Effect of neodymium on the as-extruded ZK20 magnesium alloy

The effect of Nd addition on the microstructure and mechanical properties of ZK20 magnesium alloy was investigated by room tensile test, optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to develop a magnesium alloy with higher ductility. Results showed that the crystal grains of as-extruded ZK20+0.5%Nd magnesium alloy were effectively refined, and the alloy exhibited higher strength and ductility, with the UTS of 237 MPa and the elongation of 32.8%, increasing by 5% and 50% for those of ZK20 alloy respectively. Some fine granular Mg-Zn-Nd ternary phases (tau(1), tau(4)) appeared in the as-extruded ZK20+0.5%Nd magnesium alloy. It was found that ZK20 showed brittle fracture surface, while the fracture surface of ZK20+0.5%Nd showed a mixed characteristics of brittleness and ductility.