Microstructure and mechanical properties of a cast heat-resistant rare-earth magnesium alloy

Microstructure, mechanical properties and phase transformation of a heat-resistant rare-earth (RE) Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y (wt.%) alloy were investigated. The as-cast is composed equiaxed α-Mg matrix, net-shaped Mg5RE Zr-rich phases. According to aging hardening curves tensile variation, the optimized condition solution treatment at 520 °C for 8 h subsequent 204 12 was selected. continuous secondary predominantly formed grain boundaries during solidification transforms residual discontinuous β-Mg5RE fine cuboid REH2 particles after heat treatment. annealed exhibits good comprehensive property 350 °C, with ultimate strength 153 MPa elongation fracture 6.9%. Segregation RE elements eventually RE-rich precipitation are responsible high elevated temperature.