The microstructure, mechanical properties and creep behavior of Mg–3Sm–0.5Zn–0.4Zr (wt.%) alloy produced by different casting technologies

The microstructure, mechanical properties and creep behavior of Mg–3Sm–0.5Zn–0.4Zr (wt.%) alloy produced by ingot-casting and die-casting were investigated. The die-cast alloy exhibits superior tensile properties at room temperature, while the higher tensile strength at 200 °C is obtained in the ingot-cast alloy. The results indicate that the creep behavior in the two alloys is discussed in terms of the microstructural features. The creep data and microstructural analysis reveal that dislocation creep is the dominant creep rate-controlling mechanism at 200 °C/60 MPa for the two alloys. The excellent creep resistance of the die-cast alloy is mainly attributed to the dynamic precipitation in the α-Mg matrix of a high density of fine platelets, which served as obstacles to dislocation motion.