Effect of Al Addition on the Rolled Microstructure and Mechanical Properties of Mg-4Y-3Nd Alloys

The effect of Al contents (0, 0.5, 1.0 and 1.5 wt.%) on the microstructure evolution, texture and mechanical properties of Mg-4Y-3Nd alloys rolled sheets were investigated. The results showed that the Al2RE phase was formed when Al was added into the as-cast alloys, which could refine the microstructure of the alloys. After homogenization treatment, the Al2RE phase was insoluble, and the Al2RE phase at the grain boundaries could pin the grain boundaries to prevent grain growth. The Al-containing alloys had good grain thermal stability. The Al2RE phase promoted dynamic recrystallization (DRX) through the particle-stimulated nucleation (PSN) mechanism and refined recrystallized grains during the rolling process. Al refinement will affect the texture type and strength of the alloy. The addition of 0.5 wt.% Al could improve the texture intensity, and a further increase in Al would reduce the texture intensity. When the Al content was 1.5 wt.%, the alloy had the smallest recrystallized grains, the weakest texture intensity, and the best mechanical properties. The tensile strength, yield strength and elongation were 264.4, 225.3 MPa and 9.4%, respectively.