Microstructure and High Temperature Mechanical Properties of Mg-1Si-1Y Alloy
Mg-1Si alloy doped with 1%Y was prepared by in-situ reaction synthesis. The effect of hot extrusion on the microstructure and elevated-temperature mechanical properties of the alloy was studied. The microstructures were analyzed by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffractometry. The results show that as-cast Mg-1Si-1Y alloy consists of dendritic α-Mg phase, eutectic needle-like Mg2Si phase and Mg24+xY5 phase precipitated from α-Mg, Mg2Si can be modified and refined by yttrium, and α-Mg grains can be refined by dynamic recrystallization occurred in hot extrusion process. The tensile strength and elongation of the alloy at ambient temperature are improved prominently by hot extrusion. The tensile strength and elongation of the extruded alloy is 185.3MPa and 24.3% at 120°C. The improved elevated-temperature properties of the alloy are ascribed to the fine-grained strengthening and dispersion strengthening from Mg2Si and Mg24+xY5 particles.
Huawu Liu, Yongxin Yang, Shijie Shen, Zhili Zhong, Laijiu Zheng and Peng Feng
Y. Ma et al., "Microstructure and High Temperature Mechanical Properties of Mg-1Si-1Y Alloy", Applied Mechanics and Materials, Vols. 268-270, pp. 365-370, 2013