中文摘要：

研究了固溶态Mg-5Sn-1.5Al-1Zn-1Si合金的显微组织,并从理论上分析了合金相的演化过程。结果表明合金经固溶处理后,合金晶粒出现明显球化,由树枝晶变为球状晶;合金相经溶解与脱溶,析出3~5μm的第二相颗粒。在固溶处理过程中,对于低熔点合金相,通过原子扩散或振动直接溶解到基体中,实现相的分解与形貌变化,对于高熔点合金相,通过基体中的元素浓度平衡实现扩散与分解。

英文摘要：

The microstructure of solution state Mg-5Sn-1.5Al-1Zn-1Si alloy was studied, and the evolutionary process of alloy phase was analyzed theoretically. The results indicate that the grains of Mg-5Sn-1.5Al-1Zn-1Si as-cast alloy treated by solution treatment are spheroidized obviously, and turn from dendritic grains into spherical grains. After dissolution and desolvation, the second particles of 3 μm to 5 μm are precipitated in the alloy structure. During the solid solution treatment,the low-melting-point alloy phases dissolves into matrix directly through the atomic diffusion or vibration, which achieves decomposition and morphology change of the alloy. While the high-melting-point alloy phases dissolve into matrix via element concentration balance.