(1. 中國電子科技集團(tuán) 第38研究所，合肥 230031；
2. 合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，合肥 230009)
摘 要: 采用體積可壓縮剛粘塑性有限元法對粉末多孔材料帶反壓的等通道轉(zhuǎn)角擠壓過程進(jìn)行數(shù)值模擬，獲得粉末多孔材料在該過程中的變形和致密行為。并在此基礎(chǔ)上分析反壓大小和反壓模具結(jié)構(gòu)對擠壓變形效果的影響。結(jié)果表明：采用帶反壓的方式可有效控制變形過程中粉末金屬的流動，增加試件整體變形的變形量，提高變形均勻性及致密效果；帶反壓的等通道轉(zhuǎn)角擠壓工藝可有效降低試件在擠壓過程中產(chǎn)生破壞的可能性，同無反壓方式相比，帶反壓擠壓件內(nèi)部獲得更為均勻細(xì)密的內(nèi)部組織結(jié)構(gòu)。
關(guān)鍵字: 粉末多孔材料；等通道轉(zhuǎn)角擠壓；反壓；有限元分析
extrusion process of powder porous material
（1. No.38 Institute, China Electronic Technology Group Corpration, Hefei 230031, China;
2. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract:The densification and deformation behavior of powder porous material during the equal channel angular extrusion (ECAE) process with back pressure were investigated by compressible rigid-viscoplasticity finite element method. Based on the numerical results, the distribution of strain, relative density of specimen was obtained. The finite element analysis results show that back pressure has important effect on the extrusion result. It can not only improve the ductility and density of powder porous material, but also greatly increase the strain level and the uniformity of the strain distribution. The ECAE with back pressure can reduce the destruction of specimen and obtain much more homogenous and finer grain.
Key words: powder porous material; equal channel angular extrusion; back pressure; finite element analysis
