EDAG Group in Germany, together with eight project partners, has developed an aluminum alloy for the 3D printing of automotive components. The alloy was designed to provide higher strength and elongation at the breaking point — which is especially important in the event of a crash.
Additive production has huge potential for revolutionizing the production of automotive components, while also achieving new configurations and dimensions for lightweight construction. A number of companies (such as HRL Laboratories) have been actively working to develop new 3D-printable aluminum alloys with the aim of meeting the high strength and performance demands of the automotive industry.
The three-year “CustoMat_3D” research project, led by EDAG and backed by Federal Ministry of Education and Research (BMBF), has focused on examining the entire aluminum process chain — from powder manufacture through simulation to component development. The project aims to enable aluminum to meet requirements, such as crash performance. It also looked at process design, considering how primarily highly resistant yet non-ductile material parameters can be produced.
The project used an integrated approach to develop the new aluminum alloy, which can be used to manufacture car parts that are significantly reduced in weight. The alloy is intended to make additive production available to mass production processes.
In a laboratory phase, various alloys were initially tested. The alloy definition and powder manufacture was done by the Leibniz Institute for Materials Engineering (IWU) and Kymera International. This was followed by the processing and process development stage using powder-based laser beam welding (LBM), which was carried out at Fraunhofer IAPT, GE Additive, and FKM Sintertechnik GmbH. As such, it was possible to try out the most promising alloy successfully on different LBM systems.
A demonstration of alloy’s performance was carried out by Mercedes-Benz AG and EDAG Engineering GmbH with the support of Altair Engineering. Based the material values conveyed, material cards were produced that were used in a structure optimization with Altair OptiStruct software.
Parts from different areas of the car were selected. The simulation showed that it was possible to achieve an effective weight-savings both in the dynamic heavy load-bearing wheel carrier and a complex component with high rigidity requirements from the wheel box area. Some of the savings were over 30% of the expected potential. Based on the additive production process, the part can be further adapted to the requirements of the vehicle via a load-level model.
In addition, hybrid processes like laser deposition welding and bonding techniques were examined with the new aluminum alloy. In the simulation, it was possible to channel the processes on the microscopic levels of a powder via representative elements in the macroscopic simulation of the part. In this way, a significantly shorter computing time was shown to be possible. As a result, residual stresses and delays can be made visible and minimized before production.
EDAG and its partners were able to achieve all the project goals for the new alloy, called CustAlloy®, which is expected to be made officially available in a few months. The project team believes that — due to the alloy’s ability to meet automotive requirements and wide-ranging application possibilities — the new alloy is destined for its first use in mass production. As such, the production process and the tested simulation methods are said to have given engineers effective tools to reduce car weight and the ability to use 3D printing technology in mass production.