Mg RE（RE=La

Ce

Nd

Y） master alloy and the three experimental alloys

including Mg MM Zn Zr

Mg Nd Zn Zr and Mg Nd Y Zr

were prepared under flux protection and heat treated in atmospheric environment. Mechanical properties

including hardness

tensile strength and elongation

and the microstructures of alloy in different heat treated conditions were examined. The results showed that Nd

Y containing the experimental alloy have better heat treated strengthening effect so that its hardness and tensile strength were higher than those of conventional Mg MM Zn Zr alloy. Finely dispersed RE containing strengthening phase precipitated from super saturation solid solution phase not only raise the strength but also increase the ductility of Mg alloy

and then make alloys change from brittle fracture into tough fracture.