【摘要】 通过等径角挤压可以细化镁合金晶粒。利用非线性有限元软件MSC.Marc对镁合金的ECAE变形过程进行有限元模拟,获得等效应变和等效应力分布规律,分析挤压力随变形时间的变化和摩擦对ECAE变形的影响。结果表明:挤压力-变形时间曲线可以分为快速增加阶段,慢速增加阶段和稳定阶段;等效应力分布很不均匀,模具拐角对应的区域等效应力最大;试样中部的等效应变值,大于顶部和底部;摩擦会导致变形不均匀。更多还原

【Abstract】 Equal Channel Angular Extrusion (ECAE) is a method to fabricate grain refinement of magnesium alloy. In this paper, non-linear finite element software MSC.Marc was employed to simulate ECAE process. The distribution of equal effective strain and equal effective stress was obtained through finite element simulation. And the changing of pressing load versus time and the influence of friction on the ECAE deformation process were analyzed. The results indicated that the curve of extrusion force versus time was divided into three stages:rapid increased stage, slow increased stage and steady stage. The distribution of equal effective stress was inhomogeneous, the biggest was in the corner of die. The equal effective stain value in the middle part of billet was bigger than that in top and bottom part. Friction resulted in inhomogeneous of deformation.更多还原