Effect of Cu/Zn on microstructure and mechanical properties of extruded Mg–Sn alloys

Abstract

In this paper, the effect of Cu and Zn addition on mechanical properties of indirectly extruded Mg–2Sn alloy was investigated. Mg–2Sn–0.5Cu alloy exhibits a moderate yield strength (YS) of 225 MPa and an ultimate strength of 260 MPa, which are much higher than those of the binary Mg–2Sn alloy, and the elongation (EL) evolves as ∼15.5%. Mechanical properties of the Mg–2Sn–0.5Cu alloy are deteriorated with more 3 wt-% Zn addition, and YS and EL are reduced as 160 MPa and ∼10%. The detailed mechanism is discussed according to the work-hardening rate and strengthening effect related to the grain sizes, second phases and macro-textures. Grain refinement and proper texture are believed to play a critical role in both strength and ductility optimisation.