1. Effects of Nd content on the microstructures and mechanical properties of ZK60 Mg alloy and corresponding strengthening mechanisms

The aim of this research was to develop high-strength Mg alloys and investigate the microstructural evolution and corresponding strengthening mechanisms of ZK60 Mg alloys with different Nd content. The results indicated that the Nd-free ZK60 alloy was mainly composed of the α-Mg matrix and MgZn, MgZn2 and Zn2Zr phases, while a new phase, Nd3Zn11, formed after the addition of Nd. The addition of Nd enhanced the precipitation. The grain size first decreased and then increased with increasing Nd content. The texture component parallel to the ED in the [ 100] direction remained unchanged after the addition of Nd, but the texture intensities sharply increased. The as-extruded Mg-6Zn-0.5Zr-3Nd (wt.%) alloy exhibited the best mechanical properties among all the as-extruded alloys, with the YS, UTS, and EL of 355 MPa, 369 MPa, and 8.9%, respectively. The YS increased by 77 MPa compared with that of the as-extruded ZK60 Mg alloy, which was mainly attributed to the texture strengthening and precipitation strengthening mechanisms.