变形的AZ91D镁合金半固态等温压缩的力学行为

为了了解等径道角挤压(ECAE)的AZ91D镁合金在半固态压缩变形中的力学特征,利用半固态温压缩实验、Gleeble1500实验机和金相显微镜对其在半固态压缩变形中的力学行为进行了研究.结果表明:ECAE的AZ91D镁合金在半固态等温压缩中变形由固相晶粒本身的塑性变形、液相包围着固相晶粒的滑动和转动构成;该材料的真应力-真应变曲线由应力激增阶段、应力下降阶段、稳态阶段和应力增加阶段组成;随保温时间的增加或变形温度的升高,获得相同应变量的真应力明显下降,稳态应力和峰值应力也明显下降;随应变速率的增加,稳态应力增加.

Mechanical behavior of deformed AZ91D magnesium alloy during semi-solid isothermal compression

In order to know the mechanical characteristic of processed AZ91D magnesium alloy by equal channel angular extrusion(ECAE) during semi-solid isothermal compression,its mechanical behavior during semi-solid isothermal compression was investigated using semi-solid isothermal compression test,Gleeble1500 test machine and metalloscope.The results showed during semi-solid isothermal compression,deformation mainly of semi-solid billet depended on plastic deformation of solid phases and their rotation and sliding.There were drastic increase of true stress,drastic falling of true stress,steady stage and increase of true stress in its true stress-strain curve.With the increase of holding time or compression temperature,required true stress for obtaining same true strain fell evidently and peak stress and steady stress also fell in true stress-strain curve.With increasing strain rate,steady stress also increased.