等径角挤压工艺的无网格数值模拟研究  

Numerical study on equal channel angular pressing based on element-free Galerkin method

作　　者：管延锦[1] 赵国群[1] 路平[1] 曹伟[2] 吴欣[3] 

机构地区：[1]山东大学材料科学与工程学院,济南250061 [2]烟台汽车工程职业学院,烟台150001 [3]杭州电子科技大学机械工程学院,杭州310018

出　　处：《塑性工程学报》2008年第2期15-21,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(50575125);国家杰出青年基金资助项目(50425517)。

摘　　要：等径角挤压(Equal Channel Angular Pressing,ECAP)工艺,是一种通过材料的剧烈塑性变形,获得大块超细晶材料的有效方法。采用无网格伽辽金法对等径角挤压工艺进行了数值模拟研究,分析了挤压过程中材料的流动规律,研究了模具圆心角、挤压件与模具间的摩擦状况对ECAP挤压效果的影响。随着模具圆心角的减小,挤压件的等效应变增大并且变得更加均匀,但是模具圆心角越小,挤压载荷越大,严重影响模具的使用寿命;摩擦状况对挤压件的等效应变的影响较小,对挤压载荷影响显著。无网格模拟分析结果与实验结果吻合良好。The equal channel angular pressing （ECAP） is an effective method to obtain ultra-fine grain materials using severe plastic deformation. The equal channel angular pressing process is simulated numerically based on the rigid plastic/viscoplastic element-free Galerkin （EFG） method. Numerical results such as material flow patterns of the forming process, effective strain, ef- fective stress and effective strain-rate distributions are obtained. The influence of curve angle ψ and frictional status on the forming effect of ECAP is studied. The effective strains become larger and more uniform with the increase of the curve angle ψ. On the other hand, the forming load increases greatly with the increase of the curve angle ψ. The effective strains change slightly with the change of the frictional status between the die and the workpiece. However, the frictional status influences greatly the forming load.

关 键 词：等径角挤压 ECAP 无网格伽辽金法 数值模拟 

分 类 号：TG376[金属学及工艺—金属压力加工]