Preliminary investigations about effects of Zr, Sc and Ce additions on as-cast microstructure and mechanical properties of Mg–3Sn–1Mn (wt.%) magnesium alloy

In this paper, the effects of Zr, Sc and Ce additions on the as-cast microstructure and mechanical properties of Mg–3Sn–1Mn (wt.%) magnesium alloy were preliminarily investigated and compared. The results indicate that adding 0.36 wt.% Sc and 0.87 wt.% Ce to the Mg–3Sn–1Mn alloy, respectively leads to the formation of the extra phases of Mg–Sn–Sc and Mg12Ce while adding 0.43 wt.% Zr does not cause the formation of any new phases. At the same time, adding 0.43 wt.% Zr or 0.87 wt.% Ce can refine the grains while adding 0.36 wt.% Sc coarsens the grains. Among the Zr- and Ce-containing alloys, the grains of the latter are relatively finer than those of the former. In addition, adding 0.43 wt.% Zr, 0.36 wt.% Sc and 0.87 wt.% Ce to the Mg–3Sn–1Mn alloy can improve the tensile and/or creep properties of the alloy. However, the addition of 0.43 wt.% Zr is not beneficial to the creep properties. Among the Zr-, Sc- and Ce-containing alloys, the alloy with the addition of 0.87 wt.% Ce exhibits the optimal tensile and creep properties.