双通道等径角挤压试样变形不均匀性有限元分析  

Finite element analysis of DECAP deformation heterogeneity

作　　者：薛克敏[1] 易成坷 段自豪 甘国强[1] 李萍[1] XUE Ke-min;YI Cheng-ke;DUAN Zi-hao;LI Ping(School of Material Seience and Engineering,Hefei University of Teehnology,Hefei 230009,China;School of Industry and Equipment Technology,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009 [2]合肥工业大学工业装备与技术研究院,安徽合肥230009

出　　处：《塑性工程学报》2018年第4期33-39,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51675154;51575153)

摘　　要：通过对双通道等径角挤压变形过程的数值模拟,获得了不同路径4个道次各变形区的等效应变分布图,分析了挤压试样变形不均匀现象及其形成原因。结果表明,双通道等径角挤压中存在4种变形区,其中与冲头接触的区域应变值几乎保持挤压前的水平,该区域的存在是造成试样变形不均匀的主要原因。多道次挤压中试样的均匀性不仅与旋转方式有关,还与试样的放置方式有关。采用A路径的试样应变均匀性优于B路径;采用A路径进行挤压,在2道次挤压后试样左右剪切变形区等效应变呈现一端大一端小的分布状态,在3、4道次挤压中采取大＋小剪切变形区处于冲头一侧的放置方式,试样等效应变的均值最高;采取小＋大剪切变形区处于冲头一侧的放置方式,制备试样等效应变分布最为均匀。By using the numerical simulation of double equal channel angular pressing（DECAP）,the effective strain distribution of DECAP deformation area under different routes after four passes were obtained,and the deformation heterogeneity phenomenon and its causes were analyzed. The results show that there are four deformation areas in DECAP,the strain value of the area contacting with the punch is almost as same as the value before extrusion,and the existence of the area is the main reason for the deformation heterogeneity. The homogeneity of the sample in multi-pass extrusion is not only related to the rotation mode but also to the sample placement mode. The homogeneity of effective strain of A-path is better than that of B-path. Under the A-path,the effective strain of the shear zone in the left and right sides shows a small distribution at one end and a large distribution at the other end after the second pass. During the third and fourth passes,taking the large ＋ small shear deformation area on the punch side,the average effective strain reaches the highest level. Taking the small ＋ large shear deformation area on the punch side,the effective strain distribution on the sample is the most homogeneous.

关 键 词：DECAP 有限元模拟 变形不均匀性 

分 类 号：TG376.2[金属学及工艺—金属压力加工]