Effect of solution treatment on the microstructure and mechanical properties of Mg-Zn-Y-Mn-(V) magnesium alloy

The effects of solution treatment on the microstructure and mechanical properties of Mg-Zn-Y-Mn-(V) magnesium alloy were investigated by using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), microhardness tester, and electronic universal testing machine. The results showed that the addition of an appropriate amount of V can effectively refined the grains, promoted the formation of LPSO phase, and suppressed the generation of W phase. When 0.5 at.% V is added, the alloy achieved the optimal microstructure and mechanical properties. Subsequently, the Mg 93.5 Zn 2.5 Y 2.5 Mn 1 V 0.5 alloy was subjected to solution treatment. It was found that the solution treatment can transformed the network W phase to be spherical W phase while inducing the formation of lamellar 14H LPSO phase within the grains. After 40 h of solution treatment, the alloy achieved optimal microstructure and mechanical properties, with the tensile strength of 268 MPa, yield strength of 162 MPa, and elongation of 11.7%.