Effects of Nd on microstructure and mechanical properties of as-cast Mg-12Gd-2Zn-xNd-0.4Zr alloys with stacking faults

In order to study the effects of Nd addition on microstructure and mechanical properties of Mg-Gd-Zn-Zr alloys, the microstructure and mechanical properties of the as-cast Mg-12Gd-2Zn-xNd-0.4Zr (x = 0, 0.5wt%, and 1wt%) alloys were investigated by using optical microscope, scanning electron microscope, X-ray diffractometer, nano indentation tester, microhardness tester, and tensile testing machine. The results show that the microstructures mainly consist of alpha-Mg matrix, eutectic phase, and stacking faults. The addition of Nd plays a significant role in grain refinement and uniform microstructure. The tensile yield strength and microhardness increase but the compression yield strength decreases with increasing Nd addition, leading to weakening tension-compression yield asymmetry in reverse of the Mg-12Gd-2Zn-xNd-0.4Zr alloys. The highest ultimate tensile strength (194 MPa) and ultimate compression strength (397 MPa) are obtained with 1wt% Nd addition of the alloy.

Automated summary

The effects of Nd addition on microstructure and mechanical properties of Mg-Gd-Zn-Zr alloys were studied. The addition of Nd significantly refines the grain and achieves a uniform microstructure. With increasing Nd content, the tensile yield strength and microhardness increase, while the compression yield strength decreases, resulting in a weakening of tension-compression yield asymmetry in the alloy.