Effect of solidification mode on microstructure evolution and properties of magnesium alloy with long-period stacking ordered phase

The solidification methods of electromagnetic stirring (EMS) and non-electromagnetic stirring were employed to prepare Mg–6Gd–3Y– x Zn–0.6Zr ( x = 1, 1.5, 2, 3) alloys. The evolution of alloy microstructures and the changes in properties were analyzed for different Zn contents. It has been observed that in alloys without electromagnetic stirring, as the Zn content increases, the alloy structure gradually refines. The primary second phase transitions from Mg 5 RE phase to long-period stacking ordered (LPSO) phase, resulting in improved hardness and elongation. In alloys subjected to electromagnetic stirring, there is a relatively higher content of the second phase, primarily consisting of LPSO phase. After applying electromagnetic stirring, the quantity and the type of LPSO phase in the alloy change. The alloy structure becomes more uniform with electromagnetic stirring, resulting in increased hardness and reduced hardness gradients within the grains. The mechanical properties of alloys with electromagnetic stirring are superior to those without electromagnetic stirring.