Effects of Sn on microstructure and mechanical properties of as-rolled Mg–5Zn–1Mn alloy

Abstract

ABSTRACTEffects of Sn on microstructure and mechanical properties of Mg–5Zn–1Mn alloy subjected to high strain rate rolling (9.1 s-1), 300°C and 80% pass reduction are investigated. With higher Sn content, the dynamic recrystallisation (DRX) grain size gradually decreases due to the stronger pinning of nano-scale precipitates at grain boundaries and the DRX fraction first increases due to the enhanced effect on DRX by decreasing stacking fault energy and then decreases due to more precipitates at grain boundaries. Ultimate tensile strength (UTS) and elongation to rupture (Er) of as-rolled alloys increase and then decrease. Alloy with 0.9 mass% Sn exhibits the highest DRX fraction (95 vol.-%), the finer DRX grain size (1.22 µm), UTS of 358 MPa and Er of 20.4%.