Effect of Mg on microstructure and mechanical properties of heat-treated free Al-Mg-Si alloy by squeeze casting

Abstract To meet the stringent requirements for high-quality die-cast components in new energy vehicles, it is essential to further enhance the strength and ductility of heat-treatable free-aluminum alloys. In this study, Al–Mg–Si series alloys with varying Mg contents were investigated via squeeze casting. The microstructure, mechanical properties, and hot tearing susceptibility of Al– (4.1–10.3) Mg–2.6Si alloys were systematically investigated. The results indicate that within a specific Mg content range (6.5 – 9.8 wt.%), the ultimate tensile strength (UTS) and elongation (EL) are improved, whereas the yield strength (YS) and hot tearing susceptibility are reduced. Notably, the Al–6.5Mg–2.6Si alloy exhibits low hot tearing tendency and excellent comprehensive properties, achieving a YS of 247 MPa, a UTS of 345 MPa, and an EL of 9.8%.