On the podium with magnesium
Scientists from the Helmholtz-Zentrum Hereon, in close cooperation with the centre's own technical centre, are supporting the student association e-gnition Hamburg e.V. with lightweight components for the construction of their formula racing cars. The environmentally friendly electric car "egn23" is competing in various international competitions this season, including the renowned Formula Student Germany.
The "egn23" at the pre-event "VDE E-Race" for the season 2023. Photo: e-gnition/ Timon Suhk
Magnesium is considered one of the key elements in lightweight construction - especially in mobility. A lighter body means less energy consumption for the same performance. The students at e-gnition Hamburg e. V. have been using this principle to build their formula racing cars for over 10 years. Since then, the future engineers have been drawing on the expertise of the Hereon and have selected components manufactured as custom-made parts from magnesium, aluminium alloys and carbon fibre-reinforced plastic in the centre's technical centre. Hereon not only manufactures the components, but also develops new alloys and material combinations in its institutes for materials research. This way, for example, magnesium alloys are produced that meet higher requirements. And with success: the electric racing car "egn22" made it onto the podium in various categories at competitions in Hungary, Austria and Germany last year.
From block to component
Formula Student is the world's largest international engineering design competition. The concept of the racing cars is revised every season and a completely new car is built. In kick-off meetings with the respective Hereon institutes, the sponsored components are discussed so that the technical drawings usually reach the Hereon technicians at the beginning of the year. On this basis, they create a digital 3D version of the component, which is precisely milled or cut out of the material in one piece using state-of-the-art machines. Due to its material properties, magnesium must be processed under special protective measures.
"When processing the material, it is particularly important to avoid the formation of sparks and the accumulation of chips outside the storage containers provided for this purpose - because magnesium can spontaneously ignite in the oxygen in the air. Only the right machines, specially trained staff and suitable equipment allow us to process magnesium safely," explains Felix Krüger, one of the persons responsible for project steering in the technical centre.
Back in the student workshop, the components are inserted and tested. For the current season's electric racing car "egn23", Hereon has made a new wheel hub, a steering box and 120 inserts - 14 different types of them. Last year, 12 of the 14 insert types were still made of aluminium.
"The inserts from the Helmholtz Zentrum Hereon are essential for the functionality of our monocoque and thus an important component of our car. By replacing our previously installed aluminium inserts with equivalents made of magnesium, we were able to save a total of 32 % of the weight," says a pleased Sascha Behrendt, mechanical engineering manager at e-gnition.
The magnesium steering box being assembled in the student workshop. Photo: e-gnition/ Torben Salihi
Inserts are water jet parts which are worked into the carbon monocoque, i.e. the body of the racing car. Since a conventional screw connection is not easy to realise in carbon, the inserts serve as a fastening point for dynamically and statically loaded assemblies such as the chassis. Magnesium materials are ideally suited here because they are easy to machine. In addition, the components are largely protected from external environmental influences and associated corrosion by being bonded into the CFRP monocoque.
The "egn23" already completed its first races: At the Formula Student East (FSEast) in Hungary, the car won a whole eight titles, including 3rd place in the "Electric Overall" category and 2nd place in "Driverless Overall". Now the team is in preparation for Formula Student Germany, which starts next week at the Hockenheimring.
The Technical Centre
For Hereon researchers, the technical centre is the central point of contact for the conception, development and construction of scientific devices and components. A wide range of state-of-the-art development tools, manufacturing technologies and metrological equipment enables the interdisciplinary team to create versatile and sophisticated products.
Further information
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Institute of Material and Process Design
Phone: +49 (0) 4152 87-2548