Aluminum alloys provide significant potential for the realization of modern and sustainable lightweight constructions due to their good formability and versatile properties. In the context of electric mobility, a high demand for lightweight components persists in the automotive industry to counteract the rising vehicle weights resulting from the required battery. Aluminum alloys of the 6xxx series are of special interest, as they offer the possibility of enhanced strength and excellent corrosion resistance. One of the main issues associated with the rising demand for aluminum alloys is the high amount of CO2-emissions that result from the primary aluminum production. Thus, usage of secondary aluminum from End of Life (EoL)-scrap for alloy production is a strong research trend, which has the potential to reduce fabrication-related CO2-emissions of aluminum alloys by up to 95 percent. In this regard, it is crucial to understand the influence of the secondary material to avoid a degradation of the mechanical and corrosive properties and to facilitate the application of recycled aluminum alloys in technical safety components.
In order to achieve a strong effect on sustainability, the highest possible amount of secondary aluminum from sorted EoL-scrap should be used. This aim is counteracted by the above-mentioned technological demands. Thus, existing alloy compositions have to be reviewed whether they can be improved for the sake of using a high amount of secondary aluminum, whereby material simulation plays an important role. Specifically, in secondary alloys the content of minor elements, like iron and copper, must be monitored. Therefore, modifications of the entire process chain for the production of wrought aluminum alloys are necessary as a way to the establishment of alloys that fulfil the given requirements despite the varying compositions.
In this work, two secondary wrought aluminum alloys were produced after material simulation using JMatPro, beginning with alloy-specific material sorting from EoL-aluminum scrap based on Laser Induced Breakdown Spectroscopy. After casting, the billets were extruded, then forged to their final shape and heat treated to peak aged condition. The strength of the alloys under static and cyclic loading was determined by compression tests and fatigue tests. In addition, the intergranular corrosion resistance of the alloys was investigated and the findings were interpreted based on microstructure analyses using SEM and EBSD.