Influence of secondary aluminum content on casting and weldability of high pressure die cast materials for sustainable automotive body concepts

Sustainability is becoming increasingly important in vehicle production. The e-mobility transition has shifted the CO2 footprint from use to production phase, where secondary aluminum alloys in structural castings are known to offer significant CO2 reduction potential. However, accumulation of copper, iron, manganese and zinc and the hydrogen content in the melt pose major challenges for casting and subsequent joining processes. In laser welding, dynamic modulation of intensity distributions in the weld pool can overcome the latter issue. In experimental studies covering high pressure die-cast AlSi10MnMg alloys with secondary material content levels ranging from 0 wt.-% and 58 wt.-% to 89 wt.-%, castability and weldability were investigated and the structural and mechanical properties of the joint determined. The results contribute to the optimization of sustainable car body production, providing a path towards cost-effective differential lightweight design solutions as economically, technologically and ecologically competitive alternatives to large-scale casting technologies (GigaCasting).