钨粉包套等径角挤压致密行为的介观尺度分析  

Mesoscopic analysis on densification of tungsten powder material in tubes during equal channel angular pressing

作　　者：宋群超 李萍[1] 华睿[1] 薛克敏[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：《塑性工程学报》2015年第1期24-28,共5页Journal of Plasticity Engineering

基　　金：教育部新世纪优秀人才支持计划(NCET-13-0765);中央高校基本科研业务费专项资金资助(2012HGZX0030;2013HGCH0011)

摘　　要：基于离散单元法理论,建立纯钨粉末多孔材料等径角挤压的离散元模型,并对其进行单道次变形行为和致密行为的数值模拟和实验,获得了变形中颗粒簇流动过程、速度场、接触力链、致密行为等相关场量变化规律。结果表明,标记颗粒在剪切区的流动过程反映了颗粒簇在剪切力作用下的变形规律;试样头部形状及变形中内转角处的间隙都与内外转角处的速度分布不均有关;经一道次挤压后颗粒间孔隙数量减少,致密度提高,材料性能得到改善。实验结果与模拟结果较为一致,证明了所建模型的可靠性。Two-dimensional discrete element model was built based on the theory of discrete element method to analyze the de-formation and densification behavior of tungsten powder material with porosities during a single pass of equal channel angularpressing （ECAP）. The flowing process, velocity, force chain and relative density of the sample during ECAP were obtained.The flowing process of marked particles in the shear zone reflects the particles＇ deformation rule. The particles＇ final distributionstates are attributed to the inhomogeneous velocity in the inner sample. The pore is decreased, the density is increased after onepass, and the property of sample is improved. The experimental results have a good consistency with the simulation results,which shows that the established discrete element model is reliable.

关 键 词：钨粉材料 等径角挤压 离散元数值模拟 致密度 速度场 

分 类 号：TG376[金属学及工艺—金属压力加工]