Effect of Ca or/and Sr on Microstructure Evolution and Mechanical Properties of Extruded Mg-2Zn Alloy

Mg-Zn alloys with Ca and Sr additions were prepared by vacuum melting and hot extrusion. Effects of Ca or/and Sr on microstructure, mechanical properties of hot extruded Mg-2Zn-xCa-ySr (x = 0, 1) were studied. The results show that Ca addition into Mg-2Zn alloys significantly refine grains of Mg-2Zn alloys, while Sr addition greatly improves homogeneity of the grain structure. Fine and homogeneous microstructure is obtained by compound addition of Ca and Sr into Mg-2Zn alloy. With Ca and Sr addition, the best comprehensive mechanical properties are obtained in Mg-2Zn-1Ca-1Sr alloy with ultimate tensile strength of 308 MPa and elongation of 19%.