等通道转角挤压工艺有限元分析

Finite Element Analysis of Equal Channel Angular Pressing

用SOLIDWORKS建立等通道转角挤压(ECAP)的几何模型,用有限元软件DEFORM-3D对不同摩擦系数、不同冲头速度时的挤压过程进行了模拟,获得了相应的应变场以及载荷行程曲线,得到了模具的应力分布。模拟结果表明:变形区域集中在两个通道的相交部分;等效应变速率与冲头的运动速度成正比;摩擦系数对应变的分布和变形载荷有较大影响;在一定的摩擦条件下,完成ECAP所需的变形抗力与材料流动应力成线性关系;当通道表面粗糙度Ra为1.6μm时,模具危险点工作应力不会超过变形体流动应力的4.5倍。

A model of equal channel angular pressing (ECAP) is built up by SOLIDWORKS, the extrusion processes are simulated at various punch speeds and with different friction factor between workpiece and die using finite element method analysis software DEFORM-3D.The strain field, load-stroke curve,and stress distribution on the die are obtained. Simulation results show that the deformation zone is mainly located around the cross area of the two channels; the equivalent strain rate is proportional to the punch speed; friction factor between the work piece and die has great effect on the distribution of the strain field and deformation load; the load needed for ECAP divided by the punch cross section is linearity relation with material flow stress with determinate friction factor; the maximum stress on the die will not exceed 4.5 times of the flow stress, when channel surface roughness Ra is 1.6μm.