Effect of Ce-rich rare earth on microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy

To improve the comprehensive mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy, different amount of Ce-rich rare earth (RE) was added to the alloy, and the effect of RE addition on the microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb alloy was investigated by means of Brinell hardness measurement, scanning electron microscopy (SEM), energy dispersive spectroscope (EDS) and X-ray diffraction (XRD). The results show that an appropriate amount of Ce-rich rare earth addition can make the Al4Ce phase particles and CeSb phase disperse more evenly in the alloy. These phases refine the alloy's matrix and make the secondary phases [tau-Mg-32(Al,Zn)(49) phase and phi-Al2Mg5Zn2 phase] finer and more dispersive, therefore significantly improve the mechanical properties of the Mg-10Zn-5Al-0.1Sb alloy. When the RE addition is 1.0 wt.%, the tensile strengths of the alloy both at room temperature and 150 degrees C reach the maximum values while the impact toughness is slightly lower than that of the matrix alloy. The hardness increases with the increase of RE addition.