(1. 徐州工程學(xué)院 機電工程學(xué)院，徐州 221111；
2. 徐州工程學(xué)院 江蘇省大型工程裝備檢測與控制重點建設(shè)實驗室，徐州 221111；
3. 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熱力耦合有限元法，對純鋁粉末-包套ECAPT變形行為進行數(shù)值模擬，并實驗分析其在ECAPT過程中顯微組織和力學(xué)性能的演變規(guī)律。結(jié)果表明：ECAPT工藝對純鋁粉末材料具有強烈的致密和細(xì)化效果；變形坯料在模具轉(zhuǎn)角和螺旋通道兩處所受剪切變形程度最大，擠壓載荷增幅最為明顯；ECAPT工藝在提高材料應(yīng)變累積量的同時可顯著改善其變形分布的均勻性。模擬分析與實驗結(jié)果具有較好的一致性，純鋁粉末坯料經(jīng)1道次ECAPT變形后實現(xiàn)有效固結(jié)，顯微組織顯著細(xì)化，力學(xué)性能大幅度提高。
關(guān)鍵字: 純鋁粉末；大塑性變形；等徑角擠扭；數(shù)值模擬
（1. School of Mechanical and Electrical Engineering, Xuzhou Institute of Technology, Xuzhou 221111, China;
2. Jiangsu Key Laboratory of Large Engineering Equipment Detection and Control,
Xuzhou Institute of Technology, Xuzhou 221111, China;
3. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract:The deformation behavior of pure aluminum powder in tubes during ECAPT was obtained by the coupled thermo-mechanical analysis based on the compressible rigid viscoplastic finite element method (FEM). Moreover, the microstructure and mechanical properties evolutions were investigated through experimental analysis. The results show that ECAPT process has a great efficiency on powder consolidation and grain refinement. The intense shear strains are imposed on the billet when passed the intersection part and twist channel, which causes the sharp increase of extrusion load. ECAPT process can lead to higher homogeneity of the effective strain distribution as well as higher values of the imposed strain for each pass. The FEM results and experimental results agree well. After 1 pass of ECAPT, full dense bulk aluminum achieves from powders with refined microstructures and improved mechanical properties.
Key words: pure aluminum powder; severe plastic deformation(SPD); equal channel angular pressing and torsion (ECAPT); numerical simulation
