不同热处理状态下Mg-Ce合金的组织结构及断口分析

Metallograph and Fracture Structure about Mg-Ce Alloy after Different Heat Treatment

通过金相显微分析、拉伸断口扫描分析,研究了Mg-Ce合金不同热处理状态下的显微组织结构及拉伸断口。从金相显微照片中可以看到,铸态时有离异共晶和析出物,均匀化退火后离异共晶消失了但是析出物有所增多,经过均匀化退火+固溶处理之后析出物及强化相都固溶于基体之中,而经过均匀化退火+固溶处理+时效强化之后,基体中又析出了强化相Mg9Ce。断口扫描分析结果显示,经过均匀化退火+固溶处理+时效强化的试样不同于其他3种状态下的断口,呈现明显的镜面对称,是孪晶。

The metallograph and fracture structure about Mg-Ce alloy after different heat treatment are analyzed in this paper. According to the metallograph, we can find that： there is divorced eutectic and extract in molten magnesium alloy. Then, after homogenizing annealing, the divorce eutectic disappeared increasingly and the extract increased gradually. And, after homogenizing annealing and solution, the extract is soluted in the matrix. Furthermore, after the time heating on that basis, the extract from the matrix, which plays the role of strengthening the matrix, is Mg^Ce. The result of the fracture scan is that the fracture scan after the homogenizing annealing and solution and aging is different from the other three heat treatment state, which has the obvious mirror symmetry that is twinned phenomenon.