Impacts of vehicle electrification on Al-Si castings: an overview of current manufacturing processes, mechanical properties, and applications

Abstract The transition from internal combustion engines (ICEs) to battery or fuel-cell electric vehicles (EVs) directly impacts the metal casting industry, presenting both opportunities and challenges. Traditional manufacturing processes in foundries have primarily focused on ICE vehicles for decades, while the shift to EV impacts existing infrastructure necessitating new requirements and investments. The demand for lightweight materials in EVs continues to increase, outpacing the requirements of current ICE vehicles. Cast Al alloys play an indispensable role in automotive light weighing, offering an attractive combination of properties including strength and ductility, corrosion resistance and castability. Despite predictions regarding market share, and growth of Al in EVs, relatively few studies have analysed the impacts of casting alloys, manufacturing processes and alloy distribution in EV applications. Therefore, this overview aims to explore the effects of EVs on cast components by focusing on the changes to drive systems and the parts lost or gained due to this transition. The methodologies and manufacturing process are reviewed for design and simulation, microstructure refinement, and mechanical properties. More emphasis is provided on advanced/hybrid methods (mega castings, rheo- and compound casting) and functional designs utilizing metal and sand 3D printing processes. Most research findings indicate the lightweighting, along with structural and functional integration will drive the casting applications for EVs. Secondly, castings for EVs create a surging demand for primary alloys and significantly reduce the market share of secondary alloys in the future. Potential avenues for future research on alloy development, process variables and upgradation, and recyclability issues are highlighted.