摘要
采用简化的切片平面应变假设,利用增量叠加法对椭圆截面螺旋等通道挤压(ECSEE)过程的应变累积进行了分析计算。通过对横截面上某一质点进行追踪,将ECSEE变形过程分解为两种基本变形方式:圆-椭圆/椭圆-圆截面过渡变形和椭圆截面扭转过渡变形,然后利用MATLAB软件编程求解,得到了组合后材料内部追踪点的累积等效应变沿模具通道长度的变化规律和横截面上等效应变累积的分布规律,并与Deform-3D有限元软件模拟结果进行了对比。结果表明:ECSEE扭转变形所得累积应变要大于其他变形形式累积的应变,ECSEE变形方式主要是剪切变形;坯料横截面的等效应变从坯料外围到中心呈梯度减小趋势;有限元模拟结果也验证了解析解的工程准确性。
The simplified slice-plain-strain method and the incorporating incremental superposition theory were adopted for the cumulative effective strain （CES） of elliptical cross-section spiral equal-channel extrusion （ECSEE） process. The ECSEE deformation was divided into two basic deformation modes： round-ellipse/ellipse-round cross-section transitional channel deformation and ellip-tical cross-section torsion transitional channel deformation, through tracking a particle of the cross section. The change laws for the combined CES of the particle with the channel length and the combined effective strain （ES） distribution were obtained by MATLAB software programming, and the results were compared with these via Deform-3D finite element method （FEM）. The results show that the ECSEE accumulation torsion strain is greater than that of other forms, and the shear deformation is dominant. The blank cross-section ES presents the gradient decreasing trend from the periphery to the center. The FEM results also verify the accuracy of analytical solution.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2013年第4期679-683,共5页
Rare Metal Materials and Engineering
基金
Aeronautical Science Foundation of China (2011ZE53059)
Graduate Starting Seed Fund of Northwestern Polytechnical University (Z2011006)
关键词
椭圆截面螺旋等通道挤压
剧烈塑性变形
超细晶材料
解析解
有限元法
elliptical cross-section spiral equal-channel extrusion （ECSEE）
severe plastic deformation （SPD）
ultrafine-grained material
analytical solution
finite element method （FEM）
