Homogenization treatment of Mg-6Zn-3Sn (wt.%) alloy and its effects on microstructure and mechanical properties

With DSC, OM, XRD, SEM, TEM, Vickers hardness tester, and universal testing machine, the evolution of the microstructure and mechanical properties of Mg-6Zn-3Sn alloy during homogenization was studied, the reason for overburning and diffusion kinetics of the alloy were analyzed, and the homogenization scheme was determined. The results show that the decomposition of the Mg2Zn3 phase, accompanied by the precipitation of the Mg2Sn phase, occurs after the single-stage homogenization. When the homogenization temperature increases to 350 degrees C, the Mg2Zn3 phase leads to overburning. The suitable homogenization scheme for the alloy is (335 degrees C, 24 h) + (400 degrees C, 6 h). During the double-stage homogenization, the hardness of the alloy decreases continuously and the mechanical properties show an increase first and then decrease, which is related to the solid solution of Zn and Sn atoms and the precipitation of the Mg2Sn phase.

Automated summary

The evolution of microstructure and mechanical properties of Mg-6Zn-3Sn alloy during homogenization was studied using various techniques. The overburning and diffusion kinetics of the alloy were analyzed, and an optimized homogenization scheme was determined. The results showed that decomposition of Mg2Zn3 phase and precipitation of Mg2Sn phase occurred after single-stage homogenization. Overburning was observed when the homogenization temperature increased to 350°C. The suitable homogenization scheme for the alloy was found to be (335°C, 24 h) + (400°C, 6 h) double-stage homogenization. The hardness of the alloy decreased continuously during double-stage homogenization, while the mechanical properties initially increased and then decreased, which was attributed to solid solution of Zn and Sn atoms and precipitation of Mg2Sn phase.