(1. 徐州工程学院 机电工程学院，徐州 221111；
2. 徐州工程学院 江苏省大型工程装备检测与控制重点建设实验室，徐州 221111；
3. 合肥工业大学 材料科学与工程学院，合肥 230009)
摘 要: 采用体积可压缩刚粘塑性热力耦合有限元法，对纯铝粉末-包套ECAPT变形行为进行数值模拟，并实验分析其在ECAPT过程中显微组织和力学性能的演变规律。结果表明：ECAPT工艺对纯铝粉末材料具有强烈的致密和细化效果；变形坯料在模具转角和螺旋通道两处所受剪切变形程度最大，挤压载荷增幅最为明显；ECAPT工艺在提高材料应变累积量的同时可显著改善其变形分布的均匀性。模拟分析与实验结果具有较好的一致性，纯铝粉末坯料经1道次ECAPT变形后实现有效固结，显微组织显著细化，力学性能大幅度提高。
关键字: 纯铝粉末；大塑性变形；等径角挤扭；数值模拟
（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
