Comparison of recycled High Pressure Die Casting AlSi10MnMg alloys for automotive structural components produced in laboratory and industrial environment

Aluminum has a key role in the automotive industry, thanks to its lightweight, easy recyclability and corresponding achievable low carbon footprint. Its employment will continue to increase, with castings having the heaviest role. High Pressure Die Casting products are usually produced with secondary material but characterized by low mechanical properties, due to the high Fe content and the detrimental β-Al5FeSi phases. HPDC structural components, used in the vehicle BiW, are instead cast with primary aluminum for achieving high ductility and strength. The decarbonization of the automotive industry is requiring new alloys with higher recycled amounts and high mechanical properties. The laboratory casting validation and the upscaling to structural components is an important step during the development of new alloys. This study presents the comparison and characterization of a 70% end-of-life scrap AlSi10MnMg alloy, suitable for structural components, first cast in laboratory and then in industrial facility. Casting quality, assessed through evaluation of defects and microstructure, along with the mechanical properties are compared. The industrial process leads to fewer casting defects (cold flakes and cold joints) and rare α-Al15(Fe,Mn)3Si2 sludge particles. The hardness is affected by the different thickness and the small variation in chemical composition, but in all cases is compliant to with EN 1706 minimum values. The bending test, scarcely sensitive to defects compared to standard tensile test, gives similar ductility results with higher values for the industrial component. The microstructure, hardness and corrosion behavior are comparable to primary alloy’s ones.