中文摘要：

通过对不同变形路径等径弯曲通道（Equal Channel Angular Pressing,ECAP）变形过程的数值模拟,获得了4种路径8道次ECAP变形的等效应变分布图,分析了挤压试样变形不均匀现象及其形成原因。结果表明,试样尾部与冲头的摩擦、头部未发生明显剪切变形是这两个部位变形程度低的主要原因,造成了ECAP变形的不均匀现象,而这两个部位的不同转移方式,又形成了各种挤压路径的ECAP变形差异。试样中间截面上平均等效应变排序为C〉BC〉A〉BA,分别为10.416、10.358、8.669和8.530;试样中间截面等效应变不均匀程度的系数排序为C〉BC〉A〉BA,分别为0.090、0.112、0.154和0.467。若追求细化效果应选择路径BC和路径C;如果追求试样材料整体均匀性,可以采用路径A。

英文摘要：

By using the numerical simulation of equal channel angular pressing（ECAP）under different deformation routes,the effective strain distributions ECAP deformation under four paths eight passes are obtained,and uneven deformation phenomenon of the extruded specimen and its causes are analyzed.The results show that the friction between the specimen and the punch tail and no obvious shear deformation occurred in the head are the main reason for the low degree of deformation for these two parts,which causes the uneven phenomenon of ECAP deformation,viz.,the different transfer mode of the two part results in the deformation difference of various ECAP route.The ranking of the average effective strain in the middle section of the sample from large to small is C〉BC〉A〉BA,viz.,10.416,10.358,8.669 and 8.530;the sort of the effective strain inhomogeneous coefficient in ascending order is C〉BC〉A〉BA,viz.,0.090,0.112,0.154 and 0.467.The path Cand path BCshould be chosen for the refinement effect,and the path Acan be used for pursuit of the overall uniformity of the specimen material.