Effect of Nd on Microstructure and High-Temperature Mechanical Properties of As-cast Mg-Y-Nd-Zn-Zr Alloy

The microstructure evolution and mechanical performance of Mg-5Y-xNd-3Zn-0.6Zr (x = 0, 1, 2, 3) alloys with long period stacking ordered phase (LPSO phase) at elevated temperature (250 degrees C, 275 degrees C, and 300 degrees C) were systematically investigated in this work. The microstructure analyses show that the Mg-5Y-xNd-3Zn-0.6Zr alloys consist of alpha-Mg with different second phase including LPSO phase and W phase whose volume fraction can be raised by the Nd addition. The Nd addition can refine the alpha-Mg grain, and the alloy with 3% Nd can refine the grain size by 30% compared to the alloy without Nd. The mechanical properties tests show that the Nd addition can improve the elevated-temperature strength of the alloys, and the optimum mechanical property is achieved at the Nd content of 3%. At the test temperature of 250 degrees C, 275 degrees C, and 300 degrees C, the tensile strength of Mg-5Y-3Nd-3Zn-0.6Zr is 233.3 MPa, 217.0 MPa, and 191.0 MPa, and the elongation of WEZK5330 alloy is 21.6%, 22.2%, and 24.9%, respectively.