Microstructure, mechanical properties and yield asymmetry of Mg–4Al–2Sn–xY alloys

Abstract

ABSTRACTThe effect of 0, 0.3, 0.6, 0.9 wt-% Y addition on the microstructure and mechanical properties of extruded Mg–4Al–2Sn alloys were investigated. The results show that α-Mg, Mg17Al12, Mg2Sn and Al2Y phases form in the extruded Y-containing alloys. Mg17Al12 phase, containing trace amounts of Y, tends to distribute on the grain boundaries in the form of needles. When the Y content is 0.6 wt-%, the alloy has the best combination mechanical properties. Its tensile yield strength, ultimate tensile strength and tensile elongation are 172 MPa, 270 MPa and 11.2%, respectively. As the Y content increases, the tensile and compressive asymmetries in the Mg–4Al–2Sn–xY alloy decrease, due to grain refinement and the weakening of texture.