On the one hand, the availability of pure and uncontaminated aluminum alloys becomes increasingly difficult. On the other hand, the demand increases continuously, e. g. for e-cars in the automotive sector, as the use of the damage-tolerant light metal for major parts enables a significant weight reduction and range extension. To satisfy the needs, recycling is becoming more and more important. It is feasible to separate and remelt scraps by complex sorting, but there is only one sorting system available at Hydro Aluminum Recycling Deutschland GmbH which is capable to produce pure aluminum alloys from shredded aluminum scraps without adding primary aluminum. Generally, aluminum alloys are recycled by adding a large amount (≥ 50 %) of primary aluminum to ensure homogenous alloy compositions with a high degree of purity. However, primary aluminum is gained in a very energy-intensive electrolysis process, which requires 20 times more energy than the remelting of aluminum scraps. Therefore, it is essential to develop smart and robust technologies which are capable to compensate the influences of alloy variations on the part properties and to adjust property profiles by using various recyclates.

This is the starting point for the presented study, in which a resilient manufacturing process for damage-tolerant parts from unpurified aluminum recyclates is to be developed. Due to the higher degrees of freedom in comparison to conventional manufacturing technologies, the process chain of the laser powder bed fusion (LPBF) based additive manufacturing is selected. Here, the interrelations between the manufacturing process, the forming microstructure and the resulting mechanical properties are investigated in detail by using nano- and microanalytical methods. Starting point is the atomization of aluminum recyclates into powder respectively the use of recycled aluminum powder for additive manufacturing. On this basis, a material-oriented additive manufacturing approach is developed to produce pore-free parts with homogenous mechanical properties. This approach is supported by a load-adapted design of the part. The process development is accompanied by a digital representation of the entire process chain from the recyclate to the complex final part.

The presentation gives a general overview about the different research aspects investigated and insights into the first results obtained.