圆形挤压件多道次等通道弯角挤压变形机理

来源期刊：中国有色金属学报2007年第12期

论文作者：徐淑波 张国良 任国成 王志刚

文章页码：1928 - 1935

关键词：等通道弯角挤压；超细晶粒；有限元分析；等轴晶粒；工艺路线

Key words：equal channel angular extrusion; ultra-fine grains; finite element analysis; equiaxed grains; processing route

摘    要：采用数值模拟和实验研究方法分析圆形纯铝挤压件多道次等通道弯角挤压工艺，发现单道次挤压获得的挤压件的变形分布沿挤压件中心横截面竖直方向变形分布不均匀。通过节点映射法实现各工艺路线的多道次挤压，不同的工艺路线对应的多道次挤压变形分布具有明显差异。多道次挤压后晶粒得到显著细化，变形后晶粒结构较挤压前的退火等轴晶粒大为不同，而且各工艺路线的晶界取向也各不相同，其中旋转90？挤压能够获得大角度晶界分布的等轴晶粒试样，实验结果与有限元分析结果十分吻合。

Abstract: Multi-pass equal channel angular extrusion (ECAE) processes for round workpieces were investigated by using numerical simulations and experimental studies. The single-pass ECAE is a non-uniform shear deformation process in the cross-section of the workpiece. The different processing routes for equal round channel angular pressing process were conducted by using node mapping method in multi-pass pressing. The effective strain distributions of different processing routes are obviously different. The grains in the workpiece are refined obviously after multi-pass extrusion. The microstructures of the processed workpieces are different from the equiaxed grains of the annealing initial workpiece. And the microstructure evolution of the workpiece can be changed via different processing routes. The route with turning angle of 90？ can get a distribution of high angle grain boundaries in the workpiece. In addition, the experimental results are in agreement with the finite element analysis results. The microstructure evolutions of grain refinement mechanisms for different multi-pass ECAE processing routes accord with the accumulated effective strain rules in the workpiece.

基金信息：国家自然科学基金资助项目
山东省优秀中青年科学家科研奖励基金资助项目