粉末多孔材料等径角挤压热力耦合有限元数值分析  

Coupled thermo-mechanical finite element analysis of metal with porosities during equal channel angular pressing process

作　　者：周明智[1] 薛克敏[1] 李萍[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《中国有色金属学报》2006年第9期1510-1516,共7页The Chinese Journal of Nonferrous Metals

基　　金：高等学校博士学科点专项基金资助项目(040310B2);安徽省优秀青年科技基金资助项目(04044058)

摘　　要：等径角挤压是获得块体超细晶材料的一种重要工艺方法。针对粉末多孔材料,采用体积可压缩刚粘塑性热力耦合有限元法对其等径角挤压过程进行模拟分析。结果显示,等径角挤压工艺对粉末多孔材料具有强烈的致密效果,变形温度和接触摩擦状况对变形及致密存在明显的影响。研究表明,材料所处的静水压力状态对多孔材料的挤压效果影响显著,高的静水压力状态有利于提高粉末材料的变形能力及致密效果,改进的带背压工艺有利于提高变形的均匀性,扩大工艺的应用范围。The purpose of equal channel angular pressing （ECAP） is to obtain ultra-fine grained （UFG） materials. The densification and deformation behavior of porous materials during the ECAP process were investigated by thermo-mechanical coupling finite element method. The distributions of temperature, strain, relative density and stress of specimen were obtained. The results show that the ECAP process is a useful tool to eliminate the porosities and more effective in high temperature and friction conditions. The finite element analysis shows that the hydrostatic stress state has important effect on the result. It is beneficial to improve the ductility and density of material with porosities in high hydrostatic stress state. And the back pressure applied to the ECAP can greatly increase the strain level, while can not reduce the uniformity of the strain distribution.

关 键 词：粉末多孔材料 等径角挤压 热力耦合 有限元分析 静水压力 

分 类 号：TG376[金属学及工艺—金属压力加工]