Abstract Aluminium-silicon (Al-Si) cast alloys play a crucial role in the automotive industry, with increasing demand in electric vehicles (EVs). In EV applications, aluminium components are often exposed to atmospheric conditions, making corrosion resistance a critical factor, as well as mechanical performance. This study examines the effects of melt treatments - grain refinement and modification - along with chemical composition on the corrosion resistance and mechanical properties of Al-Si alloys. Three common alloys (AlSi9Cu3, AlSi10, and AlSi12) are cast using sand casting and gravity die casting to evaluate the influence of casting processes with different cooling rates. Each alloy is tested under three conditions: untreated, grain refined, and grain refined/modified. Mechanical properties are evaluated via tensile tests according to DIN 50125, while corrosion resistance is assessed through immersion in an HCl-NaCl solution, based on ISO 11846. Results indicate that iron content reduces ductility due to formation of β-Al 5 FeSi, while modification enhances elongation, particularly in die-cast samples. Copper presence in AlSi9Cu3 significantly deteriorated its corrosion resistance. Higher cooling rates and modification treatment further decrease corrosion resistance. This study provides insights into the correlation between casting methods, alloy composition, and melt treatments on the corrosive and mechanical performance of Al-Si cast alloys.
Kremer et al. (Tue,) studied this question.