Effect of zinc additions on the microstructure mechanical properties and creep behavior of as-cast Mg–3Sm–0.4Zr (wt.%) alloy

The influence of zinc (Zn) additions (0, 0.5, 1 wt.%) on the microstructure, mechanical properties of as-cast Mg–3Sm–0.4Zr (wt.%) alloy has been investigated in the present study. Compared with the Zn-free alloy, addition of 0.5 wt.% Zn results in the formation of great amounts of fine precipitates in the regions close to grain boundaries, which effectively retard dislocation motion and dramatically enhance the tensile strength at 200 and creep resistance. For the alloy containing higher zinc content (=1 wt.%), the excellent creep resistance is mainly attributed to the suppression of non-basal dislocation slip due to the presence of planar defects.