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According to the current state of technology, structural die cast components for automotive applications are usually subjected to a complex heat treatment in order to obtain mechanical properties needed, meet crash requirements and resist aging of vehicle structures. The company RHEINFELDEN ALLOYS GmbH & Co. KG has developed two new high-pressure die-cast aluminum alloys, Castaduct-42 and Magsimal-plus. They already achieve the desired material properties without the mentioned heat treatment. As a result, the energy-intensive, time-consuming and costly heat treatment can be eliminated. In order to investigate the possible uses of these alloys in crash-impact areas of a vehicle structure, crashworthiness studies were conducted at the DLR Institute for Vehicle Concepts with the three-point bending flexural tests of top-hat profiles at low and high strain rates. The tests showed no strain rate dependent behavior of the stress-strain curve. However, the elongation at break and thus also the ultimate strength showed a strain rate dependency. The higher strain rate resulted in a higher elongation at break of the alloy-specific stress-strain curve. The insights gained were used to create a strain rate dependent material model for each alloy. The material models were implemented in already validated simulation models and compared to the reference results to provide the proof of potential for the new Castaduct-42 and Magsimal-plus die cast alloys. The talk will focus on the findings, the proof of potential through simulation, as well as the advantages and disadvantages of these two new alloys, and give an outlook on possible applications, e.g. as in e-mobility. |
