Comparative studies on as-cast microstructures and mechanical properties between Mg—3Ce—1.2Mn—0.9Sc and Mg—3Ce—1.2Mn—1Zn magnesium alloys

The as-cast microstructures and mechanical properties of Mg—3Ce—1.2Mn—0.9Sc and Mg—3Ce—1.2Mn—1Zn magnesium alloys were investigated and compared. The results indicate that the Sc-containing alloy mainly consists of α-Mg, Mg12Ce and Mn2Sc phases, and the Zn-containing alloy is mainly composed of α-Mg and Mg12Ce phases. The morphologies of the Mg12Ce phases in the two as-cast alloys are different. The Mg12Ce phases in the Sc- and Zn-containing alloys mainly exhibit particle-like shapes and continuous and/or quasti-continuous nets, respectively. Furthermore, the grains of the Sc-containing alloy are finer than those of the Zn-containing alloy. In addition, the Sc- and Zn-containing alloys have similar as-cast tensile properties at room temperature and 300°C. However, the Sc-containing alloy exhibits higher creep-resistant properties at 300°C and 30 MPa for 100 h than the Zn-containing alloy.