaction is predicted from the thermodynamic calculations at melting temperatures; solidification simulations are also performed. These predictions from thermodynamic simulations are validated by experimental data using in situ synchrotron radiation diffraction. %0 conference lecture %@ %A Tolnai, D.,Staron, P.,Staeck, A.,Eckerlebe, H.,Schell, N.,Mueller, M.,Groebner, J.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T In Situ Synchrotron Radiation Diffraction of The Solidification of Mg-Dy(-Zr) Alloys %U %X %0 conference paper %@ %A Tolnai, D.,Staron, P.,Staeck, A.,Eckerlebe, H.,Schell, N.,Mueller, M.,Groebner, J.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 15-21 %R doi:10.1002/9781119274803.ch6 %T In Situ Synchrotron Radiation Diffraction of The Solidification of Mg-Dy(-Zr) Alloys %U https://doi.org/10.1002/9781119274803.ch6 %X Mg-Dy alloys are attractive for biomaterial applications. Their mechanical property profile is close to that of cortical bone, they are non-toxic, osseoconductive and degradable. Their macroscopic characteristics depend on their microstructure, which can be tailored through the alloy composition and the solidification parameters. In situ synchrotron radiation diffraction is a tool to unequivocally follow the phase formation and grain growth during cooling, thus determining the solidification sequence. In the present study Mg alloys containing Dy and Zr were investigated to characterize the solidification phenomenon during cooling from 660°C to 200°C. Samples, contained in steel crucibles, were melted in a modified induction furnace for in situ synchrotron radiation measurements at the HZG beamline P07B (HEMS) at PETRA III, DESY, with the temperature controlled by type K thermocouples during the measurements. The results give an experimental validation of the thermodynamic calculations and input for refining the existing thermodynamic models. This contributes to a better understanding of the microstructure evolution thus to control desirable macroscopic characteristics. %0 conference paper %@ %A Szakacs, G.,Mendis, C.,Tolnai, D.,Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Wolff, M.,Schmidt-Fetzer, R.,Schell, N.,Kainer, K.U.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 23-27 %R doi:10.1002/9781119274803.ch7 %T As solidified microstructure investigation of Mg15Y and MgxYyGd (x+y=15 wt.%) ternary alloys %U https://doi.org/10.1002/9781119274803.ch7 %X MgxYyGd (x+y=15 wt.%) alloys were produced via permanent mould casting to investigate the microstructure evolution during solidification of the ternary system The microstructure of the as-solidified samples was characterized with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In situ synchrotron radiation diffraction experiments were performed during the solidification of the alloys at the P07 (HEMS) Beamline of PETRA III at DESY. The phase evolution observed during controlled cooling at 20 and 100 K/min and the resultant microstructures were compared with the as-cast conditions. The experimental results were correlated with the calculations from the Pandat thermodynamic software. In the case of the ternary alloys the equilibrium phase diagram suggests the formation of the Mg24Y5 phase at elevated temperatures followed by the formation of the Mg5Gd phase at eutectic temperatures. However, the experiment shows only the formation of Mg24Y5 phase at eutectic temperatures even with a cooling rate (CR) of 100 K/min. %0 conference lecture %@ %A Gu, J.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T Role of SiC in Grain Refinement of Aluminum-Free Mg-Zn Alloys %U %X %0 conference paper %@ %A Gu, J.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 177-181 %R doi:10.1002/9781119274803.ch36 %T Role of SiC in Grain Refinement of Aluminum-Free Mg-Zn Alloys %U https://doi.org/10.1002/9781119274803.ch36 %X The addition of SiC particles effectively refined the grains of a range of aluminum-free Mg-Zn alloys. Simultaneously, the corresponding mechanism of grain refinement has also been discussed. In the present work the effect of SiC on the microstructure of as-cast Mg-Zn alloy was investigated using optical and scanning electron microscopy. The results show that the primary alloying element Zn segregates at the grain boundaries and the phase Mg7Zn3 locates inside Mg matrix of Mg-Zn grains. The efficiency of SiC as a grain refiner can be seen with 45% average grain size reduction of Mg-3Zn alloy at 0.3 wt% SiC addition, indicating an existence of close relationship between the contents of SiC and Zn to affect the grain size. The interaction between SiC and the impurities such as Mn and Fe in Mg-Zn alloys is suggested to explain the grain refinement. %0 conference lecture %@ %A Schmid-Fetzer, R.,Kozlov, A.,Wiese, B.,Mendis, C.L.,Tolnai, D.,Kainer, K.U.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %R doi:10.1002/9781119274803.ch15 %T Thermodynamic Description of Reactions between Mg and CaO %U https://doi.org/10.1002/9781119274803.ch15 %X %0 journal article %@ 0013-4686 %A Lu, X.,Blawert, C.,Huang, Y.,Ovri, H.,Zheludkevich, M.L.,Kainer, K.U. %D 2016 %J Electrochimica Acta %N %P 20-33 %R doi:10.1016/j.electacta.2015.11.033 %T Plasma electrolytic oxidation coatings on Mg alloy with addition of SiO2 particles %U https://doi.org/10.1016/j.electacta.2015.11.033 %X The addition of particles into plasma electrolytic oxidation (PEO) electrolyte provides a possibility to produce functionalized coatings with a wider range of compositions and new phases. In this study, nano- and micro-sized SiO2 particles were in-situ incorporated into phosphate-based coatings and the effect of these particles on the microstructure, composition and properties of the coatings was investigated. It was observed that the size and the melting point of the particles have a synergistic effect on the uptake and incorporation mode. The uptake of the nanoparticles occurred mainly via discharge channels and open pores, while micro-sized particles were mainly absorbed via the coating surface. Different particle properties result in reactive and inert incorporation for the nano- and micro-sized SiO2 particles, respectively. The results show that particle additions improve the wear resistance of PEO coating, although corrosion resistance is slightly reduced. Due to superior wear performance and degradability, PEO coatings with reactively incorporated nanoparticles on Mg alloy might be suitable for bio-medical application. %0 journal article %@ 0022-2461 %A Song, J.,Wang, Z.,Huang, Y.,Srinivasan, A.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2016 %J Journal of Materials Science %N 5 %P 2687-2704 %R doi:10.1007/s10853-015-9583-y %T Hot tearing characteristics of Mg–2Ca–xZn alloys %U https://doi.org/10.1007/s10853-015-9583-y 5 %X Influence of Zn content (0, 0.5, 1.5, 4 and 6 wt%) on the hot tearing characteristics of Mg–2 wt% Ca alloy was investigated. The constrained rod casting (CRC) apparatus equipped with a load cell and data acquisition system was used. The initiation of hot tearing was monitored during solidification. The effect of mould temperatures (250 and 450 °C) on the hot tearing was also investigated. The formed tears were evaluated using X-ray tomography and the tear volumes were measured. Results show that hot tearing susceptibility (HTS) of Mg–2Ca–xZn (x = 0, 0.5, 1.5, 4 and 6 wt%) alloys increases with increase in Zn content up to 1.5 wt%, then decreases with further increase in the Zn content to 6 wt%. Higher initial mould temperature (450 °C) improves the hot tearing resistance. The observations on the microstructures and the fracture surfaces suggest that the hot tear initiated at the grain boundaries and propagated along them through the thin liquid film rupture and liquid metal embrittlement of solid bridges. Tear healing by low melting point eutectic liquid is also observed in some of the alloys. %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2016 %J International Conference and Expo on Magnesium, iMagCon 2016 %N %P %T Mechanical property enhancement of magnesium alloys by reinforcing with nanoparticles: A review %U %X %0 conference lecture %@ %A Xu, Y.,Ren, Z.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2016 %J 145th Annual Meeting and Exhibition, TMS 2016 %N %P %T Solid solution strengthening in Mg-Gd alloys %U %X %0 conference lecture %@ %A Xu, Y.,Ren, Z.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2016 %J Magnesium Technology 2016, TMS 2016 Supplemental Proceedings, 145th Annual Meeting and Exhibition, TMS 2016 %N %P 135-139 %R doi:10.1002/9781119274803.ch27 %T Solid solution strengthening in Mg-Gd alloys %U https://doi.org/10.1002/9781119274803.ch27 %X In order to improve mechanical properties and formability of magnesium alloys, a range of new rare earth (RE) containing alloys was developed. However, the strengthening mechanisms of RE alloys are still unclear to a certain extent. In the present work numerous Mg-Gd and Mg-Gd-0.5Zr alloys were prepared. The effects of solute Gd atoms on hardness and yield stress were investigated with its contents in the range from 0.32 to 2.57 at. %. The hardness linearly increases with the increment of Gd content. The ultimate tensile strength and tensile yield strength increase obviously after adding Gd element. The maximum values of elongation were observed for Mg10Gd and Mg2GdZr alloys, respectively. After the extraction of grain size strengthening, the yield strength of Mg-Gd alloys increases linearly with cn, where c is the Gd concentration and n=1/2 or 2/3. %0 journal article %@ 0921-5093 %A Yu, Z.,Huang, Y.,Gan, W.,Mendis, C.L.,Zhong, Z.,Brokmeier, H.-G.,Hort, N.,Meng, J. %D 2016 %J Materials Science and Engineering A %N %P 259-268 %R doi:10.1016/j.msea.2016.01.071 %T Microstructure evolution of Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy during deformation and its effect on strengthening %U https://doi.org/10.1016/j.msea.2016.01.071 %X Microstructure and texture evolutions during tensile and compression deformation of an as-extruded Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy have been investigated using in-situ synchrotron radiation diffraction and subsequent microscopy. The alloy consists of 〈View the MathML source101¯0〉 fiber texture, {View the MathML source112¯0}[0001] and {View the MathML source112¯0}〈View the MathML source101¯0〉 texture components prior to deformation. The texture evolves from [0001] to 〈View the MathML source101¯0〉 in tension, but from 〈View the MathML source101¯0〉 to [0001] in compression. The evolution of texture is attributed to the activity of the tensile twinning and non-basal 〈a〉 type slip. The tendency of texture evolution depends on the favorable texture component for the activation of above deformation modes. The grain refinement, Mg5(Gd, Y, Nd) and LPSO phases, and the texture contribute to the improvement in strength. %0 journal article %@ 0925-8388 %A Gil-Santos, A.,Moelans, N.,Hort, N.,Biest, O.van der %D 2016 %J Journal of Alloys and Compounds %N %P 123-133 %R doi:10.1016/j.jallcom.2016.01.221 %T Identification and description of intermetallic compounds in Mg–Si–Sr cast and heat-treated alloys %U https://doi.org/10.1016/j.jallcom.2016.01.221 %X The ternary Mg–Si–Sr system is experimentally investigated in this work. Twelve compositions located in the Mg rich corner of the ternary system are processed. The microstructure and phase content of the different alloys are analysed in the as-cast condition and after additional heat treatments.,Apart from the Mg matrix, various intermetallic phases are observed. The binary compounds Mg2Si and Mg17Sr2 are identified, as well as, two ternary phases MgSiSr and MgSi2Sr.The morphology and distribution of the intermetallic phases is discussed with particular interest on the ternary intermetallics MgSiSr and MgSi2Sr for which only scarce information is available in literature. The phase stability and the stability of the intermetallic phases in these alloys are discussed.,The Mg-rich side of the Mg–Si–Sr phase diagram is constructed based on descriptions of the binary phase diagrams Mg–Si, Mg–Ca and Ca–Si from literature and assuming complete solubility (i.e. a line compound) between the ternary phase MgSiSr and the binary phase Sr2Si. It is also assumed that MgSi2Sr is a stoichiometric compound. These assumptions were made based on the chemical similarities between Ca and Sr and between Si and Sn, and the similarity in crystal structures between the two studied ternary compounds of the Mg–Si–Sr diagram and the ternary compounds present in the Ca–Mg–Si and Mg–Sn–Sr system. A good agreement is found between the constructed phase diagram and the experimental results. %0 journal article %@ 1742-7061 %A Tie, D.,Guan, R.,Liu, H.,Cipriano, A.,Liu, Y.,Wang, Q.,Huang, Y.,Hort, N. %D 2016 %J Acta Biomaterialia %N %P 455-467 %R doi:10.1016/j.actbio.2015.11.014 %T An in vivo study on the metabolism and osteogenic activity of bioabsorbable Mg–1Sr alloy %U https://doi.org/10.1016/j.actbio.2015.11.014 %X Previous studies indicated that local delivery of strontium effectively increased bone quality and formation around osseointegrating implants. Therefore, implant materials with long-lasting and controllable strontium release are avidly pursued. The central objective of the present study was to investigate the in vivo biocompatibility, metabolism and osteogenic activity of the bioabsorbable Mg–1Sr (wt.%, nominal composition) alloy for bone regeneration. The general corrosion rate of the alloy implant as a femoral fracture fixation device was 0.55 ± 0.03 mm · y−1 (mean value ± standard deviation) in New Zealand White rabbits which meet the bone implantation requirements and can be adjusted by material processing methods. All rabbits survived and the histological evaluation showed no abnormal physiology or diseases 16 weeks post-implantation. The degradation process of the alloy did not significantly alter 16 primary indexes of hematology, cardiac damage, inflammation, hepatic functions and metabolic process. Significant increases in peri-implant bone volume and direct bone-to-implant contact (48.3% ± 15.3% and 15.9% ± 5.6%, respectively) as well as the expressions of four osteogenesis related genes (runt-related transcription factor 2, alkaline phosphatase, osteocalcin, and collagen, type I, alpha 1) were observed after 16 weeks implantation for the Mg–1Sr group when compared to the pure Mg group. The sound osteogenic properties of the Mg–1Sr alloy by long-lasting and controllable Sr release suggesting a very attractive clinical potential. %0 journal article %@ 0921-5093 %A Gavras, S.,Zhu, S.M.,Nie, J.F.,Gibson, M.A.,Easton, M.A. %D 2016 %J Materials Science and Engineering A %N %P 65-75 %R doi:10.1016/j.msea.2016.08.046 %T On the microstructural factors affecting creep resistance of die-cast Mg–La-rare earth (Nd, Y or Gd) alloys %U https://doi.org/10.1016/j.msea.2016.08.046 %X Creep properties of high-pressure die-cast Mg–La-RE (Nd, Y or Gd) alloys, varying in ternary RE additions and in different heat treatment conditions, have been investigated. Through the use of short-term solution treatments (1 h at 520 °C) it was shown that the continuous intermetallic phase present in the eutectic at grain boundaries became discontinuous. This effect, in combination with the likely removal of the localised region of supersaturated solute in solid solution near grain boundaries, reduced the creep resistance. When relatively high concentrations of ternary alloying additions were used, solid solution strengthening and precipitation hardening appeared to compensate for the negative effect of reduced grain boundary reinforcement. Microstructural investigation revealed that Nd-containing alloys had fewer and larger dynamic precipitates present in the α-Mg matrix following creep testing at 177 °C and 90 MPa. It was concluded that grain boundary reinforcement in combination with the thermal stability of the precipitates formed, which is ultimately related to the diffusivity of solute in solid solution, are also contributing factors to creep resistance. %0 conference paper %@ %A Rao, K.P.,Lam, S.W.,Hort, N.,Dieringa, H. %D 2016 %J Proceedings of 7th TSME International Conference on Mechanical Engineering, ICoME 2016 %N %P 108-113 %T High Temperature Deformation Behavior of a Newly Developed Mg Alloy Containing Al, Ba and Ca %U %X Newer magnesium alloys that showed promise of high strength and creep resistance are based on Mg-Al-Ba-Ca (ABaX) system. Al, Ba, and Ca are less expensive as alloying elements compared with rare-earth elements and are also flame retarding. ABaX844 is a candidate alloy possessing high creep strength but may pose problems of workability due to heavy alloying. In this study, the deformation characteristics of ABaX844 alloy have been studied using compression tests over a large temperature range of 300 – 500 oC and strain rate range of 0.0003 – 10 s-1 using a 6x6 experimental matrix. The alloy has exhibited two domains for hot working, requiring a minimum temperature of 340 oC and a strain rate of less than 0.2 s-1. Although the strain rate limit is relatively low compared to many other metallic materials, it is similar to the hot working range of other magnesium alloys that are being used currently. The alloy exhibited extensive dynamic recrystallization resulting in a fine-grained microstructure after hot working in these domains, and the binary and ternary intermetallic phases got well distributed at high temperatures. Also, flow instability manifesting as adiabatic shear band and flow localization occurred at strain rates >0.1 s-1. The mechanical properties of the alloy in the typical service temperature range been evaluated, and it is found that the yield strength and ultimate tensile strength are stable up to 175 oC. %0 conference lecture (invited) %@ %A Tolnai, D. %D 2016 %J Seminar der Physik Institut der Eoetvoes Lorand Universitaet %N %P %T Elevated temperature deformation behaviour of RE modified ZK40 alloys %U %X %0 journal article %@ 2213-9567 %A Huang, Y.,Yang, L.,You, S.,Gan, W.,Kainer, K.U.,Hort, N. %D 2016 %J Journal of Magnesium and Alloys %N 3 %P 173-180 %R doi:10.1016/j.jma.2016.08.002 %T Unexpected formation of hydrides in heavy rare earth containing magnesium alloys %U https://doi.org/10.1016/j.jma.2016.08.002 3 %X Mg–RE (Dy, Gd, Y) alloys show promising for being developed as biodegradable medical applications. It is found that the hydride REH2 could be formed on the surface of samples during their preparations with water cleaning. The amount of formed hydrides in Mg–RE alloys is affected by the content of RE and heat treatments. It increases with the increment of RE content. On the surface of the alloy with T4 treatment the amount of formed hydride REH2 is higher. In contrast, the amount of REH2 is lower on the surfaces of as-cast and T6-treated alloys. Their formation mechanism is attributed to the surface reaction of Mg–RE alloys with water. The part of RE in solid solution in Mg matrix plays an important role in influencing the formation of hydrides. %0 journal article %@ 1003-6326 %A Zeng, R.,Hu, Y.,Zhang, F.,Huang, Y.,Wang, Z.,Li, S.,Han, E. %D 2016 %J Transactions of Nonferrous Metals Society of China %N 2 %P 472-483 %R doi:10.1016/S1003-6326(16)64102-X %T Corrosion resistance of cerium-doped zinc calcium phosphate chemical conversion coatings on AZ31 magnesium alloy %U https://doi.org/10.1016/S1003-6326(16)64102-X 2 %X Zinc calcium phosphate (Zn–Ca–P) coating and cerium-doped zinc calcium phosphate (Zn–Ca–Ce–P) coating were prepared on AZ31 magnesium alloy. The chemical compositions, morphologies and corrosion resistance of coatings were investigated through energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), electron probe micro-analysis (EPMA) and scanning electron microscopy (SEM) together with hydrogen volumetric and electrochemical tests. The results indicate that both coatings predominately contain crystalline hopeite (Zn3(PO4)2·4H2O), Mg3(PO4)2 and Ca3(PO4)2, and traces of non-crystalline MgF2 and CaF2. The Zn–Ca–Ce–P coating is more compact than the Zn–Ca–P coating due to the formation of CePO4, and displays better corrosion resistance than the Zn–Ca–P coating. Both coatings protect the AZ31 Mg substrate only during an initial immersion period. The micro-galvanic corrosion between the coatings and their substrates leads to an increase of hydrogen evolution rate (HER) with extending the immersion time. The addition of Ce promotes the homogenous distribution of Ca and formation of hopeite. The Zn–Ca–Ce–P coating has the potential for the primer coating on magnesium alloys. %0 journal article %@ 1738-494X %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2016 %J Journal of Mechanical Science and Technology %N 6 %P 2699-2705 %R doi:10.1007/s12206-016-0531 %T Forging of cast Mg-3Sn-2Ca-0.4Al-0.4Si magnesium alloy using processing map %U https://doi.org/10.1007/s12206-016-0531 6 %X Mg-3Sn-2Ca (TX32) alloy has good creep resistance but limited workability. Minor amounts of Al and Si have been added to TX32 for improving its hot workability. The processing map for the TX32-0.4Al-0.4Si alloy exhibited two workability domains in the temperature and strain rate ranges: (1) 310-415°C/0.0003-0.003 s-1 and (2) 430-500°C/0.003-3 s-1. The alloy exhibited flow instability at temperatures < 350°C at strain rates > 0.01 s-1. The alloy has been forged to produce a cup shape component to validate these findings of processing map. Finite-element (FE) simulation has been performed for obtaining the local variations of strain and strain rate within the forging. The microstructures of the forged components under the optimal domain conditions revealed dynamically recrystallized grains, and those forged in the flow instability regime have fractured and exhibited flow localization bands and cracks. The experimental loadstroke curves correlated well with those obtained by FE simulation. %0 journal article %@ 1438-1656 %A Easton, M.A.,Zhu, S.,Abbott, T.B.,Dargusch, M.,Murray, M.,Savage, G.,Hort, N.,Gibson, M.A. %D 2016 %J Advanced Engineering Materials %N 6 %P 953-962 %R doi:10.1002/adem.201500407 %T Evaluation of Magnesium Die-Casting Alloys for Elevated Temperature Applications: Castability %U https://doi.org/10.1002/adem.201500407 6 %X This paper presents a thorough evaluation of the castability of the most common Mg die-casting alloys developed for elevated temperature applications. The alloys evaluated include AS31, AJ52, MRI153A, MRI153M, MRI230D, AXJ530, AE44, and AM-HP2plus. Among the various alloys evaluated, AE44, MRI153A, and AS31 are found to have better castability than the other alloys. AM-HP2plus also has acceptable castability, but it shows signs of hot tearing in some samples. The alloys containing significant levels of Ca, such as MRI153M, MRI230D, and AXJ530, tend to oxidize rapidly, leading to poor melt handling. The comparison of the castability of the selected alloys sheds some light on alloying elements that are of greatest importance in developing a castable alloy. %0 conference object %@ 1473-2262 %A Wohlfender, F.,Saxer, S.,Wiese, B.,Rueegg, J.,Dietschy, A.,Schumacher, R.,de Wild, M. %D 2016 %J European Cells and Materials %N S1 %P 24 %T Preliminary microstructural investigation of Mg cubes produced by SLM %U S1 %X No abstract %0 doctoral thesis %@ %A Wiese, B. %D 2016 %J %N %P %R doi:10.21268/20170504-133828 %T The Effect of CaO on Magnesium and Magnesium Calcium Alloys (Dissertation) %U https://doi.org/10.21268/20170504-133828 %X %0 journal article %@ 1044-5803 %A Medina, J.,Perez, P.,Garces, G.,Tolnai, D.,Stark, A.,Schell, N.,Adeva, P. %D 2016 %J Materials Characterization %N %P 186-198 %R doi:10.1016/j.matchar.2016.05.019 %T Microstructural changes in an extruded Mg-Zn-Y alloy reinforced by quasicrystalline I-phase by small additions of calcium, manganese and cerium-rich mischmetal %U https://doi.org/10.1016/j.matchar.2016.05.019 %X The effects of calcium, manganese and cerium-rich mischmetal additions on the microstructure and texture of the extruded Mg6Zn1Y (wt.%) alloy have been investigated. The microstructure of the alloys consisted of a magnesium matrix embedding second phase particles aligned along the extrusion direction. The nature and volume fraction of the second phases depended on the alloying element. Thus, Ce-rich mischmetal promoted the formation of T-phase while calcium additions resulted in the formation of a ternary MgZnCa compound. Only, manganese additions did not affect the existence of the I-phase present in the ternary alloy. The texture was measured and it was found that calcium addition has a significant effect weakening the extrusion texture. %0 conference object %@ 1473-2262 %A Steinacker, A.,Mendis, C.L.,Mohedano, M.,Feyerabend, F.,Stekker, M.,Maier, P.,Kainer, K.U.,Hort, N. %D 2016 %J European Cells and Materials %N 6 %P 11 %T Microstructure evolution and corrosion behaviour of the biodegradable EZK1110 alloy %U 6 %X No abstract %0 conference lecture %@ %A Steinacker, A.,Mendis, C.L.,Mohedano, M.,Feyerabend, F.,Stekker, M.,Maier, P.,Kainer, K.U.,Hort, N. %D 2016 %J 8th Symposium on Biodegradable Metals for Biomedical Applications, Biometal 2016 %N %P %T Microstructure evolution and corrosion behaviour of the biodegradable EZK1110 alloy %U %X %0 conference object %@ 1473-2262 %A Maier, P.,Gonzalez, J.,Peters, R.,Feyerabend, F.,Ebel, T.,Hort, N. %D 2016 %J European Cells and Materials %N S 6 %P 22 %T Degradation morphology and pitting factor compared to degradation rate %U S 6 %X No abstract %0 journal article %@ 2193-0651 %A Myrissa, A.,Martinalli, E.,Szakacs, G.,Berger, L.,Eichler, J.,Fischerauer, S.F.,Kleinhans, C.,Hort, N.,Schaefer, U.,Weinberg, A.M. %D 2016 %J BioNanoMaterials %N 3-4 %P 121-130 %R doi:10.1515/bnm-2016-0006 %T In vivo degradation of binary magnesium alloys – a long-term study %U https://doi.org/10.1515/bnm-2016-0006 3-4 %X Bioresorbable magnesium materials are widely investigated because of their promising properties as orthopedic devices. Pure magnesium (99.99%) and two binary magnesium alloys (Mg2Ag and Mg10Gd) were used to investigate the degradation behavior, the bone adherence and bone-implant interface mechanics of these materials in growing Sprague-Dawley® rats in a long-term study of 36 weeks. In vivo micro-computed tomography (μCT) scans were performed at specific time points to observe the longitudinal degradation of each alloy within the same animal. Pin volume and surface, gas volume and degradation rates were calculated. The results showed a slower degradation of pure magnesium and Mg2Ag in comparison to the fast disintegrating Mg10Gd. Changes in bone morphology were determined by high resolution ex vivo μCT scans and bone sections stained with Toluidine blue. Pure magnesium and Mg2Ag were well integrated and surrounded by bony tissue 24 weeks after implantation. On the contrary, Mg10Gd remnants were surrounded by fibrous and bone tissue. Push-out tests revealed higher bone-implant-interface strengths of pure magnesium pins compared to Mg2Ag and Mg10Gd. Mg10Gd induces less beneficial tissue reactions, while Mg2Ag showed adequate biodegradation and no adverse reactions in bone healing process which might be promising as an orthopedic device. %0 lecture %@ %A Hort, N. %D 2016 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 lecture %@ %A Hort, N. %D 2016 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 journal article %@ 1044-5803 %A Garces, G.,Requena, G.,Tolnai, D.,Perez, P.,Medina, J.,Stark, A.,Schell, N.,Adeva, P. %D 2016 %J Materials Characterization %N %P 514-518 %R doi:10.1016/j.matchar.2016.06.032 %T Formation of an 18R long-period stacking ordered structure in rapidly solidified Mg88Y8Zn4 alloy %U https://doi.org/10.1016/j.matchar.2016.06.032 %X The formation of the long-period stacking ordered structure (LPSO) in a Mg88Y8Zn4(at%) ribbon produced by melt spinning was studied using high energy X-ray synchrotron radiation diffraction during in-situ isochronal heating and transmission electron microscopy. The microstructure of the rapidly solidified ribbons is characterised by fine magnesium grains with yttrium and zinc in solid solution and primary 18R LPSO-phase segregated at grain boundaries. Using differential scanning calorimetry, a strong exothermal peak was observed around 300 °C which was associated with the development of the 18R-type LPSO-phase in the magnesium grains. The apparent activation energy calculated using the Kissinger model was 125 KJmol− 1 and it is related to simultaneous diffusion of Y and Zn through magnesium basal plane. %0 conference lecture %@ %A Rao, K.P.,Bagheripoor, M.,Dieringa, H.,Hort, N. %D 2016 %J 13th Asia-Pacific Symposium on Engineering Plasticity and its Applications, AEPA 2016 %N %P %T High Temperature Deformation of Cast ZW11 Magnesium Alloy with Very Large Grain Size %U %X %0 journal article %@ 1047-4838 %A Tolnai, D.,Buzolin, R.H.,D`Elia, F.,Subroto, T.,Gavras, S.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2016 %J JOM: Journal of the Minerals, Metals and Materials Society %N 12 %P 3051-3056 %R doi:10.1007/s11837-016-2159-8 %T The Role of Zn on the Elevated Temperature Compression Behavior of Mg5Nd: An In Situ Synchrotron Radiation Diffraction Study %U https://doi.org/10.1007/s11837-016-2159-8 12 %X As-cast Mg5Nd, Mg5Nd3Zn, Mg5Nd5Zn and Mg5Nd7Zn alloys were investigated with in situ synchrotron radiation diffraction during compression at 350°C. The results and the post-mortem microscopy investigations suggest that twinning was active during deformation, and was most pronounced in the binary alloy whereas in the ternary alloys grain rotation could be observed. Sub-grain formation could be detected in all the alloys. The reinforcing capacity of the intermetallic network was the largest in Mg5Nd and Mg5Nd3Zn. %0 conference lecture %@ %A Schmid-Fetzer, R.,Kozlov, A.,Wiese, B.,Mendis, C.,Tolnai, D.,kainer, K.U.,Hort, N. %D 2016 %J Materials Science and Engineering, MSE 2016 %N %P %T Thermodynamic description of reactions between Mg and CaO %U %X %0 conference paper %@ %A Rao, K.P.,Bagheripoor, M.,Dieringa, H.,Hort, N. %D 2016 %J Proceedings of 9th Pacific Rim International Conference Advanced Materials and Processing, PRICM 9 %N %P 390-394 %T High Temperature Deformation Processing of Dilute Magnesium Alloy Z1 for Bioimplant Application %U %X Magnesium alloys are under consideration as biocompatible materials because they are light weight and biodegradable or bioabsorable in body fluids without causing health hazards. Zn,is an essential micro-nutrient in the body and its bio-absorption is beneficial when an orthopedic implant corrodes in a controlled manner, as is generally the case with wrought magnesium alloys. Hot working of cast material is an essential step towards obtaining optimal microstructure. In this investigation, the hot working behavior of Mg-1Zn alloy has been,investigated in the temperature range 300 – 500 oC and strain rate range 0.0003 – 10 s-1 with a view to evaluate the optimum processing parameters. A processing map has been developed on the basis of the flow stress data obtained from compression tests. The processing map reveals a narrow window of workability at low strain rates and a wide regime of flow instability,that should be avoided while forming this alloy. %0 conference lecture %@ %A Rao, K.P.,Bagheripoor, M.,Dieringa, H.,Hort, N. %D 2016 %J 9th Pacific Rim International Conference Advanced Materials and Processing, PRICM 9 %N %P %T High Temperature Deformation Processing of Dilute Magnesium Alloy Z1 for Bioimplant Application %U %X %0 conference lecture %@ %A Rao, K.P.,Lam, S.W.,Hort, N.,Dieringa, H. %D 2016 %J 7th TSME International Conference on Mechanical Engineering, ICoME 2016 %N %P %T High Temperature Deformation Behavior of a Newly Developed Mg Alloy Containing Al, Ba and Ca %U %X %0 journal article %@ 0268-3768 %A Huang, Y.,Wang, Y.,Wan, L.,Liu, H.,Shen, J.,dos Santos, J.F.,Zhou, L.,Feng, J. %D 2016 %J The International Journal of Advanced Manufacturing Technology %N 1 %P 1115-1123 %R doi:10.1007/s00170-016-8603-7 %T Material-flow behavior during friction-stir welding of 6082-T6 aluminum alloy %U https://doi.org/10.1007/s00170-016-8603-7 1 %X Material-flow behavior during friction-stir welding of 6082-T6 aluminum alloy has been visualized by marker insert technique. Four stacked layers were evolved in welding nugget zone (WNZ) in the transverse section. The material-flow behavior in vertical direction was detected by observing the distribution of Cu foil fragments and Al-Cu intermetallic compounds. The downward and upward flows encounter each other at the advancing side in the material depositing process, changing the morphology of WNZ. A conceptual balanced-flow model and a plastic material-flow model were used to describe the material-flow behavior, and the origin of the downward material flow in the advancing side was discussed. The excess-material flow derived by the welding tool due to the existence of the tilt angle is crucial to the weld formation. %0 conference lecture (invited) %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2015 %J European Congress and Exhibition on Advanced Materials and Processes, EUROMAT 2015 %N %P %T Magnesium Matrix Composites - Challenges and Opportunities %U %X %0 journal article %@ 0261-3069 %A Song, J.,Wang, Z.,Huang, Y.,Srinivasan, A.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2015 %J Materials and Design %N %P 157-170 %R doi:10.1016/j.matdes.2015.08.026 %T Effect of Zn addition on hot tearing behaviour of Mg–0.5Ca–xZn alloys %U https://doi.org/10.1016/j.matdes.2015.08.026 %X The influence of Zn addition (0, 0.5, 1.5, 4.0 and 6.0 wt.%) on hot tearing behaviour of Mg–0.5 wt.% Ca alloy was investigated using a constrained rod casting (CRC) apparatus. The effects of mould temperature and grain refinement on the hot tearing susceptibility (HTS) were studied. Hot tears were observed with 3D X-ray tomography and the tear volumes were quantified. Results show that the Zn addition increases the HTS of Mg–0.5Ca alloys. At a mould temperature of 250 °C, all alloys investigated except Mg–0.5Ca–6Zn alloy show severe HTS. An increase in the mould temperature from 250 °C to 450 °C did not reduce the HTS in Mg–0.5Ca–1.5Zn and Mg–0.5Ca–4Zn alloys. Among all the investigated alloys, Mg–0.5Ca–4Zn alloy exhibits severe HTS as it completely broke away from the sprue–rod junction. The HTS of alloys was well correlated with the susceptible temperature range (ΔTs). An increase in ΔTs increased the HTS. The hot tears propagated along the grain boundaries through liquid film rupture. Grain refinement by Zr addition improved the hot tearing resistance of Mg–0.5Ca–4Zn alloy as the fine grain structure facilitated the easy feeding of liquid into the last area of solidification and accommodated the developed strain more effectively. %0 journal article %@ 0921-5093 %A Yu, Z.,Huang, Y.,Dieringa, H.,Mendis, C.L.,Guan, R.,Hort, N.,Meng, J. %D 2015 %J Materials Science and Engineering A %N %P 213-224 %R doi:10.1016/j.msea.2015.08.001 %T High temperature mechanical behavior of an extruded Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy %U https://doi.org/10.1016/j.msea.2015.08.001 %X The microstructure–property relation of an extruded Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy was investigated by conducting hot compression and high temperature creep at temperatures upto 250 °C. The alloy exhibits an average compressive yield strength (σCYSσCYS) of 363±1 MPa and an average elongation to failure (εCFεCF) of 10.5±0.2% at room temperature, 301±13 MPa and 12.8±1.1% at 200 °C. In creep the minimum creep strain rate (View the MathML sourceε̇min) is 1.94×10−9 s−1 at 175 °C/160 MPa and 6.67×10−9 s−1 at 200 °C/100 MPa. The obtained stress exponent n is in the range of 3.7–4.7, suggesting that the creep is controlled by the dislocation climb mechanism. The improvement in compressive strength and creep resistance is attributed to the fine recrystallized grains, SFs in the grain interior, Mg5RE and LPSO phases at grain boundaries. The alloy exhibits a bimodal texture with 〈0001〉 and 〈View the MathML source101¯0〉 components. Its strengthening effect is determined by the competition between these two texture components. In compressive deformation, the textural evolution from 〈View the MathML source101¯0〉 to 〈0001〉 is mainly attributed to the operation of basal 〈a〉 slip and {View the MathML source101¯2}〈View the MathML source101¯1〉 tensile twinning. This texture evolution is not seen in creep. %0 conference lecture %@ %A Szakacs, G.,Mendis, C.,Wiese, B.,Stark, A.,Kainer, K.U.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T In situ synchroton radiation diffraction during solidification of Mg4Y2Nd and Mg4Y2Ag1Nd alloys %U %X %0 conference paper %@ %A Hort, N.,Wiese, B.,Dieringa, H.,Kainer, K.U. %D 2015 %J Light Metals Technology 2015, 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P 78-81 %T Magnesium Melt Protection %U %X %0 conference paper %@ %A Maier, P.,Peters, R.,Szakacs, G.,Hort, N. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 376-381 %T Role of post-heat treatment on hardness, bending strength and corrosion of Mg4Gd wire compared to pure Mg wire %U %X Mg4Gd wires in as-drawn condition show strong local corrosion, which greatly reduces the remaining,tensile and bending strength. The initial strength and ductility is rather high due to the fine grained microstructure as a result of recrystallization during the complex forming procedures. Small grains and intermetallics increase strength. However, intermetallics have a pronounced influence on corrosion. Pitting can be either caused by,microgalvanic corrosion or by forming passive layers (here not stable enough). Mechanical and corrosion properties are studied using microhardness, tensile- and bending tests, corrosion itself and stress corrosion (Ringer solution, 37°C) in comparison with as-drawn and T4 material. T4 relieves inner stress and leads to less anodiccathodic,coupling due to dissolved intermetallics. Hardness increase caused by tensile and compressive stresses during 3-point-bending has been investigated as well as its influence on corrosion. Tensile stresses cause open pores within the oxide layer and accelerate corrosion. Mechanical and corrosive properties are compared to pure Mg wires. Post-heat treatment tailors properties between higher strength, but higher corrosion rate (as-drawn), and,less strength, but lower corrosion rate (T4) and influences the life time in stress corrosion. Stress corrosion,cracking is either driven by continuous cracking resulting in dissolution within crack front or by cleavage fracture leading to discontinuous crack propagation. An improvement of corrosion behavior by post-heat treatment is seen. %0 journal article %@ 0972-8279 %A Charyeva, O.,Thormann, U.,Lips, K.S.,Heimann, L.,Sommer, U.,Szalay, G.,Alt, V.,Hort, N.,Schnettler, R.,Rauschmann, M.,Schmidt, S. %D 2015 %J Journal of Maxillofacial and Oral Surgery %N 3 %P 637-645 %R doi:10.1007/s12663-015-0743-z %T Histological Comparison of New Biodegradable Magnesium-Based Implants for Maxillofacial Applications %U https://doi.org/10.1007/s12663-015-0743-z 3 %X Background,A variety of materials have been used for bone augmentation, distraction osteotomy, and in post-cancer patients following tumor removal. However, a temporary metal implant that would resorb after successful treatment is a new concept. Magnesium was suggested as a suitable material for these purposes because it is biocompatible, has better mechanical properties than titanium, and stimulates new bone formation. This study evaluates histological appearance of magnesium-based implants and the surrounding bone.,Materials and Methods,Three magnesium-based biomaterials were tested in a rabbit bone defect model: magnesium–hydroxyapatite (Mg–HA), W4 (96 % magnesium, 4 % yttrium), and pure magnesium (pure Mg). Animals were sacrificed after 6 and 12 weeks and the samples were analyzed histologically and histomorphometrically.,Results,Mg–HA had the highest mean amount of tartrate-resistant acid phosphatase (TRAP) positive cells at the implantation site of all groups. It had shown the fastest degradation rate already at 6 weeks but the least amount of new bone formation. New bone was seen forming in direct contact with pure Mg and W4. The mean gas volume was highest in W4 compared to pure Mg and Mg–HA but this difference was not statistically significant. W4 had the lowest mean number of TRAP-positive cells of all materials.,Conclusion,Pure Mg and W4 were shown to be the most promising materials in this study in respect to the bone response to the implant material. They could be used for screws and plates in bone augmentation procedures. %0 journal article %@ 0921-5093 %A Buzolin,R.H.,Tolnai, D.,Mendis, C.L.,Stark, A.,Schell, N.,Pinto, H.,Kainer, K.U.,Hort, N. %D 2015 %J Materials Science and Engineering A %N %P 129-136 %R doi:10.1016/j.msea.2015.05.096 %T In situ synchrotron radiation diffraction study of the role of Gd, Nd on the elevated temperature compression behavior of ZK40 %U https://doi.org/10.1016/j.msea.2015.05.096 %X As-cast ZK40, ZK40-2Gd and ZK40-2Nd Mg alloys were investigated by in situ synchrotron radiation diffraction during compression at elevated temperature. The addition of rare earth elements increased the compressive yield strength from 23 MPa in the ZK40 alloy up to 40 MPa in the alloy with Nd or Gd. The azimuthal angle–time plots and electron back scattered diffraction maps from the compressed samples reveal that all the three alloys deform by grain rotation and crystallographic slip to obtain the final texture after compression. Continuous dynamic recrystallization played an important role in the ZK40 alloy during deformation, while twinning was not dominant. Discontinuous dynamic recrystallization was observed in the ZK40-2Gd. In the ZK40-2Gd and ZK40-2Nd alloys twinning also plays an important role during deformation at 350 °C. It is proposed that the pinning of the grain boundaries by the intermetallic phases was a main factor responsible for the observed differences in the deformation behavior. %0 journal article %@ 0255-5476 %A Dieringa, H.,Das, S.,Eskin, D.,Fan, Z.,Katsarou, L.,Horstmann, M.,Kurz, G.,Mendis, C.,Hort, N.,Kainer, K.U. %D 2015 %J Materials Science Forum, Light Metals Technology 2015 %N %P 35-40 %R doi:10.4028/www.scientific.net/MSF.828-829.35 %T Twin-roll Casting after Intensive Melt Shearing and Subsequent Rolling of an AM30 Magnesium Alloy with Addition of CaO and SiC %U https://doi.org/10.4028/www.scientific.net/MSF.828-829.35 %X Intensive melt shearing is a process that can be used for mixing ceramic particles into magnesium melt. It applies shear stress to the melt and can de-agglomerate nanoparticle additions to magnesium melts without the use of electromagnetic fields or ultrasound. A wrought magnesium alloy AM30 was selected for processing with intensive melt shearing and subsequent twin-roll,casting. AM30 with additions of CaO and SiC were also processed by this route and the hardness and microstructure were investigated. Sheets were rolled and their tensile strength was determined.,The work was done as part of the European Union research project ExoMet. Its target includes the,production of high-performance magnesium-based materials by exploring novel grain refinement,and nanoparticle addition in conjunction with melt treatment by means of external fields. %0 conference paper %@ %A Dieringa, H.,Das, S.,Eskin, D.,Fan, Z.,Katsarou, L.,Horstmann, M.,Kurz, G.,Mendis, C.,Hort, N.,Kainer, K.U. %D 2015 %J Light Metals Technology 2015, 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P 35-40 %T Twin-roll Casting after Intensive Melt Shearing and Subsequent Rolling of an AM30 Magnesium Alloy with Addition of CaO and SiC %U %X %0 conference lecture %@ %A Wiese, B.,Mendis, C.,Kainer, K.U.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Can defects improve properties of metallic biomaterials %U %X %0 journal article %@ 1598-9623 %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2015 %J Metals and Materials International %N 1 %P 134-146 %R doi:10.1007/s12540-015-1016-6 %T Comparative study of microstructure and texture of cast and homogenized TX32 magnesium alloy after hot deformation %U https://doi.org/10.1007/s12540-015-1016-6 1 %X The effect of homogenization on the hot deformation behavior and texture evolution of Mg-3Sn-2Ca (TX32) alloy is investigated. The cast-homogenized alloy samples were hot compressed in the temperature and strain rate ranges of 300–500 °C and 0.0003–10 s−1, respectively, and a processing map has been developed by using the flow stress data. The map revealed two dynamic recrystallization (DRX) domains with a peak efficiency of 44% at 360 °C/0.0003 s−1 (Domain 1) and 43% at 485 °C/0.1 s−1 (Domain 2). When compared with the map for as-cast condition, it is observed that both the domains moved towards higher temperatures although the shift of Domain 1 is more noticeable. The apparent activation energy values in the two domains and the regime of flow instability are nearly unchanged by homogenization, suggesting that Mg2Ca and CaMgSn particles in the microstructure are thermally stable. Specimens deformed under conditions in Domain 1 have high Schmid factors for {0001} ⟨112 ¯ 0⟩ basal slip and {11 ¯ 00} ⟨112 ¯ 0⟩ prismatic slip, while in Domain 2 the deformation progressed due to {112 ¯ 2 ¯ } ⟨112 ¯ 3 ¯ ⟩ second-order pyramidal slip. %0 conference lecture %@ %A Hort, N.,Mendis, C.,Maier, P. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Phase Diagrams: Which information you can get from them for alloy and process design? %U %X %0 conference object %@ %A Wiese, B.,Mendis, C.,Kainer, K.U.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-23 %T Can defects improve properties of metallic biomaterials %U %X %0 conference object %@ %A Hort, N.,Mendis, C.,Maier, P. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-18 %T Phase Diagrams: Which information you can get from them for alloy and process design? %U %X %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Microstructure of as-cast and T4 heat-treated Mg2Gd-x(Ag,Ca) ternary alloys %U %X %0 conference object %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-19 %T Microstructure of as-cast and T4 heat-treated Mg2Gd-x(Ag,Ca) ternary alloys %U %X %0 conference object %@ 1473-2262 %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 19 %T Microstructure of as-cast and T4 heat-treated Mg2Gd-x(Ag,Ca) ternary alloys %U S 3 %X No abstract %0 journal article %@ 0255-5476 %A Hort, N.,Wiese, B.,Dieringa, H.,Kainer, K.U. %D 2015 %J Materials Science Forum, Light Metals Technology 2015 %N %P 78-81 %R doi:10.4028/www.scientific.net/MSF.828-829.78 %T Magnesium Melt Protection %U https://doi.org/10.4028/www.scientific.net/MSF.828-829.78 %X Mg especially in the molten state is well known for its high affinity to O2. When O2 content of the atmosphere is larger than 4%, molten Mg will burn! To avoid this, melt protection is necessary. At present mostly SF6 is used during primary production and processing of Mg and its alloys. Unfortunately SF6 is a very potent greenhouse gas that is > 23,000 times more effective than CO2. This also affects life cycle considerations e.g. for the use of Mg alloys in transportation.,However, other protective gases like SO2 or fluorinated hydrocarbons like HFC134a, Novec 612, or AMCover (=HFC134a) have been suggested to replace SF6. Additionally fluxes mixed from,different salts may be used again as well to protect molten Mg. But fluxes and feasible replacements,of SF6 also have disadvantages. Moreover SF6 and other fluorinated hydrocarbons are under,discussion especially in Europe. There is an existing EU legislation that will ban SF6 from 2018 and,there are similar discussions regarding all other fluorinated hydrocarbons. Due to this, new innovative ways have to be found or old methods have to be renewed to allow Mg industries further safe processing of molten magnesium. This contribution will report the state of the art in protecting molten Mg and alternatives to the use of SF6. %0 conference object %@ 1473-2262 %A Szakacs, G.,Mendis, C.,Wiese, B.,Stark, A.,Kainer, K.U.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 22 %T In situ synchroton radiation diffraction during solidification of Mg4Y2Nd and Mg4Y2Ag1Nd alloys %U S 3 %X No abstract %0 conference object %@ %A Szakacs, G.,Mendis, C.,Wiese, B.,Stark, A.,Kainer, K.U.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-22 %T In situ synchroton radiation diffraction during solidification of Mg4Y2Nd and Mg4Y2Ag1Nd alloys %U %X %0 conference lecture %@ %A Dieringa, H.,Das, S.,Eskin, D.,Fan, Z.,Katsarou, L.,Horstmann, M.,Kurz, G.,Mendis, C.,Hort, N.,Kainer, K.U. %D 2015 %J 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P %T Twin-roll Casting after Intensive Melt Shearing and Subsequent Rolling of an AM30 Magnesium Alloy with Addition of CaO and SiC %U %X %0 conference lecture %@ %A Gil-Santos, A.,Szakacs, G.,Moelans, N.,Hort, N.,Biest, O.van der %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T Correlation between mechanical behaviour and microstructure in the Mg-Ca-Si-Sr system for degradable biomaterials based on thermodynamic calculations %U %X %0 conference lecture %@ %A Hort, N.,Wiese, B.,Dieringa, H.,Kainer, K.U. %D 2015 %J 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P %T Magnesium Melt Protection %U %X %0 conference lecture %@ %A Maier, P.,Szakacs, G.,Wala, M.,Hort, N. %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T Mechanical and Corrosive Properties of Two Magnesium Wires: Mg4Gd and Mg6Ag %U %X %0 journal article %@ 0925-8388 %A Wiese, B.,Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Reichel, H.-P.,Brueckner, R.,Kainer, K.U.,Hort, N. %D 2015 %J Journal of Alloys and Compounds %N %P 64-66 %R doi:10.1016/j.jallcom.2014.08.151 %T CaO dissolution during melting and solidification of a Mg–10 wt.% CaO alloy detected with in situ synchrotron radiation diffraction %U https://doi.org/10.1016/j.jallcom.2014.08.151 %X The phase dissolution and evolution during the melting and the solidification of Mg containing 10 wt.% CaO was investigated in the temperature range of 20–680 °C. The dissolution of CaO and the formation of Mg2Ca were detected with in situ synchrotron radiation diffraction. The dissolution of CaO was observed at ∼407 °C with the detection of a peak unique to the Mg2Ca phase prior to melting of Mg. After the solidification no CaO was detected, and Mg2Ca and MgO phases were observed. %0 journal article %@ 1013-9826 %A Huang, Y.,Dieringa, H.,Kainer, K.U.,Hort, N. %D 2015 %J Key Engineering Materials, Advances in Fracture and Damage Mechanics XIII %N %P 365-368 %R doi:10.4028/www.scientific.net/KEM.627.365 %T Deformation-induced dynamic precipitation during creep in magnesium-tin alloys %U https://doi.org/10.4028/www.scientific.net/KEM.627.365 %X The oversaturated solutes in the alloy matrix, which are caused by nonequilibrium phase transformation during casting or T4 treatment, can precipitate in the subsequent annealing treatments or during service at high temperatures. Under deformation the precipitation could be enhanced in comparison to conventional isothermal ageing. The present work investigates the dynamic precipitation of oversaturated Mg-Sn alloys during creep. The influence of this dynamic precipitation on creep properties is discussed. It is found that the distribution of deformation-induced precipitates is inhomogeneous. These precipitates are first formed at grain boundaries and then at deformation bands which are kinetically and thermodynamically favourable. The dynamic precipitation accompanies the volume change of phases, which influences the subsequent formation and growth of voids. Consequently, the creep behaviour also changes due to different precipitation under deformation. %0 journal article %@ 0921-5093 %A Yu, Z.,Huang, Y.,Mendis, C.L.,Hort, N.,Meng, J. %D 2015 %J Materials Science and Engineering A %N %P 23-31 %R doi:10.1016/j.msea.2014.11.061 %T Microstructural evolution and mechanical properties of Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr alloy prepared via pre-ageing and hot extrusion %U https://doi.org/10.1016/j.msea.2014.11.061 %X The Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy was pre-aged prior to hot extrusion. Pre-ageing treatment introduced uniform distribution of plate-like Mg5RE precipitates, which transformed into nano-scale globular Mg5RE particles by split and spheroidization during hot extrusion. These globular Mg5RE particles contributed to continuous dynamic recrystallization by promoting the evolution of low misorientation sub-grain boundaries to high misorientation grain boundaries and caused grain refinement through grain boundary pinning. The improved mechanical properties were ascribed to the grain refinement, globular Mg5RE and LPSO precipitates. The ratio of compressive to tensile yield strength is 1.2. The yield strength asymmetry was attributed to the deformation asymmetry of LPSO phase and non-isotropic deformation behaviors of Mg matrix in tension and compression. %0 conference poster %@ %A Wiese, B.,Tolnai, D.,Mendis, C.L.,Szakacs, G.,Stark, A.,Schell, N.,Reichel, H.-P.,Kainer, K.U.,Hort, N. %D 2015 %J DESY Photon Science Users´ Meeting 2015 %N %P %T In situ diffraction of CaO dissolution during melting and solidification of a Mg-20CaO alloy %U %X %0 journal article %@ 1751-6161 %A Shi, L.-L.,Huang, Y.,Yang, L.,Feyerabend, F.,Mendis, C.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2015 %J Journal of the Mechanical Behavior of Biomedical Materials %N %P 38-48 %R doi:10.1016/j.jmbbm.2015.03.003 %T Mechanical properties and corrosion behavior of Mg−Gd−Ca−Zr alloys for medical applications %U https://doi.org/10.1016/j.jmbbm.2015.03.003 %X Magnesium alloys are promising candidates for biomedical applications. In this work, influences of composition and heat treatment on the microstructure, the mechanical properties and the corrosion behavior of Mg−Gd−Ca−Zr alloys as potential biomedical implant candidates were investigated. Mg5Gd phase was observed at the grain boundaries of Mg−10Gd−xCa−0.5Zr (x=0, 0.3, 1.2 wt%) alloys. Increase in the Ca content led to the formation of additional Mg2Ca phase. The Ca additions increased both the compressive and the tensile yield strengths, but reduced the ductility and the corrosion resistance in cell culture medium. After solution heat treatment, the Mg5Gd particles dissolved in the Mg matrix. The compressive strength decreased, while the corrosion resistance improved in the solution treated alloys. After ageing at 200 °C, metastable β’ phase formed on prismatic planes and a new type of basal precipitates have been observed, which improved the compressive and tensile ultimate strength, but decreased the ductility. %0 conference lecture %@ %A Stuepp, C.A.,Szakacs, G.,Mendis, C.,Gensch, F.,Mueller, S.,Feyerabend, F.,Hotza, D.,Fredel, M.C.,Hort, N. %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T Powder Metallurgical Synthesis of Biodegradable Mg-Hydroxyapatite Composites for Biomedical Applications %U %X %0 conference lecture %@ %A Szakacs, G.,Mendis, C.,Tolnai, D.,Stark, A.,Schell, N.,Ovri, H.,Wolff, M.,Kainer, K.U.,Groebner, J.,Schmid-Fetzer, R.,Hort, N. %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T In Situ Synchrotron Radiation Diffraction during Solidification of Mg15Gd: Effect of Cooling Rate %U %X %0 conference paper %@ %A Szakacs, G.,Mendis, C.,Tolnai, D.,Stark, A.,Schell, N.,Ovri, H.,Wolff, M.,Kainer, K.U.,Groebner, J.,Schmid-Fetzer, R.,Hort, N. %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 79-84 %T In Situ Synchrotron Radiation Diffraction during Solidification of Mg15Gd: Effect of Cooling Rate %U %X %0 conference paper %@ %A Stuepp, C.A.,Szakacs, G.,Mendis, C.,Gensch, F.,Mueller, S.,Feyerabend, F.,Hotza, D.,Fredel, M.C.,Hort, N. %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 425-429 %T Powder Metallurgical Synthesis of Biodegradable Mg-Hydroxyapatite Composites for Biomedical Applications %U %X %0 conference paper %@ %A Maier, P.,Szakacs, G.,Wala, M.,Hort, N. %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 393-398 %T Mechanical and Corrosive Properties of Two Magnesium Wires: Mg4Gd and Mg6Ag %U %X %0 journal article %@ 0034-8570 %A Garces, G.,Requena, G.,Tolnai, D.,Perez, P.,Adeva, P.,Jimenez, J.A.,Stark, A.,Schell, N. %D 2015 %J Revista de Metalurgia %N 2 %P e043 %R doi:10.3989/revmetalm.043 %T Thermal expansion behaviour of Long-Period Stacking Ordered (LPSO) phase %U https://doi.org/10.3989/revmetalm.043 2 %X The lineal thermal expansion coefficient of the 18R Long-Period Stacking Ordered (LPSO) structure was determined in the range between room temperature and 400 °C by dilatometry and synchrotron radiation diffraction. Results clearly show that the lineal thermal expansion coefficients for magnesium and the LPSO phase are similar and therefore no mismatch thermal stresses are generated at their interface in two-phase Mg-Y-Zn alloys containing this phase during thermomechanical processing. %0 conference lecture %@ %A Vogt, C.,Zimmermann, F.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Challenges for accurate determination of rare earth elements in degradable Mg alloys %U %X %0 conference paper %@ %A Gil-Santos, A.,Szakacs, G.,Moelans, N.,Hort, N.,Biest, O. van der %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 431-436 %T Correlation between mechanical behaviour and microstructure in the Mg-Ca-Si-Sr system for degradable biomaterials based on thermodynamic calculations %U %X %0 conference lecture %@ %A Buzolin,R.H.,Tolnai, D.,Mendis, C.,Stark, A.,Schell, N.,Pinto, H.,Kainer, K.U.,Hort, N. %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T Investigation of Compression Behavior of Mg-4Zn-2(Nd,Gd)-0.5Zr at 350°C by In Situ Synchrotron Radiation Diffraction %U %X %0 conference paper %@ %A Buzolin,R.H.,Tolnai, D.,Mendis, C.,Stark, A.,Schell, N.,Pinto, H.,Kainer, K.U.,Hort, N. %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 103-107 %T Investigation of Compression Behavior of Mg-4Zn-2(Nd,Gd)-0.5Zr at 350°C by In Situ Synchrotron Radiation Diffraction %U %X %0 conference lecture %@ %A Katsarou, L.,Suresh, K.,Rao, K.P.,Hort, N.,Blawert, C.,Mendis, C.,Dieringa, H. %D 2015 %J 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology %N %P %T Microstructure and Properties of Magnesium Alloy Mg-1Zn-1Ca (ZX11) %U %X %0 conference paper %@ %A Katsarou, L.,Suresh, K.,Rao, K.P.,Hort, N.,Blawert, C.,Mendis, C.,Dieringa, H. %D 2015 %J Collected Proceedings, 144th Annual Meeting & Exhibition, TMS 2015 - Magnesium Technology 2015 %N %P 419-423 %T Microstructure and Properties of Magnesium Alloy Mg-1Zn-1Ca (ZX11) %U %X %0 journal article %@ 1073-5623 %A Wang, Z.,Song, J.,Huang, Y.,Srinivasan, A.,Liu, Z.,Kainer, K.U.,Hort, N. %D 2015 %J Metallurgical and Materials Transactions A %N 5 %P 2108-2118 %R doi:10.1007/s11661-015-2755-1 %T An Investigation on Hot Tearing of Mg-4.5Zn-(0.5Zr) Alloys with Y Additions %U https://doi.org/10.1007/s11661-015-2755-1 5 %X In this work, the hot tearing susceptibility (HTS) of Mg-4.5Zn-xY (x = 0, 0.4, 0.9, 2 wt pct) alloys is investigated using constrained rod casting apparatus equipped with a load cell and data acquisition system. The effect of grain refinement by Zr addition on the HTS has also been investigated. The results show that the HTS first increases with increasing the Y content, reaches the maximum at 0.9 wt pct Y, and then reduces with further increase in the Y content to 2.0 wt pct. The high HTS observed in the alloys with 0.4 and 0.9 wt pct Y is attributed to their coarse columnar grains and their large freezing ranges. The results also suggest that the resistance to the hot tearing can apparently be improved by increasing the initial mold temperature. In addition, a fine microstructure reduces the HTS. Numerical simulations using ProCAST software on HTS of Mg-4.5Zn-xY alloys are in good agreement with the experimental results. %0 journal article %@ 1359-6454 %A Garces, G.,Morris, D.G.,Munoz-Morris, M.A.,Perez, P.,Tolnai, D.,Mendis, C.,Stark, A.,Lim, H.K.,kim, S.,Shell, N.,Adeva, P. %D 2015 %J Acta Materialia %N %P 78-86 %R doi:10.1016/j.actamat.2015.04.048 %T Plasticity analysis by synchrotron radiation in a Mg97Y2Zn1 alloy with bimodal grain structure and containing LPSO phase %U https://doi.org/10.1016/j.actamat.2015.04.048 %X Deformation behaviour has been examined by synchrotron radiation diffraction in an extruded magnesium – long-period-stacking-order phase alloy comprising three components of microstructure. The variation of internal strains and intensities of the important crystallographic planes of the two phases has been examined during compression at several temperatures. The long-period-stacking-order phase remains elastic to stresses beyond the macroscopic yield stress while deformation in the magnesium matrix is dominated by twinning and basal slip, with the coarse-grained regions deforming plastically at stresses well below the macroscopic yield stress while regions with fine grain size deform plastically only at much higher stresses. %0 journal article %@ 2379-6294 %A Charyeva, O.,Feyerabend, F.,Willumeit, R.,Zukowski, D.,Gasqueres, C.,Szakacs, G.,Agha, N.A.,Hort, N.,Gensch, F.,Cecchinato, F.,Jimbo, R.,Wennerberg, A.,Lips, K.S. %D 2015 %J MOJ Toxicology %N 1 %P 23-28 %R doi:10.15406/mojt.2015.01.00004 %T In Vitro Resorption of Magnesium Materials and its Effect on Surface and Surrounding Environment %U https://doi.org/10.15406/mojt.2015.01.00004 1 %X Introduction: Magnesium has attracted much attention for its potential use in trauma and orthopedics fields due to its mechanical properties, biocompatibility, biodegradability and the possible ability to stimulate bone formation. It is desirable for magnesium-based alloys to have a low toxicity rate so the fractured bone heals before the implant resorbs.,Materials and methods: Corrosion properties of Mg2Ag, Mg10Gd, WE43 and 99.99% pure Mg were studied under physiological conditions. The samples were placed in DMEM containing 10% fetal bovine serum (FBS) and corrosion was studied after immersion and by gas evolution tests. The corrosion rate (CR), osmolality, pH and Ca2­+ concentrations, as well as surface changes in the form of average surface roughness (Sa), developed surface area ratio (Sdr) and summit density (Sds), were determined.,Results:WE43 showed the highest CR of all the materials tested-1.057 mm/year, which is almost twice as high as in the other samples. The lowest mean CR was in the Mg2Ag group. All alloys made pH more alkaline and decreased the concentration of free Ca2­+ in the solution. Osmolality decreased in all samples after day 7. Pure Mg had the most constant Sa and Sdr while WE43 had the most stable Sds of all materials over the observation period.,Conclusion: The surface of alloys changed as the implants corroded: the summits became lower with time, while the pitting corrosion progressed. Mg2Ag was the most promising of all the studied materials with regard to toxicity. %0 conference object %@ 1473-2262 %A Wiese, B.,Mendis, C.,Kainer, K.U.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 23 %T Can defects improve properties of metallic biomaterials %U S 3 %X No abstract %0 conference object %@ 1473-2262 %A Hort, N.,Mendis, C.,Maier, P. %D 2015 %J European Cells and Materials %N S 3 %P 18 %T Phase Diagrams: Which information you can get from them for alloy and process design? %U S 3 %X No abstract %0 conference object %@ %A Vogt, C.,Zimmermann, F.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Cor-3 %T Challenges for accurate determination of rare earth elements in degradable Mg alloys %U %X %0 conference paper %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Dieringa, H. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 97-104 %T Microstructural Response to Hot Working of Mg-4Al-2Ba-1Ca (ABaX421) as Revealed by Processing Map %U %X The hot working mechanisms that occur in ABaX421 alloy have been evaluated using processing maps in the temperature range 300–500 oC and strain rate range 0.0003–10 s-1. The map exhibited two domains in the ranges: (1) 340–480 oC and 0.0003–0.001 s-1 with a peak efficiency of 40% at 420 oC/0.0003 s-1, and (2) 450– 500 oC and 0.003–0.6 s-1 with a peak efficiency of 38% at 500 oC/0.06 s-1. Dynamic recrystallization occurs in both the domains and is caused by basal+prismatic slip and climb in the first domain and by second order pyramidal slip and cross-slip in the second domain. Fine grained microstructures are produced in specimens deformed in both the domains along with ductile fracture in tension, indicating that the alloy has good hot workability. The apparent activation energy values estimated in the Domain 1 and Domain 2 are 211 and 243 kJ/mole, respectively. These values are higher than that for lattice self-diffusion in Mg, indicating that the back stress caused by the intermetallic particles is significant. Also, in the temperature range 300–380 oC at strain rates >0.01 s-1, flow instability occurs in the form of adiabatic shear band and flow localization. %0 conference object %@ %A Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kodetova, V.,Szakacs, G.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-33 %T Heat treatment of Mg-Y- based alloys with addition of Ca or Ag %U %X %0 conference object %@ 1473-2262 %A Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kodetova, V.,Szakacs, G.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 33 %T Heat treatment of Mg-Y- based alloys with addition of Ca or Ag %U S 3 %X No abstract %0 conference lecture %@ %A Wiese, B.,Kainer, K.U.,Hort, N. %D 2015 %J Werkstoffwoche 2015 %N %P %T Koennen Legierungselemente Schutzgase in der Produktion von Magnesium ersetzen? %U %X %0 journal article %@ 0016-9781 %A Wiese, B.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2015 %J Giesserei-Praxis : Fachzeitschrift fuer alle Bereiche der Giessereitechnik %N 12 %P 601-603 %T Schutz von Magnesiumschmelzen %U 12 %X Im schmelzflüssigen Zustand zeigt Magnesium eine hohe Affinität zu Sauerstoff. Sobald der Sauerstoffgehalt in der Atmosphäre 4 % übersteigt, wird Mg daher entflammen! Damit ergibt sich die Notwendigkeit, Mg-Schmelzen zu schützen. Zurzeit wird standardmäßig SF6 während der Primärproduktion und beim Verarbeiten von Mg-Schmelzen eingesetzt. Bedauerlicherweise ist SF6 jedoch ein Treibhausgas, das ungefähr 23.000 mal wirksamer ist, als CO2. Damit muss SF6 auch bei der Lebensdaueranalyse z.B. von Fahrzeugen berücksichtigt werden. Andere Schutzgase wie zum Beispiel SO2 oder fluorierte Kohlenwasserstoffe wie HFC134a, Novec 612, oder AMCover (= HFC134a) sind bereits als Schutzgase in der Diskussion. Zusätzlich gibt es noch eine Reihe von Schmelzsalzen, die ebenfalls in der Lage sind, Mg-Schmelzen effektiv zu schützen. Allerdings haben Schmelzsalze auch einige Nachteile und fluorierte Gase sind in der EU zusätzlich in der Diskussion. Die aktuellen Regelungen in Europa sehen zudem vor, dass SF6 ab 2018 nicht mehr oder nur sehr beschränkt eingesetzt werden darf. Eine ähnliche Diskussion wird auch für andere fluorierte Gase geführt. Daher ist es notwendig, bekannte Maßnahmen zum Schutz von Mg-Schmelzen neu zu bewerten oder neue Methoden zu entwickeln. %0 journal article %@ 1073-5623 %A Song, J.,Wang, Z.,Huang, Y.,Srinivasan, A.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2015 %J Metallurgical and Materials Transactions A %N 12 %P 6003-6017 %R doi:10.1007/s11661-015-3165-0 %T Hot Tearing Susceptibility of Mg-Ca Binary Alloys %U https://doi.org/10.1007/s11661-015-3165-0 12 %X Hot tearing is known as one of the most critical solidification defects commonly encountered during casting practice. As most Mg alloys are initially prepared by casting, ingots must have superior quality with no casting defects for the further processing. Due to the extensive potential biodegradable applications of binary Mg-Ca alloys, it is of great importance to investigate their hot tearing behavior. In the present study, the influence of Ca content (0.1, 0.2, 0.5, 1.0, and 2.0 wt pct) on hot tearing susceptibility (HTS) of Mg-Ca binary alloys was investigated using a constrained rod casting apparatus equipped with a load cell and data acquisition system. Tear volumes were quantified with 3D X-ray tomography. Results showed that the influence of Ca content on HTS followed a “Λ” shape: the HTS increased with increase in Ca content, reached a maximum at 0.5 to 1 wt pct Ca, and then decreased with further increasing the Ca content to 2.0 wt pct. The wide solidification range and reasonably high volume of intermetallic in the Mg-0.5 wt pct Ca and Mg-1 wt pct Ca alloys resulted in high HTS. Microstructure analysis suggested that the hot tear initiated at grain boundaries and propagated along them through thin film rupture or across the eutectic. %0 conference paper %@ %A Wiese, B.,Mendis, C.L.,Ovri, H.,Reichel, H.-P.,Lorenz, U.,Kainer, K.U.,Hort, N. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 814-819 %T Role of CaO and Cover Gases on Protecting the Cast Surface of Mg %U %X Previous investigations show the protective nature of CaO on Mg and commercial Mg alloys during high temperature oxidation. The addition of CaO to Mg alloys increases the health and safety at workplaces and the quality of the cast surface by increasing the oxidation resistance. However, the role the Ca or CaO on influencing the oxidation resistance is not clear. To understand the effect of Ca on the oxidation behaviour we focused on pure Mg and the investigation is conducted on Mg and Mg-CaO castings and their interaction with and without Ar-SF6 as cover gas during the casting process. The oxide layers are investigated with SEM and TEM to characterise the role of Ca and CaO. %0 conference lecture %@ %A Wiese, B.,Mendis, C.L.,Ovri, H.,Reichel, H.-P.,Lorenz, U.,Kainer, K.U.,Hort, N. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Role of CaO and Cover Gases on Protecting the Cast Surface of Mg %U %X %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 604-612 %T Effect of Sn to Ca Ratio on the Processing Maps and Hot Deformation Mechanisms in Mg-Sn-Ca Alloys %U %X The effect of Sn/Ca ratio on the hot deformation mechanisms in Mg-Sn-Ca alloy has been studied by analyzing the processing maps for a series of alloys classified into two sets. In set 1, the Sn content is increased from 2 to 6 wt.% keeping the Ca content constant at 2 wt.%, and in set 2, the Sn/Ca ratio is maintained at 3 by using different amounts of Sn and Ca. For set 1 alloys with Sn/Ca ratio less than 2.5, the microstructure consists of CaMgSn phase in the matrix and Mg2Ca phase at the grain boundaries, while it is entirely CaMgSn phase for Sn/Ca of 3 for set 2. The processing maps exhibited two domains of dynamic recrystallization (DRX). In Domain 1, where basal slip+climb occurs to cause DRX, the increasing volume content of CaMgSn phase with increasing Sn content (set 1) generates higher back stress which requires higher temperatures for continuing slip. At higher temperature where Domain 2 occurs, second order pyramidal slip + cross-slip causes DRX. In set 2, the maps are essentially the same, although the domain sizes got smaller with higher alloying content due to an increase in the volume content of CaMgSn particles. %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Dieringa, H. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Microstructural Response to Hot Working of Mg-4Al-2Ba-1Ca (ABaX421) as Revealed by Processing Map %U %X %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Effect of Sn to Ca Ratio on the Processing Maps and Hot Deformation Mechanisms in Mg-Sn-Ca Alloys %U %X %0 conference lecture %@ %A Maier, P.,Peters, R.,Szakacs, G.,Hort, N. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Role of post-heat treatment on hardness, bending strength and corrosion of Mg4Gd wire compared to pure Mg wire %U %X %0 conference object %@ 1473-2262 %A Vogt, C.,Zimmermann, F.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 41 %T Challenges for accurate determination of rare earth elements in degradable Mg alloys %U S 3 %X No abstract %0 conference lecture %@ %A Stuepp, C.A.,Mendis, C.L.,Mohedano, M.,Szakacs, G.,Gensch, F.,Mueller, S.,Feyerabend, F.,Hortza, D.,Fredel, M.C.,Hort, N. %D 2015 %J 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P %T Powder Metallurgical Synthesis of Biodegradable Mg-Hydroxyapatite Composites for Biomedical Applications %U %X %0 conference paper %@ %A Stuepp, C.A.,Mendis, C.L.,Mohedano, M.,Szakacs, G.,Gensch, F.,Mueller, S.,Feyerabend, F.,Hortza, D.,Fredel, M.C.,Hort, N. %D 2015 %J Light Metals Technology 2015, 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P 165-171 %T Powder Metallurgical Synthesis of Biodegradable Mg-Hydroxyapatite Composites for Biomedical Applications %U %X %0 journal article %@ 0255-5476 %A Stuepp, C.A.,Mendis, C.L.,Mohedano, M.,Szakacs, G.,Gensch, F.,Mueller, S.,Feyerabend, F.,Hortza, D.,Fredel, M.C.,Hort, N. %D 2015 %J Materials Science Forum, Light Metals Technology 2015 %N %P 165-171 %R doi:10.4028/www.scientific.net/MSF.828-829.165 %T Powder Metallurgical Synthesis of Biodegradable Mg-Hydroxyapatite Composites for Biomedical Applications %U https://doi.org/10.4028/www.scientific.net/MSF.828-829.165 %X Biodegradable Mg alloys are a new class of temporary implant materials for musculo-skeletal surgery. Recent studies show that Mg-based alloys can be biocompatible and there is a high demand to design Mg alloys with adjustable corrosion rates and suitable mechanical properties. An approach to solving this challenge might be the use of Mg metal matrix composites (Mg-MMC). In this study, a Mg-MMC composed of ZK60 was investigated as the base material and hydroxyapatite (HA) particles were added for tailoring its properties. The composite was produced by high-energy ball milling followed by hot extrusion. This processing route was chosen, as HA in contact with molten Mg releases a toxic gas (phosphine – PH3). The HA particles were homogeneously distributed in the ZK60 matrix after ball milling and the composite was consolidated by hot extrusion. This work presents the influence of different amounts of HA on corrosion behavior and mechanical properties of the composite. Corrosion properties were evaluated by immersion and electrochemical measurements in physiological media at 37 °C. A slight improvement in the corrosion resistance was observed for Mg-MMC due to the presence of more stable corrosion products. Compression tests were used to measure the mechanical properties. Under compression, samples showed a slight increase in the compressive yield strength with the addition of HA, while the ultimate strength did not change significantly. %0 lecture %@ %A Hort, N. %D 2015 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 lecture %@ %A Hort, N. %D 2015 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 journal article %@ 0587-4246 %A Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2015 %J Acta Physica Polonica A %N 6 %P 606-610 %R doi:10.12693/APhysPolA.128.606 %T In Situ Investigation of Microstructure Evolution during Solidification of Mg10CaxGd (x=5, 10, 20) Alloys %U https://doi.org/10.12693/APhysPolA.128.606 6 %X Mg-Ca-Gd based alloys are investigated as a potential alloy for degradable biomaterials with some promising results. In this investigation the Mg10CaxGd (x=5, 10, 20) were investigated with synchrotron radiation X-ray diffraction during solidification to follow the phase evolution at two different cooling rates at 5 and 50 K min-1. All three alloys show formation of α -Mg followed by Mg2Ca phase, while only Mg10Ca20Gd alloy contained Mg5Gd phase during solidification. During cooling α -Mg was first observed between 628 and 632°C at a cooling rate of 5 K min-1 while this decreased to 620-628°C with the increase in cooling rate to 50 K min-1. The change in cooling rate from 5 to 50 K min-1 did not change the types of intermetallic phases observed but resulted in suppressing temperatures at which the intermetallic phases were first detected. %0 conference lecture %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Microstructure and Mechanical Properties of Mg-2Gd-x(Ag, Ca) Ternary Alloys Developed for Biomedical Applications %U %X %0 conference paper %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 543-550 %T Microstructure and Mechanical Properties of Mg-2Gd-x(Ag, Ca) Ternary Alloys Developed for Biomedical Applications %U %X The effects of modification of Mg-2Gd alloy with Ag and Ca elements on its microstructure and mechanical properties were investigated. Mg-2Gd alloy and two ternary alloy systems Mg-2Gd-xAg (x=1, 2 wt%), Mg-2Gd-xCa (x=0.4, 0.8 wt%) were prepared by permanent mould casting. The additions of Ag or Ca contribute to a visible change in the microstructure and mechanical properties. For Mg-2Gd-xAg alloys, a new ternary intermetallic phase (IMP) Mg52Gd3Ag5 is formed. Besides the ternary phase, Mg-Gd binary IMP Mg5Gd is also present in both Mg-2Gd-xAg alloys. With increasing the content of Ag, their grain size decreases and the amount of eutectic phase rises, which lead to improvement of the tensile and compressive properties. For Mg-2Gd-xCa alloys, the Ca addition leads to the formation of Mg2Ca while Mg5Gd is still present. Small amount of Ca addition also leads to improvement of tensile and compressive properties. In contrast, more addition of Ca reduces the tensile strength, because the grain size increases and becomes non-uniform, although the volume fraction of Mg2Ca increases. Both Ag and Ca contribute to slight improvement of the hardness. %0 conference lecture %@ %A Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kodetova, V.,Szakacs, G.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Heat treatment of Mg-Y- based alloys with addition of Ca or Ag %U %X %0 conference lecture %@ %A Mendis, C.L.,Hehenberger, M.,Tolnai, D.,Peyman, N.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T In situ synchrotron radiation diffraction investigation on the deformation behaviour of ZKQX6000 and ZQX600 extruded alloys %U %X %0 journal article %@ 0255-5476 %A Maier, P.,Mendis, C.,Wolff, M.,Mueller, S.,Hort, N. %D 2015 %J Materials Science Forum, Light Metals Technology 2015 %N %P 311-317 %R doi:10.4028/www.scientific.net/MSF.828-829.311 %T Twinning Assisted Crack Propagation of Magnesium-Rare Earth Casting and Wrought Alloys under Bending %U https://doi.org/10.4028/www.scientific.net/MSF.828-829.311 %X Due to their high specific strength, good corrosion resistance and high temperature strength Magnesium alloys containing Rare Earth additions are promising candidates for structural and engine applications in the transportation industry. Also medical applications, like bone screws and nails, benefit from their moderate corrosion rate and biocompatibility. All applications need materials which show a high strength, ductility and fracture toughness in case a crack has formed during service to keep safety against rupture. In this study four extruded Mg10Gd based alloys modified with Nd and La have been 3-point-bend tested at low a deformation speed to evaluate the influence of the microstructure on crack growth. A comparison to the cast material (subjected to T4 to increase ductility and to reduce the dendritic microstructure) shows an increase in strength and ductility due to the fine grained microstructure as a result of recrystallization during extrusion. The maximum bending strength and outer strain to crack initiation is also strongly influenced by the alloying system itself. The influence of Nd and La to the binary alloy Mg10Gd is discussed in using tensile, compression and bending tests. The increase in strength results in reduced elongation to fracture in tension loading as well as the outer strain for the crack initiation during bending tests. Tensile tests are often discussed to be not a reliable method for determining the Young’s modulus of magnesium. Therefore resonance frequency damping analysis has been applied to determine the dynamic modulus of elasticity, which is compared with the flexural (bending) modulus. Crack growth is discussed using light microscopy and correlated with bending stress-strain curves. The crack growth rate of the extruded, fine grained material is many times higher than of the cast, coarse grained material. Crack propagation is mostly transgranular and assisted by twinning. %0 conference lecture %@ %A Charyeva, O.,Feyerabend, F.,Willumeit, R.,Szakacs, G.,Cecchinato, F.,Agha, N.A.,Hort, N.,Wennerberg, A.,Dakischew, O.,Heiss, C.,Schnettler, R.,Lips, K.S. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Resorption of magnesium materials and its effect on human mesenchymal stem cells in vitro %U %X %0 conference lecture %@ %A Peters, R.,Maier, P.,Mendis, C.,Hort, N. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Precipitation hardening on hardness, grain size and corrosion of WE32 %U %X %0 conference object %@ %A Peters, R.,Maier, P.,Mendis, C.,Hort, N. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Cor-18 %T Precipitation hardening on hardness, grain size and corrosion of WE32 %U %X %0 conference object %@ 1473-2262 %A Peters, R.,Maier, P.,Mendis, C.,Hort, N. %D 2015 %J European Cells and Materials %N S 3 %P 56 %T Precipitation hardening on hardness, grain size and corrosion of WE32 %U S 3 %X No abstract %0 conference paper %@ %A Maier, P.,Mendis, C.,Wolff, M.,Mueller, S.,Hort, N. %D 2015 %J Light Metals Technology 2015, 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P %T Twinning Assisted Crack Propagation of Magnesium-Rare Earth Casting and Wrought Alloys under Bending %U %X %0 conference lecture %@ %A Bartosch, M.,Peters, H.,Schmitt, B.,Berger, F.,Hort, N.,Witte, F. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Tensile and microstructural properties of annealed Mg10Gd-alloy wires %U %X %0 conference object %@ %A Bartosch, M.,Peters, H.,Schmitt, B.,Berger, F.,Hort, N.,Witte, F. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-31 %T Tensile and microstructural properties of annealed Mg10Gd-alloy wires %U %X %0 conference object %@ 1473-2262 %A Bartosch, M.,Peters, H.,Schmitt, B.,Berger, F.,Hort, N.,Witte, F. %D 2015 %J European Cells and Materials %N S 3 %P 30 %T Tensile and microstructural properties of annealed Mg10Gd-alloy wires %U S 3 %X No abstract %0 journal article %@ 0925-8388 %A Seetharaman, S.,Blawert, C.,Ng, B.M.,Wong, W.L.E.,Goh, C.S.,Hort, N.,Gupta, M. %D 2015 %J Journal of Alloys and Compounds %N %P 759-770 %R doi:10.1016/j.jallcom.2015.05.284 %T Effect of erbium modification on the microstructure, mechanical and corrosion characteristics of binary Mg–Al alloys %U https://doi.org/10.1016/j.jallcom.2015.05.284 %X In this study, new erbium modified Mg–Al alloys were developed by integrating trace erbium (in the form of Al94.67Er5.33 master alloy) into pure Mg using disintegrated melt deposition technique. The developed Er- modified Mg–Al alloys were investigated for their microstructural, mechanical and corrosion characteristics in comparison with their unmodified counterparts. Microstructural investigation revealed (i) improved purity, (ii) (marginal) grain refinement, (iii) more uniform second phase distribution and (iv) Al3Er phase formation due to Er modification. Mechanical property measurements revealed an overall enhancement under indentation, tension and compression loads. A remarkable improvement in tensile ductility (without adverse effects on strength) by +19%, +29%, and +58% was obtained in Mg–3Al–0.1Er, Mg–6Al–0.3Er and Mg–9Al–0.5Er when compared to Mg–3Al, Mg–6Al and Mg–9Al respectively. While the Mg–6Al–0.3Er alloy exhibited best ductility, the Mg–9Al–0.5Er has the best strength under both tension and compression loads. Corrosion characteristics evaluated by hydrogen evolution, salt spray and electrochemical impedance experiments revealed improved corrosion resistance of Er modified Mg–Al alloys by the enhanced purity levels and the formation of Al–Er phases. %0 conference lecture %@ %A Song, J.,Wang, Z.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2015 %J 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P %T Influences of Ca Addition on the Hot Tearing Behaviour of Mg-4Zn-xCa Alloys %U %X %0 conference paper %@ %A Song, J.,Wang, Z.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2015 %J Proceedings of 10th International Conference on Magnesium Alloys and Their Applications, Mg 2015 %N %P 825-834 %T Influences of Ca Addition on the Hot Tearing Behaviour of Mg-4Zn-xCa Alloys %U %X Hot tearing or hot cracking is a critical casting defect and has a significant impact on the quality of casting products. It has been extensively studied on steel and aluminum alloys in the past decades. For magnesium alloys, the investigations on hot tearing have been focused on binary Mg-Zn, Mg-Ca, Mg-Al, Mg-Y and Mg-Gd alloys and ternary Mg-Al-Zn, Mg-Al-Ca, Mg-Al-Sr, Mg-Zn-Gd, and Mg-Zn-Y alloys. The cast Mg–Zn–Ca alloys exhibit a high hardness and good creep resistance, owing to the formation of fine precipitates in the matrix. In addition, Mg-4Zn-xCa alloys were reported to have a satisfied combination of mechanical properties, corrosion resistance and biocompatibility. Therefore, investigation on hot tearing behaviour of Mg-4Zn-xCa is of great interest. In the present work, the influence of Ca content (0, 0.2, 0.5, 1.0 and 2.0 wt. %) on the hot tearing of Mg-4 wt. % Zn alloy was investigated using a constrained rod casting (CRC) apparatus equipped with a load cell and data acquisition system. The effect of different mould temperatures (250 ⁰C and 450 ⁰C) on hot tearing susceptibility was also studied. The initiation as well as propagation of hot tearing was monitored during CRC experiments. Hot tears were observed and evaluated by a digital camera and 3D X-ray tomography. Microstructures and fracture surfaces were characterized by optical microscopy and scanning electron microscopy. Results show that Mg-4Zn-0.5Ca alloy exhibit the highest hot tearing susceptibility. Mould temperature improves the hot tearing resistance of Mg-4Zn-xCa alloys. Liquid film is observed on the fracture surface, indicating that the hot tearing may proceed by liquid film rupturing. %0 journal article %@ 0921-5093 %A Yu, Z.,Huang, Y.,Qiu, X.,Wang, G.,Meng, F.,Hort, N.,Meng, J. %D 2015 %J Materials Science and Engineering A %N %P 121-130 %R doi:10.1016/j.msea.2014.10.077 %T Fabrication of a high strength Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy by thermomechanical treatments %U https://doi.org/10.1016/j.msea.2014.10.077 %X A high strength Mg–11Gd–4.5Y–1Nd–1.5Zn–0.5Zr (wt%) alloy has been successfully fabricated via hot extrusion, cold rolling and ageing treatment. The alloy exhibits an average 0.2% proof stress (YS) of 481.6±19.9 MPa, an average ultimate tensile strength (UTS) of 517.4±27.5 MPa and an average elongation to failure of 2.0±0.4% at room temperature. The best mechanical property obtained in the present study has a YS of 502.0 MPa, an UTS of 546.8 MPa and an elongation to failure of 2.6%. The high strength of this alloy is attributed to the fine grains, stacking faults (SFs), long period stacking ordered (LPSO) phase, and precipitates of Mg5RE phase at grain boundaries and of β′ phase inside the grains. Cold rolling improves the mechanical properties and enhances the ageing hardening response, but decreases the ductility. Two texture components are found simultaneously in the deformed alloy. One is the typical Mg–RE texture and another one is the unusual prismatic texture. %0 conference object %@ %A Charyeva, O.,Feyerabend, F.,Willumeit, R.,Szakacs, G.,Cecchinato, F.,Agha, N.A.,Hort, N.,Wennerberg, A.,Dakischew, O.,Heiss, C.,Schnettler, R.,Lips, K.S. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Vit-6 %T Resorption of magnesium materials and its effect on human mesenchymal stem cells in vitro %U %X %0 conference poster %@ %A Gil-Santos, A.,Szakacs, G.,Marco, I.,Moelans, N.,Hort, N.,Biest, O.van der %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Effect of composition on the microstructure and properties of Mg-Si-Sr alloys for resorable material applications %U %X %0 conference lecture %@ %A Gil-Santos, A.,Szakacs, G.,Marco, I.,Moelans, N.,Hort, N.,Biest, O.van der %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Met-26 %T Effect of composition on the microstructure and properties of Mg-Si-Sr alloys for resorable material applications %U %X %0 conference object %@ 1473-2262 %A Gil-Santos, A.,Szakacs, G.,Marco, I.,Moelans, N.,Hort, N.,Biest, O.van der %D 2015 %J European Cells and Materials %N S 3 %P 26 %T Effect of composition on the microstructure and properties of Mg-Si-Sr alloys for resorable material applications %U S 3 %X No abstract %0 conference poster %@ %A Liu, Z.,Willumeit-Roemer, R.,Hort, N.,Schade, R.,Feyerabend, F. %D 2015 %J 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P %T Cytotoxicity and antibacterial property of Mg-Ag alloys %U %X %0 conference object %@ 1473-2262 %A Charyeva, O.,Feyerabend, F.,Willumeit, R.,Szakacs, G.,Cecchinato, F.,Agha, N.A.,Hort, N.,Wennerberg, A.,Dakischew, O.,Heiss, C.,Schnettler, R.,Lips, K.S. %D 2015 %J European Cells and Materials %N S 3 %P 70 %T Resorption of magnesium materials and its effect on human mesenchymal stem cells in vitro %U S 3 %X No abstract %0 conference lecture %@ %A Liu, Z.,Willumeit-Roemer, R.,Hort, N.,Schade, R.,Feyerabend, F. %D 2015 %J Abstract Book, 7th BIOMETAL, Symposium on Biodegradable Metals for Biomedical Applications %N %P Vit-1 %T Cytotoxicity and antibacterial property of Mg-Ag alloys %U %X %0 conference lecture %@ %A Maier, P.,Mendis, C.,Wolff, M.,Mueller, S.,Hort, N. %D 2015 %J 7th Internaternational Light Metals Technology Conference, LMT 2015 %N %P %T Twinning Assisted Crack Propagation of Magnesium-Rare Earth Casting and Wrought Alloys under Bending %U %X %0 conference object %@ 1473-2262 %A Liu, Z.,Willumeit-Roemer, R.,Hort, N.,Schade, R.,Feyerabend, F. %D 2015 %J European Cells and Materials %N S 3 %P 65 %T Cytotoxicity and antibacterial property of Mg-Ag alloys %U S 3 %X No abstract %0 journal article %@ 0022-2461 %A Dharmendra, C.,Rao, K.P.,Zhao, F.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J Journal of Materials Science %N 17 %P 5885-5898 %R doi:10.1007/s10853-014-8300-6 %T Effect of aluminum on microstructural evolution during hot deformation of TX32 magnesium alloy %U https://doi.org/10.1007/s10853-014-8300-6 17 %X The effect of Al (0.4 and 1 wt%) addition on the hot deformation behavior of the Mg–3Sn–2Ca (TX32) alloy has been studied with the help of processing maps generated in the temperature and strain rate ranges of 300–500 °C and 0.0003–10 s−1. The deformed specimens have been examined as regards changes in texture and microstructure using electron back scatter diffraction and transmission electron microscopy, respectively. The map for the TX32 base alloy exhibited two dynamic recrystallization (DRX) domains in the temperature and strain rate ranges: (1) 300–350 °C and 0.0003–0.001 s−1, and (2) 390–500 °C and 0.005–0.6 s−1. While 0.4 wt% Al addition to TX32 did not result in any significant change in the processing map, the map for the alloy with 1 wt% Al (TX32-1Al) exhibited four domains in the ranges: (1) 300–325 °C and 0.0003–0.001 s−1, (2) 325–430 °C and 0.001–0.04 s−1, (3) 430–500 °C and 0.01–0.5 s−1, and (4) 430–500 °C and 0.0003–0.002 s−1. In the first three domains, DRX has occurred, whereas in the fourth domain, grain boundary sliding takes place causing intercrystalline cracking in tension. In Domain 1 for all the alloys, DRX has occurred predominantly by basal slip and recovery by climb as confirmed by the resulting basal texture and tilt type sub-boundary structure. In Domain 2 of the base alloy and Domain 3 of the alloy with 1 wt% Al, second-order pyramidal slip dominates associated with cross-slip which randomizes the texture, and forms tangled dislocations and twist type sub-boundaries in the microstructure. The addition of 1 wt% Al causes solid solution strengthening and results in Domain 2 of the map of TX32-1Al alloy and in this domain basal+prismatic slip dominate. %0 journal article %@ 0261-3069 %A Gan, W.M.,Huang, Y.D.,Wang, R.,Wang, G.F.,Srinivasan, A.,Brokmeier, H.-G.,Schell, N.,Kainer, K.U.,Hort, N. %D 2014 %J Materials and Design %N %P 83-88 %R doi:10.1016/j.matdes.2014.05.057 %T Microstructures and mechanical properties of pure Mg processed by rotary swaging %U https://doi.org/10.1016/j.matdes.2014.05.057 %X Microstructures and tensile properties of commercial pure magnesium processed by rotary swaging (RS) technique were investigated. Bulk and gradient textures in the RS processed Mg were characterised by neutron and synchrotron diffractions, respectively. Grains of the pure Mg were gradually refined with increase in the RS passes, which largely contributed to an increase in the tensile yield strength. A dominated basal fibre texture was observed in the RS processed pure Mg. Accommodated twinning deformation was also observed. Both the optical observations and texture analyses through the diameter of the swaged rod showed a gradient evolution in microstructure. %0 conference lecture %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2014 %J 22nd Annual International Conference on Composites/Nanoengineering, ICCE 22 %N %P %T Magnesium Matrix Composites for Transportation Industries %U %X %0 journal article %@ 0261-3069 %A D´Elia, F.,Ravindran, C.,Sediako, D.,Kainer, K.U.,Hort, N. %D 2014 %J Materials and Design %N %P 44-55 %R doi:10.1016/j.matdes.2014.07.024 %T Hot tearing mechanisms of B206 aluminum–copper alloy %U https://doi.org/10.1016/j.matdes.2014.07.024 %X In this study, the mechanisms of hot tearing in B206 aluminum alloy were investigated. Castings were produced at three mold temperatures (250 °C, 325 °C and 400 °C) and with two levels of titanium (0.02 wt% and 0.05 wt%) to investigate the effects of cooling rate and grain refinement. A constrained-rod casting mold attached to a load cell was used to monitor the contraction force during solidification and subsequently determine the onset temperature of hot tearing in B206. The corresponding onset solid fraction of hot tearing was estimated from the solid phase evolution of α-Al in B206 using in situ neutron diffraction solidification analysis. Hot tears were found to occur at solid fractions ranging from 0.81 to 0.87. Higher mold temperatures significantly reduced hot tearing severity in B206 but did not alter the onset solid fraction. In contrast, additions of titanium to B206 were effective at eliminating hot tears by transforming the grain structure from coarse dendrites to finer and more globular grains. Finally, in situ neutron diffraction solidification analysis also successfully determined the solid phase evolution of intermetallic Al2Cu during solidification, which in turn, provided a better understanding of the role of Al2Cu in the development of hot tears in B206. %0 journal article %@ 0947-5117 %A Tie, D.,Feyerabend, F.,Hort, N.,Hoeche, D.,kainer, K.U.,Willumeit, R.,Mueller, W.D. %D 2014 %J Materials and Corrosion %N 6 %P 569-576 %R doi:10.1002/maco.201206903 %T In vitro mechanical and corrosion properties of biodegradable Mg–Ag alloys %U https://doi.org/10.1002/maco.201206903 6 %X Binary magnesium–silver (Mg–Ag) alloys were designed as antibacterial material to treat infections in an implant site. The mechanical and electrochemical measurements were performed on three casting Mg–Ag alloys under cell culture conditions. The composition and distribution of the corrosion layer was analyzed by microscopy and X-ray photoelectron spectroscopy. In cell culture media, Mg–Ag alloys show higher, but still acceptable general corrosion rates while less susceptibility to pitting corrosion than pure Mg with increasing content of silver. This study indicates that Mg–Ag alloys have satisfactory corrosion properties and much better mechanical properties than pure magnesium as a functional biodegradable material. %0 conference paper %@ %A Maier, P.,Tober, G.,Mendis, C.L.,Mueller, S.,Hort, N. %D 2014 %J Proceedings of International Conference on Processing and Manufacturing of Advanced Materials, Thermec 2013 %N %P 419-424 %T Influence of Nd in extruded Mg10Gd base alloys on fatigue strength %U %X %0 journal article %@ 1022-6680 %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2014 %J Advanced Materials Research, AMI Light Metals Conference 2014 %N %P 177-183 %R doi:10.4028/www.scientific.net/AMR.1019.177 %T Microstructure and Compression Creep Strength of the Newly Developed Magnesium Alloy DieMag422 %U https://doi.org/10.4028/www.scientific.net/AMR.1019.177 %X Magnesium alloys have been finding increasingly more types of application in the,automotive and aerospace industries for over twenty years. Despite the fact conventional,magnesium alloys have limited high-temperature strength and creep resistance, especially when,they contain aluminium as an alloying element. Aluminium is necessary to improve the castability,when high-pressure die casting is the favoured process. Applications with higher operating,temperatures require additional alloy elements, which form precipitates with the aluminium during,solidification and therefore prevent the formation of Mg17Al12, which is responsible for the low,creep resistance of magnesium alloys that contain aluminium. The precipitates formed may also,strengthen grain boundaries and so improve the creep strength. Barium and calcium were,investigated as elements in a magnesium alloy containing aluminium (DieMag422: 4 wt.-% Al,,2 wt.-% Ba, 2 wt.-% Ca). The compression creep strength was compared at 240°C for stresses,between 60 and 120 MPa with two commercial creep-resistant magnesium alloys, AE42 and,MRI230D. The stress exponents were calculated from the stress dependence of the minimum creep,rate. The concept of a threshold stress was applied and true stress exponents nt close to 5 were,found. The new alloy DieMag422 exhibits improved creep strength compared to both commercial,alloys and also has proven it is die castable. %0 journal article %@ 0957-0233 %A Cheng, J.,Groebner, J.,Hort, N.,Kainer, K.U.,Schmid-Fetzer, R. %D 2014 %J Measurement Science and Technology %N 6 %P 062001 %R doi:10.1088/0957-0233/25/6/062001 %T Measurement and calculation of the viscosity of metals - A review of the current status and developing trends %U https://doi.org/10.1088/0957-0233/25/6/062001 6 %X Viscosity is an important rheological property of metals in casting because it controls the rate of transport of liquid metals, which may lead to casting defects such as hot tearing and porosity. The measurement methods and numerical models of the viscosity of liquid and semi-solid state metals that have been published to date are reviewed in this paper. Most experimental measurements have been performed with rotational and oscillatory viscometers, which offer advantages at low viscosities in particular. Besides these two traditional methods for measuring viscosities, a couple of studies also introduced the technique of isothermal compression for alloys in the semi-solid state, and even an optical basicity method for the viscosity of slags. As to numerical models, most published results show that the viscosity of liquid and semi-solid state metals can be described by the Arrhenius, Andrade, Kaptay or Budai–Bemkő–Kaptay equations. In addition, there are some alternative models, such as the power model and the isothermal stress–strain model. %0 journal article %@ 2213-9567 %A Huang, Y.,Gan, W.,Kainer, K.U.,Hort, N. %D 2014 %J Journal of Magnesium and Alloys %N 1 %P 1-7 %R doi:10.1016/j.jma.2014.01.005 %T Role of multi-microalloying by rare earth elements in ductilization of magnesium alloys %U https://doi.org/10.1016/j.jma.2014.01.005 1 %X The present work investigates the influences of microalloying with rare earths on the mechanical properties of magnesium alloys. The amount of each rare earth element is controlled below 0.4 wt.% in order not to increase the cost of alloy largely. The synergic effects from the multi-microalloying with rare earths on the mechanical properties are explored. The obtained results show that the as-cast magnesium alloys multi-microalloying with rare earths possesses a quite high ductility with a tensile strain up to 25–30% at room temperature. Moreover, these alloys exhibit much better corrosion resistance than AZ31 alloy. The preliminary in situ neutron diffractions on the deformation of these alloys indicate that the multi-microalloying with rare earths seems to be beneficial for the activation of more slip systems. The deformation becomes more homogeneous and the resultant textures after deformation are weakened. %0 conference paper %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J Proceedings of International Conference on Processing and Manufacturing of Advanced Materials, Thermec 2013 %N %P 449-454 %T Hot forging of cast magnesium alloy TX31 using semi-closed die and its finite element simulation %U %X %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2014 %J Light Metals Conference 2014 %N %P %T Microstructure and Compression Creep Strength of the Newly Developed Magnesium Alloy DieMag422 %U %X %0 conference lecture (invited) %@ %A Hort, N.,Huang, Y. %D 2014 %J 2014 China International Forum on Advanced Materials and Commercialization %N %P %T State of the Art of Cast Magnesium Alloys %U %X %0 conference lecture (invited) %@ %A Hort, N.,Huang, Y. %D 2014 %J Seminar of the Taizhou Enze Medical Centre %N %P %T Degradable Mg implant materials %U %X %0 conference lecture (invited) %@ %A Hort, N.,Huang, Y. %D 2014 %J Seminar of the North Eastern University %N %P %T Applications of Magnesium Alloys %U %X %0 journal article %@ 0022-2461 %A Garcers, G.,Requena, G.,Tolnai, D.,Perez, P.,Adeva, P.,Stark, A.,Schell, N. %D 2014 %J Journal of Materials Science %N 7 %P 2714-2722 %R doi:10.1007/s10853-013-7967-4 %T Influence of rare-earth addition on the long-period stacking ordered phase in cast Mg–Y–Zn alloys %U https://doi.org/10.1007/s10853-013-7967-4 7 %X The microstructure and thermal stability of the Mg97Y2Zn1 (at.%) alloy, modified with the addition of 0.5 at.% of gadolinium or neodymium, have been examined by synchrotron radiation diffraction during in situ differential scanning calorimetry. The microstructure of the three alloys consists of magnesium dendrites with the Long Period Stacking Ordered (LPSO) phase at interdendritic regions. Rare-earth atoms substitute yttrium atoms in the LPSO phase, promoting the formation of the 14H structure. Lattice parameters of the LPSO do not change significantly with the rare-earth addition. However, they reduce the melting point of the LPSO phase, especially in the case of neodymium addition. %0 journal article %@ 0921-5093 %A Lalpoor, M.,Miroux, A.,Mendis, C.L.,Hort, N.,Offerman, S.E. %D 2014 %J Materials Science and Engineering A %N %P 116-124 %R doi:10.1016/j.msea.2014.04.095 %T The interaction of precipitation and deformation in a binary Mg–Ca alloy at elevated temperatures %U https://doi.org/10.1016/j.msea.2014.04.095 %X The effect of pre-deformation on precipitation hardening response as well as the work-hardening behavior of a binary Mg–Ca alloy are investigated. Our results show that application of 5% pre-deformation increases the precipitation hardening response of the material and decreases the annealing time by 50%. The dislocations introduced during the pre-deformation process act as predominant nucleation sites and result in a higher number of precipitates of smaller size. During the thermomechanical treatments, the work hardening behavior is altered by the state of the precipitates, namely, under-aged, peak-aged and over-aged. After the elastic–plastic transition, under-aged and peak-aged materials show a continuously decreasing work-hardening rate, while the over-aged material has an initial constant work-hardening rate. The absolute values of the work hardening rate are far less sensitive to the precipitation stage compared to aluminum alloys; a fact that explains the low work hardening capacity of magnesium compared to aluminum. %0 conference lecture %@ 0255-5476 %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J Materials Science Forum, Thermec 2013 %N %P 449-454 %R doi:10.4028/www.scientific.net/MSF.783-786.449 %T Hot forging of cast magnesium alloy TX31 using semi-closed die and its finite element simulation %U https://doi.org/10.4028/www.scientific.net/MSF.783-786.449 %X Magnesium alloys based on Mg-Sn-Ca system have shown improved corrosion and creep properties. In this type of alloys,Sn forms a solid solution with Mg that improves the corrosion resistance while Ca forms thermally stable intermetallic phases in the matrix enhancing the creep resistance. The Sn to Ca ratio is an important variable in deciding the type of intermetallic phases that form in the microstructure.In Mg-3Sn-1Ca alloy (TX31), a single intermetallic phase CaMgSnforms, which is responsible for its improved creep strength.With a view to evaluate its forgeability,isothermal forging experiments of TX31 were conducted on a hydraulic press in the temperature range of 350 °C to 500 °C and at speeds of 0.01 mm s-1to 10 mm s-1 using a semi-closed die. Finite-element (FE) simulation of the forging process was also conducted using the software DEFORM 2D to obtain the local variations of strain and strain rate. The effectivestrain values are below2.4 in the forged components and the forging loads predicted using FE simulation correlated well with the experimental data for all the forging conditions. The microstructures of the forgings show that CaMgSn phase is well distributed in the matrix which exhibited dynamically recrystallized microstructure as predicted by the processing map. %0 conference lecture %@ %A Maier, P.,Mendis, C.L.,Wolff, M.,Hort, N. %D 2014 %J 143rd Annual Meeting & Exhibition, TMS 2014 %N %P %T Crack Propagation under Bending in Cast Mg10GdxNd-T4 Alloys %U %X %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Hort, N.,Kainer, K.U. %D 2014 %J 143rd Annual Meeting & Exhibition, TMS 2014 %N %P %T Spike-Forging of As-Cast TX32 Magnesium Alloy %U %X %0 conference paper %@ %A Mendis, C.L.,Srinivasan, A.,Huang, Y.,Hort, N.,Kainer, K.U. %D 2014 %J Proceedings of 22nd International Conference on Processing and Fabrication of Advanced Materials, PFAM XXII %N %P 120-127 %T Precipitate formation during creep of Mg10Gd(2-6)Zn alloys %U %X %0 conference paper %@ %A Rao, K.P.,Suresh, K.,Hort, N.,Kainer, K.U. %D 2014 %J Magnesium Technology 2014, Proceedings of 143rd Annual Meeting & Exhibition, TMS 2014 %N %P 275-279 %R doi:10.1002/9781118888179.ch52 %T Spike-Forging of As-Cast TX32 Magnesium Alloy %U https://doi.org/10.1002/9781118888179.ch52 %X %0 conference lecture %@ %A Tober, G.,Maier, P.,Mueller, S.,Hort, N. %D 2014 %J 143rd Annual Meeting & Exhibition, TMS 2014 %N %P %T Low Cycle Fatigue Properties of Extruded Mg10GdxNd Alloys %U %X %0 conference paper %@ %A Tober, G.,Maier, P.,Mueller, S.,Hort, N. %D 2014 %J Magnesium Technology 2014, Proceedings of 143rd Annual Meeting & Exhibition, TMS 2014 %N %P 115-120 %R doi:10.1002/9781118888179.ch25 %T Low Cycle Fatigue Properties of Extruded Mg10GdxNd Alloys %U https://doi.org/10.1002/9781118888179.ch25 %X %0 book part %@ %A Requena, G.,Tolnai, D.,Asghar, Z.,Degischer, H.-P.,Koch, T.,Soldera, F.,Mueklich, F. %D 2014 %J Imagerie 3D en mecanique des materiaux %N %P 53-83 %T Imagerie 3D en mecanique des materiaux %U %X The study of the microstructure of materials by imaging sections of properly prepared samples is a well-established characterisation technique. For this, two-dimensional (2D) cuts are prepared for light optical reflecting metallography (LOM) or scanning electron microscopy (SEM). LOM is very sensitive to topographic irregularities owing to the small depth of field in the range < 0.3 µm. The achievable lateral resolution is > 0.2 µm, if there is sufficient reflecting contrast. Etching is a well-known methodology to create topographical differences between phases or of phase boundaries. The contrast depends on the phases’ reflectivity, which can be modified by the wavelength of the illuminating light and by surface treatments (interference coating) of surfaces neatly polished either mechanically or by ion bombardment. %0 conference paper %@ %A Maier, P.,Mendis, C.L.,Wolff, M.,Hort, N. %D 2014 %J Magnesium Technology 2014, Proceedings of 143rd Annual Meeting & Exhibition, TMS 2014 %N %P 77-82 %R doi:10.1002/9781118888179.ch18 %T Crack Propagation under Bending in Cast Mg10GdxNd-T4 Alloys %U https://doi.org/10.1002/9781118888179.ch18 %X %0 conference lecture %@ %A Wiese, B.,Mendis, C.L.,Tolnai, D.,Szakacs, G.,Stark, A.,Schell, N.,Reichel, H.-P.,Brueckner, R.,Hort, N.,Kainer, K.U. %D 2014 %J 143rd Annual Meeting & Exhibition, TMS 2014 %N %P %T In Situ Synchrotron Radiation Diffraction during Melting and Solidification of Mg-Al Alloys Containing CaO %U %X %0 conference paper %@ %A Wiese, B.,Mendis, C.L.,Tolnai, D.,Szakacs, G.,Stark, A.,Schell, N.,Reichel, H.-P.,Brueckner, R.,Hort, N.,Kainer, K.U. %D 2014 %J Magnesium Technology 2014, Proceedings of 143rd Annual Meeting & Exhibition, TMS 2014 %N %P 191-195 %R doi:10.1002/9781118888179.ch38 %T In Situ Synchrotron Radiation Diffraction during Melting and Solidification of Mg-Al Alloys Containing CaO %U https://doi.org/10.1002/9781118888179.ch38 %X %0 journal article %@ 0022-2461 %A Wang, Z.,Huang, Y.,Srinivasan, A.,Liu, Z.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2014 %J Journal of Materials Science %N %P 353-362 %R doi:10.1007/s10853-013-7712-z %T Experimental and numerical analysis of hot tearing susceptibility for Mg–Y alloys %U https://doi.org/10.1007/s10853-013-7712-z %X The influences of Y content and initial mold temperatures on the hot tearing susceptibility (HTS) of binary Mg–Y alloys were investigated using a constrained rod casting (CRC) apparatus, which is equipped with a load cell and data acquisition systems. The hot crack formation was monitored during CRC experiments. The experimental results show that HTS first increases with increase in the Y content, reaches the maximum at about 1.5 wt% Y and then decreases with further increase in the content of Y. The severest of hot tearing is found in Mg–1.5 wt% Y alloy which is due to its large columnar grain structure, wide solidification range, and small amount of eutectic. The resistance to hot tearing is apparently improved by increasing the initial mold temperature. ProCAST simulation software was used to predict the hot tearing of Mg–Y alloys in CRC. The simulation results show a good agreement with the experimental measurements. The numerical simulations will be helpful and valuable to optimize the alloy composition and casting parameters to minimize the hot tearing defects. %0 conference lecture %@ %A Hort, N. %D 2014 %J 12. Bielefelder Werkstofftag %N %P %T Magnesium – Stand der Technik und Potential %U %X %0 journal article %@ 1047-4838 %A Suresh, K.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J JOM: Journal of the Minerals, Metals and Materials Society %N 2 %P 322-328 %R doi:10.1007/s11837-013-0820-z %T A Study on the Hot Deformation Behavior of Cast Mg-4Sn-2Ca (TX42) Alloy %U https://doi.org/10.1007/s11837-013-0820-z 2 %X The hot deformation behavior of as-cast Mg-4Sn-2Ca (TX42) alloy has been studied using compression tests in the temperature range of 300°C to 500°C, and strain rate range of 0.0003 s−1 to 10 s−1. Based on the flow stress data, a processing map has been developed, which exhibited two domains of dynamic recrystallization in the temperature and strain rate ranges: (I) 300°C to 380°C and 0.0003 s−1 to 0.001 s−1, and (II) 400°C to 500°C and 0.004 s−1 to 6 s−1. While hot working may be conducted in either of these domains, the resulting grain sizes are finer in the first domain than in the second. The apparent activation energy values estimated by kinetic analysis of the temperature and strain rate dependence of flow stress in the domains 1 and 2 are 182 kJ/mol and 179 kJ/mol, respectively. Both the values are much higher than that for self-diffusion in pure magnesium, indicating that the thermally stable CaMgSn particles in the matrix cause significant back stress during the hot deformation of this alloy. The alloy exhibits a regime of flow instability at lower temperatures and higher strain rates, which manifested as flow localization. %0 conference lecture %@ 0255-5476 %A Maier, P.,Tober, G.,Mendis, C.L.,Mueller, S.,Hort, N. %D 2014 %J Materials Science Forum, Thermec 2013 %N %P 419-424 %R doi:10.4028/www.scientific.net/MSF.783-786.419 %T Influence of Nd in extruded Mg10Gd base alloys on fatigue strength %U https://doi.org/10.4028/www.scientific.net/MSF.783-786.419 %X Magnesium alloys containing Rare Earth elements have proven to be suitable candidates for uses at high temperatures due to their good creep resistance as well as for use in biodegradable implants due to their adequate corrosion rate and biocompatibility. This work investigates the fatigue strength and cyclic deformation behavior of an extruded Mg10Gd1Nd in comparison to Mg10Gd and possible benchmark alloys WE43 and AZ31. The influence of the alloying element Nd is remarkable. The finite life fatigue strengths of Mg10Gd1Nd in the SN-diagram (Wöhler curve) are strongly improved compared to Mg10Gd and almost reach the strength values of WE43. Fracture surface morphology and crack propagation are discussed with attention given to low and high cycle fatigue. The very fine grain size, as the result of dynamic recrystallization during extrusion, offers high elongation at fracture. Therefore the residual fracture surface, where rapid failure occurs, is rather small in the high cycle fatigue samples. The size of the slow crack growth area has been determined by the appearance of benchmark ridges and fatigue striations and is discussed in correlation to stress and number of cycles. Scatter behavior of fatigue life was investigated by optical microcopy. The microstructure consists of second phase alignments in the extrusion direction, which differs in length, precipitate size and distance. Crack branching appears depending on microstructure and the load applied. %0 lecture %@ %A Hort, N. %D 2014 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 journal article %@ 0921-5093 %A Dharmendra, C.,Rao, K.P.,Zhao, F.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J Materials Science and Engineering A %N %P 11-23 %R doi:10.1016/j.msea.2014.03.087 %T Effect of silicon content on hot working, processing maps, and microstructural evolution of cast TX32–0.4Al magnesium alloy %U https://doi.org/10.1016/j.msea.2014.03.087 %X The effect of silicon (0.2–0.8 wt%) addition on the hot working behavior and deformation mechanisms of the Mg–3Sn–2Ca–0.4Al (TX32–0.4Al) alloy has been evaluated by generating processing maps in the temperature and strain rate ranges of 300–500 °C and 0.0003–10 s−1. The processing map for the base TX32–0.4Al alloy exhibited two dynamic recrystallization (DRX) domains in the ranges (1) 300–360 °C and 0.0003–0.001 s−1 and (2) 400–500 °C and 0.003–0.7 s−1. While 0.2% Si addition did not result in any significant change in the processing map of the base TX32–0.4Al alloy, 0.4% Si addition has enhanced hot workability by widening the processing window(s) and by reducing flow instability. The rate controlling mechanism in Domain 1 is identified as climb, whereas it is cross-slip in Domain 2. When the Si content is increased to 0.6 and 0.8%, the volume fraction of hard intermetallic particles has increased nearly two fold. The processing map for the alloy with 0.6% Si addition exhibited an additional Domain 3 at higher temperatures and high strain rates (475–500 °C and 0.01–10 s−1). However, cracking has occurred in Domain 1 due to void formation at hard particles. In Domains 2 and 3, DRX occurred predominantly by basal slip with climb as a recovery process, as confirmed by the resulting basal texture and tilt type sub-boundary structure. This is attributed to the large back stress generated by the increased volume fraction of intermetallic particles due to which the extensive activation of basal slip required considerably high temperatures. Increase in the volume fraction of hard particles due to higher Si content reduces the flow instability by generating a high rate of entropy production through increasing the nucleation sites for power dissipation and enhances the occurrence of void formation and/or ductile fracture. %0 journal article %@ 0921-5093 %A Srinivasan, A.,Huang, Y.,Mendis, C.L.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2014 %J Materials Science and Engineering A %N %P 224-234 %R doi:10.1016/j.msea.2013.12.016 %T Investigations on microstructures, mechanical and corrosion properties of Mg-Gd-Zn alloys %U https://doi.org/10.1016/j.msea.2013.12.016 %X Microstructure, mechanical and corrosion properties of four alloys, Mg–2Gd–2Zn, Mg–2Gd–6Zn, Mg–10Gd–2Zn and Mg–10Gd–6Zn (all are in weight percentages), prepared by gravity permanent mold casting were investigated. The results indicated that the intermetallic phases in the Mg–2Gd–2Zn alloy consisted mainly of (Mg, Zn)3Gd phase whereas the Mg–2Gd–6Zn alloy consisted of both I (Mg3Zn6Gd) and (Mg, Zn)3Gd phases. In addition, few Mg–Gd and Mg–Zn binary phases were also present in both the alloys. Lamellar long period stacking ordered (LPSO) phase was observed in alloys containing high concentrations of Gd (Mg–10Gd–2Zn and Mg–10Gd–6Zn alloys) in addition to the continuously distributed (Mg,Zn)3Gd phase along the interdendritic regions and grain boundaries. A small fraction of X phase (Mg12ZnGd) was also present in Mg–10Gd–2Zn alloy. Mg–10Gd–xZn alloys (x=2,6) exhibited higher yield strength due to the higher solute contents and the presence of LPSO phase in the matrix, but showed poor elongation due to the coarse continuous second phase at the boundary. Low Gd-containing alloys showed better elongation to failure and moderate strength due to the lower volume fraction of fine scale second phases. Corrosion resistances of the alloys decreased with increase in the total amount of alloying elements. Increase in Zn content from 2% to 6% in Mg–2Gd–xZn alloys did not alter the corrosion properties much; however, this increase in the high Gd-containing alloys had significant detrimental effects on the corrosion properties due to the significant increase in the volume of the second phases. In all the alloys, galvanic corrosion due to the second phase and filiform corrosion dominated the earlier stages of corrosion, and after long immersion times, the second phase, (Mg,Zn)3Gd, was found to become unstable and dissolved, leading to intergranular corrosion. %0 conference lecture %@ %A Lukac, F.,Vlcek, M.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kekule, T.,Szakacs, G.,Hort, N.,Kainer, K.U. %D 2014 %J 23rd International Conference on Metallurgy and Materials, METAL 2014 %N %P %T Magnesium Alloy Containing Silver for Degradable Biomedical Implants %U %X %0 book part %@ %A Dieringa, H.,Hort, N.,Bohlen, J.,Letzig, D.,Kainer, K.U. %D 2014 %J Essential Readings in Magnesium Technology %N %P 19-24 %T Advances in manufacturing processes for magnesium alloys %U %X The present paper reviews the present potential of magnesium and,its alloys as structural light-weight material in transportation,industry. An overview will be given on the state of the art in,casting technologies of magnesium alloys in order to broaden,possible applications in light weight construction. Further,,wrought magnesium will be emphasized as a challenge for,developing magnesium towards a competitive constructional,material. Future needs in all regards involve further alloy,development which has to need the special requirements for each,process. An overview on actual research activities in Europe and,also especially in Germany will be given. %0 conference paper %@ %A Szakacs, G.,Wiese, B.,Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Nair, M.,Kainer, K.U.,Hort, N. %D 2014 %J Magnesium Technology 2014, Proceedings of 143rd Annual Meeting & Exhibition, TMS 2014 %N %P 213-218 %R doi:10.1002/9781118888179.ch42 %T In situ synchrotron radiation diffraction during solidification of Mg4Y and Mg4YxGd alloys (x - 1, 4 wt.%) %U https://doi.org/10.1002/9781118888179.ch42 %X %0 conference poster %@ %A Song, J.,Wang, Z.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2014 %J Junior Euromat 2014 %N %P %T Influence of Zn addition on hot tearing behaviour of Mg-0.5Ca-xZn alloys %U %X %0 conference poster %@ %A Song, J.,Dieringa, H.,Huang, Y.,Gan, W.,Kainer, K.U.,Hort, N. %D 2014 %J Light Metals Conference 2014 %N %P %T Mechanical Properties and Microstructures of Nano SiC Reinforced ZE10 Composites Prepared with Ultrasonic Vibration %U %X %0 journal article %@ 1022-6680 %A Song, J.,Dieringa, H.,Huang, Y.,Gan, W.,Kainer, K.U.,Hort, N. %D 2014 %J Advanced Materials Research, AMI Light Metals Conference 2014 %N %P 169-176 %R doi:10.4028/www.scientific.net/AMR.1019.169 %T Mechanical Properties and Microstructures of Nano SiC Reinforced ZE10 Composites Prepared with Ultrasonic Vibration %U https://doi.org/10.4028/www.scientific.net/AMR.1019.169 %X In the present investigation, SiC reinforced ZE10 alloy composites were fabricated by direct chill casting assisted with ultrasonic vibration. Two kinds of SiC with a size of 50 nm and 2 μm were chosen. For comparison, ZE10 alloys with and without ultrasound were also fabricated. The microstructures and the distribution of SiC were examined by optical microscopy and scanning electron microscopy. Neutron diffraction was also used to identify the second phases in the composites. In addition, mechanical properties such as hardness, creep and compression were evaluated. The results show that SiC was successfully introduced into the magnesium matrix. After the addition of SiC, the mechanical properties of the composites exhibit a slight decrease, which might be due to the grain coarsening. %0 journal article %@ 1022-6680 %A Song, J.,Huang, Y.,Kainer, K.U.,Gan, W.,Hort, N. %D 2014 %J Advanced Materials Research, Residual Stresses IX %N %P 592-597 %R doi:10.4028/www.scientific.net/AMR.996.592 %T Residual Stresses of the As-Cast Mg-xCa Alloys with Hot Sprues by Neutron Diffraction %U https://doi.org/10.4028/www.scientific.net/AMR.996.592 %X Residual stresses in Mg-xCa (0.5 wt. % and 1.0 wt. %) cast alloys were investigated by neutron diffraction using a mould with two preheating temperatures of 250 °C and 450 °C. Results show that the increase of Ca content decreases the residual stress in the hot sprue region. These results are quite in agreement with those obtained by the measurement of hot tearing susceptibility, which shows the increment in Ca content improves the castability of Mg-Ca alloys. %0 journal article %@ 2213-9567 %A Huang, Y.,Dieringa, H.,Kainer, K.U.,Hort, N. %D 2014 %J Journal of Magnesium and Alloys %N 2 %P 124-132 %R doi:10.1016/j.jma.2014.03.003 %T Understanding effects of microstructural inhomogeneity on creep response – New approaches to improve the creep resistance in magnesium alloys %U https://doi.org/10.1016/j.jma.2014.03.003 2 %X Previous investigations indicate that the creep resistance of magnesium alloys is proportional to the stability of precipitated intermetallic phases at grain boundaries. These stable intermetallic phases were considered to be effective to suppress the deformation by grain boundary sliding, leading to the improvement of creep properties. Based on this point, adding the alloying elements to form the stable intermetallics with high melting point became a popular way to develop the new creep resistant magnesium alloys. The present investigation, however, shows that the creep properties of binary Mg–Sn alloy are still poor even though the addition of Sn possibly results in the precipitation of thermal stable Mg2Sn at grain boundaries. That means other possible mechanisms function to affect the creep response. It is finally found that the poor creep resistance is attributed to the segregation of Sn at dendritic and grain boundaries. Based on this observation, new approaches to improve the creep resistance are suggested for magnesium alloys because most currently magnesium alloys have the commonality with the Mg–Sn alloys. %0 conference lecture %@ %A Szakacs, G.,Wiese, B.,Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Nair, M.,Kainer, K.U.,Hort, N. %D 2014 %J 143rd Annual Meeting & Exhibition, TMS 2014 %N %P %T In situ synchrotron radiation diffraction during solidification of Mg4Y and Mg4YxGd alloys (x - 1, 4 wt.%) %U %X %0 conference paper %@ %A Lukac, F.,Vlcek, M.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kekule, T.,Szakacs, G.,Hort, N.,Kainer, K.U. %D 2014 %J Conference Proceedings, 23rd International Conference on Metallurgy and Materials, METAL 2014 %N %P 1086-1091 %T Magnesium Alloy Containing Silver for Degradable Biomedical Implants %U %X %0 conference lecture %@ %A Huang, Y.,Dieringa, H.,Kainer, K.U.,Hort, N. %D 2014 %J 13th International Conference on Fracture and Damage Mechanics, FDM 2014 %N %P %T Deformation-induced dynamic precipitation during creep in magnesium-tin alloys %U %X %0 conference lecture %@ %A Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kodetova, V.,Szakacs, G.,Hort, N.,Kainer, K.U. %D 2014 %J 23rd International Conference on Metallurgy and Materials, METAL 2014 %N %P %T Precipitation Processes in Mg-Y-Nd-Ag Alloys Suitable for Biodegradable Implants %U %X %0 conference paper %@ %A Vlcek, M.,Lukac, F.,Stulikova, I.,Smola, B.,Kudrnova, H.,Vlach, M.,Kodetova, V.,Szakacs, G.,Hort, N.,Kainer, K.U. %D 2014 %J Conference Proceedings, 23rd International Conference on Metallurgy and Materials, METAL 2014 %N %P 1103-1108 %T Precipitation Processes in Mg-Y-Nd-Ag Alloys Suitable for Biodegradable Implants %U %X %0 lecture %@ %A Hort, N. %D 2014 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 conference lecture %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2014 %J Proceedings of 22nd Annual International Conference on Composites/Nanoengineering, ICCE 22 %N %P 429-430 %T Magnesium Matrix Composites for Transportation Industries %U %X %0 journal article %@ 0255-5476 %A Gan, W.M.,Huang, Y.D.,Wang, Z.,Hort, N.,Hofmann, M. %D 2014 %J Materials Science Forum, International Conference on Residual Stresses 9 %N %P 428-432 %R doi:10.4028/www.scientific.net/MSF.768-769.428 %T Residual Stresses in the Hot Sprues of as-cast Mg-Zn Alloys Investigated by STRESS-SPEC Neutron Diffractometer %U https://doi.org/10.4028/www.scientific.net/MSF.768-769.428 %X Residual strains near the sprues of ingots with different contents of Zn (6 wt. % and 9 wt. %) were measured using neutron diffraction. The results showed that the increase of Zn content decreases the residual stress in the hot sprue region. These results are good in agreement with that obtained by the measurement of hot tearing susceptibility. %0 conference lecture %@ %A Maier, P.,Erdmann, R.,Tesch, R.,Szakacs, G.,Hort, N. %D 2014 %J 6th Symposium on Biodegradable Metals %N %P %T Influence of corrosion on mechanical properties of Mg5Gd wire %U %X %0 conference lecture %@ %A Mendis, C.L.,Tolnai, D.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2014 %J 13th International Symposium on Physics of Materials, ISPMA13 %N %P %T In Situ Investigation of Microstructure Evolution during Solidification of Mg10CaxGd (x=5, 10, 20) Alloys %U %X %0 conference poster %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2014 %J Junior Euromat 2014 %N %P %T Properties of binary Mg-(Gd, Ag, Ca) alloys developed for biomedical applications %U %X %0 conference lecture %@ %A Song, J.,Huang, Y.,Kainer, K.U.,Gan, W.,Hort, N. %D 2014 %J 9th European Conference on Residual Stresses, ECRS 9 %N %P %T Residual stresses of the as-cast Mg-xCa alloys with hot sprues by neutron diffraction %U %X %0 conference poster %@ %A Lu, Y.,Huang, Y.,Feyerabend, F.,Willumeit-Roemer, R.,Kainer, K.U.,Hort, N. %D 2014 %J 6th Symposium on Biodegradable Metals %N %P %T Properties of pure Mg and low-concentrated binary Mg-(Gd, Ag, Ca) alloys %U %X %0 conference lecture %@ %A Tolnai, D.,Hehenberger, M.,Mendis, C.L.,Stark, A.,Schell, N.,Hort, N.,Kainer, K.U. %D 2014 %J 53rd Annual Conference of Metallurgists, COM 2014 %N %P %T In situ synchrotron radiation diffraction during compression of a zkqx alloy %U %X %0 conference object %@ 1473-2262 %A Maier, P.,Erdmann, R.,Tesch, R.,Szakacs, G.,Hort, N. %D 2014 %J European Cells and Materials %N S3 %P 36 %T Influence of corrosion on mechanical properties of Mg5Gd wire %U S3 %X No abstract %0 conference lecture %@ %A Gil-Santos, A.,Szakacs, G.,Hort, N.,Biest, O.van der %D 2014 %J 6th Symposium on Biodegradable Metals %N %P %T Thermodynamic calculation and experimental studies of phase relations in the Mg-Si-Ca-Sr system for degradable biomaterials %U %X %0 conference lecture %@ %A Szakacs, G.,Mendis, C.L.,Wiese, B.,Tolnai, D.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2014 %J 6th Symposium on Biodegradable Metals %N %P %T In situ synchrotron radiation diffraction during solidification of Mg15Gd %U %X %0 conference object %@ 1473-2262 %A Szakacs, G.,Mendis, C.L.,Wiese, B.,Tolnai, D.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2014 %J European Cells and Materials %N S3 %P 3 %T In situ synchrotron radiation diffraction during solidification of Mg15Gd %U S3 %X No abstract %0 conference lecture %@ %A Hort, N.,Wiese, B.,Wolff, M.,Ebel, T.,Maier, P. %D 2014 %J 6th Symposium on Biodegradable Metals %N %P %T Stiffness of metals, alloys and components %U %X %0 conference object %@ 1473-2262 %A Hort, N.,Wiese, B.,Wolff, M.,Ebel, T.,Maier, P. %D 2014 %J European Cells and Materials %N S3 %P 1 %T Stiffness of metals, alloys and components %U S3 %X No abstract %0 journal article %@ 2213-9567 %A Srinivasan, A.,Blawert, C.,Huang, Y.,Mendis, C.L.,Kainer, K.U.,Hort, N. %D 2014 %J Journal of Magnesium and Alloys %N 3 %P 245-256 %R doi:10.1016/j.jma.2014.08.002 %T Corrosion behavior of Mg–Gd–Zn based alloys in aqueous NaCl solution %U https://doi.org/10.1016/j.jma.2014.08.002 3 %X The corrosion behavior of Mg-10Gd–xZn (x = 2, 6 wt.%) alloys in 0.5 wt.% NaCl solution was investigated. Microstructures of both the alloys consisted of (Mg,Zn)3Gd phase and lamellar long period stacking ordered (LPSO) phase. The morphology of the second phase at the grain boundary differed in both alloys: it was a continuous network structure in Mg–10Gd–6Zn, whereas it was relatively discrete in Mg–10Gd–2Zn. The dendrites were finer in size and highly branched in Mg–10Gd–6Zn. The corrosion results indicated that the increase in Zn content increased the corrosion rate in Mg–10Gd–xZn alloys. Micro-galvanic corrosion occurred near the grain boundary in both alloys initially as the grain boundary phase was stable and acted as a cathode, however, filiform corrosion dominated in the later stage, which was facilitated by the LPSO phase in the matrix. Severe micro-galvanic corrosion occurred in Mg–10Gd–6Zn due to the higher volume of second phase. The stability of the second phase at the grain boundary was altered and dissolved after the long immersion times. Probably the NaCl solution chemically reacted with the grain boundary phase and de-stabilized it during the long immersion times, and was removed by the chromic acid used for the corrosion product removal. %0 journal article %@ 1359-835X %A Schoebel, M.,Requena, G.,Fiedler, G.,Tolnai, D.,Vaucher, S.,Degischer, H.P. %D 2014 %J Composites / A %N %P 103-108 %R doi:10.1016/j.compositesa.2014.07.011 %T Void formation in metal matrix composites by solidification and shrinkage of an AlSi7 matrix between densely packed particles %U https://doi.org/10.1016/j.compositesa.2014.07.011 %X Particle reinforced metals are developed as heat sink materials for advanced thermal management applications. Metal matrix composites combine the high thermal conductivity of a metal with a low coefficient of thermal expansion of ceramic reinforcements. SiC and carbon diamond particle reinforced aluminum offer suitable thermal properties for heat sink applications. These composites are produced by liquid metal infiltration of a densely packed particle preform. Wettability, interface bonding strength and thermal mismatch are critical for void formation which leads to thermal fatigue damage under operation. The evolution of voids in AlSiC and AlCD has been studied by in-situ high resolution synchrotron tomography during matrix solidification. Large irregularly shaped matrix voids form during eutectic solidification. These voids help alleviate thermal expansion mismatch stresses by visco-plastic matrix deformation during cooling to RT after solidification, if sufficient interface bonding strength is assumed. %0 conference object %@ 1473-2262 %A Gil-Santos, A.,Szakacs, G.,Hort, N.,Biest, O.van der %D 2014 %J European Cells and Materials %N S3 %P 35 %T Thermodynamic calculation and experimental studies of phase relations in the Mg-Si-Ca-Sr system for degradable biomaterials %U S3 %X No abstract %0 conference paper %@ %A Tolnai, D.,Hehenberger, M.,Mendis, C.L.,Stark, A.,Schell, N.,Hort, N.,Kainer, K.U. %D 2014 %J Proceedings of the Conference of Metallurgists, 53rd Annual Conference of Metallurgists, COM 2014 %N %P %T In situ synchrotron radiation diffraction during compression of a zkqx alloy %U %X %0 conference lecture %@ %A Tolnai, D.,Mendis, C.L,Stark, A.,Schell, N.,Hort, N. %D 2014 %J Pan American Materials Conference 2014 %N %P %T In situ synchrotron radiation diffraction of the solidification of Mg-Y-Nd alloys %U %X %0 journal article %@ 0261-3069 %A Suresh, K.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2014 %J Materials and Design %N %P 697-704 %R doi:10.1016/j.matdes.2014.01.032 %T Study of hot forging behavior of as-cast Mg–3Al–1Zn–2Ca alloy towards optimization of its hot workability %U https://doi.org/10.1016/j.matdes.2014.01.032 %X Mg–3Al–1Zn–2Ca (AZX312) alloy has been forged in the temperature range of 350–500 °C and at speeds in the range of 0.01–10 mm s−1 to produce a rib-web shape with a view to validate the processing map and study the microstructural development. The process was simulated through finite-element method to estimate the local and average strain rate ranges in the forging envelope. The processing map exhibited two domains in the following ranges: (1) 350–450 °C/0.0003–0.05 s−1 and (2) 450–500 °C/0.03–0.7 s−1 and these represent dynamic recrystallization (DRX) and intercrystalline cracking, respectively. The optimal workability condition according to the processing map is 425–450 °C/0.001–0.01 s−1. A wide flow instability regime occurred at higher strain rates diagonally across the map, which caused flow localization that should be avoided in forming this alloy. The experimental load–stroke curves correlated well with the simulated ones and the observed microstructural features in the forged components matched with the ones predicted by the processing map. %0 journal article %@ 1003-6326 %A Mert, F.,Oezdemir, A.,Kainer, K.U.,Hort, N. %D 2013 %J Transactions of Nonferrous Metals Society of China %N 1 %P 66-72 %R doi:10.1016/S1003-6326(13)62430-9 %T Influence of Ce addition on microstructure and mechanical properties of high pressure die cast AM50 magnesium alloy %U https://doi.org/10.1016/S1003-6326(13)62430-9 1 %X The influence of Ce addition on the microstructure and mechanical properties of AM50 magnesium alloy was investigated to improve its mechanical properties. The results show that the addition of Ce to AM50 alloy results in the grain refinement and the mechanical properties of the Ce-modified AM50 at room and elevated temperatures are remarkably improved. AM50 magnesium alloy containing 1% Ce (mass fraction) shows better refinement and mechanical properties compared with the AM50 magnesium alloy with 0.5% Ce and even AM50 alloy without any Ce. %0 conference object %@ 1473-2262 %A Maier, P.,Mendis, C.L.,Tober, G.,Briesemeister, J.,Minciel, E.,Hort, N. %D 2013 %J European Cells and Materials %N S 5 %P 23 %T Bending strength and crack propagation in cast Mg10Gd influenced by corrosion %U S 5 %X No abstract %0 conference poster %@ %A Maier, P.,Mendis, C.L.,Tober, G.,Briesemeister, J.,Minciel, E.,Hort, N. %D 2013 %J 5th Symposium on Biodegradable Metals for Biomedical Applications, Biometal 2013 %N %P %T Bending strength and crack propagation in cast Mg10Gd influenced by corrosion %U %X %0 conference lecture %@ %A Wiese, B.,Mendis, C.,Tolnai, D.,Szakacs, G.,Stark, A.,Schell, N.,Reichel, H.-P.,Brueckner, R.,Hort, N.,Kainer, K.U. %D 2013 %J International Congress and Exhibition on Light Materials Aluminium, Magnesium, Titanium and their Alloys, Euro LightMAT 2013 %N %P %T In situ synchrotron diffraction of the solidification of Mg-Al alloys containing CaO %U %X %0 conference lecture (invited) %@ %A Hort, N. %D 2013 %J Materials Science Seminar of CIAC %N %P %T Magnesium Alloys Containing Rare Earth %U %X %0 conference lecture %@ %A Mendis, C.,Lefebvre, W.,Yang, L.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2013 %J International Workshop on Processing-Microstructure-Mechanical Property of Magnesium Alloys %N %P %T Characterisation of Nano-scaled Precipitates in a Peak Aged Mg-8Gd-2Dy Alloy %U %X %0 journal article %@ 2193-0651 %A Klein, M.,Penning, B.,Walther, F.,Dietzel, W.,Hort, N. %D 2013 %J BioNanoMaterials %N S %P 17 %R doi:10.1515/bnm-2013-1019 %T Mikrostruktur und Ermuedungsverhalten von Magnesium Stent-Roehrchen in Luft und koerperaehnlichem Serum %U https://doi.org/10.1515/bnm-2013-1019 S %X No abstract %0 conference object %@ 1473-2262 %A Hort, N.,Mendis, C.L.,Maier, P. %D 2013 %J European Cells and Materials %N S 5 %P 1 %T Do we need alloying elements for Mg implant materials? %U S 5 %X No abstract %0 conference lecture %@ %A Hort, N.,Mendis, C.L.,Maier, P. %D 2013 %J 5th Symposium on Biodegradable Metals for Biomedical Applications, Biometal 2013 %N %P %T Do we need alloying elements for Mg implant materials? %U %X %0 conference poster %@ %A Klein, M.,Penning, B.,Walther, F.,Dietzel, W.,Hort, N. %D 2013 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien, DGBM 2013 %N %P %T Mikrostruktur und Ermuedungsverhalten von Magnesium Stent-Roehrchen in Luft und koerperaehnlichem Serum %U %X %0 journal article %@ 0255-5476 %A Tolnai, D.,Szakacs, G.,Requena, G.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Science Forum, Light Metals Technology Conference, LMT 2013 %N %P 286-290 %R doi:10.4028/www.scientific.net/MSF.765.286 %T Study of the Solidification of AS Alloys Combining in situ Synchrotron Diffraction and Differential Scanning Calorimetry %U https://doi.org/10.4028/www.scientific.net/MSF.765.286 %X In situ synchrotron diffraction experiments were performed during Differential Scanning Calorimetry (DSC) of AS31, AS33 and AS35 alloys. The samples were encapsulated in stainless steel crucibles during the measurement using an empty crucible as the reference. The samples were heated up to 680°C, melted and solidified in the beginning of the experiment in order to fill the crucible. This short cycle was followed by three subsequent cycles between 400°C and 680°C with 5, 10 and 20 K/min heating and cooling rates with 5 min of holding time in the molten state. The diffraction patterns were recorded every 6 s during the DSC program by a Perkin-Elmer XRD 1622 Flatpanel detector including an acquisition time of 3 s and the collection of reference images. The endothermic and exothermic peaks are in correlation with the dissolution and formation of new diffraction patterns, respectively. During cooling from the liquid state, first, α-Mg dendrites solidify, followed by the formation of Mg2Si and Mg17Al12 intermetallics. The results are correlated with those obtained by thermodynamic simulations performed with the software Pandat. %0 conference lecture %@ %A Tolnai, D.,Szakacs, G.,Requena, G.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2013 %J 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P %T Study of the Solidification of AS Alloys Combining in situ Synchrotron Diffraction and Differential Scanning Calorimetry %U %X %0 journal article %@ 0925-8388 %A Lalpoor, M.,Dzwonczyk, J.S.,Hort, N.,Offerman, S.E. %D 2013 %J Journal of Alloys and Compounds %N %P 73-76 %R doi:10.1016/j.jallcom.2012.12.116 %T Nucleation mechanism of Mg17Al12-precipitates in binary Mg–7 wt.% Al alloy %U https://doi.org/10.1016/j.jallcom.2012.12.116 %X We show that the classical nucleation theory that describes the critical nucleus as a coherent pill-box fits the experimentally measured nucleation rate of Mg17Al12-precipitates in undeformed Mg–7 wt.% Al alloy much more accurately than the classical theory that describes the critical nucleus as an incoherent sphere. The nucleation of Mg17Al12-precipitates takes place in the transient nucleation regime. Coarsening of the Mg17Al12-precipitates occurs just before the steady state nucleation rate is reached. %0 journal article %@ 0167-577X %A Tolnai, D.,Mendis, C.L.,Stark, A.,Szakacs, G.,Wiese, B.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Letters %N %P 62-64 %R doi:10.1016/j.matlet.2013.03.110 %T In situ synchrotron diffraction of the solidification of Mg4Y3Nd %U https://doi.org/10.1016/j.matlet.2013.03.110 %X In situ synchrotron diffraction experiments were performed during the solidification of a Mg4Y3Nd alloy. The material was melted and solidified inside a sealed stainless steel crucible in the chamber of a Bähr 805 A/D dilatometer. The sample was heated up to 680 °C and kept at this temperature for 5 min to ensure it is molten. Afterwards it was cooled down to the fully solidified state with a cooling rate of 10 K/min. During the T(t) program diffraction patterns were acquired continuously in every 25 s (∼5 K). The forming phases were identified as α-Mg at 625 °C, Mg12Nd and Mg14Y4Nd at 545 °C, and Mg24Y5 at 320 °C. The experimental results were correlated with simulations based on thermodynamic databases. %0 conference paper %@ %A Dharmendra, C.,Rao, K.P.,Hort, N.,Kainer, K.U. %D 2013 %J Magnesium Technology 2013, Proceedings of TMS 2013 Annual Meeting & Exhibition %N %P 41-45 %R doi:10.1002/9781118663004.ch7 %T High Temperature Deformation of Magnesium Alloy TX32-0.4Al-0.8Si %U https://doi.org/10.1002/9781118663004.ch7 %X %0 conference lecture %@ %A Wang, Z.,Huang, Y.,Srinivasan, A.,Zhen, L.,Kainer, K.U.,Hort, N. %D 2013 %J 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P %T Influences of Y Additions on the Hot Tearing Susceptibility of Mg-1.5wt.%Zn Alloys %U %X %0 journal article %@ 0921-5093 %A Yu, Z.J.,Huang, Y.,Qiu, X.,Yang, Q.,Sun, W.,Tian, Z.,Zhang, D.P.,Meng, J. %D 2013 %J Materials Science and Engineering A %N %P 346-353 %R doi:10.1016/j.msea.2013.04.108 %T Fabrication of magnesium alloy with high strength and heat-resistance by hot extrusion and ageing %U https://doi.org/10.1016/j.msea.2013.04.108 %X A Mg–11Gd–4.5Y–1.5Zn–1Nd–0.5Zr alloy with high-strength and heat-resistance has successfully been prepared by hot extrusion and subsequent ageing. It exhibits an ultimate tensile strength of 473 MPa, 0.2% proof stress of 373 MPa and elongation to failure of 4.1% at room temperature. At 250 °C, this alloy shows an ultimate tensile strength of 369 MPa, 0.2% proof stress of 316 MPa and elongation to failure of 6.3%. Its good mechanical properties and thermal stability are attributed to the dispersion of large volume fraction of 14H-LPSO phase, small α-Mg grains, basal-fiber texture and dense distribution of precipitates at the grain boundaries and inside the grains. %0 journal article %@ 0921-5093 %A Dieringa, H.,Huang, Y.,Wittke, P.,Klein, M.,Walther, F.,Dikovits, M.,Poletti, C. %D 2013 %J Materials Science and Engineering A %N %P 430-438 %R doi:10.1016/j.msea.2013.07.041 %T Compression-creep response of magnesium alloy DieMag422 containing barium compared with the commercial creep-resistant alloys AE42 and MRI230D %U https://doi.org/10.1016/j.msea.2013.07.041 %X The development of creep-resistant magnesium alloys that avoid the use of rare-earth alloying elements is an important area of research. The creep response of Mg–Al–Ca alloy containing barium (DieMag422) was compared to that of commercially available creep resistant magnesium alloys AE42 and MRI230D. The creep tests were performed between 175 °C and 240 °C at stresses between 60 MPa and 120 MPa. From the temperature and stress dependence of the minimum creep rate, the apparent activation energy Qc and the stress exponent n for creep were calculated. The concept of a threshold stress was applied. True stress exponents nt close to 5 were calculated. Microstructural investigations and phase analysis were performed on the as-cast materials as well as after creep. Fine precipitates could be identified that justified application of the concept of threshold stress. The DieMag422 alloy shows an improvement in creep resistance at low stresses compared with the other two alloys AE42 and MRI230D. %0 journal article %@ 1742-7061 %A Yang, L.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Mendis, C.,Kainer, K.U.,Hort, N. %D 2013 %J Acta Biomaterialia %N 10 %P 8499-8508 %R doi:10.1016/j.actbio.2013.03.017 %T Microstructure, mechanical and corrosion properties of Mg–Dy–Gd–Zr alloys for medical applications %U https://doi.org/10.1016/j.actbio.2013.03.017 10 %X In previous investigations, a Mg–10Dy (wt.%) alloy with a good combination of corrosion resistance and cytocompatibility showed great potential for use as a biodegradable implant material. However, the mechanical properties of Mg–10Dy alloy are not satisfactory. In order to allow the tailoring of mechanical properties required for various medical applications, four Mg–10(Dy + Gd)–0.2Zr (wt.%) alloys were investigated with respect to microstructure, mechanical and corrosion properties. With the increase in Gd content, the number of second-phase particles increased in the as-cast alloys, and the age-hardening response increased at 200 °C. The yield strength increased, while the ductility reduced, especially for peak-aged alloys with the addition of Gd. Additionally, with increasing Gd content, the corrosion rate increased in the as-cast condition owing to the galvanic effect, but all the alloys had a similar corrosion rate (∼0.5 mm year−1) in solution-treated and aged condition. %0 journal article %@ 1073-5623 %A Srinivasan, A.,Wang, Z.,Huang, Y.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2013 %J Metallurgical and Materials Transactions A %N 5 %P 2285-2298 %R doi:10.1007/s11661-012-1593-7 %T Hot Tearing Characteristics of Binary Mg-Gd Alloy Castings %U https://doi.org/10.1007/s11661-012-1593-7 5 %X Hot tearing characteristics of Mg-xGd (x = 1, 2, 5 and 10 wt pct) binary alloys have been studied in a constrained rod casting apparatus attached with a load cell and data acquisition system. The onset temperature of the hot tearing was identified from the force drop in the force–temperature–time curve, and the corresponding onset solid fraction was obtained from the fraction solid–temperature curve derived using Scheil non-equilibrium solidification model. The results indicate that the onset solid fraction for the hot tear decreased as the Gd content increased. The susceptibility defined by the total tear volume measurements by the X-ray micro-tomography technique indicates that the susceptibility increased with increase in Gd content to reach a maximum at 2 pct and then reduced with further increase in Gd to reach a minimum with 10 pct Gd. The high susceptibility observed in Mg-2 pct Gd was attributed to its cellular or columnar grain structure, which facilitated easy tear propagation, high strain at the onset with little amount of remaining liquid. In contrast, the lowest susceptibility of Mg-10 pct Gd was related to its equiaxed grain structure, which effectively accommodated the strain during solidification by reorienting themselves and the ability of the Gd-rich liquid to partially or completely refill the tear at the end of solidification. The results also indicate that the increase in mold temperature [723 K (450 °C)] significantly reduced the total crack volume and hence reduced the susceptibility, which was attributed to the increase in the hot spot size and lesser total stain at the hot spot region. %0 journal article %@ 0255-5476 %A Wang, Z.,Huang, Y.,Srinivasan, A.,Zhen, L.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Science Forum, Light Metals Technology Conference, LMT 2013 %N %P 306-310 %R doi:10.4028/www.scientific.net/MSF.765.306 %T Influences of Y Additions on the Hot Tearing Susceptibility of Mg-1.5wt.%Zn Alloys %U https://doi.org/10.4028/www.scientific.net/MSF.765.306 %X The influences of Y (0.2, 2 and 4 wt.%) additions on the hot tearing behaviour of Mg‑1.5Zn alloys were investigated using a constrained rod casting (CRC) apparatus equipped with a load cell and data acquisition system. The initiation of hot tearing was monitored during CRC experiments. It corresponds to a drop in load on the hot tearing curves. The experimental results indicate that, the hot tearing susceptibility defined by the total crack volume, which was measured by the wax penetration method, decreases with increasing the content of Y at a mould temperature of 250 °C. The reduced susceptibility is attributed to the effect of Y on the solidification behaviour: it shortens the freezing range and reduces the grain size. The highest susceptibility is observed for Mg-1.5Zn-0.2Y alloy. It is caused by its coarse microstructure and relatively larger solidification range. In contrast, the lowest susceptibility is observed for Mg-1.5Zn-4Y alloy with a small equiaxed grain microstructure. In addition, the healing of hot cracks by the subsequent refilling of the remained liquid at the later stage of solidification is also beneficial for the alleviation of hot tearing susceptibility in Mg-1.5Zn-4Y alloy. %0 journal article %@ 8756-758X %A Huang, Y.,Dieringa, H.,Kainer, K.U.,Hort, N. %D 2013 %J Fatigue and Fracture of Engineering Materials and Structures %N 4 %P 308-315 %R doi:10.1111/ffe.12000 %T Effects of Sn segregation and precipitates on creep response of Mg-Sn alloys %U https://doi.org/10.1111/ffe.12000 4 %X Mg-Sn alloys are promising for the development of new cheap creep resistant magnesium alloys. In the present paper, the creep behaviours of Mg-Sn and Mg-Sn-Ca alloys were examined at the constant temperature and different stresses. The measurements of stress exponents indicate that the dislocation climbing is the dominant mechanism during the creep of Mg-3Sn or Mg-3Sn-2Ca alloys. The poor creep resistance of the binary Mg-3Sn alloy is caused by the easy movement of dislocation and the segregation of Sn at the boundaries. Both T4 and T6 heat treatments improve the creep resistance of Mg-3Sn alloy due to the alleviation of Sn segregation at grain boundaries and the precipitation of Mg2Sn particles, respectively. Ca is an effective alloying element to increase the creep resistance of Mg-Sn alloys. The Ca addition leads to the formation of thermal stable phases Mg2Ca and CaMgSn in Mg-3Sn-Ca alloys. These two phases effectively hinder the movement of dislocations and the sliding of grain boundaries. On the other hand, the addition of Ca alleviates the segregation of Sn by the interaction of Ca with Mg and Sn to form the phase CaMgSn. %0 conference poster %@ %A Hamdani, M.,Zidane, N.,Ait Addi, A.,Douch, J.,Dietzel, W.,Dieringa, H.,Hort, N. %D 2013 %J Proceedings of Journees Electrochimie 2013 %N %P 212 %T Effect of gadolinium content on the corrosion behaviour of magnesium alloys in 1% NaCl solution %U %X %0 journal article %@ 1742-7061 %A Yang, L.,Hort, N.,Laipple, D.,Hoeche, D.,Huang, Y.,Kainer, K.U.,Willumeit, R.,Feyerabend, F. %D 2013 %J Acta Biomaterialia %N 10 %P 8475-8487 %R doi:10.1016/j.actbio.2012.10.001 %T Element distribution in the corrosion layer and cytotoxicity of alloy Mg–10Dy during in vitro biodegradation %U https://doi.org/10.1016/j.actbio.2012.10.001 10 %X The present work investigates the corrosion behaviour, the element distribution in the corrosion layer and the cytocompatibility of alloy Mg–10Dy. The corrosion experiments were performed in a cell culture medium (CCM) under cell culture conditions close to the in vivo environment. The element distribution on the surface as well as in cross-sections of the corrosion layer was investigated using scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy and X-ray diffraction. The cytocompatibility of alloy Mg–10Dy with primary human osteoblasts was evaluated by MTT, cell adhesion and live/dead staining tests. The results show that the corrosion layer was enriched in Dy, while the P and Ca content gradually decreased from the surface to the bottom of the corrosion layer. In addition, large amounts of MgCO3·3H2O formed in the corrosion layer after 28 days immersion. Both extracts and the Dy-enriched corrosion layer of alloy Mg–10Dy showed no cytotoxicity to primary human osteoblasts. %0 conference paper %@ %A Mendis, C.L.,Maier, P.,Mueller, S.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Science and Technology 2013 %N %P 1542-1549 %T Microstructure investigation of Mg-10Gd-1La containing alloy subjected to fatigue deformation %U %X %0 conference lecture %@ %A Mendis, C.L.,Maier, P.,Mueller, S.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Science and Technology 2013 %N %P %T Microstructure investigation of Mg-10Gd-1La containing alloy subjected to fatigue deformation %U %X %0 journal article %@ 0255-5476 %A Maier, P.,Richter, A.,Tober, G.,Hort, N. %D 2013 %J Materials Science Forum, Light Metals Technology Conference, LMT 2013 %N %P 491-495 %R doi:10.4028/www.scientific.net/MSF.765.491 %T Effect of Grain Size and Structure, Solid Solution Elements, Precipitates and Twinning on Nanohardness of Mg-RE alloys %U https://doi.org/10.4028/www.scientific.net/MSF.765.491 %X In this study Mg10GdxNd alloys are investigated by nanoindentation hardness measurements in several material conditions. Mg10GdxNd alloys with an average coarse grain size of 500 µm were cast by permanent mold direct chill casting. Hardness values vary due to the inhomogeneous microstructure formed during the solidification process consisting of dendrite arms with preferred orientation direction. The effect of dissolving particles during solution heat treatment (T4) and isothermal ageing (T6) was observed to a different extent depending on Nd content. Isothermal ageing promotes a duplex microstructure of coarse β1 phase precipitates and regions containing much finer precipitates. Post processing by direct extrusion changes the microstructure dramatically to an average grain size of 15 µm. The microstructure after hot extrusion shows segregation of precipitates in the extrusion direction. Near this alignment of second phases hardness and plastic deformation differ from precipitates enriched in RE elements due to depleted regions of solid solution around them. This phenomenon is known from alloying element segregation to grain boundaries. Depending on the amount and location of second phases in the as-cast microstructure and degree of cold work, recrystallization leads to an inhomogeneous microstructure, consisting of fine grains (15 µm) and very fine grains, where second phases act as nuclei during the recrystallization process. Furthermore, mechanical testing (fatigue) causes an increase in dislocation density by work hardening and extensive twinning near the fractured surface. Here the hardening effect interferes with grain size strengthening. %0 journal article %@ 0046-5933 %A Crespo, J.,Requena, G.,Degischer, H.-P.,Track, K.,Tolnai, D. %D 2013 %J International Foundry Research %N 3 %P 04 %T Three-dimensional characterisation of micropores and graphite nodules in ductile cast iron %U 3 %X Powerful non-destructive inspection techniques such as micro radiography and X-ray based multi-scale computed tomography (XCT) including synchrotron X-ray computer tomography (SCT) are capable to reveal the heterogeneities in the microstructure of ductile cast iron samples. Both graphite particles and micropores show a strong absorption contrast with respect to the iron matrix owing to the difference in X-ray absorption. The quantitative analysis of size distribution and nodularity which is usually performed by destructive optical metallography is essentially confirmed by three-dimensional tomography. An interdendritic three dimensional extension of feeding pores is revealed by XCT in the central main bearing of a nodular cast iron crankshaft. The orientation of those pores is continued by equally aligned graphite nodules. Microporosity is also revealed in between regions of homogeneous graphite distribution and is clearly discriminated by SCT. Performing in-situ tensile tests during synchrotron tomography show the micropore distribution in the gauge length and its role in crack formation and propagation in miniature tensile samples. Both micropores and graphite particles are the weakest points of the casting under tensile stress. Micropores < 150 µm in width and below 1 vol. % do not degrade the strength of the casting. Cracks form at the micropore with the largest extension perpendicular to the tensile direction and propagate along pores in regions where the local porosity is > 1 vol. %. %0 conference paper %@ %A Maier, P.,Richter, A.,Tober, G.,Hort, N. %D 2013 %J Light Metals Technology 2013, 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P 491-495 %T Effect of Grain Size and Structure, Solid Solution Elements, Precipitates and Twinning on Nanohardness of Mg-RE alloys %U %X %0 report part %@ %A Wiese, B.,Tolnai, D.,Mendis, C.,Eckerlebe, H.,Hort, N. %D 2013 %J Annual Report Photon Science 2013 %N %P %T In situ diffraction of the melting and the solidification of magnesium alloys containing CaO %U %X %0 conference lecture %@ %A Hort, N.,Ebel, T.,Wolff, M. %D 2013 %J Light Metals for Future Vehicle Concepts %N %P %T Powder Metallurgy Processing of Magnesium Alloys Challenges and Potential Contributions for Light Weight Structures %U %X %0 journal article %@ 2213-9567 %A Gan, W.M.,Huang, Y.D.,Wang, R.,Zhong, Z.Y.,Hort, N.,Kainer, K.U.,Schell, N.,Brokmeier, H.-G.,Schreyer, A. %D 2013 %J Journal of Magnesium and Alloys %N 4 %P 341-345 %R doi:10.1016/j.jma.2013.12.004 %T Bulk and local textures of pure magnesium processed by rotary swaging %U https://doi.org/10.1016/j.jma.2013.12.004 4 %X Rotary swaging processing on commercial as-cast pure Mg has been carried out. Bulk texture variation with the processing passes was investigated using large gauge volume by neutron diffraction, of which results showed a combination of different components such as {00.2} basal fibre and two weak {10.0} and {11.0} fibres. Asymmetric distribution of the basal fibre around swaging direction was observed and being related to the processing parameters. Texture gradient analysis by synchrotron radiation demonstrates a non-uniform deformation of the RS processed pure Mg from surface to the centre. %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2013 %J International Conference on Processing and Manufacturing of Advanced Materials, Thermec 2013 %N %P %T Hot forging of cast magnesium alloy TX31 using semi-closed die and its finite element simulation %U %X %0 journal article %@ 1003-6326 %A Suresh, K.,Rao, K.P.,Prasad, Y.V.R,K.,Hort, N.,Kainer, K.U. %D 2013 %J Transactions of Nonferrous Metals Society of China %N 12 %P 3604-3610 %R doi:10.1016/S1003-6326(13)62907-6 %T Microstructure and mechanical properties of as-cast Mg–Sn–Ca alloys and effect of alloying elements %U https://doi.org/10.1016/S1003-6326(13)62907-6 12 %X The effect of Sn, Ca, Al, Si and Zn addition on the compressive strength of cast Mg–Sn–Ca (TX) alloys was studied in the temperature range of 25–250 °C and correlated with the microstructure. The Sn to Ca mass ratio up to 2.5 contributes to the formation of Mg2Ca phase at the grain boundaries and CaMgSn in the matrix, while a ratio of 3 gives only CaMgSn phase mostly in the matrix. While the compressive strength decreases with the increase in temperature, for Sn/Ca up to 2.5, a plateau occurs in 100–175 °C, which is attributed to the strengthening by Mg2Ca. However, for ratio of 3, the strength is lower and decreases more gradually. Mg–3Sn–2Ca (TX32) has the highest strength and the addition of 0.4% Al increases its strength but simultaneous addition of Si lowers the strength. Likewise, the addition of Zn improves its strength but simultaneous addition of Al slightly decreases the strength. The results are correlated with the types of intermetallic phases that form in various alloys. %0 journal article %@ 2046-0147 %A Maier, P.,Mendis, C.,Tober, G.,Hort, N. %D 2013 %J Emerging Materials Research %N 5 %P 229-238 %R doi:10.1680/emr.13.00021 %T Tailoring properties of cast Mg10Gd by alloying Nd and heat treatment %U https://doi.org/10.1680/emr.13.00021 5 %X Magnesium-rare Earth alloys receive growing interest for medical applications as implant material due to their non-toxicity, high specific strength with moderate corrosion rate and elastic modulus comparable with bone. In this study, the corrosion properties of cast Mg10Gd modified with neodymium have been investigated by potentiodynamic measurements. Adding neodymium to Mg10Gd improves mechanical properties, but the influence on the corrosion behavior was rarely investigated. The heat treatment of Mg10Gd1Nd and Mg10Gd2Nd, especially T6, increased strength due to precipitation of prismatic plate precipitates. In most magnesium alloys, the degradation of α-Mg matrix preferentially due to the cathodic response of precipitates, the influence of type and distribution of the precipitates on the nature and dynamics of the corrosion process is discussed. The temperature increase from room to body temperature accelerates the corrosion processes. However, an extended repassivation is observed at higher temperatures. %0 journal article %@ 2046-0147 %A Schille, C.,Schweizer, E.,Hort, N.,Reichel, H.-P.,Geis-Gerstorfer, J. %D 2013 %J Emerging Materials Research %N 5 %P 248-262 %R doi:10.1680/emr.13.00023 %T Zone coulometry and ion-release analysis of degradable magnesium alloys %U https://doi.org/10.1680/emr.13.00023 5 %X Zone coulometry and determination of ion release of an electrolyte from anodic polarization measurements are the established calculation modes for the electrochemical behavior of dental and biomedical alloys. The aim of the study was to compare the electrochemical corrosion behavior of six different experimental magnesium alloys without manganese using artificial plasma (AP) and in phosphate-buffered saline (PBS−) as simulated body fluids through anodic polarization measurements. In addition, determination of the magnesium release of the electrolytes was performed using inductively coupled plasma optical emission spectrometry and zone coulometry. Six specimens were prepared from each alloy. Anodic polarization measurements ranging from –150 mV ~E corr to –1200 mV were performed with both of the electrolytes. From each measurement, corrosion current density, the breakdown or pitting potential and its corresponding current density, zero potential, the polarization resistance, the corrosion rate were calculated. The magnesium release of the electrolytes was compared with the calculated values using Faraday’s law. For zone coulometry, five different trials were completed, and the electrical charge was calculated for each potential range of all magnesium alloys tested and for both electrolytes. Lower corrosion values were found in AP than in PBS− for all measurements. However, the rankings of the alloys are similar in both the electrolytes. Zone coulometry using small potential ranges and determination of ion release can be additional evaluation tools for magnesium alloys. %0 conference lecture %@ %A Maier, P.,Tober, G.,Mendis, C.L.,Mueller, S.,Hort, N. %D 2013 %J International Conference on Processing and Manufacturing of Advanced Materials, Thermec 2013 %N %P %T Influence of Nd in extruded Mg10Gd base alloys on fatigue strength %U %X %0 conference lecture %@ %A Mendis, C.L.,Tolnai, D.,Blawert, C.,Hort, N. %D 2013 %J 142nd Annual Meeting & Exhibition, TMS 2013 %N %P %T Effect of Sn additions on the age hardening response, microstructures and corrosion resistance of Mg-0.8Ca (wt%) alloys %U %X %0 conference lecture (invited) %@ %A Mendis, C.L.,Srinivasan, A.,Huang, Y.,Hort, N.,Kainer, K.U. %D 2013 %J 22nd International Conference on Processing and Fabrication of Advanced Materials, PFAM XXII %N %P %T Precipitate formation during creep of Mg10Gd(2-6)Zn alloys %U %X %0 journal article %@ 1862-5282 %A Schlueter, K.,Zamponi, C.,Hapke, J.,Hort, N.,Kainer, K.U.,Quandt, E. %D 2013 %J International Journal of Materials Research %N 3 %P 286-292 %R doi:10.3139/146.110860 %T Mechanical properties and corrosion behaviour of freestanding, precipitate-free magnesium WE43 thin films %U https://doi.org/10.3139/146.110860 3 %X Magnetron sputtered freestanding thin films of two modified WE43 alloys (Mg4Y3Nd and Mg4Y3Gd) consist of a supersaturated single phase microstructure with a strong texture in [0001] direction for a wide range of deposition conditions. While the deposition conditions have no significant influence on the corrosion behaviour of these samples, they strongly influence the mechanical properties, which can be tuned between extremely brittle behaviour for high sputtering pressures (2.0 × 10−2 mbar) and ductile behaviour with a maximum strain of about 18 % at room temperature for low sputtering pressures (8.0 × 10−4 mbar) for both investigated alloys. %0 conference lecture %@ %A Maier, P.,Richter, A.,Tober, G.,Hort, N. %D 2013 %J 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P %T Effect of Grain Size and Structure, Solid Solution Elements, Precipitates and Twinning on Nanohardness of Mg-RE alloys %U %X %0 lecture %@ %A Hort, N. %D 2013 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 conference lecture %@ %A Blawert, C.,Stoermer, M.,Huang, Y.,Hoeche, D. %D 2013 %J Tagungsband, 9. ThGOT Thementage Grenz- und Oberflaechentechnik %N %P 56-60 %T Alternative metallische Korrosionsschutzschichten fuer Magnesiumlegierungen %U %X %0 conference paper %@ %A Tolnai, D.,Szakacs, G.,Requena, G.,Stark, A.,Schell, N.,Kainer, K.U.,Hort, N. %D 2013 %J Light Metals Technology 2013, 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P 286-290 %T Study of the Solidification of AS Alloys Combining in situ Synchrotron Diffraction and Differential Scanning Calorimetry %U %X %0 conference paper %@ %A Wang, Z.,Huang, Y.,Srinivasan, A.,Zhen, L.,Kainer, K.U.,Hort, N. %D 2013 %J Light Metals Technology 2013, 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P 306-310 %T Influences of Y Additions on the Hot Tearing Susceptibility of Mg-1.5wt.%Zn Alloys %U %X %0 conference paper %@ %A Srinivasan, A.,Huang, Y.,Mendis, C.,Dieringa, H.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2013 %J Light Metals Technology 2013, 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P 28-32 %T Microstructure, Mechanical and Corrosion Properties of Mg-Gd-Zn Alloys %U %X %0 journal article %@ 1742-7061 %A Scheideler, L.,Fueger, C.,Schille, C.,Rupp, F.,Wendel, H.-P.,Hort, N.,Reichel, H.P.,Geis-Gerstorfer, J. %D 2013 %J Acta Biomaterialia %N 10 %P 8740-8745 %R doi:10.1016/j.actbio.2013.02.020 %T Comparison of different in vitro tests for biocompatibility screening of Mg alloys %U https://doi.org/10.1016/j.actbio.2013.02.020 10 %X Standard cell culture tests according to ISO 10993 have only limited value for the biocompatibility screening of degradable biomaterials such as Mg alloys. The correlation between in vitro and in vivo results is poor. Standard cytotoxicity tests mimic the clinical situation to only a limited extent, since in vivo proteins and macromolecules in the blood and interstitial liquid will influence the corrosion behaviour and, hence, biocompatibility of Mg alloys to a significant extent. We therefore developed a modified cytotoxicity test simulating the in vivo conditions by use of bovine serum as the extraction vehicle instead of the cell culture medium routinely used in standard cytotoxicity testing according to ISO 10993-5. The modified extraction test was applied to eight experimental Mg alloys. Cytotoxicity was assayed by inhibition of cell metabolic activity (XTT test). When extraction of the alloy samples was performed in serum instead of cell culture medium the metabolic activity was significantly less inhibited for six of the eight alloys. The reduction in apparent cytotoxicity under serum extraction conditions was most pronounced for MgZn1 (109% relative metabolic activity with serum extracts vs. 26% in Dulbecco’s modified Eagle’s medium (DMEM)), for MgY4 (103% in serum vs. 32% in DMEM) and for MgAl3Zn1 (84% vs. 17%), resulting in a completely different cytotoxicity ranking of the tested materials when serum extraction was used. We suppose that this test system has the potential to enhance the predictability of in vivo corrosion behaviour and biocompatibility of Mg-based materials for biodegradable medical devices. %0 journal article %@ 1438-1656 %A Dharmendra, C.,Rao, K.P.,Venkata, Y.,Prasad, R.K.,Hort, N.,Kainer, K.U. %D 2013 %J Advanced Engineering Materials %N 8 %P 761-766 %R doi:10.1002/adem.201200379 %T High Temperature Deformation and Microstructural Features of TXA321 Magnesium Alloy: Correlations with Processing Map %U https://doi.org/10.1002/adem.201200379 8 %X The hot deformation of cast TXA321 alloy has been studied in the temperature range 300–500 °C and in the strain rate range 0.0003–10 s−1 by developing a processing map. The map exhibited four domains in the temperature and strain rate ranges: (1) 300–325 °C and 0.0003–0.001 s−1, (2) 325–430 °C and 0.001–0.04 s−1, (3) 430–500 °C and 0.01–0.5 s−1, and (4) 430–500 °C and 0.0003–0.002 s−1. The first three domains represent dynamic recrystallization, resulting in finer grain sizes in the first two domains and coarser in the third domain. In the fourth domain, the alloy exhibited grain boundary sliding resulting in intercrystalline cracking in tension and is not useful for its hot working. Two regimes of flow instability were identified at higher strain rates, one at temperatures <380 °C and the other at >480 °C. %0 journal article %@ 0925-8388 %A Hampl, M.,Blawert, C.,Silva Campos, M.R.,Hort, N.,Peng, Q.,Kainer, K.U.,Schmid-Fetzer, R. %D 2013 %J Journal of Alloys and Compounds %N %P 166-177 %R doi:10.1016/j.jallcom.2013.07.042 %T Thermodynamic assessment and experimental study of MgGd alloys %U https://doi.org/10.1016/j.jallcom.2013.07.042 %X The solid solubility of Gd in (Mg) is studied experimentally using microstructure, chemical and EDX analysis on permanent mould chill cast samples which were annealed for 1–14 days at 300–550 °C. Based on those key data and all the critically assessed experimental phase equilibrium and thermodynamic data of the Mg–Gd system two Calphad-type thermodynamic descriptions are developed. This provides calculated phase diagrams, and an inherent inconsistency between the vapor pressure data and the Mg-rich phase diagram is indicated. A previous misperception of “experimental” enthalpy of formation data of binary GdxMgy intermetallic compounds is also revealed. The assumption of systematic trends in these key thermodynamic data for the series of rare earth elements R = (La, Ce, Pr, Nd, Sm, Gd) is scrutinized. %0 journal article %@ 1478-6435 %A Rao, K.P.,Ip, H.Y.,Suresh, K.,Prasad, Y.V.R.K.,Wu, C.M.L.,Hort, N.,Kainer, K.U. %D 2013 %J Philosophical Magazine %N 35 %P 4364-4377 %R doi:10.1080/14786435.2013.830202 %T Compressive strength and hot deformation mechanisms in as-cast Mg-4Al-2Ba-2Ca (ABaX422) alloy %U https://doi.org/10.1080/14786435.2013.830202 35 %X The behaviour of an as-cast ABaX422 Mg alloy has been evaluated with regard to its compressive strength in the temperature range 25–250 °C and hot working characteristics in the range 260–500 °C. The microstructure of the as-cast alloy has intermetallic phases Mg17Ba2 and (Al, Mg)2Ca at the grain boundaries and is fine grained. The alloy has compressive strength better than AZ31 with Ca and Zn, which was attributed to the finer grain size. A processing map developed to characterize its hot working behaviour revealed two dynamic recrystallization domains in the temperature and strain rate ranges of (1) 300–390 °C/0.0003–0.001 s−1 and (2) 400–500 °C/0.0003–0.5 s−1. In the first domain, basal + prismatic slip occurs along with recovery by climb while in the second domain, second-order pyramidal slip dominates and recovery occurs by cross-slip. The apparent activation energy estimated in Domains 1 and 2 are 169 and 263 kJ/mol respectively, both being higher than that for self-diffusion suggesting that the intermetallic particles in the matrix cause considerable back stress. Bulk metal working of this alloy may be done in Domain 2 which ensures high workability while finish working may be done in Domain 1 in order to achieve a fine grained component. The alloy exhibits flow instability regimes at higher strain rates, in both the lower and higher temperature regions of the processing map, the manifestation being adiabatic shear band formation and flow localization respectively. %0 lecture %@ %A Tolnai, D. %D 2013 %J %N %P %T Electrons, Neutrons and Synchrotron Radiation for Engineering Materials %U %X %0 journal article %@ 0921-5093 %A Tolnai, D.,Requena, G.,CCloetens, P.,Lendvai, J.,Degischer, H.P. %D 2013 %J Materials Science and Engineering A %N %P 480-487 %R doi:10.1016/j.msea.2013.06.033 %T Effect of solution heat treatment on the internal architecture and compressive strength of an AlMg4.7Si8 alloy %U https://doi.org/10.1016/j.msea.2013.06.033 %X The evolution of the microstructure of an AlMg4.7Si8 alloy is investigated by scanning electron microscopy and ex situ synchrotron tomography in as-cast condition and subsequent solution treatments for 1 h and 25 h at 540 °C, respectively. The eutectic Mg2Si phase, which presents a highly interconnected structure in the as-cast condition, undergoes significant morphological changes during the solution heat treatment. Statistical analyses of the particle distribution, the sphericity, the mean curvatures and Gaussian curvatures describe the disintegration of the interconnected seaweed-like structure followed by the rounding of the disintegrated fractions of the eutectic branches quantitatively. The ternary eutectic Si resulting from the Si-surplus to the stoichiometric Mg2Si ratio of the alloy undergoes similar changes. The morphological evolution during solution heat treatment is correlated with results of elevated temperature compression tests at 300 °C. The elevated temperature compressive strength is more sensitive to the degree of interconnectivity of the three dimensional Mg2Si network than to the shape of the individual particles. %0 conference lecture (invited) %@ %A Hort, N. %D 2013 %J International Conference on Processing and Manufacturing of Advanced Materials, Thermec 2013 %N %P %T Challenges in the development of degradable Mg implant materials %U %X %0 conference paper %@ %A Mendis, C.L.,Tolnai, D.,Blawert, C.,Hort, N. %D 2013 %J Magnesium Technology 2013, Proceedings of TMS 2013 Annual Meeting & Exhibition %N %P 237-241 %R doi:10.1002/9781118663004.ch39 %T Effect of Sn additions on the age hardening response, microstructures and corrosion resistance of Mg-0.8Ca (wt%) alloys %U https://doi.org/10.1002/9781118663004.ch39 %X %0 conference lecture %@ %A Dharmendra, C.,Rao, K.P.,Hort, N.,Kainer, K.U. %D 2013 %J 142nd Annual Meeting & Exhibition, TMS 2013 %N %P %T High Temperature Deformation of Magnesium Alloy TX32-0.4Al-0.8Si %U %X %0 conference paper %@ %A Lalporr, M.,Dzwonczyk, J.S.,Hort, N.,Offermann, S.E. %D 2013 %J Magnesium Technology 2013, Proceedings of TMS 2013 Annual Meeting & Exhibition %N %P 259-262 %R doi:10.1002/9781118663004.ch43 %T Nucleation Kinetics of the Gamma-Phase in a Binary Mg-Al Alloy %U https://doi.org/10.1002/9781118663004.ch43 %X %0 conference lecture %@ %A Wiese, B.,Mendis, C.L.,Blawert, C.,Hort, N.,Kainer, K.U.,Nyberg, E. %D 2013 %J 142nd Annual Meeting & Exhibition, TMS 2013 %N %P %T A new magnesium alloy system: TEXAS %U %X %0 journal article %@ 1742-7061 %A Kuhlmann, J.,Bartsch, I.,Willbold, E.,Schuchardt, S.,Holz, O.,Hort, N.,Hoeche, D.,Heineman, W.R.,Witte, F. %D 2013 %J Acta Biomaterialia %N 10 %P 8714-8721 %R doi:10.1016/j.actbio.2012.10.008 %T Fast Escape of Hydrogen From Gas Cavities Around Corroding Magnesium Implants %U https://doi.org/10.1016/j.actbio.2012.10.008 10 %X Magnesium materials are of increasing interest in the development of biodegradable implants as they exhibit properties that make them promising candidates. However, formation of gas cavities after implantation of magnesium alloys is widely reported in literature. The gas composition and the concentration of in these bubbles are not clearly known as only a few studies using techniques not specific for were done about 60 years ago. Currently, many researchers assume that these cavities contain primarily hydrogen because it is a product of magnesium dissolution in aqueous media. In order to clearly answer this question, we implanted rare earth containing magnesium alloy disks in mice and determined the concentration of hydrogen gas for up to ten days using an amperometric hydrogen sensor and mass spectrometric measurements. We were able to directly monitor the hydrogen concentration over a period of ten days and to show that the gas cavities only contained a low concentration of hydrogen gas, even shortly after the formation of the cavities. This means that hydrogen must be exchanged very quickly after implantation. To confirm these results, hydrogen gas was directly injected subcutaneously and most of the hydrogen gas was found to exchange within the first hour after injection. Overall, our results disprove the common misbelief that these cavities mainly contain hydrogen and show how quickly this gas is exchanged with the surrounding tissue. %0 conference lecture %@ %A Blawert, C.,Stoermer, M.,Huang, Y.,Hoeche, D. %D 2013 %J 9. ThGOT Thementage Grenz- und Oberflaechentechnik %N %P %T Alternative metallische Korrosionsschutzschichten fuer Magnesiumlegierungen %U %X %0 journal article %@ 0261-3069 %A Wang, Z.,Huang, Y.,Srinivasan, A.,Zheng, L.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2013 %J Materials and Design %N %P 90-100 %R doi:10.1016/j.matdes.2012.12.044 %T Hot tearing susceptibility of binary MgY alloy castings %U https://doi.org/10.1016/j.matdes.2012.12.044 %X The influence of Y content on the hot tearing susceptibility (HTS) of binary Mg–Y alloys has been predicted using thermodynamic calculations based on Clyne and Davies model. The calculated results are compared with experimental results determined using a constrained rod casting (CRC) apparatus with a load cell and data acquisition system. Both thermodynamic calculations and experimental measurements indicate that the hot tearing susceptibility as a function of Y content follows the “λ” shape. The experimental results show that HTS first increases with increase in Y content, reaches the maximum at about 0.9 wt.%Y and then decreases with further increase the Y content. The maximum susceptibility observed in Mg–0.9 wt.%Y alloy is attributed to its coarsened columnar microstructure, large solidification range and small amount of eutectic at the time of hot tearing. The initiation of hot cracks is monitored during CRC experiments. It corresponds to a drop in load increment on the force curves. The critical solid fractions at which the hot cracks are initiated are in the range from 0.9 to 0.99. It is also found that it decreases with increasing the content of Y. The hot cracks propagate along the dendritic or grain boundaries through the interdendritic separation or tearing of interconnected dendrites. Some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids. %0 conference poster %@ %A Wiese, B.,Mendis, C.,Tolnai, D.,Stark, A.,Schell, N.,Hort, N.,Kainer, K.U.,Reichel, H.-P.,Brueckner, R. %D 2013 %J European XFEL / DESY Photon Science Users Meeting %N %P %T In situ solidification of a Mg-10 wt% CaO %U %X %0 conference poster %@ %A Hamdani, M.,Zidane, N.,Ait Addi, A.,Douch, J.,Dietzel, W.,Dieringa, H.,Hort, N. %D 2013 %J Journees Electrochimie 2013 %N %P %T Effect of gadolinium content on the corrosion behaviour of magnesium alloys in 1% NaCl solution %U %X %0 book part %@ %A Sillekens, W.,Hort, N. %D 2013 %J Structural Materials and Processes in Transportation %N %P 113-151 %T Magnesium and Magnesium Alloys %U %X %0 conference lecture %@ %A Srinivasan, A.,Huang, Y.,Mendis, C.,Dieringa, H.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2013 %J 6th Internaternational Light Metals Technology Conference, LMT 2013 %N %P %T Microstructure, Mechanical and Corrosion Properties of Mg-Gd-Zn Alloys %U %X %0 journal article %@ 0255-5476 %A Srinivasan, A.,Huang, Y.,Mendis, C.,Dieringa, H.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2013 %J Materials Science Forum, Light Metals Technology Conference, LMT 2013 %N %P 28-32 %R doi:10.4028/www.scientific.net/MSF.765.28 %T Microstructure, Mechanical and Corrosion Properties of Mg-Gd-Zn Alloys %U https://doi.org/10.4028/www.scientific.net/MSF.765.28 %X Microstructure, mechanical and corrosion properties of Mg-10Gd-2Zn and Mg-10Gd-,6Zn (all in wt.%) were evaluated in the as-cast condition. The microstructures of both alloys,contained (Mg, Zn)3Gd phase at the interdendritic regions and long period stacking ordered (LPSO),phase distributed in the matrix. The Mg-10Gd-6Zn alloy consisted of a high volume fraction of,(Mg,Zn)3Gd intermetallic phases continuously distributed along the grain boundaries. The tensile,properties, especially the elongation to failure of the Mg-10Gd-6Zn alloy were slightly lower than,those of Mg-10Gd-2Zn. An enhancement in creep resistance was observed with Mg-10Gd-2Zn,alloy with the post creep tested microstructure showing dynamic precipitation. Corrosion studies,indicated that increased Zn content, from 2 to 6 % in Mg-10Gd alloys, significantly reduced the,corrosion resistance. %0 lecture %@ %A Hort, N. %D 2013 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2013 %J AeroMat 2013 %N %P %T Magnesium Alloys in Aerospace %U %X %0 conference paper %@ %A Wiese, B.,Mendis, C.L.,Blawert, C.,Hort, N.,Kainer, K.U.,Nyberg, E. %D 2013 %J Magnesium Technology 2013, Proceedings of TMS 2013 Annual Meeting & Exhibition %N %P 231-235 %R doi:10.1002/9781118663004.ch38 %T A new magnesium alloy system: TEXAS %U https://doi.org/10.1002/9781118663004.ch38 %X %0 conference lecture %@ %A Wang, Z.,Huang, Y.,Zhen, Z.,Liu, Z.,Kainer, K.U.,Hort, N. %D 2013 %J 70th Annual World Magnesium Conference %N %P %T Hot Tearing of Magnesium Alloys %U %X %0 conference lecture %@ %A Tolnai, D.,Mendis, C.L.,Stark, A.,Szakacs, G.,Wiese, B.,Kainer, K.U.,Hort, N. %D 2013 %J 142nd Annual Meeting & Exhibition, TMS 2013 %N %P %T In situ synchrotron diffraction of the solidification of Mg-RE alloys %U %X %0 conference lecture %@ %A Cheng, J.,Hort, N.,Kainer, K.U.,Siyoung, K. %D 2013 %J 22nd International Conference on Metallurgy and Materials, Metal 2013 %N %P %T Effect of Internal Defects on Tensile Properties of A356 Casting Alloys %U %X %0 conference lecture %@ %A Lalporr, M.,Dzwonczyk, J.S.,Hort, N.,Offermann, S.E. %D 2013 %J 142nd Annual Meeting & Exhibition, TMS 2013 %N %P %T Nucleation Kinetics of the Gamma-Phase in a Binary Mg-Al Alloy %U %X %0 conference paper %@ %A Wang, Z.,Huang, Y.,Zhen, Z.,Liu, Z.,Kainer, K.U.,Hort, N. %D 2013 %J Proceedings of 70th Annual World Magnesium Conference %N %P 53-63 %T Hot Tearing of Magnesium Alloys %U %X %0 conference paper %@ %A Cheng, J.,Hort, N.,Kainer, K.U.,Kwak, S. %D 2013 %J METAL 2013 - 22nd International Conference on Metallurgy and Materials, Conference Proceedings %N %P 1171-1176 %T Effect of Internal Defects on Tensile Properties of A356 Casting Alloys %U %X %0 journal article %@ 0921-5093 %A Fechner, D.,Blawert, C.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2013 %J Materials Science and Engineering A %N %P 222-230 %R doi:10.1016/j.msea.2013.03.053 %T Development of a magnesium secondary alloy system for mixed magnesium post-consumer scrap %U https://doi.org/10.1016/j.msea.2013.03.053 %X Six alloys were prepared by high pressure die casting in order to develop a magnesium secondary alloy system for mixed post-consumer scrap. The alloys were investigated with regard to intermetallic phases, grain structures, mechanical properties and performance in the salt spray test. The results are discussed in relation to the characteristics of the high pressure die casting process. The effect of contamination by copper and compensation for this effect by the addition of zinc were thoroughly investigated for the most promising alloy. It is evident that the alloying elements strontium, silicon and calcium are incorporated in the ternary Zintl phase Sr6.33Mg16.67Si13, while aluminium, zinc, copper and magnesium form the tau-phases Mg32(Alx,Cu1−x)49 and Mg32(Al,Zn)49. The two tau-phases can merge due to isomorphism. Mg32(Al,Zn)49 ensures improved corrosion resistance after the addition of copper. %0 conference paper %@ %A Tolnai, D.,Mendis, C.L.,Stark, A.,Szakacs, G.,Wiese, B.,Kainer, K.U.,Hort, N. %D 2013 %J Magnesium Technology 2013, Proceedings of TMS 2013 Annual Meeting & Exhibition %N %P 253-257 %R doi:10.1002/9781118663004.ch42 %T In situ synchrotron diffraction of the solidification of Mg-RE alloys %U https://doi.org/10.1002/9781118663004.ch42 %X %0 conference paper %@ %A Schlueter, K.,Zamponi, C.,Schuermann, U.,Hort, N.,Kienle, L.,Kainer, K.U.,Quandt, E. %D 2012 %J Proceedings of the 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P 129-133 %T Amorphous Thin Films Consisting of Ternary MgZnCa-Alloys %U %X %0 conference paper %@ %A Xu, S.,Shen, G.,Williams, G.,Anopuo, O.,Hort, N.,Kainer, K.U.,Staron, P. %D 2012 %J Proceedings of the 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P 689-694 %T Development of a Standard Test to Evaluate Bolt-Load Retention of Magnesium Alloys %U %X %0 conference lecture %@ %A Xu, S.,Shen, G.,Williams, G.,Anopuo, O.,Hort, N.,Kainer, K.U.,Staron, P. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T Development of a Standard Test to Evaluate Bolt-Load Retention of Magnesium Alloys %U %X %0 journal article %@ 0010-938X %A Schlueter, K.,Zamponi, C.,Hort, N.,Kainer, K.U.,Quandt, E. %D 2012 %J Corrosion Science %N %P 234-238 %R doi:10.1016/j.corsci.2012.06.005 %T Polycrystalline and amorphous MgZnCa thin films %U https://doi.org/10.1016/j.corsci.2012.06.005 %X The corrosion properties of thin films fabricated from the alloys Mg50Zn5Ca and Mg35Zn5Ca by magnetron sputter deposition were investigated in phosphate buffered saline solution (PBS). Microstructural investigations revealed that the deposition conditions have a huge influence on the thin films’ microstructure. Such the fabrication of polycrystalline microstructures with precipitates was possible as well as amorphous films. Corrosion tests indicated a significant decrease of the corrosion rate from nearly 80 to 3.5 μm/month for Mg50Zn5Ca and from about 40 to 4 μm/month for Mg35Zn5Ca, respectively upon the change of the microstructure from polycrystalline with precipitates to amorphous. %0 conference paper %@ %A Hapke, J.,Abu Leil, T.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2012 %J Proceedings of the 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P 143-148 %T The Influence of Micro-Alloying Elements Al and Si on Properties of the Alloy Mg-3Sn-2Ca %U %X %0 conference lecture %@ %A Morales Garza, E.D.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P %T Microstructure and Creep Properties of MEZ Magnesium Alloy Processed by Thixocasting %U %X %0 conference lecture %@ %A Hapke, J.,Abu Leil, T.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T The Influence of Micro-Alloying Elements Al and Si on Properties of the Alloy Mg-3Sn-2Ca %U %X %0 journal article %@ 1359-6454 %A Tolnai, D.,Townsend, P.,Requena, G.,Salvo, L.,Lendvai, J.,Degischer, H.P. %D 2012 %J Acta Materialia %N 6-7 %P 2568-2577 %R doi:10.1016/j.actamat.2012.01.024 %T In situ synchrotron tomographic investigation of the solidification of an AlMg4.7Si8 alloy %U https://doi.org/10.1016/j.actamat.2012.01.024 6-7 %X The solidification sequence of an AlMg4.7Si8 alloy is imaged in situ by synchrotron microtomography. Tomograms with (1.4 μm)3/voxel have been recorded every minute while cooling the melt from 600 °C at a cooling rate of 5 K min−1 to 540 °C in the solid state. The solidification process starts with the three-dimensional evolution of the α-Al dendritic structure at 590 °C. The growth of the α-Al dendrites is described by curvature parameters that represent the coarsening quantitatively, and ends in droplet-like shapes of the secondary dendrite arms at 577 °C. There, the eutectic valley of α-Al/Mg2Si is reached, forming initially octahedral Mg2Si particles preferentially at the bases of the secondary dendrite arms. The eutectic grows with seaweed-like Mg2Si structures, with increasing connectivity. During this solidification stage Fe-aluminides form and expand as thin objects within the interdendritic liquid. Finally, the remaining liquid freezes as ternary α-Al/Mg2Si/Si eutectic at 558 °C, increasing further the connectivity of the intermetallic phases. The frozen alloy consists of four phases exhibiting morphologies characteristic of their mode of solidification: α-Al dendrites, eutectic α-Al/Mg2Si “Chinese script” with Fe-aluminides, and interpenetrating α-Al/Mg2Si/Si ternary eutectic. %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2012 %J Proceedings of the 15th European Conference on Composite Materials, ECCM 15 %N %P %T Ultrasonic Stirring as a Production Process for Nanoparticle Reinforced Magnesium Alloys and the Compression Creep Response of Ze10 Reinforced with Ceria Nanoparticles %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2012 %J 15th European Conference on Composite Materials, ECCM 15 %N %P %T Ultrasonic Stirring as a Production Process for Nanoparticle Reinforced Magnesium Alloys and the Compression Creep Response of Ze10 Reinforced with Ceria Nanoparticles %U %X %0 book part %@ %A Luthringer, B.J.C.,Hort, N.,Feyerabend, F. %D 2012 %J Wiley Encyclopedia of Composites, 2nd Edition %N %P 1756-1777 %R doi:10.1002/9781118097298.weoc144 %T Metal Matrix Composites: Magnesium %U https://doi.org/10.1002/9781118097298.weoc144 %X In this article, special attention is drawn to magnesium-based metal matrix composites (MMCs). The first part reviews the conventional and the newer processing techniques appropriate for the fabrication of magnesium matrix composites. These routes are divided into liquid- and solid-state fabrication, in situ, and spray forming methods. After introducing the matrix and its properties, reinforcements are described (continuous and discontinuous) and the obtained composites are discussed. The interface is also described. Finally, recent applications, such as medical purpose, are reported. %0 journal article %@ 1478-422X %A Yang, L.,Hort, N.,Willumeit, R.,Feyerabend, F. %D 2012 %J Corrosion Engineering Science and Technology %N 5 %P 335-339 %R doi:10.1179/1743278212Y.0000000024 %T Effects of corrosion environment and proteins on magnesium corrosion %U https://doi.org/10.1179/1743278212Y.0000000024 5 %X Magnesium and its alloys have a great potential to be used as degradable biomaterials for clinical applications, which only need temporary support. However, the corrosion of Mg under physiological conditions is not well understood yet. The aim of this study was to determine the effect of proteins and complex corrosion environments. The corrosion rates of dysprosium containing magnesium alloys in technical and physiological corrosion set-ups were compared. Moreover, pure magnesium was immersed under cell culture conditions in simple and complex protein solutions. Corrosion rates showed huge variations depending on the corrosion environment. Proteins delayed corrosion and altered the ion composition of the solutions. In conclusion, the choice of appropriate corrosion environment is crucial for in vitro experiments. %0 journal article %@ 0010-938X %A Qiao, Z.,Shi, Z.,Hort, N.,Abidin, N.I.Z.,Atrens, A. %D 2012 %J Corrosion Science %N %P 185-207 %R doi:10.1016/j.corsci.2012.04.030 %T Corrosion behaviour of a nominally high purity Mg ingot produced by permanent mould direct chill casting %U https://doi.org/10.1016/j.corsci.2012.04.030 %X The corrosion behaviour was characterized using hydrogen evolution, weight loss, electrochemical impedance spectroscopy (EIS) and cathodic polarization curves, in 3.5% NaCl saturated with Mg(OH)2, with tests lasting up to 14 days, and compared with the corrosion behaviour of the HP Mg used in our prior research at UQ. The corrosion behaviour was consistent with the uni-positive Mg+ ion Mg corrosion mechanism, particularly the fact that the corrosion rate measured using electrochemical techniques was consistently lower than that measured independently by weight loss or hydrogen evolution, as predicted by the uni-positive Mg+ ion Mg corrosion mechanism. %0 journal article %@ 1438-1656 %A Peng, Q.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2012 %J Advanced Engineering Materials %N 3 %P 178-184 %R doi:10.1002/adem.201100176 %T Development of High Performance Single-Phase Solid Solution Magnesium Alloy at Low Temperature %U https://doi.org/10.1002/adem.201100176 3 %X Magnesium (Mg) alloys are well known as potential candidates for engineering structural materials due to their low density and high specific strength. However, compared with traditional steel or aluminum materials, Mg alloys have not been widely used. Up to now, these present commercial products are mainly fabricated by cast. In contrast to cast products, wrought Mg alloys only have a market share of less than 5%.Most of the barriers preventing wrought produces from widespread applications arising from low ductility/toughness and poor corrosion. Therefore, to improve the formability and corrosion resistance becomes an urgent problem to extend the applications of deformed Mg materials. %0 conference lecture (invited) %@ %A Hort, N. %D 2012 %J Seminar des Instituts fuer Werkstoffphysik %N %P %T Entwicklung von Mg Legierungen im MagIC %U %X %0 journal article %@ 0022-2461 %A Fechner, D.,Hort, N.,Blawert, C.,Dieringa, H.,Stoermer, M.,Kainer, K.U. %D 2012 %J Journal of Materials Science %N 14 %P 5461-5469 %R doi:10.1007/s10853-012-6436-9 %T The formation of Sr6.33Mg16.67Si13 in magnesium alloy AM50 and its effect on mechanical properties %U https://doi.org/10.1007/s10853-012-6436-9 14 %X The increasing use of magnesium castings for automotive components and the number of newly developed,alloys raise the question of suitable recycling processes. Remelting offers a high potential of energy saving and,thereby improves the live cycle balance of magnesium components. Effective recycling processes are likely to involve the mixing of different alloys but little is known,about the interaction of alloying elements. In order to approach this issue, the influence of strontium, silicon and calcium on phase formation and mechanical properties of magnesium alloy AM50 has been investigated. After strontium,addition, X-ray diffraction demonstrated the formation,of the Al4Sr and the Mg17Sr2 phases. However, after simultaneous alloying with strontium, silicon and calcium the ternary Zintl phase Sr6.33Mg16.67Si13 was detected. This phase forms preferably instead of Al4Sr,Mg17Sr2 andMg2Si. Compared to the two strontium-containing phases, precipitates of the ternary Zintl phase exhibit a rather compact morphology. This results in a higher elongation-at-fracture under tensile stress. %0 conference paper %@ %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P 295-300 %T Texture Evolution During Hot Deformation Processing of Mg-3sn-2ca-0.4Al Alloy %U %X %0 conference lecture %@ %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P %T Texture Evolution During Hot Deformation Processing of Mg-3sn-2ca-0.4Al Alloy %U %X %0 journal article %@ 0021-8898 %A Gan, W.,Huang, Y.,Yang, L.,Kainer, K.U.,Jiang, M.,Brokmeier, H.-G.,Hort, N. %D 2012 %J Journal of Applied Crystallography %N %P 17-21 %R doi:10.1107/S0021889811053088 %T Identification of unexpected hydrides in Mg-20 wt% Dy alloy by high-brilliance synchrotron radiation %U https://doi.org/10.1107/S0021889811053088 %X An unexpected precipitate phase was observed in Mg-20 wt% Dy alloy, with a cuboid morphology not compatible with any shown in the Mg-Dy binary phase diagram. As observed by scanning electron microscopy and energy-dispersive X-ray analysis, the ratio of atomic percent of Dy to Mg is very high in these particles, probably largely because of the poor spatial resolution of that technique but already showing the mismatch with any previously characterized Mg-Dy compound. High-brilliance synchrotron diffraction and transmission electron microscopy experiments confirmed that these particles are composed of DyH2. They are formed during sample preparation at room temperature when hydrogen-containing sources such as water are used. %0 conference paper %@ %A Maier, P.,Mueller, S.,Dieringa, H.,Hort, N. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P 253-259 %T Mechanical and Corrosion Properties of As-Cast and Extruded Mg10gd Alloy for Biomedical Application %U %X %0 conference lecture %@ %A Maier, P.,Mueller, S.,Dieringa, H.,Hort, N. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P %T Mechanical and Corrosion Properties of As-Cast and Extruded Mg10gd Alloy for Biomedical Application %U %X %0 report part %@ %A Wiese, B.,Tolnai, D.,Mendis, C.,Stark, A.,Kainer, K.U.,Hort, N. %D 2012 %J Annual Report Photon Science 2012 %N %P %T In situ solidifcation of a Mg-10 wt% CaO %U %X %0 conference lecture (invited) %@ %A Blawert, C.,Srinivasan, B.,Liang, J.,Huang, Y.,Hoeche, D. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T PEO processing of magnesium alloys using particle containing electrolytes %U %X %0 journal article %@ 0957-4530 %A Feyerabend, F.,Druecker, H.,Laipple, D.,Vogt, C.,Stekker, M.,Hort, N.,Willumeit, R. %D 2012 %J Journal of Materials Science: Materials in Medicine %N 1 %P 9-24 %R doi:10.1007/s10856-011-4490-5 %T Ion release from magnesium materials in physiological solutions under different oxygen tensions %U https://doi.org/10.1007/s10856-011-4490-5 1 %X Although magnesium as degradable biomaterial already showed clinical proof of concepts, the design of new alloys requires predictive in vitro methods, which are still lacking. Incubation under cell culture conditions to obtain ‘‘physiological’’ corrosion may be a solution. The,aim of this study was to analyse the influence of different solutions, addition of proteins and of oxygen availability on the corrosion of different magnesium materials (pure Mg, WE43, and E11) with different surface finishing. Oxygen content in solution, pH, osmolality and ion release were determined. Corrosion led to a reduction of oxygen in,solution. The influence of oxygen on pH was enhanced by proteins, while osmolality was not influenced. Magnesium ion release was solution-dependent and enhanced in the initial phase by proteins with delayed release of alloying elements. The main corrosion product formed was magnesium carbonate. Therefore, cell culture conditions are proposed as first step toward physiological corrosion. %0 conference paper %@ %A Mert, F.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2012 %J Proceedings of the 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P 203-208 %T Corrosion Behaviour of High Pressure Die Cast Mg-5al-0.4mn-Xce(X=0, 0.5, 1) Alloys %U %X %0 conference lecture %@ %A Gan, W.M.,Huang, Y.D.,Wang, Z.,Hort, N.,Hofmann, M. %D 2012 %J International Conference on Residual Stress, ICRS-9 %N %P %T Residual stresses near the hot sprues of as-cast Mg-Zn alloys investigated by STRESS-SPEC neutron diffractometer %U %X %0 conference poster %@ %A Feyerabend, F.,Tie, D.,Schade, R.,Liefeith, K.,Hoeche, D.,Laipple, D.,Mueller, W.-D.,Kainer, K.U.,Schreyer, A.,Hort, N.,Willumeit, R. %D 2012 %J 9th World Biomaterials Congress %N %P %T Magnesium silver alloys as multifunctional biodegradable biomaterials %U %X %0 conference paper %@ %A Mert, F.,Oezdemir, A.,Kainer, K.U.,Hort, N. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P 149-154 %T Microstructure and Mechanical Properties of High Pressure Die Cast Am50 Magnesium Alloy Containing Ce %U %X %0 conference lecture %@ %A Mert, F.,Oezdemir, A.,Kainer, K.U.,Hort, N. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P %T Microstructure and Mechanical Properties of High Pressure Die Cast Am50 Magnesium Alloy Containing Ce %U %X %0 conference paper %@ %A Morales Garza, E.D.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2012 %J Magnesium Technology 2012, TMS Annual Meeting & Exhibition, Symposium %N %P 385-389 %T Microstructure and Creep Properties of MEZ Magnesium Alloy Processed by Thixocasting %U %X %0 conference lecture %@ %A Mert, F.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T Corrosion Behaviour of High Pressure Die Cast Mg-5al-0.4mn-Xce(X=0, 0.5, 1) Alloys %U %X %0 conference lecture %@ %A Schlueter, K.,Zamponi, C.,Schuermann, U.,Hort, N.,Kienle, L.,Kainer, K.U.,Quandt, E. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T Amorphous Thin Films Consisting of Ternary MgZnCa-Alloys %U %X %0 conference lecture %@ %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P %T Effect of Deformation Conditions on Microstructure and Texture During Compression of Mg-3Sn-2Ca-0.4Al-0.4Si Alloy %U %X %0 journal article %@ 0254-0584 %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J Materials Chemistry and Physics %N 2-3 %P 1081-1091 %R doi:10.1016/j.matchemphys.2012.08.054 %T Hot working mechanisms and texture development in Mg-3Sn-2Ca-0.4Al alloy %U https://doi.org/10.1016/j.matchemphys.2012.08.054 2-3 %X Hot deformation mechanisms in Mg-3Sn-2Ca (TX32) alloy containing 0.4% Al are evaluated in the temperature and strain rate ranges of 300–500 °C and 0.0003–10 s−1 using processing map and kinetic analysis. The evolution of microstructure and texture during high temperature compression of the alloy has been studied using an electron back scatter diffraction (EBSD) technique. The processing map for hot working revealed two domains of dynamic recrystallization (DRX) occurring in the temperature and strain rate ranges of: (1) 300–360 °C and 0.0003–0.001 s−1 and (2) 400–500 °C and 0.005–0.7 s−1, which are the two safe hot workability windows for this alloy. A regime of flow instability occurs at higher strain rates and lower temperatures where adiabatic shear banding and flow localization are the microstructural manifestations. The onset of DRX during compression at lower temperatures and strain rates (Domain 1) resulted in a fine, partially recrystallized and necklaced grain microstructure along with a texture where the basal poles are spread along 30° from the compression direction. Specimens deformed at temperatures higher than 450 °C (Domain 2) resulted in a fully recrystallized microstructure and an almost random crystallographic texture, which was attributed to the significant occurrence of pyramidal slip and associated cross-slip. %0 conference lecture %@ %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J International Conference on Mechanical Engineering and Materials, ICMEM 2012 %N %P %T Deformation Microstructures and Textures of Cast Mg-3Sn-2Ca Alloy under Uniaxial Hot Compression %U %X %0 journal article %@ 1660-9336 %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J Applied Mechanics and Materials, Mechanical Engineering and Materials %N %P 322-325 %R doi:10.4028/www.scientific.net/AMM.152-154.322 %T Deformation Microstructures and Textures of Cast Mg-3Sn-2Ca Alloy under Uniaxial Hot Compression %U https://doi.org/10.4028/www.scientific.net/AMM.152-154.322 %X The influence of deformation conditions on the microstructure and texture evolution during hot compression of Mg-3Sn-2Ca (TX32) has been studied. Cylindrical samples were compressed uniaxially at different combinations of temperatures and strain rates in the ranges 300-500 oC and 0.0003-10 s-1. The crystallographic orientation information of the as-cast and deformed specimens was obtained by EBSD micro-texture analysis. Activation of different slip systems was investigated using Schmid factor analysis and the results reinforce the importance of non-basal slip,for deformation at high temperatures. Samples deformed at 500 oC/0.1 s-1 resulted in a fully,recrystallized microstructure with near random crystallographic texture. %0 conference paper %@ %A Dharmendra, C.,Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2012 %J Proceedings of the 9th International Conference on Magnesium Alloys and their Applications, MG 2012 %N %P 473-478 %T Effect of Deformation Conditions on Microstructure and Texture During Compression of Mg-3Sn-2Ca-0.4Al-0.4Si Alloy %U %X %0 lecture %@ %A Hort, N. %D 2012 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 conference lecture %@ %A Feyerabend, F.,Yang, L.,Huang, Y.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2012 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien, DGBM 2012 %N %P %T Influence of Ageing Treatment on Microstructure, Mechanical and Bio-corrosion Properties of Mg-Dy alloys %U %X %0 book part %@ %A Wang, Z.,Huang, Y.,Srinivasan, A.,Liu, Z.,Kainer, K.U.,Hort, N. %D 2012 %J Developments in mechanical engineering %N %P 191-197 %T Prediction of hot tearing tendency for binary Mg-Y alloys %U %X No abstract %0 conference lecture %@ %A Yang, L.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2012 %J 9th World Biomaterial Congress %N %P %T Influence of Ageing Treatment on Microstructure, Mechanical and Bio-corrosion Properties of Mg-Dy alloys %U %X %0 conference lecture %@ %A Yang, L.,Feyerabend, F.,Blawert, C.,Willumeit, R.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2012 %J 4th International Symposium on Biodegradable Metals %N %P %T Influence of Dy on the bio-corrosion behavior of binary Mg-Dy alloys in cell culture medium %U %X %0 conference lecture %@ %A Ebel, T.,Wolff, M.,Wiese, B.,Deussing, J. %D 2012 %J 25. MIM Expertenkreis Sitzung %N %P %T MIM von Magnesium %U %X %0 journal article %@ 0972-2815 %A Srinivasan, A.,Wang, Z.,Huang, Y.,Beckmann, F.,Kainer, K.U.,Hort, N. %D 2012 %J Transactions of the Indian Institute of Metals %N 6 %P 701-706 %R doi:10.1007/s12666-012-0210-1 %T Hot Tearing Susceptibility of Magnesium–Gadolinium Binary Alloys %U https://doi.org/10.1007/s12666-012-0210-1 6 %X Hot tearing susceptibility of Mg–Gd alloys are investigated using instrumented constrained rod casting (CRC) apparatus, and found that the susceptibility increases with increase in Gd content, and reaches a maximum at 2 % after which it decreases to a minimum with 10 % Gd. The high susceptibility observed with 2 % Gd is due to its columnar structure and low amount of eutectic liquid at the time of cracking, whereas equiaxed grain and high liquid content which facilitates crack healing are the reasons for the low susceptibility of Mg–10 Gd alloy. %0 journal article %@ 0921-5093 %A Tolnai, D.,Requena, G.,Cloetens, P.,Lendvai, J.,Degischer, H.-P. %D 2012 %J Materials Science and Engineering A %N %P 214-221 %R doi:10.1016/j.msea.2012.04.060 %T Sub-micrometre holotomographic characterisation of the effects of solution heat treatment on an AlMg7.3Si3.5 alloy %U https://doi.org/10.1016/j.msea.2012.04.060 %X A strip cast AlMg7.3Si3.5 alloy is investigated by sub-micrometre holotomographic analysis achieving a voxel size of (60 nm)3 by cone beam magnification of the focused synchrotron beam using Kirkpatrick–Baez mirrors. The three-dimensional microstructure of the same specimen volume in the as-cast state is compared with that after exposure to 540 °C for 30 min resolving microstructural features down to 180 nm. The three-dimensional analysis of the architecture of the eutectic Mg2Si and the Fe-aluminides reveals how the as-cast microstructure changes during the solution treatment. The alloy in the as-cast condition contains a highly interconnected seaweed-like Mg2Si eutectic. The level of three-dimensional interconnectivity of the Mg2Si eutectic phase decreases by only partial disintegration during the heat treatment correcting the two-dimensional metallographic impression of isolated round particles. Statistical analyses of the particle distribution, sphericity, mean curvatures and Gaussian curvatures describe quantitatively the architectural changes of the Mg2Si phase. This explains the decrease of the high temperature strength of the alloy by the solution treatment tested in hot compression. %0 journal article %@ 0010-938X %A Mert, F.,Blawert, C.,Kainer, K.U.,Hort, N. %D 2012 %J Corrosion Science %N %P 145-151 %R doi:10.1016/j.corsci.2012.08.011 %T Influence of cerium additions on the corrosion behaviour of high pressure die cast AM50 alloy %U https://doi.org/10.1016/j.corsci.2012.08.011 %X The influence of Ce additions to AM50 magnesium alloy prepared by high pressure die casting on the microstructure and corrosion behaviour has been investigated. The corrosion behaviour was evaluated by hydrogen evolution, salt spray, potentiodynamic polarization and electrochemical impedance experiments. The results show that Ce addition promotes the formation of Al11Ce3 phase and reduces the amount of β-phase (Mg17Al12). The corrosion resistance is improved with increasing Ce content which can be attributed to the formation of Al11Ce3 phase, reduction of β-phase (reduced galvanic effects) and higher purity of AME50X alloys (melt cleaning effects). %0 lecture %@ %A Hort, N. %D 2012 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 journal article %@ 0921-5093 %A Rao, K.P.,Prasad, Y.V.R.K.,Suresh, K.,Hort, N.,Kainer, K.U. %D 2012 %J Materials Science and Engineering A %N %P 444-450 %R doi:10.1016/j.msea.2012.05.068 %T Hot deformation behavior of Mg–2Sn–2Ca alloy in as-cast condition and after homogenization %U https://doi.org/10.1016/j.msea.2012.05.068 %X The hot deformation behavior of Mg–2Sn–2Ca (TX22) alloy has been characterized in the temperature range 300–500 °C and strain rate range 0.0003–10 s−1 using isothermal constant true strain rate tests. A processing map has been developed on the basis of flow stress data obtained as a function of temperature and strain rate, which revealed two windows or domains for hot working the alloy: (1) 300–370 °C/0.0003–0.001 s−1 and (2) 400–500 °C/0.005–1 s−1. Microstructural observations indicated that dynamic recrystallization occurs in both these windows with a finer resulting grain size in the first window. Apparent activation energy values of 183 and 178 kJ/mole have been estimated in these windows, respectively and these are much higher than that for self-diffusion in Mg suggesting that considerable back stress is being generated due to the intermetallic particles (CaMgSn) present in the matrix. The mechanisms involving basal + prismatic slip and recovery by climb in the first domain and that of second order pyramidal slip and softening by cross-slip in the second domain are suggested to be occurring in these two domains. The processing map obtained on homogenized alloy is identical to that of the as-cast alloy suggesting that there is no benefit of homogenization treatment as regards hot workability and this is attributed to the thermal stability of the as-cast microstructure. %0 journal article %@ 0257-8972 %A Blawert, C.,Sah, S.P.,Liang, J.,Huang, Y.,Hoeche, D. %D 2012 %J Surface and Coatings Technology %N %P 48-58 %R doi:10.1016/j.surfcoat.2012.10.013 %T Role of sintering and clay particle additions on coating formation during PEO processing of AM50 magnesium alloy %U https://doi.org/10.1016/j.surfcoat.2012.10.013 %X In this study sintering of electrochemical conversion products on the surface of AM50 magnesium alloy by the discharges was identified as an essential step in the coating formation in PEO processing. Clay particles were selected as suitable additives because of their relative low melting point and possible reactions with the substrate-electrolyte conversion products. The comparison of coatings formed in electrolytes with and without particles clearly indicates a complete change in the microstructure. In the standard electrolytes the coatings are crystalline while they are amorphous if particles are present though the energy input (process parameters) was more or less the same. Only the presence and incorporation of the particles into the coating has obviously induced a low temperature reactive liquid phase formation process, reaching a coating composition with glass forming ability which is likely due to the fast cooling by the electrolyte. In contrast, the coating formation in standard electrolytes has to be considered more like a solid phase sintering. However the results clearly indicate that the sintering of reaction/conversion products by the high energy discharges is a very important step in the coating formation and that the sintering by the discharges in PEO processing can be influenced by the use of additives similar to traditional sintering processes. %0 journal article %@ 0167-577X %A Peng, Q.,Huang, Y.,Kainer, K.U.,Hort, N. %D 2012 %J Materials Letters %N %P 209-212 %R doi:10.1016/j.matlet.2011.08.009 %T High ductile as-cast Mg–RE based alloys at room temperature %U https://doi.org/10.1016/j.matlet.2011.08.009 %X A variety of novel single phase solid solution as-cast Mg–RE based alloys have been developed. The as-cast alloys exhibit high ductility at room temperature. Mg–0.32Y–0.46Gd–0.34Dy–0.16Zr (wt.%) alloy exhibits high ductility expanding known performance boundaries of as-cast Mg alloys. The average tensile elongation and compression ratio at room temperature is over 30%. Meanwhile, the yield strength of tension is nearly the same as that of compression. The remarkable ductility is mainly associated with homogenous deformed microstructure, fine grain size and low mechanical anisotropy. These new developed alloys provide some implications for the development of high performance deformed Mg-based components in the future. %0 journal article %@ 1751-6161 %A Yang, L.,Huang, Y.,Feyerabend, F.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2012 %J Journal of the Mechanical Behavior of Biomedical Materials %N %P 36-44 %R doi:10.1016/j.jmbbm.2012.04.007 %T Influence of ageing treatment on microstructure, mechanical and bio-corrosion properties of Mg–Dy alloys %U https://doi.org/10.1016/j.jmbbm.2012.04.007 %X Mg–Dy alloys have shown to be promising for medical applications. In order to investigate the influence of ageing treatment on their mechanical and corrosion properties, three Mg–xDy alloys (x=10, 15, 20 wt%) were prepared. Their microstructure, mechanical and corrosion behavior were investigated. The results indicate that ageing at 250 °C has little influence on the mechanical and corrosion properties. In contrast, ageing at 200 °C significantly increases the yield strength, and reduces the ductility. After ageing at 200 °C, the corrosion rate of Mg–20Dy alloy increases largely in 0.9 wt% NaCl solution, but remains unchanged in cell culture medium. %0 journal article %@ 2075-4701 %A Rao, K.P.,Prasad, Y.V.R.K.,Dzwonczyk, J.,Hort, N.,Kainer, K.U. %D 2012 %J Metals %N 3 %P 292-312 %R doi:10.3390/met2030292 %T Hot Deformation Mechanisms in AZ31 Magnesium Alloy Extruded at Different Temperatures: Impact of Texture %U https://doi.org/10.3390/met2030292 3 %X The hot deformation characteristics of AZ31 magnesium alloy rod extruded at temperatures of 300 °C, 350 °C and 450 °C have been studied in compression. The extruded material had a fiber texture with parallel to the extrusion axis. When extruded at 450 °C, the texture was less intense and the direction moved away from the extrusion axis. The processing maps for the material extruded at 300 °C and 350 °C are qualitatively similar to the material with near-random texture (cast-homogenized) and exhibited three dynamic recrystallization (DRX) domains. In domains #1 and #2, prismatic slip is the dominant process and DRX is controlled by lattice self-diffusion and grain boundary self-diffusion, respectively. In domain #3, pyramidal slip occurs extensively and DRX is controlled by cross-slip on pyramidal slip systems. The material extruded at 450 °C exhibited two domains similar to #1 and #2 above, which moved to higher temperatures, but domain #3 is absent. The results are interpreted in terms of the changes in fiber texture with extrusion temperature. Highly intense texture, as in the rod extruded at 350 °C, will enhance the occurrence of prismatic slip in domains #1 and #2 and promotes pyramidal slip at temperatures >450 °C. %0 conference lecture %@ %A Hort, N. %D 2012 %J Cost Efficient Cast Components %N %P %T State of the Art for Cast Magnesium – A Material for the Future %U %X %0 conference lecture %@ %A Hort, N.,Vogt, C. %D 2012 %J 4th International Symposium on Biodegradable Metals %N %P %T Impurities in the Production and Processing of Magnesium Alloys %U %X %0 conference lecture %@ %A Di, T.,Feyerabend, F.,Schade, R.,Liefeith, K.,Hoeche, D.,Laipple, D.,Mueller, W.-D.,Kainer, K.U.,Schreyer, A.,Hort, N.,Willumeit, R. %D 2012 %J 4th International Symposium on Biodegradable Metals %N %P %T Magnesium Silver Alloys as Multifunctional Biodegradable Biomaterials %U %X %0 conference lecture (invited) %@ %A Blawert, C.,Srinivasan, P.B.,Liang, J.,Huang, Y.,Hoeche, D.,Scharnagl, N.,Heitmann, V.,Burmester, U. %D 2012 %J 2012 Fall Meeting of the Korean Institute of Surface Engineering %N %P %T Changing PEO coating formation on Mg alloys by particle additions to the treatment electrolyte %U %X %0 conference poster %@ %A Willumeit, R.,Fischer, J.,Poertner, R.,Di, T.,Hort, N.,Kainer, K.U.,Wilde, F.,Schreyer, A.,Feyerabend, F. %D 2012 %J 9th World Biomaterials Congress %N %P %T Magnesium corrosion in a bioreactor %U %X %0 journal article %@ 0587-4246 %A Huang, Y.,Wang, Z.,Srinivasan, A.,Kainer, K.U.,Hort, N. %D 2012 %J Acta Physica Polonica A %N 3 %P 497-500 %T Metallurgical Characterization of Hot Tearing Curves Recorded during Solidification of Magnesium Alloys %U 3 %X This work investigates the hot tearing behavior of Mg-Al and Mg-Zn alloys quantitatively based on the measurement of contraction force using an experimental setup which was developed at MagIC. An emphasis is given on the analysis of typical hot tearing curves to understand the corresponding metallurgical phenomena shown by these curves. The recorded hot tearing curves, i.e. the contraction force vs. temperature or time, contain valuable metallurgical information. They give not only the precise temperature at which the hot tearing initiates, but also depict information about the propagation of hot cracks. Combined with thermodynamic calculations, the critical solid fraction corresponding to the occurrence of hot tearing can be calculated. Further microstructural observations were performed. Several phenomena such as the crack propagation and refilling of cracks, which influence the slope of hot tearing curves, are also discussed. %0 conference lecture %@ %A Yang, L.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Hort, N. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Corrosion Behavior of As-Cast Binary Mg-Dy Alloys %U %X %0 conference paper %@ %A Easton, M.A.,Gibson, M.A.,Gershenzon, M.,Savage, G.,Tyagi, V.,Abbott, T.B.,Hort, N. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 61-64 %R doi:10.4028/www.scientific.net/MSF.690.61 %T Castability of some Magnesium Alloys in a Novel Castability Die %U https://doi.org/10.4028/www.scientific.net/MSF.690.61 %X %0 journal article %@ 0966-9795 %A Peng, Q.,Huang, Y.,Meng, J.,Li, Y.,Kainer, K.U. %D 2011 %J Intermetallics %N 3 %P 382-389 %R doi:10.1016/j.intermet.2010.11.001 %T Strain induced GdH2 precipitate in Mg-Gd based alloys %U https://doi.org/10.1016/j.intermet.2010.11.001 3 %X A new rectangle-shape GdH2 precipitate was identified in MgeGd based alloys after mechanical polishing or compressive deformation. The precipitate was mainly distributed near the dendrite or grain boundaries where gadolinium element was segregated owing to non-equilibrium solidification. It is,confirmed that hydrogen-containing medium, deformation and gadolinium segregation were the prerequisites to form GdH2 precipitate. The amount of GdH2 precipitate was mostly associated with deformation and the gadolinium content. A model was introduced to explain the formation mechanism of GdH2 precipitate. The hydrogen in GdH2 precipitate principally came from the outside medium. Moreover, the diffusion and transportation of hydrogen were improved by the movement of dislocation. %0 journal article %@ 0255-5476 %A Anopuo, O.,Huang, Y.,Hort, N.,Kainer, K.U.,Maier, P. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 278-281 %R doi:10.4028/www.scientific.net/MSF.690.278 %T Modeling Bolt Load Retention of Ca Modified AS41 Using Compliance-Creep Method %U https://doi.org/10.4028/www.scientific.net/MSF.690.278 %X Adequate quantification of the degree of fastener clamp load retained at bolted joint of Mg-Al alloys is crucial to develop new elevated temperature resistant Mg-alloys. Several attempts have been made in the past to model Bolt Load Retention (BLR) behaviour of Mg-alloys using different approaches. It must be mentioned that whereas these models attempt to predict BLR of the alloys investigated, the results of the models differ in most cases with the experiments by great margin. The BLR behaviour of Mg-alloy is geometry and material dependent. This means that, the configuration of the test sample, the compliance of the bolt/joint and creep response of the material under investigation play important role in determining the joint response under load and temperature. In this work, BLR and creep behaviour of Ca modified AS41 is investigated and compared to that of Mg4Al and AS41. A compliance-creep approach is used to model the response of these Mg-Al alloys at bolted joints. The model prediction of the BLR response and experimental results as obtained in this work are in good agreement. AS41+0.15 % Ca shows improved creep and BLR properties up to 175 °C. A correlation between the microstructures, creep and BLR results reveal that the formation of a ternary CaMgSi phase is responsible for the improved elevated temperature behaviour. %0 conference paper %@ %A Yang, L.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Hort, N. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 417-421 %T Corrosion Behavior of As-Cast Binary Mg-Dy Alloys %U %X %0 conference lecture %@ %A Easton, M.A.,Gibson, M.A.,Gershenzon, M.,Savage, G.,Tyagi, V.,Abbott, T.B.,Hort, N. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Castability of some Magnesium Alloys in a Novel Castability Die %U %X %0 conference lecture %@ %A Wolff, M.,Wiese, B.,Dahms, M.,Ebel, T. %D 2011 %J International Congress and Exhibition, EURO PM 2011 %N %P %T Binder development for Magnesium Powder Injection Moulding %U %X %0 journal article %@ 0255-5476 %A Easton, M.A.,Gibson, M.A.,Gershenzon, M.,Savage, G.,Tyagi, V.,Abbott, T.B.,Hort, N. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 61-64 %R doi:10.4028/www.scientific.net/MSF.690.61 %T Castability of some Magnesium Alloys in a Novel Castability Die %U https://doi.org/10.4028/www.scientific.net/MSF.690.61 %X This paper reports on the results of the castability of three MRI alloys (153A, 153M and 230D). MRI153A was found to cast best, with castings produced rated with a quality approaching AZ91. MRI230D produced the next best castings, whilst MRI153M showed the worst castability across a range of conditions. However, these alloys showed a tendency to build-up oxide in the melt transfer tube leading to melt transfer problems. This was particularly severe in MRI230D. %0 conference paper %@ %A Blawert, C.,Liang, J.,Huang, Y.Hoeche, D. %D 2011 %J Tagungsband, 7. Thueringer Grenz- und Oberflaechentage, ThGOT %N %P 106-111 %T Herstellung und Eigenschaften von partikelverstaerkten keramischen Schichten auf Magnesiumlegierungen %U %X %0 conference lecture %@ %A Feyerabend, F.,Yang, L.,Tie, D.,Laipple, D.,Schreyer, A.,Kainer, K.U.,Hort, N.,Druecker, H.,Vogt, C.,Willumeit, R. %D 2011 %J 24th European Conference on Biomaterials, ESB 2011 %N %P %T Factors influencing magnesium corrosion in vitro – environment, proteins and oxygen %U %X %0 journal article %@ 1359-6462 %A Huang, Y.,Kainer, K.U.,Hort, N. %D 2011 %J Scripta Materialia %N 8 %P 793-796 %R doi:10.1016/j.scriptamat.2011.01.005 %T Mechanism of grain refinement of Mg–Al alloys by SiC inoculation %U https://doi.org/10.1016/j.scriptamat.2011.01.005 8 %X The mechanism of grain refinement was investigated for Mg–Al alloys inoculated with SiC particles. Contrary to the previously,reported Al4C3 hypothesis, the ternary carbide Al2MgC2 was observed, which has a crystal structure closer to that of Mg than to,that of Al4C3. In the centre of the grains, one or more “hillocks” enriched in Al and C were observed. Based on the observed phenomena,,a novel mechanism is suggested to explain the grain refinement of Mg–Al alloys with the addition of SiC particles. %0 conference lecture %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Kainer, K.U.,Maier, P. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Modeling Bolt Load Retention of Ca Modified AS41 Using Compliance-Creep Method %U %X %0 conference paper %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Kainer, K.U.,Maier, P. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 373-376 %T Modeling Bolt Load Retention of Ca Modified AS41 Using Compliance-Creep Method %U %X %0 journal article %@ 0921-5107 %A Yang, L.,Huang, Y.,Peng, Q.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Hort, N. %D 2011 %J Materials Science and Engineering B %N 20 %P 1827-1834 %R doi:10.1016/j.mseb.2011.02.025 %T Mechanical and Corrosion Properties of Binary Mg-Dy Alloys for Medical Application %U https://doi.org/10.1016/j.mseb.2011.02.025 20 %X Microstructure, mechanical and corrosion properties of binary magnesium–dysprosium (Mg-5, 10, 15, 20 wt.% Dy) alloys were investigated for medical applications. In the as-cast condition, the distribution of Dy is quite inhomogeneous. Mg–10Dy alloy exhibits a moderate tensile and compression yield strength, and the best elongation and corrosion resistance. After T4 (solutionizing) treatment, the distribution of Dy becomes homogeneous. The tensile and compression yield strength of all Mg–Dy alloys decreases. The elongation remains unchanged, while the corrosion resistance is largely improved after T4 treatment. %0 journal article %@ 1364-0461 %A Zhou, L.,Huang, Y.,Mao, P.,Kainer, K.U.,Liu, Z.,Hort, N. %D 2011 %J International Journal of Cast Metals Research %N 3-4 %P 170-176 %R doi:10.1179/136404611X13001912813942 %T Influence of composition on hot tearing in binary Mg‐Zn alloys %U https://doi.org/10.1179/136404611X13001912813942 3-4 %X Mg‐Zn alloys have a large freezing zone, and their susceptibility to hot tearing is high. Investigations on their hot tearing are necessary for both materials science and practical applications. The present work evaluates the susceptibility of hot tearing of Mg‐Zn alloy using Clyne and Davies’s modelling combined with thermodynamic calculations. In order to compare with the calculated results, the susceptibility of hot tearing was measured using previously developed quantitative experimental method. It is found that the simulation results are in agreement with the experimental results. Both of them show that the curves of the susceptibility of hot tearing versus the content of Zn has a typical ‘Λ’ shape. With increasing content of Zn, the susceptibility of hot tearing first increases, reaches the maximum at 2‐4%Zn and then decreases again. Experimental investigations also demonstrate that the hot tearing susceptibility decreases with increasing initial mould temperature. %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 270-273 %T Compression creep at 240°C of extruded magnesium alloys containing Gadolinium %U %X %0 journal article %@ 0023-432X %A Hort, N.,Huang, Y.D.,Abu Leil, T.,Rao, K.P.,Kainer, K.U. %D 2011 %J Kovove materialy / Metallic materials %N 3 %P 163-177 %R doi:10.4149/km_2011_3_163 %T Properties and processing of magnesium-tin-calcium alloys %U https://doi.org/10.4149/km_2011_3_163 3 %X The development of new creep resistant magnesium alloys has become a major issue in recent years and therefore further alloy development is necessary. Newly developed alloys are based on the binary system Mg-Sn. Sn as major alloying element was chosen due to its high solid solubility over a wide temperature range and due to the possible formation of Mg2Sn intermetallic precipitates with a high melting temperature of about 770 °C. These characteristics suggest that a fairly large volume fraction of thermally stable Mg2Sn particles can be formed during solidification. This makes it possible that the Mg-Sn alloys can be developed as creep resistant magnesium alloys and/or wrought magnesium alloys. Previous investigations indicate that the Mg-Sn alloys have a comparable or even better creep property than AE42 alloy. This paper presents an overview about recent works on the developments of Mg-Sn alloys performed in MagIC, Helmholtz-Zentrum Geesthacht Centre, which includes: microstructural characterization, creep deformation and hot deformation, and corrosion behaviour. Very positive results have been obtained and show Mg-Sn-Ca alloy systems can be developed for power train and hand tool applications. %0 conference lecture (invited) %@ %A Lilleodden, E.,Kim, G.S.,Sangbong,Y.,Huang, Y. %D 2011 %J Plasticity 2011 %N %P %T Slip and twinning in Mg single crystals %U %X %0 conference paper %@ %A Zhou, L.,Huang, Y.,Mao, P.,Kainer, K.U.,Liu, Z.,Hort, N. %D 2011 %J Magnesium Technology 2011, TMS 2011 Annual Meeting & Exhibition %N %P 125-130 %R doi:10.1002/9781118062029.ch24 %T Investigations on hot tearing of Mg-Zn-(Al) alloys %U https://doi.org/10.1002/9781118062029.ch24 %X %0 conference lecture %@ %A Zhou, L.,Huang, Y.,Mao, P.,Kainer, K.U.,Liu, Z.,Hort, N. %D 2011 %J TMS 2011 Annual Meeting & Exhibition, Magnesium Technology %N %P %T Investigations on hot tearing of Mg-Zn-(Al) alloys %U %X %0 conference lecture %@ %A Blawert, C.,Liang, J.,Huang, Y.Hoeche, D. %D 2011 %J 7. Thueringer Grenz- und Oberflaechentage, ThGOT %N %P %T Herstellung und Eigenschaften von partikelverstaerkten keramischen Schichten auf Magnesiumlegierungen %U %X %0 conference lecture %@ %A Feyerabend, F.,Yang, L.,Hort, N.,Kainer, K.U.,Schreyer, A.,Vogt, C.,Druecker, H.,Willumeit, R. %D 2011 %J European Symposium on Biomaterials and Related Areas,, EuroBioMat 2011 %N %P %T Physiological corrosion – Towards in vitro setups for degradable metals %U %X %0 conference lecture %@ %A Salgado-Ordorica, M.,Punessen, W.,Yi, S.,Bohlen, J.,Kainer, K.U.,Hort, N. %D 2011 %J TMS 2011 Annual Meeting & Exhibition, Magnesium Technology %N %P %T Macrostructure evolution in directionally solidified Mg-RE alloys %U %X %0 conference lecture (invited) %@ %A Feyerabend, F.,Yang, L.,Hort, N.,Kainer, K.U.,Schreyer, A.,Vogt, C.,Druecker, H.,Willumeit, R. %D 2011 %J Internationale Conference on Processing & Manufacturing of Advanced Materials, THERMEC 2011 %N %P %T Magnesium corrosion in vitro – towards physiological environments %U %X %0 conference paper %@ %A Salgado-Ordorica, M.,Punessen, W.,Yi, S.,Bohlen, J.,Kainer, K.U.,Hort, N. %D 2011 %J Magnesium Technology 2011, TMS 2011 Annual Meeting & Exhibition %N %P 113-118 %R doi:10.1002/9781118062029.ch22 %T Macrostructure evolution in directionally solidified Mg-RE alloys %U https://doi.org/10.1002/9781118062029.ch22 %X %0 journal article %@ 0921-5093 %A Peng, Q.,Meng, J.,Li, Y.,Huang, Y.,Hort, N. %D 2011 %J Materials Science and Engineering A %N 4-5 %P 2106-2109 %R doi:10.1016/j.msea.2010.11.042 %T Effect of yttrium addition on lattice parameter, Young's modulus and vacancy of magnesium %U https://doi.org/10.1016/j.msea.2010.11.042 4-5 %X The effect of yttrium addition on fundamental characters of magnesium has been investigated by calculated and experimental methods. It was found that the lattice parameter increased and the axial ratio c/a decreased with the increment of yttrium in solid solution. The approximately linear relationship between Young's modulus and the content of yttrium in solid solution was observed in the single phase solid solution Mg–Y alloys (T4 state). However, Young's modulus was closely relevant to the fraction of second precipitate except the content of saturated yttrium in matrix for the aged Mg–Y alloys (T6 state). The concentration of vacancy increased with the increased content of yttrium in solid solution, which was mainly caused by the atomic size misfit and the difference of valence electrons between yttrium and magnesium. %0 conference lecture %@ %A Hort, N. %D 2011 %J Fizika Tverdogo Tela : FTT %N %P %T Legierungsentwicklung fuer degradierbare Magnesumimplantate %U %X %0 conference poster %@ %A Tie, D.,Willumeit, R.,Feyerabend, F.,Hort, N.,Kainer, K.U.,Mueller, W.D. %D 2011 %J Internationale Conference on Processing & Manufacturing of Advanced Materials, THERMEC 2011 %N %P %T Effects of the Heat Treatmenton the Corrosion Behaviorof Mg-Ag Biodegradable Alloys %U %X %0 conference lecture %@ %A Schlueter, K.,Reverey, J.,Hort, N.,Zamponi, C.,Quandt, E. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Mechanical behaviour and corrosion performance of thin film magnesium WE alloys %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Mueller, S.,Kainer, K.U. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Compression creep at 240°C of extruded magnesium alloys containing Gadolinium %U %X %0 journal article %@ 0921-5107 %A Fischer, J.,Proefrock, D.,Hort, N.,Willumeit, R.,Feyerabend, F. %D 2011 %J Materials Science and Engineering B %N 11 %P 830-834 %R doi:10.1016/j.mseb.2011.04.008 %T Improved cytotoxicity testing of magnesium materials %U https://doi.org/10.1016/j.mseb.2011.04.008 11 %X Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials. %0 journal article %@ 0255-5476 %A Dieringa, H.,Hort, N.,Mueller, S.,Kainer, K.U. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 270-273 %R doi:10.4028/www.scientific.net/MSF.690.270 %T Compression creep at 240°C of extruded magnesium alloys containing Gadolinium %U https://doi.org/10.4028/www.scientific.net/MSF.690.270 %X For uses at high temperatures, magnesium alloys containing rare earths have proven to be very suitable. High proportions of melting precipitates contribute to strengthening, even at temperatures above 200°C. If these alloys are extruded, their creep resistance rises even further due to the resulting fine-grained structure. In this paper, magnesium alloys with 10% Gd and additional small amounts of La and Nd are compared with WE43 for compression creep at temperatures of 240°C and stresses between 80 and 150 MPa. The minimum creep rates are determined and the stress exponent evaluated in accordance with the Norton equation. By calculating the threshold stress, the true stress exponents are determined. %0 journal article %@ 0255-5476 %A Yang, L.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Hort, N. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 417-421 %R doi:10.4028/www.scientific.net/MSF.690.417 %T Corrosion Behavior of As-Cast Binary Mg-Dy Alloys %U https://doi.org/10.4028/www.scientific.net/MSF.690.417 %X The addition of rare earth elements (REE) is an effective way to improve the corrosion properties of magnesium alloys. Dysprosium has a very high solubility in Mg (25.3 wt.% at 561 °C) and could therefore be a promising alloying element for Mg based implants. In this study, four,binary Mg-xDy (x=5, 10, 15 and 20 in wt.%) alloys were prepared by permanent mould direct chill,casting. Microstructure and Dy distribution were investigated using optical microscope and EDX,analysis. Corrosion rate was measured with hydrogen evolution method and corrosion morphology,was observed after immersion for different time in 0.9 wt% NaCl solution with optical and SEM.,The results show that with the increase of Dy, the amount of Dy in Mg matrix and area of Dy,segregation are both increased. At the same time, the amount of second phase is also increased.,Filiform corrosion is reduced while pitting corrosion is increased with the increment of Dy. As a,result, lowest corrosion rate is obtained at Mg-10Dy alloy. %0 journal article %@ 0255-5476 %A Schlueter, K.,Reverey, J.,Hort, N.,Zamponi, C.,Quandt, E. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 286-289 %R doi:10.4028/www.scientific.net/MSF.690.286 %T Mechanical behaviour and corrosion performance of thin film magnesium WE alloys %U https://doi.org/10.4028/www.scientific.net/MSF.690.286 %X Mg based thin films are of increasing interest due to the potential in varying the corrosion properties in comparison to bulk alloys of the same nominal composition.,In this work the mechanical behaviour and the corrosion performance of sputtered thin films,consisting of magnesium alloys with the compositions Mg4Y3Gd and Mg4Y3Nd were investigated,by tensile tests and electrochemical corrosion tests, respectively.,The tensile tests showed that the sputtering parameters have an enormous influence on the,mechanical properties of the thin films. By variation of the Ar sputtering pressure and the DC,sputtering power it was possible to fabricate films with widely varying mechanical behaviour,reaching from brittle to very ductile films which could be strained to more than 30%. The,determined dependency between mechanical properties and deposition conditions was found to be,present in both investigated alloys. The corrosion tests revealed that the corrosion behaviour of the,investigated samples is not correlated to the mechanical properties of the thin films, as the rate of,corrosion and the tendency to localized corrosion do not change significantly upon the deposition,conditions, which dramatically influence the mechanical properties. %0 conference paper %@ %A Schlueter, K.,Reverey, J.,Hort, N.,Zamponi, C.,Quandt, E. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 286-289 %T Mechanical behaviour and corrosion performance of thin film magnesium WE alloys %U %X %0 conference paper %@ %A Kainer, K.U.,Hort, N. %D 2011 %J Proceedings of the John Hunt International Symposium %N %P 137-148 %T Contributions of Alloy Development for Extending the Range of Applications of Magnesium Alloys %U %X %0 conference object %@ %A Witte, F.,Hort, N.,Feyerabend, F. %D 2011 %J Magnesium Technology 2011, TMS 2011 Annual Meeting & Exhibition %N %P 17 %R doi:10.1002/9781118062029.ch5 %T Biodegradable Magnesium Implants - How Do They Corrode in-vivo? %U https://doi.org/10.1002/9781118062029.ch5 %X %0 journal article %@ 0921-5107 %A Schille, C.,Braun, M.,Wendel, H.P.,Scheideler, L.,Hort, N.,Reichel, H.-P.,Schweizer, E.,Geis-Gerstorfer, J. %D 2011 %J Materials Science and Engineering B %N 20 %P 1797-1801 %R doi:10.1016/j.mseb.2011.04.007 %T Corrosion of experimental magnesium alloys in blood and PBS: A gravimetric and microscopic evaluation %U https://doi.org/10.1016/j.mseb.2011.04.007 20 %X Corrosion tests for medical materials are often performed in simulated body fluids (SBF). When SBF are used for corrosion measurement, the open question is, how well they match the conditions in the human body. The aim of the study was to compare the corrosion behaviour of different experimental magnesium alloys in human whole blood and PBSminus (phosphate buffered saline w/o Ca and Mg) as a simulated body fluid by gravimetric weight measurements and microscopic evaluation. Eight different experimental magnesium alloys, containing neither Mn nor other additives, were manufactured. With these alloys, a static immersion test in PBSminus and a dynamic test using the Chandler-loop model with human whole blood over 6 h were performed. During the static immersion test, the samples were weighed every hour. During the dynamic test, the specimens were weighed before and after the 6 h incubation period in the Chandler-loop. From both tests, the total mass change was calculated for each alloy and the values were compared. Additionally, microscopic pictures from the samples were taken at the end of the test period. All alloys showed different corrosion behaviour in both tests, especially the alloys with high aluminium content, MgAl9 and MgAl9Zn1. Generally, alloys in PBS showed a weight gain due to generation of a microscopically visible corrosion layer, while in the blood test system a more or less distinct weight loss was observed. When alloys are ranked according to corrosion susceptibility, the results differ also between the test systems. The MgAl9 alloy, showing the most pronounced corrosion in PBS, was one of the least corroding alloys under simulated in vivo conditions in blood. Thus, the ranking concerning clinical suitability of the magnesium alloys tested in this study is different, depending on the used electrolyte and the kind of method. For a possible clinical use, the alloy MgAl9Zn1 might be preferable for further investigations. %0 journal article %@ 0921-5107 %A Geis-Gerstorfer, J.,Schille, C.,Schweizer, E.,Rupp, E.,Scheideler, L.,Reichel, H.-P.,Hort, N.,Nolte, A.,Wendel, H.P. %D 2011 %J Materials Science and Engineering B %N 20 %P 1761-1766 %R doi:10.1016/j.mseb.2011.06.006 %T Blood triggered corrosion of magnesium alloys %U https://doi.org/10.1016/j.mseb.2011.06.006 20 %X Intravascular stents manufactured out of bioabsorbable magnesium (Mg) or Mg-alloys are considered as auspicious candidates for the next stent generation. However, before clinical application numerous physical and biological tests, especially to predict the clinically highly important degradation kinetics in vivo, have to be performed. In a Chandler-Loop model, the initial degradation of eight different magnesium alloys during 6 h in contact with human whole blood was investigated. The magnesium release varied between 0.91 ± 0.33 mg/cm2 (MgAl9Zn1) and 2.57 ± 0.38 mg/cm2 (MgZn1). No correlation could be found with Mg release data obtained after immersion in simulated body fluid (SBF). This pilot study showed that Mg corrosion is highly influenced by the biological test environment (SBF or blood, etc.) and that a modified Chandler-Loop model with human whole blood may be superior to predict corrosion of Mg alloys under clinical conditions than the SBF models presently used. %0 conference lecture %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Suresh, K.,Dharmendra, C.,Hort, N.,Kainer, K.U. %D 2011 %J TMS 2011 Annual Meeting & Exhibition, Magnesium Technology %N %P %T Compressive Strength and Hot Deformation Behavior of TX32 Magnesium Alloy with 0.4% Al and 0.4% Si Additions %U %X %0 conference paper %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Suresh, K.,Dharmendra, C.,Hort, N.,Kainer, K.U. %D 2011 %J Magnesium Technology 2011, TMS 2011 Annual Meeting & Exhibition %N %P 169-174 %R doi:10.1002/9781118062029.ch33 %T Compressive Strength and Hot Deformation Behavior of TX32 Magnesium Alloy with 0.4% Al and 0.4% Si Additions %U https://doi.org/10.1002/9781118062029.ch33 %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N. %D 2011 %J The John Hunt International Symposium %N %P %T Contributions of Alloy Development for Extending the Range of Applications of Magnesium Alloys %U %X %0 conference lecture %@ %A Feyerabend, F.,Tie, D.,Yang, L.,Hort, N.,Kainer, K.U.,Schreyer, A.,Vogt, C.,Druecker, H.,Willumeit, R. %D 2011 %J Euromag 2011 %N %P %T Degradation of magnesium alloys by “physiological” corrosion – setups and influencing factors %U %X %0 journal article %@ 1742-7061 %A Willumeit, R.,Fischer, J.,Feyerabend, F.,Hort, N.,Bismayer, U.,Heidrich, S.,Mihailova, B. %D 2011 %J Acta Biomaterialia %N 6 %P 2704-2715 %R doi:10.1016/j.actbio.2011.03.004 %T Chemical surface alteration of biodegradable magnesium exposed to corrosion media %U https://doi.org/10.1016/j.actbio.2011.03.004 6 %X The understanding of corrosion processes of metal implants in the human body is a key problem in modern biomaterial science. Because of the complicated and adjustable in vivo environment, in vitro experiments require the analysis of various physiological corrosion media to elucidate the underlying mechanism of “biological” metal surface modification. In this paper magnesium samples were incubated under cell culture conditions (i.e. including CO2) in electrolyte solutions and cell growth media, with and without proteins. Chemical mapping by high-resolution electron-induced X-ray emission spectroscopy and infrared reflection microspectroscopy revealed a complex structure of the formed corrosion layer. The presence of CO2 in concentrations close to that in blood is significant for the chemistry of the oxidised layer. The presence of proteins leads to a less dense but thicker passivation layer which is still ion and water permeable, as osmolality and weight measurements indicate. %0 conference paper %@ %A Wolff, M.,Wiese, B.,Dahms, M.,Ebel, T. %D 2011 %J Proceedings of EURO PM 2011, International Congress and Exhibition %N %P 271-276 %T Binder development for Magnesium Powder Injection Moulding %U %X %0 conference lecture %@ %A Huang, Y.,Wang, Z.,Srinivasan, A.,Kainer, K.U.,Hort, N. %D 2011 %J 12th International Symposium on Physics of Materials, ISPMA 12 %N %P %T Metallurgical Characterization of Hot Tearing Curves Recorded during Solidification of Magnesium Alloys %U %X %0 book part %@ %A Witte, F.,Hort, N.,Feyerabend, F.,Vogt, C. %D 2011 %J Corrosion of Magnesium Alloys %N %P 403-425 %T Magnesium Corrosion: A Challenging Concept for Degradable Implants %U %X Degradable metals are breaking the current paradigm in biomaterial science to develop only corrosion-resistant metals. In particular,,metals which consist of trace elements existing in the human body are promising candidates for temporary implant materials. Such implants would be needed for a short time to provide mechanical support during the healing process of the injured or pathological tissue. Magnesium (Mg) and its alloys have been investigated recently by many authors as a suitable degradable biomaterial. The degradation of Mg alloys in vivo has been investigated in several animal studies. The findings of these studies will be critically discussed and related to Mg corrosion principles. In contrast to slow corroding metals the designated complete degradation or corrosion,of Mg alloys is conjunct with the limited use of the standard procedure,for biocompatibility testing (ISO 10993). In particular, established test,systems for biocompatibility and cytotoxicity of long-term biomaterials have limited use and reliability when used to investigate degradable Mg alloys. Additionally, the results obtained in vitro are substantially different from in vivo observations. The physiological background and possible hypotheses,will be elucidated and possible mechanism of in vivo corrosion of Mg alloys will be discussed. Several approaches to simulate the in vivo conditions on the laboratory scale have been investigated in the literature so far. These approaches will be presented and critically reviewed. This chapter will summarize the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce Mg alloys that are intended to perform clinically with an appropriate host response. %0 lecture %@ %A Hort, N. %D 2011 %J %N %P %T Einfuehrung in Werkstoffkunde II %U %X %0 lecture %@ %A Hort, N. %D 2011 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 conference lecture %@ %A Witte, F.,Hort, N.,Feyerabend, F. %D 2011 %J TMS 2011 Annual Meeting & Exhibition, Magnesium Technology %N %P %T Biodegradable Magnesium Implants - How Do They Corrode in-vivo? %U %X %0 journal article %@ 0921-5093 %A Rao, K.P.,Prasad, Y.V.R.K.,Dharmendra, C.,Hort, N.,Kainer, K.U. %D 2011 %J Materials Science and Engineering A %N 22-23 %P 6964-6970 %R doi:10.1016/j.msea.2011.05.088 %T Compressive strength and hot deformation behavior of TX32 magnesium alloy with 0.4% Al and 0.4% Si additions %U https://doi.org/10.1016/j.msea.2011.05.088 22-23 %X Mg–3 wt.%Sn–2 wt.%Ca (TX32) alloy has good corrosion and creep resistance although its strength does not match that of AZ31 alloy. In this paper, the influence of additions of 0.4 wt.%Al and 0.4 wt.%Si on the compressive strength and hot working characteristics of TX32 is reported. Although the room temperature compressive strength improved marginally with the alloying additions, the drop in higher-temperature strength is significant. By comparing with the alloy having only 0.4% Al, it is inferred that the Si addition is responsible for this deterioration. The hot working behavior is characterized by processing maps which revealed that TX32 exhibits two domains of dynamic recrystallization occurring in the temperature and strain rate ranges: (1) 300–350 °C and 0.0003–0.001 s−1 and (2) 390–500 °C and 0.005–0.6 s−1. In Al and Si containing TX32, both the domains moved to higher temperatures and the flow instability is reduced thereby improving the hot workability. In both the domains, the apparent activation energy is 177 kJ/mol, which is higher than that for self-diffusion in magnesium implying that there is a significant contribution from the back stress generated by the hard particles present in the matrix. %0 journal article %@ 0257-8972 %A Zeng, R.,Lan, Z.,Kong, L.,Huang, Y.,Cui, H. %D 2011 %J Surface and Coatings Technology %N 11 %P 3347-3355 %R doi:10.1016/j.surfcoat.2010.11.027 %T Characterization of calcium-modified zinc phosphate conversion coatings and their influences on corrosion resistance of AZ31 alloy %U https://doi.org/10.1016/j.surfcoat.2010.11.027 11 %X Two kinds of phosphate conversion coatings, including zinc phosphate coating and zinc–calcium phosphate coating, were prepared on the surface of AZ31 alloy in phosphate baths. The morphologies of these coatings were observed using scanning electron microscopy. Their chemical compositions and structures were characterized using energy-dispersive X-ray spectrum, X-ray photoelectron spectroscopy and X-ray diffraction. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization technique. The results show that the flowerlike Zn–Ca phosphate conversion coatings are mainly composed of hopeite (Zn3(PO4)2·4H2O). They have a quite different morphology from the dry-riverbed-like Zn phosphate coatings that consist of MgO, MgF2, Zn or ZnO and hopeite. Both of the zinc and zinc–calcium phosphate coatings can remarkably reduce the corrosion current density of the substrates. The Zn–Ca coating exhibits better corrosion resistance than the Zn coating. Introduction of calcium into the phosphate baths leads to the full crystallinity of the Zn–Ca coating. %0 journal article %@ 0921-5107 %A Hornberger, H.,Witte, F.,Hort, N.,Mueller, W.-D. %D 2011 %J Materials Science and Engineering B %N 20 %P 1746-1755 %R doi:10.1016/j.mseb.2011.07.018 %T Effect of fetal calf serum on the corrosion behaviour of magnesium alloys %U https://doi.org/10.1016/j.mseb.2011.07.018 20 %X The corrosion behaviour of WE43 magnesium alloys using the mini cell system was studied. Voltammetry and impedance spectroscopy were applied to study on the one hand the effect of microstructure of the working electrode and on the other hand the effect of proteins in the electrolyte. Two types of alloy samples were produced (i) by permanent mould casting and (ii) by gas atomization followed by extrusion. The results showed that the microstructure was strongly influenced by the production process. The extruded samples showed an improved homogeneity of phase distribution compared with cast samples as it was aimed for. Due to increased homogeneity it was expected to find higher corrosion resistance. However, the electrochemical results are contradictory and suggest an additional phase in the extruded microstructure. Using energy dispersive X-ray spectroscopy (EDX) the secondary magnesium rare earths (RE) phase of extruded samples showed differing composition than of cast samples as well as additional oxide phases. After the samples were electrochemically investigated in cell medium with and without fetal calf serum (FCS), an impact of FCS was detected in voltammetry due to the length of the polarisation curve. As the tip of the mini cell in contact with the working electrode is small, developing gases tend to spread on the working electrode and break the contact of liquid to the counter electrode; which results in disrupting the current flow. This effect was more pronounced when rising the voltage and was found reduced when using electrolytes with FCS. Impedance spectra were slightly deformed by FCS, seen as a kinetic effect but not as a basic differing corrosion reaction. The insight into the effects of FCS was provided by the mini cell system as this system enables to collect entire series of measurements. In contrast of two single measurements, those series reflected the slight difference caused by FCS. The focus of the electrochemical corrosion study was set on the first half hour of immersion. %0 conference paper %@ %A Staron, P.,Beckmann, F.,Lippmann, T.,Stark, A.,Oehring, M.,Pyczak, F.,Salgado, M,Hort, N.,Eckerlebe, H.,Kainer, K.U.,Mueller, M.,Schreyer, A. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 192-197 %T In situ studies of light metals with synchrotron radiation and neutrons %U %X %0 conference lecture %@ %A Elsayed, F.R.,Hort, N.,Salgado-Ordorica, M.,Kainer, K.U. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Magnesium Permanent Mold Castings Optimization %U %X %0 journal article %@ 0255-5476 %A Elsayed, F.R.,Hort, N.,Salgado-Ordorica, M.,Kainer, K.U. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 65-68 %R doi:10.4028/www.scientific.net/MSF.690.65 %T Magnesium Permanent Mold Castings Optimization %U https://doi.org/10.4028/www.scientific.net/MSF.690.65 %X Permanent mold casting is a well-established route for casting large magnesium alloys components. Casting parameters like superheat, mold temperature, and holding time can often result in inhomogeneous properties, porosity, and segregation problems in the cast part. In order to,optimize the casting process, control of the casting parameters including mold temperatures and holding times is essential to promote directional solidification, and ensure defect free homogenous structure. Binary Mg-9wt.%Al and Mg-10wt.%Gd alloys were used to investigate the effect of,casting parameters such as melt temperature and holding time on the part macro and microstructure. %0 conference lecture %@ %A Zander, D.,Heilig, M.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groebner, J.,Schmid-Fetzer, R. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Influence of cerium on the formation of micro-galvanic corrosion elements of AZ91 %U %X %0 conference paper %@ %A Zander, D.,Heilig, M.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groebner, J.,Schmid-Fetzer, R. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 381-384 %T Influence of cerium on the formation of micro-galvanic corrosion elements of AZ91 %U %X %0 journal article %@ 0255-5476 %A Zander, D.,Heilig, M.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groebner, J.,Schmid-Fetzer, R. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 381-384 %R doi:10.4028/www.scientific.net/MSF.690.381 %T Influence of cerium on the formation of micro-galvanic corrosion elements of AZ91 %U https://doi.org/10.4028/www.scientific.net/MSF.690.381 %X Investigations of AZ91D revealed a strong influence of mainly the following microstructural,parameters on corrosion: porosity, the eutectic, the Al-content of the Mg-phase as well as the volume fraction and distribution of gamma-Al12Mg17. Further an improved corrosion resistance was observed by the addition of rare earth elements. The influence of Ce on microstructure and corrosion of sand cast and high pressure die cast AZ91D with 0.5-2.0 wt.% Ce was investigated by SEM before and after potentiodynamic polarization measurements in pH7.5 (bi-distilled water adjusted with KOH). It was observed that Ce significantly improved the corrosion resistance by,changing the microstructure. A strong influence of Ce on the average grain size, the fraction of the,eutectic, changes in morphology and/or volume fraction of gamma Al12Mg17 and formation of a Cerich,intermetallic phase was observed. Therefore, not only the chemical composition but also the change of microstructure and the formation of micro-galvanic elements influence the local corrosion mechanism of AZ91D with cerium. %0 conference lecture %@ %A Staron, P.,Beckmann, F.,Lippmann, T.,Stark, A.,Oehring, M.,Pyczak, F.,Salgado, M,Hort, N.,Eckerlebe, H.,Kainer, K.U.,Mueller, M.,Schreyer, A. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T In situ studies of light metals with synchrotron radiation and neutrons %U %X %0 conference paper %@ %A Elsayed, F.R.,Hort, N.,Salgado-Ordorica, M.,Kainer, K.U. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 65-68 %T Magnesium Permanent Mold Castings Optimization %U %X %0 journal article %@ 0255-5476 %A Staron, P.,Beckmann, F.,Lippmann, T.,Stark, A.,Oehring, M.,Pyczak, F.,Salgado, M,Hort, N.,Eckerlebe, H.,Kainer, K.U.,Mueller, M.,Schreyer, A. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 192-197 %R doi:10.4028/www.scientific.net/MSF.690.192 %T In situ studies of light metals with synchrotron radiation and neutrons %U https://doi.org/10.4028/www.scientific.net/MSF.690.192 %X High-energy X-rays and neutrons offer the large penetration depths that are often required for the determination of bulk properties in engineering material research. In addition, new sources provide very high intensities on the sample, which can be used not only for high spatial resolution using very small beams, but also for high time resolution in combination with a fast detector. This opens up possibilities for a wide range of specific engineering in situ experiments. Typical examples that are already widely used are heating or tensile testing in the beam. However, there are also more challenging experiments in the field of light metals, like e.g. friction stir welding, dilatometry, solidification, or cutting. Selected examples are presented. %0 conference lecture %@ %A Maier, P.,Anopuo, O,Malchau, F.,Wienck, G.,Hort, N. %D 2011 %J 5th International Light Metals Technology Conference 2011 %N %P %T Cyclic deformation of newly developed Magnesium cast alloys in corrosive environment %U %X %0 conference paper %@ %A Maier, P.,Anopuo, O,Malchau, F.,Wienck, G.,Hort, N. %D 2011 %J Proceedings of the Fifth International Light Metals Technology Conference 2011 %N %P 495-498 %T Cyclic deformation of newly developed Magnesium cast alloys in corrosive environment %U %X %0 journal article %@ 0255-5476 %A Maier, P.,Anopuo, O,Malchau, F.,Wienck, G.,Hort, N. %D 2011 %J Materials Science Forum, Light Metals Technology V %N %P 495-498 %R doi:10.4028/www.scientific.net/MSF.690.495 %T Cyclic deformation of newly developed Magnesium cast alloys in corrosive environment %U https://doi.org/10.4028/www.scientific.net/MSF.690.495 %X The moderate corrosion rate exhibits by Mg-RE alloys make it candidate material for biodegradable implant. Owing to the operating environment, implants are subjected to stochastic cyclic load and chemical condition. The alloys response to the subjected condition determines its degree of applicability. This work studies the cyclic deformation of newly developed Mg10GdxNd alloys both in air and under corrosive environment. The corrosion fatigue test was carried out in Ringer-Acetate solution and was evaluated using mechanical,hysteresis and pH-value measurements. The microstructural changes in correlation to the deformation parameters and fracture surfaces were characterized using SEM. Results show that alloying Mg10Gd with Neodymium improved its fatigue live both in air and corrosive medium. Chilled casted Mg10Gd and Mg10GdxNd were found to undergo brittle fracture in both media. Loading in Ringer-Acetate was found to reduce the fatigue life of the investigated alloys due to the interaction of corrosion and fatigue processes on the microstructure of the alloys. EDX analysis suggests that the improved fatigue life observed on the Mg10GdxNd is,connected to the new ternary Mg-Gd-Nd phase observed in the microstructure. %0 conference lecture %@ %A Peng, Q.,Huang, Y.,Hort, N.,Kainer, K.U. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Rheological Behaviour of Semi-Solid Mg-Y Alloys %U %X %0 conference lecture %@ %A Pokorny, M.G.,Monroe, C.A.,Beckermann, C.,Zhen, Z.,Hort, N. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Simulation of Stresses During Casting of Binary Magnesium-Aluminum Alloys %U %X %0 conference paper %@ %A Pokorny, M.G.,Monroe, C.A.,Beckermann, C.,Zhen, Z.,Hort, N. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 401-407 %T Simulation of Stresses During Casting of Binary Magnesium-Aluminum Alloys %U %X %0 conference lecture %@ %A El Sayed, F.,Abuleil, T.,El Aziz, A.,Kainer, K.U.,Hort, N. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Investigations on Microstructure and Properties of Mg-Sn-Ca alloys with 3% Al additions %U %X %0 conference paper %@ %A El Sayed, F.,Abuleil, T.,El Aziz, A.,Kainer, K.U.,Hort, N. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 395-400 %T Investigations on Microstructure and Properties of Mg-Sn-Ca alloys with 3% Al additions %U %X %0 journal article %@ 1742-7061 %A Feyerabend, F.,Fischer, J.,Holtz, J.,Witte, F.,Willumeit, R.,Druecker, H.,Vogt, C.,Hort, N. %D 2010 %J Acta Biomaterialia %N 5 %P 1834-1842 %R doi:10.1016/j.actbio.2009.09.024 %T Evaluation of short-term effects of rare earth and other elements used in magnesium alloys on primary cells and cell lines %U https://doi.org/10.1016/j.actbio.2009.09.024 5 %X Degradable magnesium alloys for biomedical application are on the verge of being used clinically. Rare earth elements (REEs) are used to improve the mechanical properties of the alloys, but in more or less undefined mixtures. For some elements of this group, data on toxicity and influence on cells are sparse. Therefore in this study the in vitro cytotoxicity of the elements yttrium (Y), neodymium (Nd), dysprosium (Dy), praseodymium (Pr), gadolinium (Gd), lanthanum (La), cerium (Ce), europium (Eu), lithium (Li) and zirconium (Zr) was evaluated by incubation with the chlorides (10–2000 μM); magnesium (Mg) and calcium (Ca) were tested at higher concentrations (200 and 50 mM, respectively). The influence on viability of human osteosarcoma cell line MG63, human umbilical cord perivascular (HUCPV) cells and mouse macrophages (RAW 264.7) was determined, as well as the induction of apoptosis and the expression of inflammatory factors (TNF-α, IL-1α). Significant differences between the applied cells could be observed. RAW exhibited the highest and HUCPV the lowest sensitivity. La and Ce showed the highest cytotoxicity of the analysed elements. Of the elements with high solubility in magnesium alloys, Gd and Dy seem to be more suitable than Y. The focus of magnesium alloy development for biomedical applications should include most defined alloy compositions with well-known tissue-specific and systemic effects. %0 conference paper %@ %A Peng, Q.,Huang, Y.,Hort, N.,Kainer, K.U. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 329-332 %T Rheological Behaviour of Semi-Solid Mg-Y Alloys %U %X %0 conference lecture %@ %A Heilig, M.,Zander, D.,Olson, D.,Mishra, B.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groebner, J.,Schmid-Fetzer, R. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Influence of Cerium on Stress Corrosion Cracking in AZ91D %U %X %0 conference paper %@ %A Huang, Y.,Zheng, X.,Liu, B.,Anopuo, O.,Hort, N.,Kainer, K.U.,Kim, G.S. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 419-424 %T Grain Refinement of Mg-Al Alloys by Carbon Inoculation %U %X %0 conference lecture %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Approaching Bolt Load Retention Behaviour of AS41 Through Compliance and Creep Deformation %U %X %0 conference paper %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 215-220 %T Approaching Bolt Load Retention Behaviour of AS41 Through Compliance and Creep Deformation %U %X %0 conference lecture %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Effect of Aluminum Addition on the Strengthening and High Temperature Deformation Behaviour of Mg-3Sn-2Ca Alloy %U %X %0 conference paper %@ %A Heilig, M.,Zander, D.,Olson, D.,Mishra, B.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groebner, J.,Schmid-Fetzer, R. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 305-309 %T Influence of Cerium on Stress Corrosion Cracking in AZ91D %U %X %0 conference lecture %@ %A Gesing, A.J.,Reade, N.G.,Sokolowski, J.H.,Blawert, C.,Fechner, D.,Hort, N. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Development of Recyclable Mg-Based Alloys: AZ91D and AZC1231 Phase Information Derived from Heating/Cooling Curve Analysis %U %X %0 conference lecture %@ %A Huang, Y.,Zheng, X.,Liu, B.,Anopuo, O.,Hort, N.,Kainer, K.U.,Kim, G.S. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Grain Refinement of Mg-Al Alloys by Carbon Inoculation %U %X %0 conference paper %@ %A Gesing, A.J.,Reade, N.G.,Sokolowski, J.H.,Blawert, C.,Fechner, D.,Hort, N. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 97-105 %T Development of Recyclable Mg-Based Alloys: AZ91D and AZC1231 Phase Information Derived from Heating/Cooling Curve Analysis %U %X %0 conference poster %@ %A Fischer, J.,Proefrock, D.,Hort, N.,Willumeit, R.,Kainer, K.U.,Schreyer, A.,Feyerabend, F. %D 2010 %J 23rd European Conference on Biomaterials, ESB 2010 %N %P %T Improved in vitro Testing of Degradable Magnesium %U %X %0 conference lecture %@ %A Lilleodden, E.,Kim, G.S.,Yi, S.,Huang, Y.,Fivel, M.,Huber, N. %D 2010 %J 139th Annual Meeting & Exhibition, TMS 2010 %N %P %T Optimised fatigue behaviour of Ti-6Al-4V alloy components fabricated by MIM %U %X %0 conference paper %@ %A Fischer, J.,Feyerabend, F.,Hort, N.,Kainer, K.U.,Schreyer, A.,Willumeit, R. %D 2010 %J Magnesium, 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P 1175-1181 %T Cytotoxic and Immunological Effects of Magnesium Alloy Elements on Cells %U %X %0 journal article %@ 0255-5476 %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2010 %J Materials Science Forum, THERMEC 2009 %N %P 3616-3621 %R doi:10.4028/www.scientific.net/MSF.638-642.3616 %T High Temperature Deformation Mechanisms and Processing Map for Hot Working of Cast-Homogenized Mg-3Sn-2Ca Alloy %U https://doi.org/10.4028/www.scientific.net/MSF.638-642.3616 %X The hot working behavior of Mg-3Sn-2Ca alloy has been investigated in the temperature range 300–500 oC and strain rate range 0.0003–10 s-1, with a view to evaluate the mechanisms and optimum parameters of hot working. For this purpose, a processing map has been developed on the basis of the flow stress data obtained from compression tests. The stress-strain curves exhibited steady state behavior at strain rates lower than 0.01 s-1 and at temperatures higher than 350 oC and flow softening occurred at higher strain rates. The processing map exhibited two dynamic,recrystallization domains in the temperature and strain rate ranges: (1) 300–420 oC and 0.0003–,0.003 s-1, and (2) 420–500 oC and 0.003–1.0 s-1, the latter one being useful for commercial hot,working. Kinetic analysis yielded apparent activation energy values of 161 and 175 kJ/mole in,domains (1) and (2) respectively. These values are higher than that for self-diffusion in magnesium,suggesting that the large volume fraction of intermetallic particles CaMgSn present in the matrix,generates considerable back stress. The processing map reveals a wide regime of flow instability,which gets reduced with increase in temperature or decrease in strain rate. %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2010 %J Magnesium, 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P 62-67 %T Barium as alloying element for a creep resistant magnesium alloy %U %X %0 journal article %@ 0255-5476 %A Kainer, K.U.,Huang, Y.,Dieringa, H.,Hort, N. %D 2010 %J Materials Science Forum, THERMEC 2009 %N %P 73-80 %R doi:10.4028/www.scientific.net/MSF.638-642.73 %T Status of the Development of Creep Resistant Magnesium Materials for Automotive Applications %U https://doi.org/10.4028/www.scientific.net/MSF.638-642.73 %X The present paper presents the development status of creep resistant magnesium materials. It reviews the creep deformation mechanisms of magnesium alloys. Based on these,mechanisms, several effective approaches to improve the creep resistance are discussed, including,alloying, microstructural control and the development of new monolithic alloys and composites. %0 conference paper %@ %A Feyerabend, F.,Witte, F.,Vogt, C.,Fischer, J.,Schreyer, A.,Kainer, K.U.,Hort, N.,Willumeit, R. %D 2010 %J Magnesium, 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P 1156-1161 %T In Vitro Testing of Magnesium Alloys - Challenges and Options %U %X %0 journal article %@ 0142-9612 %A Peng, Q.,Huang, Y.,Zhou, L.,Hort, N.,Kainer, K.U. %D 2010 %J Biomaterials %N 3 %P 398-403 %R doi:10.1016/j.biomaterials.2009.09.065 %T Preparation and properties of high purity Mg–Y biomaterials %U https://doi.org/10.1016/j.biomaterials.2009.09.065 3 %X An effective zone solidification method has been found to prepare high purity Mg–Y biomaterials. The corrosion and mechanical properties of the purified middle region are improved remarkably compared with common casting method. The average gain size and secondary dendrite space decrease from the top layer to the bottom layer of the ingot. The oxides, defects and precipitates are mainly enriched in the top layer of the ingot under the impulsion of high thermal gradient. These results are in agreement with that simulated by finite elemental method using FLOW-3D software. It is confirmed that the mode of scallop symmetric solidification attributes to the purifying process. This zone solidification method not only contributes to high purity Mg-based biomaterials, but also provides a new approach to prepare high performance Mg alloys. %0 journal article %@ 1742-7061 %A Fischer, J.,Prosenc, M.H.,Wolff, M.,Hort, N.,Willumeit, R.,Feyerabend, F. %D 2010 %J Acta Biomaterialia %N 5 %P 1813-1823 %R doi:10.1016/j.actbio.2009.10.020 %T Interference of magnesium corrosion with tetrazolium-based cytotoxicity assays %U https://doi.org/10.1016/j.actbio.2009.10.020 5 %X Magnesium (Mg) alloys are promising materials for the development of biodegradable implants. However, the current in vitro test procedures for cytotoxicity, cell viability and proliferation are not always suitable for this class of materials. In this paper we show that tetrazolium-salt-based assays, which are widely used in practice, are influenced by the corrosion products of Mg-based alloys. Corroded Mg converts tetrazolium salts to formazan, leading to a higher background and falsifying the results of cell viability. Tetrazolium-based assays are therefore not a useful tool for testing the cytotoxicity of Mg in static in vitro assays. %0 journal article %@ 1742-7061 %A Hort, N.,Huang, Y.,Fechner, D.,Stoermer, M.,Blawert, C.,Witte, F.,Vogt, C.,Druecker, H.,Willumeit, R.,Kainer, K.U.,Feyerabend, F. %D 2010 %J Acta Biomaterialia %N 5 %P 1714-1725 %R doi:10.1016/j.actbio.2009.09.010 %T Magnesium alloys as implant materials – Principles of property design for Mg–RE alloys %U https://doi.org/10.1016/j.actbio.2009.09.010 5 %X Magnesium alloys have attracted increasing interest in the past years due to their potential as implant materials. This interest is based on the fact that magnesium and its alloys are degradable during their time of service in the human body. Moreover magnesium alloys offer a property profile that is very close or even similar to that of human bone. The chemical composition triggers the resulting microstructure and features of degradation. In addition, the entire manufacturing route has an influence on the morphology of the microstructure after processing. Therefore the composition and the manufacturing route have to be chosen carefully with regard to the requirements of an application. This paper discusses the influence of composition and heat treatments on the microstructure, mechanical properties and corrosion behaviour of cast Mg–Gd alloys. Recommendations are given for the design of future degradable magnesium based implant materials. %0 conference lecture %@ %A Zander, D.,Heilig, M.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groegner, J.,Schmid-Fetzer, R. %D 2010 %J TMS Annual Meeting 2010 %N %P %T Microstructure and corrosion of AZ91 with small amounts of cerium %U %X %0 conference paper %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 201-205 %T Effect of Aluminum Addition on the Strengthening and High Temperature Deformation Behaviour of Mg-3Sn-2Ca Alloy %U %X %0 conference paper %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2010 %J Advances In Light Weight Materials – Aluminum, Casting Materials, and Magnesium Technologies, 2010, SAE 2010 World Congress & Exhibition %N %P 0404 %R doi:10.4271/2010-01-0404 %T Bolt load retention and creep response of AS41 alloyed with 0.15% Ca %U https://doi.org/10.4271/2010-01-0404 %X Understanding the creep and bolt load retention (BLR) behaviour of promising Mg-Al alloys are crucial to developing elevated temperature resistance alloys. This is especially true for elevated temperature automotive applications with a prevalence of bolted joints. In this study, creep and fastener clamp load response of Mg-Al alloy AS41 was investigated and compared to that of Mg4Al and AS41 micro-alloyed with 0.15 % Ca. A compliance-creep approach was used to model the response of these Mg-Al alloys at bolted joints. The equation prediction of the BLR response and experimental results are in good agreement. AS41+0.15 Ca shows improved creep and BLR properties up to 175 °C. A correlation between the microstructures, creep and BLR results reveal that the formation of a ternary CaMgSi phase is responsible for the improved elevated temperature behaviour. %0 conference paper %@ %A Zander, D.,Heilig, M.,Hort, N.,Klaus, G.,Buehrig-Polaczek, A.,Groegner, J.,Schmid-Fetzer, R. %D 2010 %J Magnesium Technology, TMS Annual Meeting 2010 %N %P 187-191 %T Microstructure and corrosion of AZ91 with small amounts of cerium %U %X %0 conference paper %@ %A Wolff, M.,Fischer, J.,Wiese, B.,Guelck, T.,Willumeit, R.,Ebel, T. %D 2010 %J Powder Metallurgy, PM 2010, Conference Proceedings, World Congress & Exhibition %N %P 755-764 %T Sintering of porous components from ternary Mg-Y-Ca alloys for orthopedic applications %U %X %0 conference lecture %@ %A Huang, Y.,Zheng, X.,Kainer, K.U.,Hort, N. %D 2010 %J 11th International Aluminium Conference, INALCO 2010 %N %P %T Mechanism of Grain Refinement in Mg-Al Alloys with Carbon Inoculations %U %X %0 conference lecture %@ %A Hornberger, H.,Witte, F.,Hort, N.,Mueller, W.-D. %D 2010 %J 2nd Symposium on Biodegradable Metals 2010 %N %P %T Effect of fetal calf serum on the corrosion behaviour of magnesium alloys %U %X %0 conference lecture %@ %A Schille, C.,Braun, M.,Wendel, H.P.,Scheideler, L.,Hort, N.,Reichel, H.-P.,Schweizer, E.,Geis-Gerstorfer, J. %D 2010 %J 2nd Symposium on Biodegradable Metals 2010 %N %P %T Corrosion of experimental magnesium alloys in blood and PBS: A gravimetric and microscopic evaluation %U %X %0 conference lecture %@ %A Geis-Gerstorfer, J.,Schille, C.,Schweizer, E.,Rupp, E.,Scheideler, L.,Reichel, H.-P.,Hort, N.,Nolte, A.,Wendel, H.P. %D 2010 %J 2nd Symposium on Biodegradable Metals 2010 %N %P %T Blood triggered corrosion of magnesium alloys %U %X Intravascular stents manufactured out of bioabsorbable magnesium (Mg) or Mg-alloys are considered as auspicious candidates for the next stent generation. However, before clinical application numerous physical and biological tests, especially to predict the clinically highly important degradation kinetics in vivo, have to be performed. In a Chandler-Loop model, the initial degradation of eight different magnesium alloys during 6 h in contact with human whole blood was investigated. The magnesium release varied between 0.91 ± 0.33 mg/cm2 (MgAl9Zn1) and 2.57 ± 0.38 mg/cm2 (MgZn1). No correlation could be found with Mg release data obtained after immersion in simulated body fluid (SBF). This pilot study showed that Mg corrosion is highly influenced by the biological test environment (SBF or blood, etc.) and that a modified Chandler-Loop model with human whole blood may be superior to predict corrosion of Mg alloys under clinical conditions than the SBF models presently used. %0 conference poster %@ %A Tie, D.,Feyerabend, F.,Willumeit, R.,Hort, N.,Hoeche, D. %D 2010 %J Materials Science and Engineering, MSE 2010 %N %P %T XPS studies of magnesium surfaces after exposure to Dulbecco's Modified Eagle Medium, Hank's Buffered Salt Solution, Simulated Body Fluid %U %X %0 lecture %@ %A Hort, N. %D 2010 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 lecture %@ %A Hort, N. %D 2010 %J %N %P %T Einfuehrung in Werkstoffkunde I %U %X %0 conference paper %@ %A Kim, G.S.,Yi, S.,Huang, Y.,Huber, N.,Fivel, M.,Lilleodden, E. %D 2010 %J Mechanical Behavior at Small Scales - Experiments and Modeling, Symposium Proceedings MRS Fall Meeting 2009 %N %P 181-186 %T Twining and slip activity in magnesium <11-20> single crystal %U %X %0 journal article %@ 1438-1656 %A Tie, D.,Feyerabend, F.,Hort, N.,Willumeit, R.,Hoeche, D. %D 2010 %J Advanced Engineering Materials %N 12 %P B699-B704 %R doi:10.1002/adem.201080070 %T XPS studies of magnesium surfaces after exposure to Dulbecco's Modified Eagle Medium, Hank's Buffered Salt Solution and Simulated Body Fluid %U https://doi.org/10.1002/adem.201080070 12 %X Magnesium-based biomaterials are gaining increasing interest, while in vitro corrosion tests are not standardized yet. Moreover, the effects of different corrosion media on the corrosion products are still not fully understood. To compare and evaluate the three main corrosion media applied in most in vitro studies, an XPS investigation of magnesium surfaces was carried out after exposure of the specimens to Dulbecco's modified eagle medium (DMEM), Hank's buffered salt solution (HBSS), and simulated body fluid (SBF). The effects of rinsing the specimens after immersion were also determined. XPS investigations especially on the Mg 2p state showed that MgO, Mg(OH)2, and MgCO3 species were the dominant corrosion products presenting in all specimens despite of the different corrosion media. However, the ratio of corrosion products depends on the medium composition. It was also shown that rinsing specimens after immersion experiments is a necessary procedure when surface analysis is employed afterward. %0 conference lecture %@ %A Yang, L.,Huang, Y.,Peng, Q.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Hort, N. %D 2010 %J 2nd Symposium on Biodegradable Metals 2010 %N %P %T Mechanical and Corrosion Properties of Binary Mg-Dy Alloys for Medical Application %U %X %0 conference lecture %@ %A Fischer, J.,Poertner, R.,Feyerabend, F.,Hort, N.,Kainer, K.U.,Schreyer, A.,Willumeit, R. %D 2010 %J 2nd Symposium on Biodegradable Metals 2010 %N %P %T Bioreactor Test Set Up for in vitro Cytocompatiblity Testing of Magnesium Materials %U %X %0 journal article %@ 1946-3979 %A Anopuo, O.,Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2010 %J The SAE International Journal of Materials and Manufacturing %N 1 %P 202-210 %T Bolt Load Retention and Creep Response of AS41 Alloyed with 0.15 % Ca %U 1 %X Understanding the creep and bolt load retention (BLR) behaviour of promising Mg-Al alloys are crucial to developing elevated temperature resistance alloys. This is especially true for elevated temperature automotive applications with a prevalence of bolted joints. In this study, creep and fastener clamp load response of Mg-Al alloy AS41 was investigated and compared to that of Mg4Al and AS41 micro-alloyed with 0.15 % Ca. A compliance-creep approach was used to model the response of these Mg-Al alloys at bolted joints. The equation prediction of the BLR response and experimental results are in good agreement. AS41+0.15 Ca shows improved creep and BLR properties up to 175 °C. A correlation between the microstructures, creep and BLR results reveal that the formation of a ternary CaMgSi phase is responsible for the improved elevated temperature behaviour. %0 conference lecture %@ %A Huang, Y.,Zheng, X.,Kainer, K.U.,Hort, N. %D 2010 %J New Frontiers in Light Metals, Proceedings of the 11th International Aluminium Conference INALCO 2010 %N %P 451-459 %T Mechanism of Grain Refinement in Mg-Al Alloys with Carbon Inoculations %U %X Previous Al4C3 nuclei hypothesis cannot explain the grain refinement mechanism of Mg-Al alloys inoculated by carbon because this nucleant is impossible to form during solidification. In the present investigation a ternary compound Al2MgC2 was identified. It has,a closer crystal structure to Mg than Al4C3. In the centre of grains, one or more “hillocks” with Al, Mn and C-enrichment were observed. A novel grain refinement mechanism is suggested to explain the grain refinement of Mg-Al alloys with carbon inoculations. %0 conference lecture %@ %A Wolff, M.,Fischer, J.,Wiese, B.,Guelck, T.,Willumeit, R.,Ebel, T. %D 2010 %J Powder Metallurgy, World Congress and Exhibition PM 2010 %N %P %T Sintering of porous components from ternary Mg-Y-Ca alloys for orthopedic applications %U %X %0 conference lecture %@ %A Feyerabend, F.,Fischer, J.,Schreyer, A.,Druecker, H.,Mihailova, B.,Hort, N.,Kainer, K.U.,Willumeit, R. %D 2010 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien, DGBM 2010 %N %P %T Magnesium Corrosion in vitro – influence of corrosion media and environment %U %X %0 conference lecture %@ %A Anopuo, O.,Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2010 %J SAE 2010 World Congress & Exhibition %N %P %T Bolt load retention and creep response of AS41 alloyed with 0.15% Ca %U %X %0 journal article %@ 1862-5282 %A Prasad, Y.V.R.K.,Rao, K.P.,Hort, N.,Kainer, K.U. %D 2010 %J International Journal of Materials Research %N 2 %P 300-306 %R doi:10.3139/146.110269 %T Effect of thermal and mechanical treatments on the hot working response of Mg-3Sn-1Ca alloy %U https://doi.org/10.3139/146.110269 2 %X The effects of homogenization treatment and high-temperature extrusion on the hot working behavior of Mg-3Sn-1Ca alloy have been studied with a view to find an optimum processing route for the manufacture of wrought products. Processing maps and kinetic parameters have been obtained from the flow stress data recorded in hot compression experiments in the temperature range of 300–550°C and strain rate range of 0.0003–10 s–1. These reveal that the homogenization treatment has only a marginal effect on the hot workability, the result attributable to the high thermal stability of CaMgSn particles in the microstructure. High temperature extrusion, however, lowers the hot working temperature significantly (by about 150°C) and this has been attributed to grain refinement during primary processing. The mechanisms of hot deformation remained unchanged by the above treatments and the apparent activation energies for hot deformation are higher than those for self-diffusion suggesting that CaMgSn particles in the matrix cause large back-stress. %0 conference lecture %@ %A Hort, N.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Witte, F. %D 2010 %J Implantate - Materialien, Beschichtungen und Anwendungen %N %P %T Magnesium als Implantatwerkstoff %U %X %0 journal article %@ 0255-5476 %A Huang, Y.,Zheng, X.,Anopuo, O.,Kim, G.S.,Kainer, K.U.,Hort, N. %D 2010 %J Materials Science Forum, PRICM 7 %N %P 675-678 %R doi:10.4028/www.scientific.net/MSF.654-656.675 %T Aluminium-Rich Coring Structures in Mg-Al Alloys with Carbon Inoculation %U https://doi.org/10.4028/www.scientific.net/MSF.654-656.675 %X A homogeneous microstructure of as-cast magnesium alloys is necessary to improve the formability during their subsequent thermomechanical processing. In Al-containing magnesium alloys, the grain refinement by carbon inoculation is considered to be the best approach until now. However, the mechanism of grain refinement is unclear. The present work investigates the coring microstructure in Mg-Al alloys inoculated with carbon using FIB, SEM and TEM techniques. In each grain one or more “hillocks” exist, enriched with carbon, manganese and aluminium. This is possibly related to the inhomogeneous nucleation of alpha-magnesium. The precipitates in these “hillocks” are always surrounded by the aluminium-rich zones. These characteristics of microstructure observed in Mg-Al alloys with carbon inoculation are compared with that observed in Al-free magnesium alloys inoculated by zirconium. The similarities between them are discussed. A novel mechanism is suggested to explain the grain refinement in Mg-Al alloys inoculated by carbon. %0 conference paper %@ %A Hort, N.,Feyerabend, F.,Kainer, K.U.,Willumeit, R.,Witte, F. %D 2010 %J Implantate - Materialien, Beschichtungen und Anwendungen, Tagungsband %N %P 163-190 %T Magnesium als Implantatwerkstoff %U %X %0 conference lecture (invited) %@ %A Feyerabend, F.,Hort, N.,Willumeit, R. %D 2010 %J 4th International Conference on Biomaterials, Biomaterials & Medical Devices, BiomMedD 2010 %N %P %T Understanding physiological magnesium corrosion – an in vitro approach %U %X %0 journal article %@ 1073-5623 %A Pokorny, M.G.,Monroe, C.A.,Beckermann, C.,Zhen, Z.,Hort, N. %D 2010 %J Metallurgical and Materials Transactions A %N 12 %P 3196-3207 %R doi:10.1007/s11661-010-0367-3 %T Simulation of Stresses during Casting of Binary Magnesium-Aluminum Alloys %U https://doi.org/10.1007/s11661-010-0367-3 12 %X A viscoplastic stress model is used to predict contraction forces measured during casting of two binary Mg-Al alloys. Force measurements from castings that did not hot tear, together with estimates from data found in the literature, are used to obtain the high-temperature mechanical properties needed in the stress model. In the absence of hot tearing, the simulation results show reasonably good agreement with the measurements. It is found that coherency of the semisolid mush starts at a solid fraction of about 0.5 and that the maximum tensile strength for the Mg-1 and 9 wt pct Al alloys at their final solidification temperatures is 1.5 and 4 MPa, respectively. In the presence of hot tearing, the measured stresses are generally overpredicted, which is attributed to the lack of a fracture model for the mush. Based on the comparison of measured and predicted stresses, it is also shown that coupling of the stress model to feeding flow and macrosegregation calculations is needed in order to accurately predict stresses in the presence of hot tearing. %0 conference lecture %@ %A Rao, K.P.,Suresh, K.,Hort, N.,Kainer, K.U. %D 2010 %J 7th Pacific Rim International Conference on Advanced Materials and Processing, PRICM 7 %N %P %T Effect of Minor Additions of Al and Si on the Mechanical Properties of Cast Mg-3Sn-2Ca Alloys in Low Temperature Range %U %X %0 journal article %@ 0255-5476 %A Rao, K.P.,Suresh, K.,Hort, N.,Kainer, K.U. %D 2010 %J Materials Science Forum, PRICM 7 %N %P 635-638 %R doi:10.4028/www.scientific.net/MSF.654-656.635 %T Effect of Minor Additions of Al and Si on the Mechanical Properties of Cast Mg-3Sn-2Ca Alloys in Low Temperature Range %U https://doi.org/10.4028/www.scientific.net/MSF.654-656.635 %X The Mg-Sn-Ca alloys have shown superior creep properties compared to the creep resistant alloy AE42. In the present study, the effects of small amounts of Al and Si additions on the mechanical properties have been investigated on a Mg-3Sn-2Ca (TX32) alloy. The Al content in the selected alloys was 0.4 wt% and the Si content was varied from 0–0.8 wt% in steps of 0.2 wt.%. The alloys were cast in pre-heated permanent molds. Cylindrical specimens machined from the cast billets were tested in compression in the temperature range 25–250 °C at a strain rate of 0.0001 s–1. The alloy with 0.4 wt% Al shows an increased strength at all test temperatures compared with the TX32 base alloy. This is attributed to a solid solution strengthening of Al in Mg. The alloy with 0.4 wt% Al and 0.2 wt% Si has compressive strength that is closer to that of the TX32 alloy. However, increased additions of Si (from 0.4–0.8 wt%) reduce the strength, more significantly at higher temperatures. %0 conference lecture %@ %A Huang, Y.,Zheng, X.,Anopuo, O.,Kim, G.S.,Kainer, K.U.,Hort, N. %D 2010 %J 7th Pacific Rim International Conference on Advanced Materials and Processing, PRICM 7 %N %P %T Aluminium-Rich Coring Structures in Mg-Al Alloys with Carbon Inoculation %U %X %0 journal article %@ 1438-1656 %A Khan, S.,Hort, N.,Eiken, J.,Steinbach, I.,Schmauder, S. %D 2009 %J Advanced Engineering Materials %N 3 %P 162-168 %R doi:10.1002/adem.200800269 %T Numerical Determination of Heat Distribution and Castability Simulations of as Cast Mg - Al Alloys %U https://doi.org/10.1002/adem.200800269 3 %X No abstract %0 journal article %@ 0177-9516 %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2009 %J Praxis der Naturwissenschaften - Chemie in der Schule %N 3 %P 9-13 %T Neue Entwicklungen bei der Anwendung von Magnesiumlegierungen %U 3 %X No abstract %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N.,Dieringa, H. %D 2009 %J IMA 2009 Taiyuan Global Magnesium Conference and Exhibition %N %P %T Development of advanced magnesium cast alloys and technologies %U %X %0 journal article %@ 1003-6326 %A Abu Leil, T.,Hort, N.,Dietzel, W.,Blawert, C.,Huang, Y.,Kainer, K.U.,Rao, K.P. %D 2009 %J Transactions of Nonferrous Metals Society of China %N 1 %P 40-44 %R doi:10.1016/S1003-6326(08)60225-3 %T Microstructure and corrosion behavior of Mg-Sn-Ca alloys after extrusion %U https://doi.org/10.1016/S1003-6326(08)60225-3 1 %X Mg-Sn-Ca alloys promise a reasonable corrosion resistance in combination with good creep resistance, likely due to the,presence of Ca2xMgxSn and other phases. The selected alloys with 3% Sn and Ca in the range of 1%-2% have been extruded in,order to achieve more homogeneous microstructure compared with the as-cast alloys. Optical microscopy(OM) and X-ray,diffraction(XRD) techniques were used to study the microstructure and phases of these alloys. The corrosion behavior of these alloys,was investigated by means of salt spray test and potentio-dynamic measurements. The results obtained on the alloys Mg-3Sn (T3),,Mg-3Sn-1Ca (TX31), and Mg-3Sn-2Ca (TX32) indicate the presence of the same phases in as-cast and after extrusion, namely,Mg2Sn, Ca2xMgxSn, and Ca2xMgxSn/Mg2Ca, respectively. However, due to the occurrence of extensive recrystallization in the,extrusion process, the grain size has significantly reduced after extrusion. The reduction leads to the improvement of the corrosion,resistance after extrusion which is then comparable with the commercial alloy AZ91D. %0 journal article %@ 1946-3979 %A Anopuo, O.,Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U.,Abdul, K.K. %D 2009 %J The SAE International Journal of Materials and Manufacturing %N 1 %P 103-110 %T Mechanical Properties and Corrosion Performance of AZ-Mg Alloy Modified with Ca and Sr %U 1 %X Any new Mg-alloys for the power train application in the automotive industry should have better elevated temperature mechanical and corrosion properties than the traditional AZ91 magnesium alloy. The price of AZ-Mg alloy modified with Ca and Sr, which can have adequate properties suitable for its service conditions, is expected to be comparable to that of AZ91 alloy and cheaper than AE42 alloy. The formation of thermally stable intermetallics, which are necessary for the improvement of creep properties, makes it a promising candidate for high temperature applications. This work investigates the mechanical and corrosion properties of AZ-Mg alloy modified with (Ca, Sr) in comparison with those of AZ91; the work included bolt load retention (BLR) and ageing behaviour. The aim is to give a preliminary evaluation of the overall performance of this modified AZ alloy. It is found that this alloy has a superior BLR property compared to AZ91 alloy with a good corrosion resistance. %0 conference lecture %@ %A Feyerabend, F.,Witte, F.,Vogt, C.,Fischer, J.,Schreyer, A.,Kainer, K.U.,Hort, N.,Willumeit, R. %D 2009 %J 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P %T In vitro testing of magnesium alloys – Challenges and options %U %X %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2009 %J European Conference on Materials and Structures in Aerospace, EUCOMAS 2009 %N %P %T Magnesiumm Alloys and Magnesium Based MMCs for Structural Aerospace Applications %U %X %0 conference paper %@ %A Anopuo, O.,Shen, G.,Xu, S.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P 509-514 %T Elevated temperature and varied load response of AS41 at bolted joint %U %X %0 conference lecture %@ %A Anopuo, O.,Shen, G.,Xu, S.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P %T Elevated temperature and varied load response of AS41 at bolted joint %U %X %0 conference lecture %@ %A Zeng, R.,Kainer, K.U.,Blawert, C.,Dietzel, W.,Hort, N. %D 2009 %J International Conference on Materials for Advanced Technologies, ICMAT 2009 %N %P %T Influence of grain size and artificial ageing on the corrosion of an extruded magnesium alloy ZK60 component %U %X %0 conference lecture (invited) %@ %A Hort, N.,Kainer, K.U.,Witte, F.,Willumeit, R.,Feyerabend, F. %D 2009 %J Sino-German Joint Symposium on Advanced Materials and Technology %N %P %T Magnesium Based Implant Materials %U %X %0 conference paper %@ %A Fechner, D.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P 111-116 %T Magnesium recycling system prepared by permanent mould- and high pressure die casting %U %X %0 conference paper %@ %A Guenther, R.,Hartig, C.,Hort, N.,Bormann, R. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P 309-314 %T On the influence of settling of (ZrB2)p inoculants on grain refinement of magnesium alloys: experiment and theoretical calculation %U %X %0 conference lecture %@ %A Guenther, R.,Hartig, C.,Hort, N.,Bormann, R. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P %T On the influence of settling of (ZrB2)p inoculants on grain refinement of magnesium alloys: experiment and theoretical calculation %U %X %0 conference lecture (invited) %@ %A Feyerabend, F.,Witte, F.,Vogt, C.,Fischer, J.,Willumeit, R.,Kainer, K.U.,Hort, N. %D 2009 %J International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2009 %N %P %T Challenges of in vitro testing of magnesium alloys %U %X %0 journal article %@ 0921-5093 %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2009 %J Materials Science and Engineering A %N %P 382-386 %R doi:10.1016/j.msea.2008.06.051 %T Investigation of minimum creep rates and stress exponents calculated from tensile and compressive creep data of magnesium alloy AE42 %U https://doi.org/10.1016/j.msea.2008.06.051 %X Creep specimens prepared of magnesium alloy AE42 were investigated under constant load in compressive and tensile creep respectively. Material was cast via the squeeze casting process in order to obtain a dense microstructure without pores. Creep tests were performed at constant temperatures between 150°C and 240°C and constant applied stresses between 40 MPa and 120 MPa until minimum creep rate ε&s was reached. It could be seen that the minimum creep rates of compressive creep tests were smaller compared to tensile creep tests, and the difference increased with increasing applied stress. Stress exponents, n, were determined according to the Norton-equation and it was found that a threshold stress σ had to be introduced into the analysis. The threshold stress is based on strengthening by Al-RE (aluminum-rare earths) precipitates. Calculating the true stress exponent, n, deformation mechanisms during creep could be clarified. %0 conference paper %@ %A Pinheiro, G.,dos Santos, J.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P 191-196 %T Microstructural and mechanical aspects of reinforcement welds for lightweight components produced by friction hydro pillar processing %U %X %0 conference lecture %@ %A Pinheiro, G.,dos Santos, J.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P %T Microstructural and mechanical aspects of reinforcement welds for lightweight components produced by friction hydro pillar processing %U %X %0 conference lecture %@ %A Fechner, D.,Hort, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P %T Magnesium recycling system prepared by permanent mould- and high pressure die casting %U %X %0 conference paper %@ %A Zhen, Z.,Hort, N.,Utke, O.,Huang, Y.,Petri, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P 105-110 %T Investigations on hot tearing of Mg-Al binary alloys by using a new quantitative method %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Huang, Y.,Hort, N. %D 2009 %J International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2009 %N %P %T Status of the Development of Creep Resistant Magnesium Materials for Automotive Applications %U %X %0 journal article %@ 0921-5093 %A Prasad, Y.V.R.K.,Rao, K.P.,Hort, N.,Kainer, K.U. %D 2009 %J Materials Science and Engineering A %N 1-2 %P 25-31 %R doi:10.1016/j.msea.2008.10.041 %T Optimum parameters and rate-controlling mechanisms for hot working of extruded Mg-3Sn-1Ca alloy %U https://doi.org/10.1016/j.msea.2008.10.041 1-2 %X The hot working behavior of extruded Mg–3Sn–1Ca alloy has been characterized by compression testing in the temperature range of 300–550 °C and strain rate range of 0.0003–10 s−1 with a view to evaluate the optimum processing parameters as well as the rate-controlling mechanisms. Processing maps, developed on the basis of the temperature and strain rate dependence of flow stress, exhibited two domains in which dynamic recrystallization occurs. Both these are in the temperature range 325–500 °C, with one in the lower strain rate range (0.0003–0.003 s−1) and the other in the higher strain rate range (1–10 s−1), the optimum temperature being 400 °C. Kinetic analysis in the above two domains yielded apparent activation energy values of 196 and 168 kJ/mole, respectively, which are higher than that for self-diffusion in pure magnesium suggesting that the large volume fraction of CaMgSn intermetallic particles in the matrix causes significant back stress. In the change-over strain rate range (0.003–0.3 s−1), unusual grain size changes have occurred which may render microstructural control difficult. %0 journal article %@ 0024-3345 %A Fechner, D.,Hort, N.,Blawert, C.,Dietzel, W.,Kainer, K.U. %D 2009 %J Light Metal Age %N August %P 20-24 %T Magnesium Recycling: State-of-the-Art Developments, Part I %U August %X The primary production of magnesium has been increasing over the last 15 years approaching the mark of one million tonnes per year. Though this amount is still much less than the annual world production of steel or aluminum, a steadily growing fraction of primary magnesium is used for the fabrication of magnesium alloys for automotive components like gearbox housings, dashboard panel carriers, and steering wheels. The recycling of magnesium, however, has always been an issue. These days it is especially important due to its energy intensive production. Using the economic electrolytic process consumes 35 kWh/kg, and remelting magnesium consumes 10% of this energy at the most. High pressure die casting (HPDC) is by far the most established fabrication method for magnesium alloy components and the automotive industry is by far the most important user of magnesium alloys. About 50% of a HPDC shot is made up by biscuit or sprue, runner system, and gates. This excess metal is relatively clean, sorted according,to a single alloy, and can be remelted easily. It is estimated that approximately 200,000 tonnes of clean magnesium scrap are recycled and reused together with primary magnesium metal in the HPDC process. However, automotive magnesium components at the end of a products lifetime have not been recycled so far. The latter is due to the decreasing corrosion resistance of magnesium alloys with elevated contents of copper, nickel, and iron.,In this article, sources of scrap, sorting techniques, scrap classes, and the influence of oxides, in magnesium melts is presented. %0 conference lecture %@ %A Feyerabend, F.,Hort, N.,Witte, F.,Fischer, J.,Kainer, K.U.,Willumeit, R. %D 2009 %J 22nd European Conference on Biomaterials %N %P %T Rare earth element cytotoxicity and their use for magnesium alloying %U %X %0 journal article %@ 1006-9321 %A Fechner, D.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2009 %J Science in China E %N 1 %P 148-154 %R doi:10.1007/s11431-008-0288-1 %T Recycling of magnesium drive train components %U https://doi.org/10.1007/s11431-008-0288-1 1 %X With the development of new heat resistant magnesium alloys, the automotive industry has introduced several parts to the drive train. The rising number of large magnesium components will result in a higher quantity of automotive post consumer scrap. It was the aim of this work to find a reasonable alloy system for the recycling of these magnesium drive train components. A matrix of potential recycling alloys based on the magnesium alloy AM50 was prepared via permanent mould casting. The materials were investigated via tensile testing, creep tests and salt spray tests. Three alloys were selected for processing via high pressure die casting and the tests were repeated on the new materials. A promising system for recycling has been isolated and will be investigated more deeply for the influence of impurities. %0 conference lecture %@ %A Zhen, Z.,Hort, N.,Utke, O.,Huang, Y.,Petri, N.,Kainer, K.U. %D 2009 %J Magnesium Technology, TMS Annual Meeting 2009 %N %P %T Investigations on hot tearing of Mg-Al binary alloys by using a new quantitative method %U %X %0 conference lecture %@ %A Feyerabend, F.,Witte, F.,Vogt, C.,Fischer, J.,Kainer, K.U.,Hort, N.,Willumeit, R. %D 2009 %J 2nd China-Europe Symposium on Biomaterials in Regenerative Medicine %N %P %T Challenges of reliable in vitro testing of magnesium alloys %U %X %0 conference lecture %@ %A Fechner, D.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2009 %J 4th International Light Metals Technology Conference 2009 %N %P %T Influence of Strontium, Silicon and Calcium Additions on the Properties of the AM50 Alloy %U %X %0 lecture %@ %A Hort, N. %D 2009 %J %N %P %T Grundlagen der Werkstoffwissenschaften %U %X %0 journal article %@ 0024-3345 %A Fechner, D.,Hort, N.,Blawert, C.,Dietzel, W.,Kainer, K.U. %D 2009 %J Light Metal Age %N Oktober %P 34-36 %T Magnesium Recycling: State-of-the-Art Developments, Part II %U Oktober %X Editor´s Note: This is the second Part of a two Part Article on the Subject of Magnesium Recycling. Part I appeared in the August 2009 Issue of Light Metal Age and covered Sources for Magnesium Scrap, Scrap Sorting Techniques, Scrap Classes and Inclusions in Magnesium Melts. %0 conference poster %@ %A Kim, G.S.,Yi, S.,Huang, Y.,Huber, N.,Fivel, M.,Lilleodden, E. %D 2009 %J MRS Fall Meeting 2009 %N %P %T Twining and slip activity in magnesium <11-20> single crystal %U %X %0 conference paper %@ %A Kainer, K.U.,Hort, N.,Willumeit, R.,Feyerabend, F.,Witte, F. %D 2009 %J Processing and Fabrcation of Advanced Materials, Proceedings of 18th International Symposium, PFAM 18 %N %P 975-984 %T Magnesium Alloys for the Design of Implants %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N.,Willumeit, R.,Feyerabend, F.,Witte, F. %D 2009 %J 18th International Symposium on Processing and Fabrcation of Advanced Materials, PFAM 18 %N %P %T Magnesium Alloys for the Design of Implants %U %X %0 conference paper %@ %A Liu, B.,Huang, Y.,Hort, N.,Peng, Q.,Kainer, K.U.,Pan, F. %D 2009 %J Processing and Fabrcation of Advanced Materials, Proceedings of 18th International Symposium, PFAM 18 %N %P 421-430 %T Thermodynamic investigations on grain refining mechanisms of Mg-Al alloys inoculated by SiC particles %U %X %0 conference lecture (invited) %@ %A Liu, B.,Huang, Y.,Hort, N.,Peng, Q.,Kainer, K.U.,Pan, F. %D 2009 %J 18th International Symposium on Processing and Fabrcation of Advanced Materials, PFAM 18 %N %P %T Thermodynamic investigations on grain refining mechanisms of Mg-Al alloys inoculated by SiC particles %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2009 %J 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P %T Barium as alloying element for a creep resistant magnesium alloy %U %X %0 conference lecture %@ %A Feyerabend, F.,Ulmer, J.,Hort, N. %D 2009 %J DGM-Fachausschuss Biomaterialien %N %P %T In vitro Tests fuer metallische Materialien %U %X %0 journal article %@ 0255-5476 %A Fechner, D.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2009 %J Materials Science Forum, Light Metals Technology 2009 %N %P 459-462 %R doi:10.4028/www.scientific.net/MSF.618-619.459 %T Influence of Strontium, Silicon and Calcium Additions on the Properties of the AM50 Alloy %U https://doi.org/10.4028/www.scientific.net/MSF.618-619.459 %X The increasing use of heat resistant magnesium alloys for automotive applications is expected to,influence the chemical composition of upcoming post consumer scrap. Therefore it would be useful,to define alloys that resemble the future composition of the material. For this purpose a matrix of,potential recycling systems has been set up. AM50 was used as a base material to which decisive,amounts of strontium, silicon and calcium were added. The basic heat resistant alloy systems AJ,,AS, and AX have been investigated closely. This work deals with combinations of the three above,mentioned elements. Some essential observations shall be presented concerning the development of,the microstructure and its influence on the materials properties. For combined additions of,strontium, silicon and calcium the formation of a new ternary phase has been observed. The,compound has a positive influence on the fracture elongation and the corrosion rate in the salt spray,test. %0 conference lecture %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2009 %J International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2009 %N %P %T High Temperature Deformation Mechanisms and Processing Map for Hot Working of Cast-Homogenized Mg-3Sn-2Ca Alloy %U %X %0 conference lecture (invited) %@ %A Hort, N.,Huang, Y.,fechner, D.,Stoermer, M.,Blawert, C.,Witte, F.,Vogt, C.,Druecker, H.,Willumeit, R.,Kainer, K.U.,Feyerabend, F. %D 2009 %J International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2009 %N %P %T Magnesium Alloys as Implant Materials - Principles of Property Design for Mg-RE Alloys %U %X %0 journal article %@ 0255-5476 %A Zhen, Z.,Hort, N.,Huang, Y.,Petri, N.,Utke, O.,Kainer, K.U. %D 2009 %J Materials Science Forum, Light Metals Technology 2009 %N %P 533-540 %R doi:10.4028/www.scientific.net/MSF.618-619.533 %T Quantitative Determination on Hot Tearing in Mg-Al Binary Alloys %U https://doi.org/10.4028/www.scientific.net/MSF.618-619.533 %X Hot tearing, or hot cracking, is one of the most severe solidification defects commonly encountered,during casting. It is such a complicated phenomenon that a full understanding is still not yet achieved, though it has been extensively investigated for decades. Most contributions are still based,on qualitative characterisations. The purpose of this work is to develop a method that can quantitatively evaluate and investigate hot tearing behaviour. The principle is based on contraction stress/force measurements. The measured contraction force has been proven to be able to evaluate the hot tearing susceptibility as a more straightforward and quantitative index. By analyzing the contraction force curve, information can be obtained for both the initiation and the propagation of the hot tear. With this method, the influence of mould temperature and Al content on hot tearing behaviour of Mg-Al binary alloys has been investigated. The contraction force curves also indicate that the liquid refilling plays an important role during the hot crack propagation. With a lower,cooling rate and higher onset temperature of hot tear, the remaining liquid is more favourable to refill the initiated hot crack, and consequently interrupts the propagation of cracks or possibly,completely heals the cracks. %0 conference lecture %@ %A Feyerabend, F.,Witte, F.,Vogt, C.,Fischer, J.,Schreyer, A.,Kainer, K.U.,Hort, N.,Willumeit, R. %D 2009 %J 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P %T In Vitro Testing of Magnesium Alloys - Challenges and Options %U %X %0 conference lecture %@ %A Willumeit, R.,Fischer, J.,Druecker, H.,Vogt, C.,Kainer, K.U.,Schreyer, A.,Hort, N.,Feyerabend, F. %D 2009 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien, DGBM 2009 %N %P %T Optimization of in vitro corrosion of magnesium and its alloys %U %X %0 conference lecture %@ %A Feyerabend, F.,Fischer, J.,Witte, F.,Vogt, C.,Druecker, H.,Schreyer, A.,Kainer, K.U.,Blawert, C.,Hort, N.,Willumeit, R. %D 2009 %J 12th International Magnesium Symposium %N %P %T Strategies for development and testing of degradable magnesium alloys %U %X %0 conference paper %@ %A Kainer, K.U.,Huang, Y.,Peng, Q.,Hort, N. %D 2009 %J Nanostructured Metals – Fundamentals to Applications, Proceedings of the 30th Risoe International Symposium on Materials Science %N %P 81-99 %T Nanostructured Magnesium Alloys %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Huang, Y.,Peng, Q.,Hort, N. %D 2009 %J 30th Risoe International Symposium on Materials Science: Nanostructured Metals – Fundamentals to Applications %N %P %T Nanostructured Magnesium Alloys %U %X %0 conference lecture %@ %A Fechner, D.,Blawert, C.,Hort, N.,Kainer, K.V. %D 2009 %J 17th Magnesium Automotive- und Abnehmerseminar 2009 %N %P %T Recycling of Magnesium Alloys - State of the Art %U %X %0 conference lecture %@ %A Zhen, Z.,Hort, N.,Huang, Y.,Petri, N.,Utke, O.,Kainer, K.U. %D 2009 %J 4th International Light Metals Technology Conference 2009 %N %P %T Quantitative Determination on Hot Tearing in Mg-Al Binary Alloys %U %X %0 conference lecture %@ %A Fischer, J.,Feyerabend, F.,Hort, N.,Kainer, K.U.,Schreyer, A.,Willumeit, R. %D 2009 %J 8th International Conference on Magnesium Alloys and their Applications, Magnesium 2009 %N %P %T Cytotoxic and Immunological Effects of Magnesium Alloy Elements on Cells %U %X %0 conference paper %@ %A Khan, S.,Hort, N.,Subasic, E.,Schmauder, S. %D 2008 %J Proceedings of 10th Asian Foundry Congress, AFC-10 %N %P 329-334 %T Fluidity of magnesium alloys, an experimental and numerical approach %U %X %0 conference lecture %@ %A Hort, N.,Rao, K.P.,Abu Leil, T.,Dieringa, H.,Prasad, V.Y.R.K.,Kainer, K.U. %D 2008 %J 2008 TMS Annual Meeting & Exhibition %N %P %T Creep and Hot Working Behavior of a new Magnesium Alloy Mg-3Sn-2Ca %U %X %0 conference lecture %@ %A Khan, S.,Hort, N.,Subasic, E.,Schmauder, S. %D 2008 %J 10th Asian Foundry Congress, AFC-10 %N %P %T Fluidity of magnesium alloys, an experimental and numerical approach %U %X %0 conference paper %@ %A Huang, Y.,Dieringa, H.,Hort, N.,Zhen, Z.,Kainer, K.U. %D 2008 %J China-Europe Collaboration: 3rd China-Europe Advanced Materials Symposium, CEAM 3 %N %P 133-137 %T Approaches to improve high temperature creep resistance of magnesium alloys by alleviating the segregation of primary alloying elements %U %X %0 journal article %@ 1662-9779 %A Frank, H.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2008 %J Solid State Phenomena, Semi-Solid Processing of Alloys and Composites X %N %P 43-18 %R doi:10.4028/www.scientific.net/SSP.141-143.43 %T Influence of Processing Route on the Properties of Magnesium Alloys %U https://doi.org/10.4028/www.scientific.net/SSP.141-143.43 %X Magnesium alloys had gained an increasing interest in recent years due to their promising property profile for light weight constructions. They offer drastic advantages in weight reductions in automotive industries compared to steel or even aluminium. Therefore they can be used to decrease the emission of green house gases as requested by the EU directive for the reduction of CO2 emissions and moreover due to their recyclability they also help to fulfill the requirements from the EU directive regarding the end of life of vehicles. But still there are some limitations with regard to strength,,mostly at elevated temperatures above 130 °C. To overcome these limitations alloy development as,well as process optimization has to be done for further enhancement of the range of magnesium applications. This paper will show and discuss the property profiles of the standard magnesium alloy AZ91D compared to the recently developed, heat resistant magnesium alloy MRI153. The alloys have been processed using normal high pressure die casting (HPDC), New Rheocasting (NRC) and Thixomolding® (TM). As methods of investigation tensile and creep tests have been applied. The,creep properties have been determined in the temperature range of 135-150 °C and loads of 50-85 MPa. All these trials have been accompanied by metallographic observations (light optical metallography, SEM) and density measurements to investigate the influence of the processing routes,on microstructure and the porosity of the materials. It will be shown that the differences in the property profile of the chosen alloys are dependent on their different chemical compositions as well as,on different microstructures that are obtained by the different processing routes. While in the case of AZ91D, TM is showing advantages compared to HPDC for room temperature applications, the NRC in combination with the heat resistant alloy leads to an improvement of creep rates by two orders of magnitudes. %0 conference object %@ %A Yuen, C.K.,Hort, N.,Ip, W.Y. %D 2008 %J Proceedings of TERMIS-EU 2008 Meeting %N %P 452 %T Biodegradable magnesium alloys for tissue engineering and other biological applications: unexpected findings from a mouse model %U %X %0 conference poster %@ %A Yuen, C.K.,Hort, N.,Ip, W.Y. %D 2008 %J TERMIS-EU 2008 Meeting %N %P %T Biodegradable magnesium alloys for tissue engineering and other biological applications: unexpected findings from a mouse model %U %X %0 conference lecture %@ %A Pinheiro, G.,Hort, N.,dos Santos, J.,Kainer, K.U. %D 2008 %J Materials Science and Engineering, MSE 2008 %N %P %T Microstructural and Mechanical Aspects of Reinforcement Welds for Lightweight Components produced by Friction Hydro Pillar Processing %U %X %0 conference lecture %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2008 %J Husky Metal Molding Day 2008 %N %P %T Introduction in Magnesium, Thixomolding and Demands of Automotive Industry %U %X %0 conference paper %@ %A Guenther, R.,Hartig, C.,Anopuo, O.,Hort, N.,Bormann, R. %D 2008 %J Magnesium Technology 2008, TMS Annual Meeting & Exhibition %N %P 95-99 %T The Role of solutes for Grain Refinement by (SiC)p: Experiment and Theoritical Calculation %U %X %0 conference lecture %@ %A Guenther, R.,Hartig, C.,Anopuo, O.,Hort, N.,Bormann, R. %D 2008 %J 2008 TMS Annual Meeting & Exhibition %N %P %T The Role of solutes for Grain Refinement by (SiC)p: Experiment and Theoritical Calculation %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2008 %J SAMPE EUROPE 28th International Conference and Forum: Composites Forever, SEICO 08 %N %P %T Microstructure and Mechanical properties of AlSi9Cu3 Alloy Based Hybrid Composites %U %X %0 conference lecture %@ %A Huang, Y.,Dieringa, H.,Hort, N.,Zhen, Z.,Kainer, K.U. %D 2008 %J China-Europe Collaboration: 3rd China-Europe Advanced Materials Symposium, CEAM 3 %N %P %T Approaches to improve high temperature creep resistance of magnesium alloys by alleviating the segregation of primary alloying elements %U %X %0 conference paper %@ %A Anopuo, O.,Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U.,Abdul, K.K. %D 2008 %J SAE Technical Paper Series, SAE 2008 World Congress %N %P 01-0372 %T Mechanical Properties and Corrosion Performance of AZ-Mg Alloy Modified with Ca and Sr %U %X %0 conference lecture %@ %A Anopuo, O.,Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U.,Abdul, K.K. %D 2008 %J SAE 2008 World Congress %N %P %T Mechanical Properties and Corrosion Performance of AZ-Mg Alloy Modified with Ca and Sr %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2008 %J 3rd China-Europe Advanced Materials Symposium %N %P %T Tension and Compression Creep Asymmetry in Magnesium Alloy AE42 %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2008 %J SAMPE EUROPE 28th International Conference and Forum: Composites Forever, SEICO 08 %N %P 398-403 %T Microstructure and Mechanical properties of AlSi9Cu3 Alloy Based Hybrid Composites %U %X %0 conference lecture %@ %A Zeng, R.,Blawert, C.,Dietzel, W.,Hort, N.,Kainer, K.U. %D 2008 %J 3rd China-Europe Advanced Materials Symposium, CEAM 3 %N %P %T Corrosion morphologies on the extruded magnesium alloy ZK60 component %U %X %0 conference lecture %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2008 %J 2nd Annual European Magnesium in Automotive Seminar %N %P %T Alloy Development %U %X %0 conference lecture %@ %A Feyerabend, F.,Hort, N.,Kainer, K.U.,Willumeit, R. %D 2008 %J Materials Science and Engineering, MSE 2008 %N %P %T Short term effects of magnesium alloy elements on human cells %U %X %0 conference lecture %@ %A Khan, S.,Hort, N.,Steinbach, I.,Schmauder, S. %D 2008 %J 2008 TMS Annual Meeting & Exhibition %N %P %T Castability of Magnesium Alloys %U %X %0 conference lecture %@ %A Feyerabend, F.,Hort, N.,Witte, F.,Kainer, K.U.,Willumeit, R. %D 2008 %J 8th World Biomaterials Congress %N %P %T An in vitro test for corrosion and cytocompatibility of two magnesium alloys %U %X %0 journal article %@ 1359-6462 %A Huang, Y.,Dieringa, H.,Hort, N.,Abu Leil, T.,Kainer, K.U.,Liu, Y. %D 2008 %J Scripta Materialia %N 10 %P 894-897 %R doi:10.1016/j.scriptamat.2008.01.011 %T Effects of segregation of primary alloying elements on the creep response in magnesium alloys %U https://doi.org/10.1016/j.scriptamat.2008.01.011 10 %X The segregation of primary alloying elements deteriorates the high temperature creep resistance of magnesium alloys. Annealing,at high temperatures alleviating their segregations can improve the creep resistance. Present investigation on the effect of segregation,of primary alloying elements on the creep response may provide some useful information about how to improve the creep resistance,of magnesium alloys in the future. %0 journal article %@ 1359-6462 %A Witte, F.,Fischer, J.,Beckmann, F.,Stoermer, M.,Hort, N. %D 2008 %J Scripta Materialia %N 6 %P 453-456 %R doi:10.1016/j.scriptamat.2007.10.039 %T Three-dimensional microstructural analysis of Mg–Al–Zn alloys by synchrotron-radiation-based microtomography %U https://doi.org/10.1016/j.scriptamat.2007.10.039 6 %X The β phase Mg17Al12 influences the high-temperature strength as well as the corrosion properties of Mg–Al–Zn alloys. The morphology and distribution of β Mg17Al12 are normally determined by standard metallographic methods, which result in only a two-dimensional picture. Synchrotron-radiation-based microtomography can give a three-dimensional image of the microstructure and was used to characterize the distribution of Mg17Al12 and Al8Mn5 in as-cast and extruded Mg–Al–Zn alloys. %0 conference paper %@ %A Hort, N.,Rao, K.P.,Abu Leil, T.,Dieringa, H.,Prasad, V.Y.R.K.,Kainer, K.U. %D 2008 %J Magnesium Technology 2008, TMS Annual Meeting & Exhibition %N %P 401-406 %T Creep and Hot Working Behavior of a new Magnesium Alloy Mg-3Sn-2Ca %U %X %0 journal article %@ 0925-8388 %A Huang, Y.,Dieringa, H.,Hort, N.,Maier, P.,Kainer, K.U.,Liu, Y. %D 2008 %J Journal of Alloys and Compounds %N 1-2 %P 238-245 %R doi:10.1016/j.jallcom.2007.09.071 %T Evolution of microstructure and hardness of AE42 alloy after heat treatments %U https://doi.org/10.1016/j.jallcom.2007.09.071 1-2 %X The AE42 magnesium alloy was developed for high pressure die casting (HPDC) from low-aluminum magnesium alloys. In this alloy the rare earth (RE) elements were shown to increase creep resistance by forming AlxREy intermetallics along the grain boundaries. The present work investigates the microstructure of squeeze cast AE42 magnesium alloy and evaluates its hardness before and after heat treatments. The change in hardness is discussed based on the microstructural observations. Some suggestions are given concerning future design of alloy compositions in order to improve high temperature creep properties even further. It is shown that the microstructure of the squeeze-cast AE42 alloy is stable at high temperature 450 °C. The subsequent solution and ageing treatments have a limited effect on the hardness. The weak age-hardening is attributed to the precipitation of small amount of Mg17Al12-phase with the use of about 0.7 wt.% aluminum. The heat treatment to achieve a maximum increase in the hardness is: solution treatment at 450 °C for 5–10 h followed by an ageing treatment at 190–220 °C for about 5 h. %0 conference paper %@ %A Khan, S.,Hort, N.,Steinbach, I.,Schmauder, S. %D 2008 %J Magnesium Technology 2008, TMS Annual Meeting & Exhibition %N %P 197-202 %T Castability of Magnesium Alloys %U %X %0 conference lecture %@ %A Kainer, K.U.,Feyerabend, F.,Witte, F.,Hort, N. %D 2008 %J Kolloquium der Technischen Fakultaet der Christian Albrechts Universitaet %N %P %T Magnesium-Werkstoffe fuer medizinische Anwendungen %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.-U.,Witte, F.,Feyerabend, F. %D 2008 %J 17th International Symposium on Processing and Fabrication of Advance Materials, PFAM XVII %N %P %T Sophisticated magnesium alloys and composites as implant materials %U %X %0 conference paper %@ %A Hort, N.,Kainer, K.-U.,Witte, F.,Feyerabend, F. %D 2008 %J Processing and Fabrication of Advance Materials, PFAM XVII %N %P 819-831 %T Sophisticated magnesium alloys and composites as implant materials %U %X %0 conference paper %@ %A Zeng, R.,Blawert, C.,Dietzel, W.,Hort, N.,Kainer, K.U. %D 2008 %J China-Europe Collaboration, 3rd China-Europe Advanced Materials Symposium, CEAM 3 %N %P 150-153 %T Corrosion morphologies on the extruded magnesium alloy ZK60 component %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2008 %J 11th International Conference on Creep and Fracture of Engineering Materials and Structures, CREEP 2008 %N %P %T Investigation of minimum creep rates and stress exponents calculated from tensile and compressive creep data of magnesium alloy AE42 %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Zhen, Z.,Huang, Y.,Hort, N. %D 2008 %J International Summer School on High-Integrity Die Castings %N %P %T Magnesium Alloys (Die Casting) %U %X %0 journal article %@ 0167-577X %A Prasad, Y.V.R.K.,Rao, K.P.,Hort, N.,Kainer, K.U. %D 2008 %J Materials Letters %N 26 %P 4207-4209 %R doi:10.1016/j.matlet.2008.06.035 %T Hot working parameters and mechanisms in as-cast Mg-3Sn-1Ca alloy %U https://doi.org/10.1016/j.matlet.2008.06.035 26 %X The hot working characteristics of as-cast Mg–3Sn–1Ca alloy have been studied using processing-map technique and the kinetic rate equation. The map exhibited two domains; one in the lower strain rate range (0.0003–0.01 s− 1) and the other in the higher strain rate range (0.1–10 s− 1)—both falling in the same temperature range of 350–550 s− 1. Hot extrusion at 500 °C and a speed corresponding to an average strain rate of 3 s− 1 exhibited dynamically recrystallized microstructure. The estimated apparent activation energy values are higher than those for self-diffusion in pure magnesium suggesting that the large volume fraction of MgSnCa intermetallic particles causes significant back stress. %0 journal article %@ 1359-0286 %A Witte, F.,Hort, N.,Vogt, C.,Cohen, S.,Kainer, K.U.,Willumeit, R.,Feyerabend, F. %D 2008 %J Current Opinion in Solid State and Materials Science %N 5-6 %P 63-72 %R doi:10.1016/j.cossms.2009.04.001 %T Degradable biomaterials based on magnesium corrosion %U https://doi.org/10.1016/j.cossms.2009.04.001 5-6 %X Biodegradable metals are breaking the current paradigm in biomaterial science to develop only corrosion resistant metals. In particular, metals which consist of trace elements existing in the human body are promising candidates for temporary implant materials. These implants would be temporarily needed to provide mechanical support during the healing process of the injured or pathological tissue. Magnesium and its alloys have been investigated recently by many authors as a suitable biodegradable biomaterial. In this investigative review we would like to summarize the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce magnesium alloys that are intended to perform clinically with an appropriate host response. %0 journal article %@ 0966-9795 %A Kozlov, A.,Ohno, M.,Abu Leil, T.,Hort, N.,Kainer, K.U.,Schmid-Fetzer, R. %D 2008 %J Intermetallics %N 2 %P 316-321 %R doi:10.1016/j.intermet.2007.10.011 %T Phase equilibria, thermodynamics and solidification microstructures of Mg–Sn–Ca alloys, Part 2: Prediction of phase formation in Mg-rich Mg–Sn–Ca cast alloys %U https://doi.org/10.1016/j.intermet.2007.10.011 2 %X The basis of this work is a detailed investigation of phase equilibria of the Mg–Sn–Ca system for wide ranges of composition and temperature by means of a combined approach of our own key experiments, first-principles calculations of finite-temperature properties of the compounds and Calphad-type modeling. In this report, the generated thermodynamic description is applied to predict the phase formation and discuss the solidification behavior of practically important Mg-rich alloys. Solidification calculations, based on computational thermochemistry and the present dataset, are successfully applied to the analysis of experimentally observed as-cast microstructures and thermal analysis data for the Mg-rich alloy samples. %0 conference object %@ 1937-3341 %A Yuen, C.K.,Hort, N.,Ip, W.Y. %D 2008 %J Tissue Engineering A %N 5 %P 813 %R doi:10.1089/tea.2008.1504 %T Biodegradable magnesium alloys for tissue engineering and other biological applications: Unexpected findings from a mouse model %U https://doi.org/10.1089/tea.2008.1504 5 %X No abstract %0 journal article %@ 0924-0136 %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2008 %J Journal of Materials Processing Technology %N 1-3 %P 359-363 %R doi:10.1016/j.jmatprotec.2007.11.148 %T Hot workability characteristics of cast and homogenized Mg–3Sn–1Ca alloy %U https://doi.org/10.1016/j.jmatprotec.2007.11.148 1-3 %X Hot working behavior of Mg–3Sn–1Ca alloy has been evaluated with a view to explore its potential as a wrought alloy. The temperature and strain rate dependence of steady state flow stress has been analyzed. The processing maps exhibited two domains both in the temperature range 350–550 °C with one in the lower strain rate range (0.0003–0.01 s−1) and the other at higher strain rates (1–10 s−1). The apparent activation energies estimated in these two domains respectively are 217 kJ/mole and 154 kJ/mole. The activation area values obtained, after making a correction for the back-stress generated by the hard intermetallic CaMgSn particles, are in the range 13–100 b2 and decreased with increasing effective stress. The corrected results suggest that the lower strain rate domain is controlled by lattice self-diffusion and grain boundary diffusion occurs at higher strain rates. Extrusion at 500 °C and at a speed that corresponds to an average strain rate of 3 s−1 yielded a sound product with a dynamically recrystallized microstructure. %0 journal article %@ 1438-1656 %A Zeng, R.,Dietzel, W.,Witte, F.,Hort, N.,Blawert, C. %D 2008 %J Advanced Engineering Materials %N 8 %P B3-B14 %R doi:10.1002/adem.200800035 %T Progress and Challenge for Magnesium Alloys as Biomaterials %U https://doi.org/10.1002/adem.200800035 8 %X Magnesium alloys are very biocompatiable and show promise for use in orthopaedic implant. Significant progress of research on bioabsorbable magnesium stents and orthopaedic bones has been achieved in recent years. The issues on degradation, hydrogen evolution, and corrosion fatigue and erosion corrosion of magnesium alloys and various influencing factors in simulated body fluid (SBF) are discussed. The research progress on magnesium and its alloys as biomaterials and miscellaneous approaches to enhancement in corrosion resistance is reviewed. Finally the challenges and strategy for their application as orthopaedic biomaterials are also proposed. %0 journal article %@ 1753-1497 %A Hort, N.,Wolff, M. %D 2008 %J Powder Injection Moulding International %N 2 %P 63-65 %T Looking to the future: Magnesium powder injection moulding %U 2 %X No abstract %0 conference lecture %@ %A Willumeit, R.,Witte, F.,Fischer, J.,Hort, N.,Kainer, K.U.,Feyerabend, F. %D 2008 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien %N %P %T Challenges of in vitro testing of magnesium alloys %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Anapuo, O.,Kainer, K.U.,Vidrich, G.,Schiffl, A.,Liu, Y. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T Microstructural Investigations of Mg-Al Alloys Containing Small Amount of SiC Nucleants %U %X %0 conference paper %@ %A Witte, F.,Fischer, J.,Stoermer, M.,Hort, N. %D 2007 %J Magnesium Technologiony 2007, TMS Annual Meeting & Exhibit %N %P 389-394 %T 3D Characterization of Beta-Phases AZ91D by Synchrotron-Radiation Based Microtomography %U %X %0 conference lecture %@ %A Witte, F.,Fischer, J.,Stoermer, M.,Hort, N. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T 3D Characterization of Beta-Phases AZ91D by Synchrotron-Radiation Based Microtomography %U %X %0 conference paper %@ %A Fechner, D.,Hort, N.,Blawert, C.,Kainer, K.U. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 287-291 %T Development of a Magnesium Recycling Alloy Based on the AM Alloy System %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Anapuo, O.,Kainer, K.U.,Vidrich, G.,Schiffl, A.,Liu, Y. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 421-426 %T Microstructural Investigations of Mg-Al Alloys Containing Small Amount of SiC Nucleants %U %X %0 conference lecture %@ %A Fechner, D.,Hort, N.,Blawert, C.,Kainer, K.U. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T Development of a Magnesium Recycling Alloy Based on the AM Alloy System %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Dieringa, H.,Bohlen, J.,Hort, N.,Letzig, D. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T Advances in Manufacturing Processes for Magnesium Alloys %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T Threshold Stress during Tensile and Compressive Creep in AE42 Magnesium Alloy %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 395-400 %T Threshold Stress during Tensile and Compressive Creep in AE42 Magnesium Alloy %U %X %0 conference lecture %@ %A Anopuo, O.,Hort, N.,Huang, Y.,Kainer, K.U. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T The Influence of De-Icing Salts on Corrosion of Mg-Alloys %U %X %0 conference paper %@ %A Anopuo, O.,Hort, N.,Huang, Y.,Kainer, K.U. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 439-444 %T The Influence of De-Icing Salts on Corrosion of Mg-Alloys %U %X %0 conference paper %@ %A Kainer, K.U.,Dieringa, H.,Bohlen, J.,Hort, N.,Letzig, D. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 3-8 %T Advances in Manufacturing Processes for Magnesium Alloys %U %X %0 conference paper %@ %A Oberschelp, C.,Klaus, G.,Buehring-Polaczek, A.,Werner, J.,Langkamp, A.,Hufenbach, W.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 929-934 %T In Mould Heating of Continuous Carbon Fibre Preforms for Reinforced High Pressure Die Casting Magnesium Parts %U %X %0 journal article %@ 1013-9826 %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Huang, Y.,Kainer, K.U. %D 2007 %J Key Engineering Materials, Engineering Plasticity and Its Applications %N %P 89-94 %R doi:10.4028/www.scientific.net/KEM.340-341.89 %T High Temperature Deformation Behaviour of a New Magnesium Alloy %U https://doi.org/10.4028/www.scientific.net/KEM.340-341.89 %X The properties and applications of magnesium alloys have been increasingly investigated due to their light weight and high specific strength. Recent studies indicate that an addition of tin (Sn) to magnesium (Mg) significantly increases the corrosion resistance of the latter.,Also, the addition of calcium (Ca) increases the creep resistance of ternary Mg-Sn-Ca alloys.,Therefore, such alloys have been developed to address the dual demands of high corrosion and,creep resistance at service temperatures, and would be widely acceptable if they could be converted,into wrought alloys. The specific alloy selected for this study is Mg3Sn1Ca. Though this composition is synonymous with the popular AZ31 type alloys, the microstructures of these two,types are quite different. While AZ31 alloys basically involve single phase with aluminium (Al) and Zinc (Zn) present in the form of solid solution in Mg, the selected Mg-Sn-Ca alloy has two phase microstructure in the form of particles distributed in a matrix. However, such a microsturcture requires careful consideration in terms of forming operations to convert the material into wrought status. The experiments involved hot compression testing conducted over a,temperature range 300 to 550 oC and a strain rate range 0.0003 to 10 s-1 using a computer-controlled,servo-hydraulic testing machine. The recorded force and compression measurements are converted into corresponding stress - strain curves. Through the analysis of such results, conditions for good formability are identified along with characterization of the deformed material. It is found that this alloy is suitable for hot deformation and could be established as a new standard wrought material for applications requiring improvement in corrosion and creep resistance. %0 conference paper %@ %A Bursik, J.,Bursikova, V.,Jiraskova, Y.,Abu Leil, T.,Blawert, C.,Dietzel, W.,Hort, N.,Kainer, K.U. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 37-42 %T Microstructure and Micromechanical Properties of as-cast Mg-Sn-Ca and Mg-Sn-Mn Alloys %U %X %0 journal article %@ 0255-5476 %A Fechner, D.,Maier, P.,Hort, N.,Kainer, K.U. %D 2007 %J Materials Science Forum, THERMEC 2006 %N %P 108-113 %R doi:10.4028/www.scientific.net/MSF.539-543.108 %T Development of a Magnesium Recycling Alloy Based on AM50 %U https://doi.org/10.4028/www.scientific.net/MSF.539-543.108 %X Magnesium applications for structural components in the automotive industry are,constantly rising. This is based on the recent development of new alloys, new fabrication processes,,and the ambition of car manufacturers to reduce the vehicles weight and CO2 emissions according to the EU and US policy [1, 2]. A rising quantity of magnesium per vehicle leads to a rising quantity of scrap which needs to be recycled according to the European Directive on end-of life,vehicles [3]. So far post consumer scrap has not been used for structural parts. But since the metal is still expensive compared to aluminium or steel, and remelting saves more than 90 % of the energy,for primary production, magnesium recycling will significantly contribute to cost savings. %0 conference paper %@ %A Vidrich, G.,Schiffl, A.,Pravdic, F.,Ferkel, H.,Estrin, Y.,Kaufmann, H.,Hort, N. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 1027-1032 %T Production of a Fine-grained Mg Alloy AZ31 with SiC Particles %U %X %0 conference paper %@ %A Witte, F.,Fischer, J.,Maier, P.,Blawert, C.,Stoermer, M.,Hort, N. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 958-964 %T Magnesium-Hydroxyapatite Composites as an Approach to Degradable Biomaterials %U %X %0 conference paper %@ %A Goeken, J.,Stulikova, I.,Smola, B.,Steinhoff, K.,Hort, N.,Ocenasek, V. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 620-626 %T Rolling of AM50 Magnesium Cast Alloy %U %X %0 conference paper %@ %A Fechner, D.,Blawert, C.,Maier, P.,Hort, N.,Kainer, K.U. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 262-267 %T Development of an AM50 Based Magnesium Recycling Alloy %U %X %0 conference paper %@ %A Bursik, J.,Zabransky, K.,Jiraskova, Y.,Bursikova, V.,Abu Leil, T.,Blawert, C.,Huang, Y.,Dietzel, W.,Hort, N.,Kainer, K.U.,Rao, K.P. %D 2007 %J Magnesium, Proceedings of the 7th International Conference on Magnesium Alloys and their Applications %N %P 49-54 %T Effect of Heat-Treatment on the Microstructure, Microhardness and Corrosion of Cast Mg-3Sn-2Ca Alloy %U %X %0 conference lecture %@ %A Abu Leil, T.,Rao, K.P.,Hort, N.,Huang, Y.,Blawert, C.,Dieringa, H.,Kainer, K.U. %D 2007 %J 2007 TMS Annual Meeting & Exhibition %N %P %T Microstructure, Corrosion and Creep of As-Cast Magnesium Alloys Mg-2Sn-2Ca and Mg-4Sn-2Ca %U %X %0 journal article %@ 0142-9612 %A Witte, F.,Feyerabend, F.,Maier, P.,Fischer, J.,Stoermer, M.,Blawert, C.,Dietzel, W.,Hort, N. %D 2007 %J Biomaterials %N 13 %P 2163-2174 %R doi:10.1016/j.biomaterials.2006.12.027 %T Biodegradable magnesium–hydroxyapatite metal matrix composites %U https://doi.org/10.1016/j.biomaterials.2006.12.027 13 %X Recent studies indicate that there is a high demand to design magnesium alloys with adjustable corrosion rates and suitable mechanical properties. An approach to this challenge might be the application of metal matrix composite (MMC) based on magnesium alloys. In this study, a MMC made of magnesium alloy AZ91D as a matrix and hydroxyapatite (HA) particles as reinforcements have been investigated in vitro for mechanical, corrosive and cytocompatible properties. The mechanical properties of the MMC-HA were adjustable by the choice of HA particle size and distribution. Corrosion tests revealed that HA particles stabilised the corrosion rate and exhibited more uniform corrosion attack in artificial sea water and cell solutions. The phase identification showed that all samples contained hcp-Mg, Mg17Al12, and HA before and after immersion. After immersion in artificial sea water CaCO3 was found on MMC-HA surfaces, while no formation of CaCO3 was found after immersion in cell solutions with and without proteins. Co-cultivation of MMC-HA with human bone derived cells (HBDC), cells of an osteoblasts lineage (MG-63) and cells of a macrophage lineage (RAW264.7) revealed that RAW264.7, MG-63 and HBDC adhere, proliferate and survive on the corroding surfaces of MMC-HA. In summary, biodegradable MMC-HA are cytocompatible biomaterials with adjustable mechanical and corrosive properties. %0 journal article %@ 0255-5476 %A Abu Leil, T.,Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U.,Bursik, J.,Jiraskova, Y.,Rao, K.P. %D 2007 %J Materials Science Forum, Progress in Light Metals, Aerospace Materials and Superconductors %N %P 69-72 %R doi:10.4028/www.scientific.net/MSF.546-549.69 %T Effect of Heat Treatment on the Microstructure and Creep Behavior of Mg-Sn-Ca Alloys %U https://doi.org/10.4028/www.scientific.net/MSF.546-549.69 %X The development of new Mg-Sn based alloys that have shown improved corrosion resistance needs further investigations to develop standard alloys for industrial use. In the present study, the influence of heat treatment was investigated by examining the creep resistance of Mg-Sn and Mg-Sn-Ca alloys at 85 MPa under 135 °C identify the best conditions to improve the mechanical properties of such alloys. Additionally, the changes in microstructure of these alloys were studied and analysed by light microscopy, X-ray diffraction and scanning electron microscopy. It was found that the heat treatments can affect the microstructure of the binary alloy while no apparent change in the microstructure was found in the Mg-Sn-Ca alloys, indicating that the second phase CaMgSn is thermal stable in this alloy. Based on the obtained results, the relationship between the microstructure and creep behaviour are discussed. %0 journal article %@ 1013-9826 %A Huang, Y.,Hort, N.,Abu Leil, T.,Kainer, K.U.,Liu, Y. %D 2007 %J Key Engineering Materials, The Mechanical Behavior of Materials X %N %P 561-564 %R doi:10.4028/www.scientific.net/KEM.345-346.561 %T Effect of Microstructural Inhomogeneity on Creep Response of Mg-Sn Alloys %U https://doi.org/10.4028/www.scientific.net/KEM.345-346.561 %X The development of new creep resistant magnesium alloys has become a major issue in recent years. The alloys investigated in the present work are based on the binary system Mg-Sn. Sn as major alloying element was chosen due to its high solid solubility over a wide temperature range and due to the possible formation of Mg2Sn intermetallic precipitates with a high melting temperature of about 770°C. These characteristics suggest that a fairly large volume fraction of thermally stable Mg2Sn particles can be formed during solidification. This makes it possible that the Mg-Sn alloys can be developed as creep resistant magnesium alloys. In fact, previous investigations indicate that the Mg-Sn alloys have a comparable or even better creep property than AE42 alloy. The present work investigates the microstructure of Mg-Sn alloys with and without creep,deformation using SEM and TEM technique. The effects of microstructural inhomogeneity on the creep response are presented. Based on the microstructural analysis, the mechanism responsible for improving the creep resistance will be discussed. It is shown that the grain boundary sliding is a dominant creep mechanism for the Mg-Sn binary alloy. %0 conference lecture %@ %A Feyerabend, F.,Witte, F.,Hort, N.,Stoermer, M.,Kainer, K.U.,Willumeit, R. %D 2007 %J 21st European Conference on Biomaterials %N %P %T Enhanced cytocompatibility of magnesium alloy AZ91D by the addition of hydroxyapatite %U %X %0 conference paper %@ %A Abu Leil, T.,Rao, K.P.,Hort, N.,Huang, Y.,Blawert, C.,Dieringa, H.,Kainer, K.U. %D 2007 %J Magnesium Technology 2007, TMS Annual Meeting & Exhibition %N %P 257-262 %T Microstructure, Corrosion and Creep of As-Cast Magnesium Alloys Mg-2Sn-2Ca and Mg-4Sn-2Ca %U %X %0 journal article %@ 1003-6326 %A Zeng, R.,Chen, J.,Dietzel, W.,Hort, N.,Kainer, K.U. %D 2007 %J Transactions of Nonferrous Metals Society of China %N %P s166-s170 %T Electrochemical behavior of magnesium alloys in simulated body fluids %U %X Potentiodynamic electrochemical technique was utilized to study the corrosion behavior of magnesium alloys in simulated body fluids (SBFs). The influence of materials, solutions and their temperature on corrosion rate was mainly discussed. The results,demonstrate that the free corrosion potential (Ecorr) of AZ31 and AZ91 alloys rises rapidly at initial stage, and then stabilizes at some value. Ecorr of WE43 alloy increases continuously. While Ecorr of AZ91 alloy with macro-arc oxidation (MAO) coating decreases,drastically in 3 min, and then fluctuates between −1 607 mV and −1 503 mV. The WE43 alloy has better corrosion resistance in Hank’s solution, compared with AZ31 and AZ91 alloys. Corrosion rates of the alloys are sensitive to the chemical composition and temperature of SBFs. A thin MgF2 film slightly improves corrosion resistance. An MAO coating on AZ91 alloy significantly reduces corrosion rate and enhances Ecorr. Pitting corrosion occurs on both AZ31 and WE43 alloys in Hank’s solution. %0 journal article %@ 0921-5093 %A Arunachaleswaran, A.,Pereira, I.,Dieringa, H.,Huang, Y.,Hort, N.,Dhindaw, B.K.,Kainer, K.U. %D 2007 %J Materials Science and Engineering A %N %P 268-276 %R doi:10.1016/j.msea.2007.01.043 %T Creep behavior of AE42 based hybrid composites %U https://doi.org/10.1016/j.msea.2007.01.043 %X Magnesium alloy based hybrid composites with varying levels of -alumina short fibers (Saffilf®) and SiC particles (SiCp) reinforcements have been prepared by the squeeze casting technique. The results of the studies done on the basis of microstructural changes and compression creep tests show that the composites with 10 vol% Saffilf,® + 15 vol% SiCp exhibits relatively better creep resistance compared to its other counterparts with 10 vol% Saffilf® + 10 vol% SiCp and 15 vol% Saffilf® + 5 vol% SiCP. The effect of solutionising heat treatment on these composites does not yield any remarkable improvement in its creep properties. Investigations on these composites reveal the presence of Mg2Si and Al–RE precipitates.,The presence of these precipitates was found to enhance the creep resistance of AE42 hybrid composites. The composites were found to exhibit threshold creep behavior as expected. The effective stress exponents and the activation energy values calculated suggest that ‘glide and high temperature climb of dislocations’ as the predominant creep mechanism. The interfacial reaction products were MgO and Mg2Si. The interfacial reaction product MgO is more pronounced along the Saffilf® compared to SiCp. A similar behavior was observed in composites before and after,heat treatment. %0 conference lecture (invited) %@ %A Kainer, K.U.,Dieringa, H.,Hort, N. %D 2007 %J 16th International Symposium of Processing and Fabrication of Advanced Materials, PFAM 16 %N %P %T Magnesium Materials for Transportation Industries %U %X %0 conference paper %@ %A Kainer, K.U.,Rao, K.P.,Huang, Y.,Abu Leil, T.,Hort, N. %D 2007 %J 2007 China Magnesium and Automotive Conference %N %P 228-251 %T Properties and Processing of New Magnesium-Tin-Calcium Alloys for Powertrain and Hand Tool Applications %U %X %0 conference poster %@ %A Khan, S.,Eiken, J.,Hort, N.,Steinbach, I.,Schmauder, S. %D 2007 %J Multi-scale plasticity of crystalline materials, Symposium %N %P %T Microstructure evolution simulation of magnesium/aluminium alloys %U %X %0 conference object %@ %A Khan, S.S.,Hort, N.,Steinbach, I.,Schmauder, S.,Weber, U. %D 2007 %J IWCMM 17 - Book of Abstracts, 17th International Workshop on Computational Mechanics of Materials %N %P 218 %T Numerical Determination of Heat Distribution and Castability Simulations of as-cast Mg-Al alloys %U %X %0 conference poster %@ %A Khan, S.S.,Hort, N.,Steinbach, I.,Schmauder, S.,Weber, U. %D 2007 %J 17th International Workshop on Computational Mechanics of Materials %N %P %T Numerical Determination of Heat Distribution and Castability Simulations of as-cast Mg-Al alloys %U %X %0 conference lecture %@ %A Kainer, K.U.,Rao, K.P.,Huang, Y.,Abu Leil, T.,Hort, N. %D 2007 %J 2007 China Magnesium and Automotive Conference %N %P %T Properties and Processing of New Magnesium-Tin-Calcium Alloys for Powertrain and Hand Tool Applications %U %X %0 lecture %@ %A Hort, N. %D 2007 %J %N %P %T Materials Sciences %U %X %0 conference lecture %@ %A Weis Olea, C.A.,Glatz, A.,Hort, N.,Sheikhi, S.,dos Santos, J.F. %D 2007 %J EUROMAT 2007 %N %P %T Magnesium-Steel Joints Produced by Friction Stir Welding %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J Processing and Fabrication of Advanced Materials, 16th International Conference %N %P 248-255 %T Comparison of tensile and compressive creep data of AE42 magnesium alloy and its short fiber composite %U %X %0 conference lecture %@ %A Feyerabend, F.,Hort, N.,Witte, F.,Kainer, K.U.,Willumeit, R. %D 2007 %J 3rd World Congress on Regenerative Medicine %N %P %T In vitro corrosion and cytocompatibility of two magnesium alloys %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J 16th International Conference on Processing and Fabrication of Advanced Materials %N %P %T Comparison of tensile and compressive creep data of AE42 magnesium alloy and its short fiber composite %U %X %0 journal article %@ 1746-0751 %A Feyerabend, F.,Hort, N.,Witte, F.,Kainer, K.U.,Willumeit, R. %D 2007 %J Regenerative Medicine %N 5 %P 612 %T In vitro corrosion and cytocompatibility of two magnesium alloys %U 5 %X No abstract %0 conference lecture %@ %A Dieringa, H.,Huang, Y.,Hort, N.,Kainer, K.U. %D 2007 %J EUROMAT 2007 %N %P %T Creep rates and stress exponents of unreinforced and short fiber reinforced magnesium alloy AE42 %U %X %0 journal article %@ 1616-0177 %A Feyerabend, F.,Witte, F.,Hort, N.,Kainer, K.U.,Willumeit, R. %D 2007 %J Biomaterialien %N 3 %P 179 %T Erhoehung der Zellvertraeglichkeit der Magnesiumlegierung AZ91D durch die Zugabe von Hydroxylapatit - Enhanced cytocompatibility of magnesium alloy AZ91D by the addition of hydroxyapatite %U 3 %X No abstract %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J International Conference on Advanced Materials and Composites, ICAMC 2007 %N %P %T Minimum creep rates and calculated stress exponents compared in tensile and compressive creep of Saffil short fiber reinforced magnesium alloy AE42 %U %X %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J International Conference on Advanced Materials and Composites, ICAMC 2007 %N %P %T Minimum creep rates and calculated stress exponents compared in tensile and compressive creep of Saffil short fiber reinforced magnesium alloy AE42 %U %X %0 conference poster %@ %A Herzen, J.,Beckmann, F.,Mueller, B.,Witte, F.,Donath, T.,Leukers, B.,Irsen, S.H.,Stoermer, M.,Hort, N.,Schrott-Fischer, A.,Glueckert, R.,Schreyer, A. %D 2007 %J 13th Swiss Conference on Biomaterials %N %P %T Microtomography on Biomatirials using the HARWI-2 Beamline at DESY %U %X %0 journal article %@ 0019-493X %A Arunachaleswaran, A.,Dhindhaw, B.K.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2007 %J Transactions of the Indian Institute of Metals %N 2-3 %P 87-91 %T Microstructure Characterisation and creep properties of AE42 based hybrid composites prepared by squeeze casting process %U 2-3 %X Magnesium alloy based hybrid composites with varying levels,of d-alumina short fibers (Saffilf,®) and SiC particles (SiCp),reinforcements have been prepared by the squeeze casting technique. Microstructure evaluation by optical microscopy and scanning electron microscopy on these composites reveal the presence of Mg2Si and Al-RE precipitates. The presence of these precipitates was found to enhance the creep resistance of AE42 hybrid composites. The interfacial reaction products were MgO and Mg2Si. The interfacial reaction product MgO is more pronounced along the Saffilf®,compared to SiCp. Heat treatment of the composites improved the distribution of the precipitates in the composites. Hardness characteristics of the composites have been studied. %0 journal article %@ 1616-0177 %A Hort, N.,Witte, F.,Feyerabend, F.,Willumeit, R.,Kainer, K.U. %D 2007 %J Biomaterialien %N 3 %P 235 %T Festigkeit degradierbare Biowerkstoffe auf der Basis von Magnesium-Hydroxylapatit-Verbundwerkstoffen - Strength of degradable biomaterials based on Magnesium Hydroxy Apatite Composites %U 3 %X %0 journal article %@ 1473-2262 %A Herzen, J.,Beckmann, F.,Mueller, B.,Witte, F.,Donath, T.,Leukers, B.,Irsen, S.H.,Stoermer, M.,Hort, N.,Schrott-Fischer, A.,Glueckert, R.,Schreyer, A. %D 2007 %J European Cells and Materials %N 3 %P 38 %T Microtomography on Biomaterials using the HARWI-2 beamline at DESY %U 3 %X No abstract %0 conference lecture %@ %A Feyerabend, F.,Witte, F.,Hort, N.,Willumeit, R.,Kainer, K.U. %D 2007 %J Jahrestagung der Deutschen Gesellschaft fuer Biomaterialien %N %P %T Erhoehung der Zellvertraeglichkeit der Magnesiumlegierung AZ91D durch die Zugabe von Hydroxylapatit - Enhanced cytocompatibility of magnesium alloy AZ91D by the addition of hydroxyapatite %U %X %0 conference lecture %@ %A Abu Leil, T.,Hort, N.,Blawert, C.,Kainer, K.U.,Rao, P.P. %D 2006 %J 2006 TMS Annual Meeting %N %P %T Corrosion Behavior and Microstructure of a Broad Range of Mg-SnX Alloys %U %X %0 conference paper %@ %A Frank, H.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2006 %J Modeling of Casting, Welding and Advanced Soldification Processes-XI, MCWASP Conference %N %P 669-676 %T The Influence of the Casting Process on the Creep Properties of Different AZ-Based Magnesium Alloys %U %X %0 conference poster %@ %A Abu Leil, T.,Hort, N.,Blawert, C.,Huang, Y.,Dieringa, H.,Kainer, K.U. %D 2006 %J DGM-Tag 2006 %N %P %T Untersuchungen zum Korrosions- und Kriechverhalten von Mg-Sn-Ca-Legierungen fuer den Hochtemperatureinsatz %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Maier, P.,Kainer, K.U. %D 2006 %J 14th Magnesium Automotive and End User Seminar %N %P %T Creep rates of tensile and compressive creep of magnesium alloy AE42 as a consequence of different twinning behaviour %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Dieringa, H.,Dietzel, W.,Hort, N.,Blawert, C. %D 2006 %J Conference of Metallurgists, COM 2006 %N %P %T The Use of Magnesium Alloys: Past, Present and Future %U %X %0 conference lecture %@ %A Abu Leil, T.,Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U.,Bursik, J.,Jiraskova, Y.,Rao, K.P. %D 2006 %J 2006 Beijing International Materials Week %N %P %T Effect of Heat Treatment on the Microstructure and Creep Behavior of Mg-Sn-Ca Alloys %U %X %0 conference poster %@ %A Abu Leil, T.,Hort, N.,Dieringa, H.,Blawert, C.,Huang, Y.,Kainer, K.U.,Rao, K.P. %D 2006 %J Junior EuroMat 2006 %N %P %T Characterization of a new series of Mg-Sn-Ca alloys %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2006 %J TMS 2006: The Rohatgi Honorary Symposium on Solidification Processing of Metal Matrix Composites %N %P %T Effects of Interfacial Reactions During Solidification Process on Mechanical Properties in Short Fiber Reinforced AlSi12CuMgNi Composites %U %X %0 conference lecture %@ %A Bursik, J.,Bursikova, V.,Jiraskova, Y.,Abu Leil, T.,Blawert, C.,Dietzel, W.,Hort, N.,Kainer, K.U. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Microstructure and Micromechanical Properties of as-cast Mg-Sn-Ca and Mg-Sn-Mn Alloys %U %X %0 conference poster %@ %A Bursik, J.,Zabransky, K.,Jiraskova, Y.,Bursikova, V.,Abu Leil, T.,Blawert, C.,Huang, Y.,Dietzel, W.,Hort, N.,Kainer, K.U.,Rao, K.P. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Effect of Heat-Treatment on the Microstructure, Microhardness and Corrosion of Cast Mg-3Sn-2Ca Alloy %U %X %0 journal article %@ 1438-1656 %A Hort, N.,Huang, Y.,Kainer, K.U. %D 2006 %J Advanced Engineering Materials %N 4 %P 235-240 %R doi:10.1002/adem.200500202 %T Intermetallics in the Magnesium Alloys %U https://doi.org/10.1002/adem.200500202 4 %X Intermetallic phases can be found in almost every magnesium alloy. These intermetallic compounds play a very important role in optimizing the microstructure and mechanical properties. The present paper reviews the effects of intermetallics in magnesium alloys mainly based on their stabilities: dissolvable intermetallics at low temperatures and thermal stable intermetallics at elevated temperatures. The effects of intermetallics are discussed in the age hardenable and creep resistant magnesium alloys, separately. Finally, the further investigations are remarked on the intermetallics, including their precipitation processes, crystal structures and crystallographic orientation relations with magnesium matrix. The aim is to supply useful information in developing new wrought and creep-resistant magnesium alloys which will be used in the powertrain at elevated temperatures. %0 conference paper %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2006 %J TMS 2006: The Rohatgi Honorary Symposium on Solidification Processing of Metal Matrix Composites %N %P 165-172 %T Effects of Interfacial Reactions During Solidification Process on Mechanical Properties in Short Fiber Reinforced AlSi12CuMgNi Composites %U %X %0 book part %@ %A Hort, N.,Kainer, K.U. %D 2006 %J Metal Matrix Composites %N %P 243-276 %T Powder Metallurgically manufactured Metal Matrix Composites %U %X Powder metallurgical manufactured metal matrix composites (PM-MMC) offer economical solutions for the production of high performance materials. A multiplicity of material combinations can be manufactured, which can be optimally adapted to their respective application purposes. At the same time the current procedures for the production of the source powders for both the metallic matrix as well as the selected reinforcement components offer further shapeable parameters, for which the characteristics of materials and construction units can be optimally conceived to their application purpose. With manufacturing and processing methods available construction units can be produced close to the final contour, which have economically optimal characteristic combinations and also be produced in long production runs. At the same time with PM-MMC many disadvantages, associated with fusion metallurgical production of composite materials with metallic matrix (MMC) can be avoided. %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N. %D 2006 %J International Conference on Advances in Materials and Materials Processing, ICAMMP 2006 %N %P %T Magnesium Wrought Alloys Produced by Spray Forming %U %X %0 conference paper %@ %A Kainer, K.U.,Dieringa, H.,Dietzel, W.,Hort, N.,Blawert, C. %D 2006 %J Magnesium Technology in the Global Age, Conference of Metallurgists, COM 2006 %N %P 3-19 %T The Use of Magnesium Alloys: Past, Present and Future %U %X %0 conference lecture %@ %A Abu Leil, T.,Rao, K.P.,Hort, N.,Dieringa, H.,Blawert, C.,Huang, Y.,Kainer, K.U. %D 2006 %J International Symposium on Magnesium Technology in the Global Age %N %P %T Development and characterization of a series of Mg-Sn-Ca alloys %U %X %0 conference lecture %@ %A Rao, K.P.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2006 %J 8th Asia Pacific Symposium on Engineering Plasticity and its Applications, AEPA 2006 %N %P %T High Temperature Deformation Behaviour of a New Magnesium Alloy %U %X %0 conference lecture %@ %A Frank, H.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2006 %J MCWASP Conference, Modeling of Casting, Welding and Advanced Soldification Processes XI %N %P %T Creep resistant magnesium alloys for power train applications %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Maier, P.,Kainer, K.U. %D 2006 %J 14th Magnesium Automotive and End User Seminar %N %P %T Creep rates of tensile and compressive creep of magnesium alloy AE42 as a consequence of different twinning behaviour %U %X %0 conference poster %@ %A Anopuo, O.,Dieringa, H.,Huang, Y.,Meier, P.,Hort, N.,Kainer, K.U. %D 2006 %J Junior EuroMat 2006 %N %P %T A Comparative investigation of the bolt load retention behaviour of some selected Mg-alloys %U %X %0 book part %@ %A Hort, N.,Dieringa, H.,Thakur, S.K.,Kainer, K.U. %D 2006 %J Magnesium Technology, Metallurgy, Design Data, Applications %N %P 315-334 %T Magnesium Matrix Composites %U %X %0 conference lecture %@ %A Goeken, J.,Stulikova, I.,Smola, B.,Steinhoff, K.,Hort, N.,Ocenasek, V. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Rolling of AM50 Magnesium Cast Alloy %U %X %0 conference paper %@ %A Abu Leil, T.,Rao, K.P.,Hort, N.,Dieringa, H.,Blawert, C.,Huang, Y.,Kainer, K.U. %D 2006 %J Magnesium Technology in the Global Age, Conference of Metallurgists, COM 2006 %N %P 739-749 %T Development and characterization of a series of Mg-Sn-Ca alloys %U %X %0 conference lecture %@ %A Anopuo, O.,Huang, Y.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2006 %J TMS Annual Meeting 2006 %N %P %T Microstructure and Thermal Response of Mg-Sn Alloys %U %X %0 journal article %@ 0142-1123 %A Huang, Y.,Hort, N.,Dieringa, H.,Maier, P.,Kainer, K.U. %D 2006 %J International Journal of Fatigue %N 10 %P 1399-1405 %R doi:10.1016/j.ijfatigue.2006.02.038 %T Investigations on thermal fatigue of aluminium-and magnesium-alloy based composites %U https://doi.org/10.1016/j.ijfatigue.2006.02.038 10 %X Both the KS1275 piston and AE42 alloys and their composites have realistic and/or potential applications as engine components in the automotive industry. Used as engine components, the dimensional stability is of great concern. Thermal cycling experiments can simulate,the service conditions of the materials and give an evaluation how the dimension changes during their service in the changing temperature,environments. The present paper investigates the thermal fatigue of the short fiber reinforced KS1275 piston and AE42 alloys, with an emphasis on the changes in the strain and hardness before and after thermal cycling. The effects of fiber orientation and composition,,and subsequent heat treatment, on the thermal strain were discussed. It is shown that the thermal strain was affected by experimental condition of the thermal cycling and the strength of matrix. After thermal cycling, the hardness decreases due to the occurrence of the matrix overageing and recovery. %0 journal article %@ 1438-1656 %A Dzwonczyk, J.,Prasad, Y.V.R.K.,Hort, N.,Kainer, K.U. %D 2006 %J Advanced Engineering Materials %N 10 %P 966-973 %R doi:10.1002/adem.200600027 %T Enhancement of Workability in AZ31 alloy - Processing maps: Part 1, Cast material %U https://doi.org/10.1002/adem.200600027 10 %X No abstract %0 journal article %@ 1438-1656 %A Hort, N.,Huang, Y.,Abu Leil, T.,Maier, P.,Kainer, K.U. %D 2006 %J Advanced Engineering Materials %N 5 %P 359-364 %R doi:10.1002/adem.200600014 %T Microstructural Investigations of the Mg-Sn-xCa System %U https://doi.org/10.1002/adem.200600014 5 %X New magnesium-tin-calcium alloys offer the potential to improve the property profile and to extend,the range of applications for magnesium alloys. Alloy development is undertaken in accordance to the formation of intermetallic phases during casting or during subsequent heat treatment. These intermetallic phases may contribute to room temperature strength as well as to the improvement of creep properties. Therefore the behaviour and the structure of these phases needs to be understood in more detail when using these materials in the as-cast condition or after subsequent heat treatment. %0 conference lecture %@ %A Fechner, D.,Blawert, C.,Maier, P.,Hort, N.,Kainer, K.U. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Development of an AM50 Based Magnesium Recycling Alloy %U %X %0 conference lecture %@ %A Aust, E.,Elsaesser, M.,Hort, N.,Limberg, W. %D 2006 %J 2006 TMS Annual Meeting & Exhibition %N %P %T Machining of hybrid reinforced Mg-MMCs using abrasive water jetting %U %X %0 conference lecture %@ %A Oberschelp, C.,Klaus, G.,Buehring-Polaczek, A.,Werner, J.,Langkamp, A.,Hufenbach, W.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T In Mould Heating of Continuous Carbon Fibre Preforms for Reinforced High Pressure Die Casting Magnesium Parts %U %X %0 book part %@ %A Kainer, K.U.,Hort, N.,Blawert, C.,Dietzel, W.,Letzig, D.,Stoessel, R.-P.,Swiostek, J. %D 2006 %J Winnacker-Kuechler: Chemische Technik - Metalle und Metallverbindungen - Prozesse und Produkte, Metalle %N %P 567-608 %T Magnesium %U %X %0 conference lecture %@ %A Witte, F.,Fischer, J.,Maier, P.,Blawert, C.,Stoermer, M.,Hort, N. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Magnesium-Hydroxyapatite Composites as an Approach to Degradable Biomaterials %U %X %0 conference lecture %@ %A Vidrich, G.,Schiffl, A.,Pravdic, F.,Ferkel, H.,Estrin, Y.,Kaufmann, H.,Hort, N. %D 2006 %J 7th International Conference on Magnesium Alloys and their Applications %N %P %T Production of a Fine-grained Mg Alloy AZ31 with SiC Particles %U %X %0 conference lecture %@ %A Fechner, D.,Maier, P.,Hort, N.,Kainer, K.U. %D 2006 %J International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2006 %N %P %T Development of a Magnesium Recycling Alloy Based on AM50 %U %X %0 conference poster %@ %A Fechner, D.,Blawert, C.,Maier, P.,Hort, N.,Kainer, K.U. %D 2006 %J Junior EuroMat 2006 %N %P %T Magnesium Recycling Alloy Based on Automotive Post Consumer Scrap %U %X %0 conference paper %@ %A Anopuo, O.,Huang, Y.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2006 %J Magnesium Technology 2006, TMS Annual Meeting %N %P 529-534 %T Microstructure and Thermal Response of Mg-Sn Alloys %U %X %0 journal article %@ 0255-5476 %A Bowles, A.,Dieringa, H.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2005 %J Materials Science Forum, Magnesium – Science, Technology and Applications %N %P 135-138 %R doi:10.4028/www.scientific.net/MSF.488-489.135 %T Investigations in the Magnesium-Tin system %U https://doi.org/10.4028/www.scientific.net/MSF.488-489.135 %X Currently most magnesium alloys are based on the Mg-Al system and this system is reasonably well developed. Nevertheless, the alloy system has some disadvantages - while having excellent castability and adequate room temperature mechanical properties Mg-Al alloys show poor creep resistance. This has led to investigations in other magnesium based systems; magnesium forms alloys with a large number of elements and, indeed a number of magnesium systems show good creep resistance. In this work, the Mg-Sn system has been chosen for study. %0 conference poster %@ %A Fechner, D.,Hort, N.,Kainer, K.U. %D 2005 %J 2nd International Light Metals Technology Conference 2005 %N %P %T Project: Development of a Magnesium Recycling alloy %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2005 %J VDI - AK Werkstofftechnik %N %P %T Magnesium - Probleme, Anwendungen, Potenziale %U %X %0 conference lecture %@ %A Dieringa, H.,Pereira, I.M.,Hort, N.,Kainer, K.U. %D 2005 %J Fifteenth International Conference on Composite Materials, ICCM 15 %N %P %T Creep and microstructure of hybrid reinforced magnesium alloy AE42 %U %X %0 conference lecture %@ %A Hort, N.,Fechner, D.,Kainer, K.U. %D 2005 %J Autorecycling in Europa - Car Recycling in Europe %N %P %T Recycling von Magnesium - Stand der Technik, Probleme, Loesungsansaetze %U %X %0 conference paper %@ %A Hort, N.,Dzwonczyk, J.,Kainer, K.U. %D 2005 %J Proceedings of the 2nd International Light Metals Technology Conference 2005 %N %P 143-148 %T Assessment of AZ31 for wrought processing %U %X %0 conference lecture %@ %A Hort, N.,Dzwonczyk, J.,Kainer, K.U. %D 2005 %J 2nd International Light Metals Technology Conference 2005 %N %P %T Assessment of AZ31 for wrought processing %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2005 %J Grenzflaechen in mehrphasigen Werkstoffen, Workshop der ISH-Initiative Oberflaechentechnik %N %P %T Faserverstaerkte Magnesiumlegierungen - Einfluss der Grenzflaechen auf die mechanischen Eigenschaften %U %X %0 conference lecture %@ %A Blawert, C.,Morales, E.,Dietzel, W.,Hort, N.,Kainer, K.U.,Scharf, C.,Ditze, A.,Endres, F. %D 2005 %J TMS 2005, 134th Annual Meeting & Exhibition %N %P %T Corrosion properties of secondary AZ91 alloys %U %X %0 journal article %@ 0255-5476 %A Dieringa, H.,Bowles, A.,Hort, N.,Kainer, K.U. %D 2005 %J Materials Science Forum, Materials Structure & Micromechanics of Fracture %N %P 271-274 %R doi:10.4028/www.scientific.net/MSF.482.271 %T Microstructural Development in Tension and Compression Creep of Magnesium Alloy AE42 %U https://doi.org/10.4028/www.scientific.net/MSF.482.271 %X In the 30th and 40th and also in the late 80th of the last century there was a rapid increase in use of,magnesium alloys in automotive industry. Magnesium alloy gearbox housings and engine blocks,were produced by chill casting, as a result of the relatively low engine temperatures the alloys,proved adequate. Development of modern water-cooled engines increased the application,temperature and magnesium alloys were replaced by cast iron and aluminium alloys because of the,limited strength and creep resistance of magnesium alloys at higher temperatures. At the end of the,last century alloy development as well as development of magnesium based metal matrix,composites (MMCs) was carried out to improve the high temperature strength and creep resistance.,Alloy development occurred in several directions; either the reduction of aluminum and the addition,of elements that preferentially combine with aluminum or the complete elimination of aluminum as,an alloying element. The need to eliminate or to reduce the aluminum content is because it is known,that b phase (Mg17Al12) contributes to the poor creep resistance in aluminum containing alloys.,From the aluminum containing magnesium high-pressure-die-casting (HPDC) alloys, AE42,currently shows the best creep properties. This is due to the Al-RE precipitates, which suppress the,formation of Mg17Al12. %0 journal article %@ 1359-6454 %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U.,Liu, Y. %D 2005 %J Acta Materialia %N 14 %P 3913-3923 %R doi:10.1016/j.actamat.2005.04.039 %T Microstructural investigations of interfaces in short fiber reinforced AlSi12CuMgNi composites %U https://doi.org/10.1016/j.actamat.2005.04.039 14 %X Short fiber reinforced AlSi12CuMgNi composites find applications as engine components in the automobile industry. The addition of short fibers raises the interfacial reaction between the fiber and the matrix and modifies the matrix microstructure. Reaction products could change the matrix composition and alter the matrix in a physical metallurgical manner, such as the microstructure and ageing behavior. The present work investigated the microstructure in the interfacial regions and in the matrix, as well as the ageing behavior in Saffil®- and Kaowool®-fiber reinforced composites using scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis, differential thermal analysis and microhardness tests. The effects of reinforcements on the distribution of the alloying elements and on the interfacial reactions were investigated and discussed. The interfacial reaction mechanisms were analyzed based on thermodynamics and kinetics. Finally, the relationship between the interfacial reaction and ageing behavior was discussed. It was shown that the distribution of the alloying elements is affected by the addition of fibers. The degree of interfacial reaction depends on the reinforcement composition. The growth of the reaction products is controlled by the cation diffusion along the new interface between reaction product and fiber. The ageing hardening is weakened due to the depletion of the alloying element magnesium; caused by the interfacial reaction. %0 conference poster %@ %A Hort, N.,Huang, Y.,Dieringa, H.,Kainer, K.U. %D 2005 %J 15. Symposium, Verbundwerkstoffe und Werkstoffverbunde %N %P %T Mechanical Properties of Short Fiber Reinforced AlSi12CuMgNi Piston Alloys Before and After Dynamic Thermal Cycling %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U.,Liu, Y. %D 2005 %J Verbundwerkstoffe und Werkstoffverbunde %N %P 33-38 %T Interfacial reaction in the short-fiber reinforced AlSi12CuMgNi piston alloys %U %X %0 conference paper %@ %A Hort, N.,Huang, Y.,Dieringa, H.,Kainer, K.U. %D 2005 %J Verbundwerkstoffe und Werkstoffverbunde %N %P 563-563 %T Mechanical Properties of Short Fiber Reinforced AlSi12CuMgNi Piston Alloys Before and After Dynamic Thermal Cycling %U %X %0 conference lecture %@ %A Kainer, K.U.,Hort, N. %D 2005 %J Leichtbau mit metallischen Werkstoffen, VDI-Wissensforum Seminar %N %P %T Herstellung und Eigenschaften von Magnesium-Bauteilen %U %X %0 conference paper %@ %A Blawert, C.,Morales, E.,Dietzel, W.,Hort, N.,Kainer, K.U.,Scharf, C.,Ditze, A.,Endres, F. %D 2005 %J Magnesium Technology 2005, TMS 2005, 134th Annual Meeting & Exhibition %N %P 447-450 %T Corrosion properties of secondary AZ91 alloys %U %X %0 journal article %@ 0266-3538 %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2005 %J Composites Science and Technology %N 1 %P 137-147 %R doi:10.1016/j.compscitech.2004.07.002 %T Analysis of instantaneous thermal expansion coefficient curve during thermal cycling in short fiber reinforced AlSi12CuMgNi composites %U https://doi.org/10.1016/j.compscitech.2004.07.002 1 %X Short fiber reinforced AlSi12CuMgNi composites have potential applications as engine components in automobile industry. In these engine components, the dimensional stability is of great concern. Thermal cycling experiments can approximately simulate the real working conditions of the materials and give an evaluation of the dimensional changes during their service in the changing temperature environments. Due to the fact that in metal matrix composites the thermal strain is dependent on the phase transformation, the matrix plastic yielding and the physical damage of reinforcement, analysis of thermal strain curves could allow not only insight into their thermal expansion behavior but also into the phase transformation and possible matrix plastic deformation behavior caused by large internal thermal stresses. Compared with the thermal strain curve, the instantaneous CTE curve can clearly supply more information because it is the differential of thermal strain over temperature. It is useful to differentiate whether the appearance of a knee on the thermal strain curve is caused by the phase transformation and/or by the matrix plastic deformation, especially in metal matrix composites with age hardenable matrix. In the present paper, the aging behaviors in both the unreinforced and ceramic reinforced AlSi12CuMgNi piston alloys are investigated and discussed by analyzing the instantaneous CTE curve, DTA curve and hardness tests. The matrix plastic deformation caused by thermal stresses is discussed based on the observation of CTE divergence in the longitudinal and transverse directions. The effects of both the SiO2 content and subsequent heat treatment on the critical temperature, above which the CTE divergence occurs, are discussed. Finally, the effects of precipitation and matrix plastic deformation on the residual strain after thermal cycling are also preliminary evaluated. %0 conference poster %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U.,Liu, Y. %D 2005 %J 15. Symposium, Verbundwerkstoffe und Werkstoffverbunde %N %P %T Interfacial reaction in the short-fiber reinforced AlSi12CuMgNi piston alloys %U %X %0 conference poster %@ %A Dieringa, H.,Huang, Y.,Maier, P.,Hort, N.,Kainer, K.U. %D 2005 %J TMS 2005, Magnesium Technology %N %P %T Tensile and compressive creep behavior of Al2O3 (Saffil)-short fiber reinforced magnesium alloy AE42 %U %X %0 journal article %@ 0921-5093 %A Dieringa, H.,Huang, Y.,Maier, P.,Hort, N.,Kainer, K.U. %D 2005 %J Materials Science and Engineering A %N %P 85-88 %R doi:10.1016/j.msea.2005.08.005 %T Tensile and compressive creep behaviour of Al2O3 (Saffil) short fiber reinforced magnesium alloy AE42 %U https://doi.org/10.1016/j.msea.2005.08.005 %X The development of metal matrix composites (MMCs) is one possibility to overcome the disadvantage of poor high temperature creep properties of present magnesium alloys. Short fiber reinforcement improves the high temperature creep resistance of magnesium alloys. Tensile and compressive creep properties of magnesium alloy AE42 (4 wt.% aluminium and 2 wt.% rare earths) reinforced with 20 vol.% alumina (Saffil®) fibers were investigated in the temperature range of 175–300 °C and stress range of 40–140 MPa, respectively. The MMC was manufactured by direct squeeze casting. The materials investigated show different behaviour depending on type of loading. Stress exponents were calculated from the stress dependence of the minimum creep rate in order to find indications for the possible mechanisms of deformation. The need of correcting the stress dependence of the minimum creep rate by a threshold stress was found. Electron microscopy was performed to investigate the fracture surface of a tensile creep specimen. %0 conference paper %@ %A Dieringa, H.,Pereira, I.M.,Hort, N.,Kainer, K.U. %D 2005 %J Fifteenth International Conference on Composite Materials, Extended Abstracts, ICCM 15 %N %P 513-514 %T Creep and microstructure of hybrid reinforced magnesium alloy AE42 %U %X %0 conference paper %@ %A Hort, N.,Kainer, K.U. %D 2005 %J Schluesseltechnologie Leichtmetallguss im Automobilbau %N %P 25-49 %T Legierungs- und Verfahrensentwicklung fuer Mg-Bauteile im Automobilbau %U %X %0 journal article %@ 1438-1656 %A Winzer, N.,Atrens, A.,Song, G.,Ghali, E.,Dietzel, W.,Kainer, K.U.,Hort, N.,Blawert, C. %D 2005 %J Advanced Engineering Materials %N 8 %P 659-693 %R doi:10.1002/adem.200500071 %T A Critical Review of the Stress Corrosion Cracking (SCC) of Magnesium Alloys %U https://doi.org/10.1002/adem.200500071 8 %X This review aims to provide a foundation for the safe and effective use of magnesium (Mg) alloys, including practical guidelines for the service use of Mg alloys in the atmosphere and/or in contact with aqueous solutions. This is to provide support for the rapidly increasing use of Mg in industrial applications, particularly in the automobile industry. These guidelines should be firmly based on a critical analysis of our knowledge of SCC based on (1) service experience, (2) laboratory testing and (3) understanding of the mechanism of SCC, as well as based on an understanding of the Mg corrosion mechanism. %0 journal article %@ 1433-4399 %A Hort, N.,Fechner, D.,Kainer, K.U. %D 2005 %J Recycling Magazin %N 16 %P 14-17 %T Recycling von Magnesium: Stand der Technik, Probleme und Loesungen %U 16 %X Magnesium und seine Legierungen haben in den vergangenen Jahren zunehmendes Interesse vor allem in der Automobilindustrie gefunden. Gerade dort besteht ein steigender Bedarf an Leichtbauwerkstoffen, in erster Linie um den Treibstoffverbrauch und damit auch den Kohlendioxid-Ausstoss zu senken. Legierungsentwicklungen der vergangenen Jahre haben neue Einsatzgebiete fuer das leichteste Konstruktionsmetall erschlossen. %0 conference paper %@ %A Hort, N.,Huang, Y.,Dieringa, H.,Kainer, K.U. %D 2005 %J Verbundwerkstoffe und Werkstoffverbunde, 15. Symposium %N %P 563-568 %T Mechanical Properties of Short Fiber Reinforced AlSi12CuMgNi Piston Alloys Before and After Dynamic Thermal Cycling %U %X %0 conference lecture %@ %A Hort, N.,Huang, Y.,Dieringa, H.,Kainer, K.U. %D 2005 %J 15. Symposium, Verbundwerkstoffe und Werkstoffverbunde %N %P %T Mechanical Properties of Short Fiber Reinforced AlSi12CuMgNi Piston Alloys Before and After Dynamic Thermal Cycling %U %X %0 conference lecture %@ %A Hort, N.,Dieringa, H. %D 2005 %J DGM Fortbildungsseminar Magnesium %N %P %T Warmfeste Mg-Werkstoffe %U %X %0 journal article %@ 0019-493X %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2005 %J Transactions of the Indian Institute of Metals %N 4 %P 703-708 %T Hot tearing of magnesium alloys %U 4 %X Magnesium alloys are gaining increasing interest in light weight,applications in automotive industry. Due to industrial requirements,alloy development is of major importance to achieve an improvement of the property profile. Unfortunately the use of alloying elements like rare earth elements, calcium, silicon, strontium etc. is also decreasing the castability and alloys containing these elements have not yet been introduced to continuous casting as well. Therefore the new alloys have to be selected carefully in accordance to their castability regarding different casting processes. In this work AZ based alloys modified with Ca and Zn will be investigated regarding their hot tearing behavior. %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2005 %J Schluesseltechnologie Leichtmetallguss im Automobilbau %N %P %T Legierungs- und Verfahrensentwicklung fuer Mg-Bauteile im Automobilbau %U %X %0 lecture %@ %A Kainer, K.U.,Fechner, D.,Hort, N. %D 2005 %J %N %P %T Gefuege und Eigenschaften metallischer Werkstoffe %U %X %0 conference paper %@ %A Hort, N.,Huang, Y.,Kainer, K.U. %D 2005 %J 10th International Symposium on Physics of Materials, ISPMA10 %N %P 39 %T Intermetallics in the Magnesium alloys and their effects in improving mechanical properties %U %X %0 conference lecture %@ %A Hort, N.,Huang, Y.,Kainer, K.U. %D 2005 %J 10th International Symposium on Physics of Materials, ISPMA10 %N %P %T Intermetallics in the Magnesium alloys and their effects in improving mechanical properties %U %X %0 journal article %@ 0019-493X %A Thakur, S.,Dieringa, H.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2005 %J Transactions of the Indian Institute of Metals %N 4 %P 653-659 %T Thermal cycling and creep studies of AM50+Nd magnesium alloy based carbon fiber, SiC particulate and in-situ Mg2Si reinforced habrid composites %U 4 %X Magnesium based hybrid composites with carbon fiber, SiCp and in-situ Mg2Si reinforcements have been prepared through squeeze infiltration technique. The results of the studies done on measurement of the coefficient of thermal expansion (CTE) after thermal cycling have been presented. In the present paper, an attempt has been made to characterize the micro-structural evolution and the plastic deformation behaviour of these hybrid composites in the as cast condition and after thermal cycling. Attempt has also been made to study the effect of thermal treatment on the thermal expansion behaviour of the AM50+Nd magnesium based hybrid composites in terms of CTE values. Composites containing Nd show lower values of CTE compared to the base alloy. Further creep compression tests were carried out on these composites. Composites consisting of rare earth element Nd show much better creep properties as compared to the base alloy matrix. Results of creep compression tests carried out for some other Mg and Al base alloys and composites have also been included for comparison. %0 conference poster %@ %A Huang, Y.,Abu Leil, T.,Hort, N.,Kainer, K.U. %D 2005 %J EUROMAT 2005 %N %P %T Effect of Alloy Composition on Microstructure in Mg-Sn Alloys %U %X %0 report %@ %A Frank, H.,Hort, N.,Kainer, K.U. %D 2005 %J %N %P %T MATALEND, Werkstoff- und Verfahrenstechnik fuer das Metallspritzgiessen von neuen kriechbestaendigen Magnesiumlegierungen %U %X %0 journal article %@ 1438-1656 %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2004 %J Advanced Engineering Materials %N 11 %P 883-888 %R doi:10.1002/adem.200400057 %T Micro-Strain Induced by Thermal Cycling in the Short Fiber Reinforced AlSi12CuMgNi Piston Alloys and AE42 Magnesium Alloys %U https://doi.org/10.1002/adem.200400057 11 %X %0 conference lecture %@ %A Hort, N. %D 2004 %J DGM Fortbildung Metallische Verbundwerkstoffe %N %P %T Schmelzmetallurgische Herstellung von Metallmatrixverbundwerkstoffen %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2004 %J DGM Fortbildung Metallische Verbundwerkstoffe %N %P %T Pulvermetallurgisch hergestellte Verbundwerkstoffe %U %X %0 conference lecture %@ %A Blawert, C.,Hort, N. %D 2004 %J DGM Fortbildungsseminar Metallische Verbundwerkstoffe %N %P %T Bunt- und Edelmetallmatrix-Verbundwerkstoffe %U %X %0 conference lecture %@ %A Kainer, K.U.,Hort, N. %D 2004 %J Leichtbau mit metallischen Werkstoffen, VDI-Seminar %N %P %T Herstellung und Eigenschaften von Magnesium-Bauteilen %U %X %0 journal article %@ 1440-0731 %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2004 %J Advances in Technology of Materials and Materials Processing %N 2 %P 136-141 %T Magnesium based MMCs reinforced with C-fibers %U 2 %X %0 conference lecture (invited) %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2004 %J 4th International Symposium on the 21st Centurry COE Program of Nagaoka University of Technology %N %P %T Magnesium Based Metal Matrix Composites Reinforced with C-Fibers %U %X %0 conference lecture %@ %A Thakur, S.K.,Dieringa, H.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2004 %J SAMPE 2004 %N %P %T Thermal Cycling and Creep Studies of AM50+Nd Magnesium Alloy Based Carbon Fiber, SiC Particulate and IN-SITU Mg2Si Reinforced Hybrid Composites %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2004 %J 3rd International Conference on Fatigue of Composites %N %P %T Investigation on thermal fatigue of metal matrix composites %U %X %0 journal article %@ 0019-493X %A Blawert, C.,Hort, N.,Kainer, K.U. %D 2004 %J Transactions of the Indian Institute of Metals %N 4 %P 397-408 %T Automotive applications of magnesium and its alloys %U 4 %X %0 conference lecture %@ %A Dieringa, H.,Bowles, A.,Hort, N.,Kainer, K.U. %D 2004 %J 4th Internationale Conference on Materials Structure & Micromechanics of Fracture %N %P %T Microstructural development in tension and compression creep of magnesium alloy AE42 %U %X %0 conference paper %@ %A Bowles, A.L.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2004 %J Magnesium Technology 2004, TMS Annual Meeting %N %P 307-310 %T Microstructural Investigations of the Mg-Sn and Mg-Sn-Al Alloy Systems %U %X %0 journal article %@ 1359-835X %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2004 %J Composites / A %N 2 %P 249-263 %R doi:10.1016/j.compositesa.2003.09.027 %T Thermal behavior of short fiber reinforced AlSi12CuMgNi piston alloys %U https://doi.org/10.1016/j.compositesa.2003.09.027 2 %X %0 conference lecture %@ %A Bowles, A.L.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2004 %J TMS Annual Meeting %N %P %T Microstructural Investigations of the Mg-Sn and Mg-Sn-Al Alloy Systems %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N. %D 2004 %J 44th Foundry Conference %N %P %T Recent developments in magnesium die casting %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Dieringa, H.,Kainer, K.U. %D 2004 %J Fatigue of Composites, ICF 03 %N %P 63-64 %T Investigation on thermal fatigue of metal matrix composites %U %X %0 conference paper %@ %A Thakur, S.K.,Dieringa, H.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2004 %J SAMPE 2004, Conference Proceedings %N %P CD %T Thermal Cycling and Creep Studies of AM50+Nd Magnesium Alloy Based Carbon Fiber, SiC Particulate and IN-SITU Mg2Si Reinforced Hybrid Composites %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N.,Dieringa, H. %D 2004 %J International Conference on Solidification Science and Processing %N %P %T Hot Tearing of Magnesium %U %X %0 conference lecture %@ %A Hort, N.,Maier, P.,Kainer, K.U. %D 2004 %J Magnesium Forum, Zitzmann Druckguss GmbH %N %P %T Magnesium, der Werkstoff fuer innovative Produkte %U %X %0 journal article %@ 1073-5623 %A Thakur, S.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2004 %J Metallurgical and Materials Transactions A %N 3 %P 1167-1176 %T Some Studies on the Thermal-Expansion Behaviour of C-Fiber, SiCp, and In-Situ Mg2Si-Reinforced AZ31 Mg Alloy-Based Hybrid Composites %U 3 %X %0 conference lecture %@ %A Bowles, A.,Dieringa, H.,Blawert, C.,Hort, N.,Kainer, K.U. %D 2004 %J International Conference on Magnesium - Science, Technology and Applications %N %P %T Investigations in the Magnesium-Tin System %U %X %0 conference poster %@ %A Hort, N.,Morales, E.,Blawert, C.,Dietzel, W.,Kainer, K.U.,Ghali, E. %D 2003 %J 1st International Conference on Light Metals Technology 2003 %N %P %T Corrosion Behaviour of Semi-Solid Processed Mg-Zn-Ca-RE Alloys %U %X %0 journal article %@ 0255-5476 %A Thakur, S.K.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2003 %J Materials Science Forum %N 4 %P 837-842 %T Some studies on Mg alloy reinforced with ceramic discontinuous phases %U 4 %X %0 conference lecture %@ %A Hort, N.,Huang, Y.,Kainer, K.U. %D 2003 %J 14. Symposium Verbundwerkstoffe und Werkstoffverbunde %N %P %T Schaedigungen in kurzfaserverstaerktem AlSi12CuMgNi hervorgerufen durch thermisches Zyklieren %U %X %0 conference lecture (invited) %@ %A Dzwonczyk, J.,Bohlen, J.,Hort, N.,Kainer, K.U. %D 2003 %J PSTAM 2003, 2nd International Conference on Platform Science and Technology for Advanced Magnesium Alloys %N %P %T Influence of Heat Treatment on Microstructure of Hot Extruded AZ31 %U %X %0 book part %@ %A Hort, N.,Kainer, K.U. %D 2003 %J MetallischeVerbundwerkstoffe %N %P 260-295 %T Pulvermatallurgisch hergestellte Metall-Matrix-Verbundwerkstoffe %U %X %0 conference lecture %@ %A Thakur, S.K.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2003 %J Platform Science and Technology for Advanced Magnesium Alloys, PSTAM 2003 %N %P %T Some studies on Mg alloy reinforced with Ceramic discontinuous phases %U %X %0 conference poster %@ %A Illerhaus, B.,Hort, N.,Potzies, C.,Frank, H.,Goebbels, J. %D 2003 %J 6th International Conference Magnesium Alloys and their Applications %N %P %T Non-destructive testing of cast magnesium alloys by computerized tomography %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J 5. International Congress on Thermal Stresses and Related Topics, TS 2003 %N %P %T Effect of post heat treatment after squeeze casting on the micro-strain induced by thermal stress in the short fiber reinforced piston alloy %U %X %0 conference lecture (invited) %@ %A Hort, N.,Kainer, K.U. %D 2003 %J AIST-ISEM International Symposium 2003 %N %P %T New Development in Magnesium Technology for Transportation Industries %U %X %0 conference lecture %@ %A Hort, N. %D 2003 %J DGM Fortbildungsseminar Metallische Verbundwerkstoffe %N %P %T Pulvermetallurgische Herstellung von metallischen Verbundwerkstoffen %U %X %0 conference lecture %@ %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J Composites 2003, Theory and Practice %N %P %T Thermal behavior of AlSi12CuMgNi piston alloy with and without short fiber reinforced %U %X %0 conference lecture %@ %A Morales, E.D.,Ghali, E.,Hort, N.,Dietzel, W.,Kainer, K.U. %D 2003 %J PSTAM 2003, 2nd International Conference on "Platform Science and Technology for Advanced Magnesium Alloys" %N %P %T Corrosion Behaviour of Magnesium Alloys with RE Additions in Sodium Chloride Solutions %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2003 %J Intelligenter Magnesiumeinsatz im Automobil, Einfuehrungsworkshop %N %P %T Magnesium und seine Legierungen – Herstellung, Be- und Verarbeitung %U %X %0 conference lecture %@ %A Hort, N.,Blawert, C. %D 2003 %J DGM Fortbildungsseminar Metallische Verbundwerkstoffe %N %P %T Verbundwerkstoffe mit Buntmetallmatrix %U %X %0 conference lecture (invited) %@ %A Potzies, C.,Hort, N.,Kainer, K.U. %D 2003 %J 60th Annual World Magnesium Conference %N %P %T R&D Activities in Europe %U %X %0 conference lecture %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2003 %J Composites 2003, Theory and Practice %N %P %T Compression creep of short fibre reinforced magnesium alloy AE42 %U %X %0 journal article %@ 0255-5476 %A Thakur, S.K.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2003 %J Materials Science Forum %N %P 2027-2032 %T Effect of Thermal Treatment on Thermal Expansion Behaviour of Magnesium Alloy Based Hybrid Composites %U %X %0 conference lecture (invited) %@ %A Thakur, S.K.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2003 %J THERMEC 2003 %N %P %T Effect of Thermal Treatment on Thermal Expansion Behaviour of Magnesium Alloy Based Hybrid Composites %U %X %0 journal article %@ 1641-8611 %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J Kompozyty / Composites %N 7 %P 279-284 %T Thermal behavior of AlSi12CuMgNi piston alloy with and without short fiber reinforced %U 7 %X %0 conference paper %@ %A Blawert, C.,Morales, E.,Dieringa, H.,Hort, N.,Azeem, M.A.,Kumar, S. %D 2003 %J Verbundwerkstoffe, 14. Symposium Verbundwerkstoffe und Werkstoffverbunde %N %P 159-164 %T Korrosions- und Verschleisseigenschaften von kurzfaserverstaerkter Magnesiumlegierung QE22 %U %X %0 conference lecture %@ %A Morales, E.,Blawert, C.,Hort, N.,Dietzel, W.,Ghali, E.,Kainer, K.U. %D 2003 %J Environmental Degradation of Materials and Corrosion Control in Metals, COM 2003, International Symposium %N %P %T The effect of semi-solid processing on the corrosion behaviour of Mg-Zn-RE alloys %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J ICCM-14, Global Composite Advancements-Bridging Academia and Industry, Paper No.1325 %N %P CD %T Thermal expansion and dimensional stability oF short fiber reinforced AlSi12CuMgNi piston alloys %U %X %0 journal article %@ 1641-8611 %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2003 %J Kompozyty / Composites %N 7 %P 275-278 %T Compression creep of short fibre reinforced magnesium alloy AE42 %U 7 %X %0 conference lecture %@ %A Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2003 %J 14. Symposium Verbundwerkstoffe und Werkstoffverbunde %N %P %T Thermische Ausdehnung in kurzfaserverstaerkten AlSi12CuMgNi- und AE42-Legierungen %U %X %0 conference poster %@ %A Hort, N.,Kainer, K.U. %D 2003 %J 6th International Conference and Exhibition on Magnesium Alloys and their Applications %N %P %T Extending the Range of Applications for Magnesium Alloys - DFG Priority Programme 1168 - InnoMagTec %U %X %0 conference lecture (invited) %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2003 %J International Conference on Advances in Materials & Processes for Industrial Applications %N %P %T Local Materials Engineering of Magnesium Alloys %U %X %0 conference paper %@ %A Illerhaus, B.,Hort, N.,Potzies, C.,Frank, H.,Goebbels, J. %D 2003 %J Magnesium, 6th International Conference Magnesium Alloys and their Applications %N %P 747-751 %T Non-destructive testing of cast magnesium alloys by computerized tomography %U %X %0 conference paper %@ %A Morales, E.,Blawert, C.,Hort, N.,Dietzel, W.,Ghali, E.,Kainer, K.U. %D 2003 %J Environmental Degradation of Materials and Corrosion Control in Metals, COM 2003, International Symposium %N %P 3-4 %T The effect of semi-solid processing on the corrosion behaviour of Mg-Zn-RE alloys %U %X %0 conference paper %@ %A Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J 5. International Congress on Thermal Stresses and Related Topics, TS 2003 %N %P MA-3 %T Effect of post heat treatment after squeeze casting on the micro-strain induced by thermal stress in the short fiber reinforced piston alloy %U %X %0 conference lecture (invited) %@ %A Dieringa, H.,Bowles, A,Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J International Conference on Advances in Materials & Processes for Industrial Applications %N %P %T Thermal cycling behaviour of short fiber reinforced AE42 Magnesium alloy %U %X %0 conference paper %@ %A Hort, N.,Huang, Y.,Kainer, K.U. %D 2003 %J Verbundwerkstoffe, 14. Symposium Verbundwerkstoffe und Werkstoffverbunde %N %P 242-247 %T Schaedigungen in kurzfaserverstaerktem AlSi12CuMgNi hervorgerufen durch thermisches Zyklieren %U %X %0 conference paper %@ %A Potzies, C.,Hort, N.,Kainer, K.U. %D 2003 %J 60th Annual World Magnesium Conference %N %P 52-56 %T R&D Activities in Europe %U %X %0 conference paper %@ %A Hort, N.,Kainer, K.U. %D 2003 %J AIST-ISEM International Symposium 2003 %N %P 23-27 %T New Development in Magnesium Technology for Transportation Industries %U %X %0 conference paper %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2003 %J Material Show 2003, International Conference on Advances in Materials & Processes for Industrial Applications %N %P 8-13 %T Local Materials Engineering of Magnesium Alloys %U %X %0 conference paper %@ %A Dieringa, H.,Bowles, A,Huang, Y.,Hort, N.,Kainer, K.U. %D 2003 %J Materials Show 2003, International Conference on Advances in Materials & Processes for Industrial Applications %N %P 194-199 %T Thermal cycling behaviour of short fiber reinforced AE42 Magnesium alloy %U %X %0 conference paper %@ %A Dzwonczyk, J.,Hort, N.,Kainer, K.U. %D 2003 %J Magnesium, 6th International Conference Magnesium Alloys and their Applications %N %P 427-432 %T Influence of extrusion methods on microstructure and mechanical properties of AZ31 magnesium alloy %U %X %0 conference paper %@ %A Bowles, A.L.,Hort, N.,Meyer, A.,dos Santos, J.,Kainer, K.U. %D 2003 %J Magnesium, 6th International Conference Magnesium Alloys and their Applications %N %P 917-923 %T Friction Welding of Magnesium: Microstructural Characterisation %U %X %0 conference paper %@ %A Huang, Y.,Dieringa, H.,Hort, N.,Kainer, K.U. %D 2003 %J Verbundwerkstoffe, 14. Symposium Verbundwerkstoffe und Werkstoffverbunde %N %P 115-120 %T Thermische Ausdehnung in kurzfaserverstaerkten AlSi12CuMgNi- und AE42-Legierungen %U %X %0 conference lecture %@ %A Dzwonczyk, J.,Hort, N.,Kainer, K.U. %D 2003 %J 6th International Conference Magnesium Alloys and their Applications %N %P %T Influence of extrusion methods on microstructure and mechanical properties of AZ31 magnesium alloy %U %X %0 journal article %@ 0255-5476 %A Goeken, J.,Bohlen, J.,Hort, N.,Letzig, D.,Kainer, K.U. %D 2003 %J Materials Science Forum %N %P 153-160 %T New Development in Magnesium Technology for Light Weight Structures in Transportation Industries %U %X %0 journal article %@ 0255-5476 %A Dzwonczyk, J.,Bohlen, J.,Hort, N.,Kainer, K.U. %D 2003 %J Materials Science Forum %N %P 297-302 %T Influence of Heat Treatment on Microstructure of Hot Extruded AZ31 %U %X %0 conference lecture (invited) %@ %A Goeken, J.,Bohlen, J.,Hort, N.,Letzig, D.,Kainer, K.U. %D 2003 %J Thermec 2003, International Conference on Processing and Manufacturing of Advanced Materials %N %P %T New Development in Magnesium Technology for Light Weight Structures in Transportation Industries %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N.,Bohlen, J.,Dietzel, W. %D 2003 %J Euromat 2003 %N %P %T Progress in Usage of Magnesium Alloys for Light Weight Structures in Transportation Industries %U %X %0 conference paper %@ %A Lugscheider, E.,Parco, M.,Kainer, K.U.,Hort, N. %D 2003 %J Magnesium, 6th International Conference Magnesium Alloys and their Applications %N %P 860-868 %T Thermal spraying of Magnesium alloys for corrosion and wear protection %U %X %0 conference paper %@ %A Morales, E.,Hort, N.,Kainer, K.U. %D 2003 %J Magnesium, 6th International Conference Magnesium Alloys and their Applications %N %P 68-73 %T Creep Behaviour of MgZnRE Alloys Formed by Semi-Solid-Casting %U %X %0 conference poster %@ %A Bowles, A.L.,Hort, N.,Meyer, A.,dos Santos, J.,Kainer, K.U. %D 2003 %J 6th International Conference Magnesium Alloys and their Applications %N %P %T Friction Welding of Magnesium: Microstructural Characterisation %U %X %0 journal article %@ 0255-5476 %A Morales, E.D.,Ghali, E.,Hort, N.,Dietzel, W.,Kainer, K.U. %D 2003 %J Materials Science Forum %N %P 867-872 %T Corrosion Behaviour of Magnesium Alloys with RE Additions in Sodium Chloride Solutions %U %X %0 conference lecture %@ %A Dzwonczyk, J.,Bohlen, J.,Hort, N.,Kainer, K.U. %D 2002 %J Junior EUROMAT 2002 %N %P %T Influence of Extrusion Ratio on Microstructure and Mechanical Properties of Hot Extruded AZ31 %U %X %0 conference lecture %@ %A Hort, N.,Potzies, C.,Kainer, K.U. %D 2002 %J Leichtbau mit metallischen Werkstoffen, Seminar am IFAM, VDI Wissensforum %N %P %T Neue Verfahren fuer metallische Hochleistungswerkstoffe %U %X %0 conference lecture %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2002 %J IIR-Workshop: Magnesium - Einsatz im Automobilbau %N %P %T Magnesium-Matrix-Verbundwerkstoffe %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Letzig, D.,Hort, N.,Dieringa, H. %D 2002 %J Magnesium im Automobil %N %P %T Verfahrensoptimierte Legierungsentwicklungen %U %X %0 conference paper %@ %A Thakur, S.K.,Dhindaw, B.K.,Hort, N.,Kainer, K.U. %D 2002 %J 9th International Conference on Composite Materials, ICCE 9 %N %P 775-776 %T Thermal cycling of hybrid reinforced Magnesium based metal matrix composites %U %X %0 conference paper %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2002 %J CIMTEC 2002, 3rd Forum on New Materials, Advanced Inorganic Structural Fiber Composites IV %N %P 218-226 %T Thermal Cycling of Light Metal Matrix Composites Reinforced with Ceremic Short-Fibres %U %X %0 conference lecture %@ %A Hort, N.,Frank, H.,Kainer, K.U. %D 2002 %J IIR-Workshop: Magnesium - Einsatz im Automobilbau %N %P %T Herstellung, Ver- und Bearbeitung von Magnesiumlegierungen %U %X %0 conference lecture %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2002 %J IIR-Workshop: Magnesium - Einsatz im Automobilbau %N %P %T Magnesiumlegierungen %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U. %D 2002 %J CIMTEC 2002, 3rd Forum on New Materials, Advanced Inorganic Structural Fiber Composites IV %N %P 227-234 %T Behaviour of Saffil-fibre reinforced ZE 41 magnesium hybrid MMC in creep and thermal cycling %U %X %0 conference paper %@ %A Dieringa, H.,Hort, N.,Kainer, K.U.,Wesemann, J. %D 2002 %J ICCE 9, 9th International Conference on Composite Materials %N %P 169-170 %T Creep and thermal loading of in situ processed magnesium metal matrix composites %U %X %0 doctoral thesis %@ %A Hort, N. %D 2002 %J %N %P %T Zum Verhalten der Kupfer-Nickellegierung Marinel unter Zugbelastung in korrosiven Medien (Dissertation) %U %X %0 conference lecture %@ %A Dzwonczyk, J.,Bohlen, J.,Hort, N.,Kainer, K.U. %D 2002 %J Materials Week 2002 %N %P %T Influence of Heat Treatment on Microstructure and Mechanical Properties of AZ31 Extruded with different Extrusion Ratios %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Blawert, C.,Hort, N.,Letzig, D.,dos Santos, J.F. %D 2002 %J Intelligente Leichtbau Systeme, Congress %N %P %T Erweiterung der Einsatzbereiche von Magnesiumwerkstoffen unter Beruecksichtigung moderner Verbindungstechniken %U %X %0 conference lecture %@ %A Morales, E.,Hort, N.,Ghali, E.,Kainer, K.U. %D 2002 %J Junior EUROMAT 2002 %N %P %T Corrosion Behaviour of Mg-Alloys with RE additions in ASTM Water %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2001 %J Leichtbau mit metallischen Werkstoffen, VDI-Wissensforum, Seminar am IFAM %N %P %T Potential von metallischen Verbundwerkstoffen fuer den Einsatz als Leichtbauwerkstoff in der Verkehrstechnik %U %X %0 conference lecture (invited) %@ %A Hort, N.,Dieringa, H.,Kainer, K.U. %D 2001 %J DGM Fortbildungsseminar: Magnesium - Eigenschaften, Anwendungen, Potentiale %N %P %T Magnesiummatrix - Verbundwerkstoffe %U %X %0 conference paper %@ %A Hort, N.,Kainer, K.U.,Buschmann, R. %D 2001 %J Verbundwerkstoffe und Werkstoffverbunde %N %P 170-175 %T Thermozyklische Behandlung von Aluminium-Matrix-Verbundwerkstoffen %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2001 %J DGM Fachausschuss Metall-Matrix-Verbundwerkstoffe, Arbeitskreis Zuverlaessigkeit von Metallmatrix-Verbundwerkstoffen %N %P %T Kurzfaserverstaerkte Verbundwerkstoffe mit metallischer Matrix %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Potzies, C.,Hort, N.,Benzler, T.U. %D 2001 %J Zukunft Fahrzeug-Leichtbau - Optimaler Werkstoffeinsatz %N %P %T Magnesium als Werkstoff fuer den Leichtbau %U %X %0 conference lecture (invited) %@ %A Kainer, K.U.,Hort, N. %D 2001 %J MMC 8 - Metallic Composites and Foams %N %P %T Short-Fibre Reinforced Metal Matrix Composites %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U.,Buschmann, R. %D 2001 %J Verbundwerkstoffe und Werkstoffverbunde %N %P %T Thermozyklische Behandlung von Aluminium-Matrix-Verbundwerkstoffen %U %X %0 conference lecture %@ %A Hort, N.,Kainer, K.U. %D 2001 %J International Conference on Composite Materials, ICCM-13 %N %P %T Influence of thermal cycling on properties of Al based MMC's reinforced by ceramic fibres %U %X %0 conference paper %@ %A Hort, N.,Kainer, K.U. %D 2001 %J International Conference on Composite Materials, ICCM-13 %N %P CD %T Influence of thermal cycling on properties of Al based MMC's reinforced by ceramic fibres %U %X