镁合金超塑性变形的损伤演化效应

研究了AZ31B镁合金板材超塑性变形时的空洞损伤,对拉伸试样在超塑性变形各阶段轴剖面的空洞进行了观察,通过对空洞演化的分析建立了空洞体积分数与变形程度的定量关系,并推导出基于微损伤演化规律及统计细观损伤力学的损伤演化方程,通过试验得到适用于AZ31B镁合金板材超塑性变形损伤演化的特征参数C1、C2和损伤变量临界值DC.

Evolvement of micro-damage in magnesium alloy under superplastic deformation

This paper investigated the cavity damage of AZ31B magnesium alloy sheet under superplastic deformation. The cavity distributions over the longitudinal sections of tensile specimen with different elongations were observed by SEM. After quantitative analysis of the evolvement law of the cavity damage, a volume fraction of cavities as a function of tree strain have been established. The evolvement equation of micro-damage based on the law of the micro-damage evolution and statistical mechanics of micro-damage was derived out through superplastic tensile test and the quantitative analysis on the volume fraction of cavities. The characteristic parameter C1, C2 and the critical value Dc of damage variable in superplastic AZ31B magnesium alloy sheet were obtained by experiment.