Effects of solution treatment on microstructures and properties of Mg-Nd-Zn-Y-Zr alloy

The effects of solution treatment on microstructures and properties of Mg-2.4Nd-0.2Zn-6.0Y-0.5Zr alloy were studied. The research conclusions show that the cast alloy is comprised of α-Mg, Mg12Nd, Mg24Y5, MgYx, α-Zr phases. After solution treatment, the Mg12Nd and Mg24Y5 phases gradually dissolve into the matrix, while there are also MgYx and α-Zr phases near the grain boundary. The weakening of the second phases strengthening and fine grain strengthening offset the solid solution strengthening, resulting in a slight improvement of the tensile strength and yield strength. However, the elongation of alloy increases by 125%, which attributes to the elimination of the crack sources. The best solution treatment for the alloy is 500°C × 8 h.