Crash-proof aluminum alloy developed

Additive manufacturing has enormous potential to revolutionize the production of tomorrow and at the same time achieve new dimensions in lightweight construction. Until now, the aluminum alloys available have not yet met the high requirements for use in series production in the automotive industry. These include, for example, crash performance and their variable usability. Added to this is the current process design, with which primarily high-strength but non-ductile material properties can be achieved.

Over the past three years, the entire process chain from powder production to simulation and component development has been examined. A holistic approach should make additive manufacturing accessible for series processes. The newly researched alloy is suitable for establishing highly weight-reduced components in vehicles.

In a laboratory phase, various alloys were initially tested experimentally. The most promising alloy was successfully tested on various laser beam melting systems. The special feature of the alloy is its versatility: a very wide range of properties can be produced from a single alloy. These properties can be flexibly adjusted by means of subsequent heat treatment. Material cards were generated from the determined material properties and used in a structural optimization with the Altair OptiStruct software in order to reduce the weight of components while maintaining the same performance. A special feature here is that the requirements from the additive manufacturing process, such as component alignment, can also be taken into account.

Components from various areas of the vehicle were selected. Effective weight savings were achieved for both the dynamically highly stressed wheel carrier and a complex component with high rigidity requirements from the wheel arch area. At over 30% in some cases, this was above the expected potential. Thanks to the additive manufacturing process, the component can be specifically adapted to the requirements of the respective vehicle using a load stage model.

Hybrid processes such as laser deposition welding and joining processes with the newly developed material were also investigated. In the simulation, it was possible to transfer the processes at the microscopic level of the powder to the macroscopic simulation of the component using representative elements. This enables a greatly reduced calculation time. As a result, residual stresses and distortions can be made visible and reduced even before production.

The newly developed alloy will be conventionally available under the brand name CustAlloy® in a few months. The project partners have already drawn a thoroughly positive conclusion. Due to its broad applicability and the fact that corrosion, joining technology and many other requirements of the automotive industry have already been safeguarded, the alloy is predestined for initial series applications. All project goals have been achieved and the new alloy, the associated processing method and the tried-and-tested simulation methods provide the experts with effective tools for reducing vehicle weight and using 3D printing technology in series production.