(1. 徐州工程學(xué)院 機(jī)電工程學(xué)院，徐州 221018；
2. 中國礦業(yè)大學(xué) 機(jī)電工程學(xué)院，徐州 221116；
3. 高端工程機(jī)械智能制造國家重點(diǎn)實(shí)驗(yàn)室，徐州 221004)
摘 要: 將“球形分流”和“膨脹擠壓”概念引入傳統(tǒng)ECAP技術(shù)，提出一種新型等通道球形轉(zhuǎn)角膨脹擠壓(ECAEE-SC)工藝。采用有限元模擬和實(shí)驗(yàn)驗(yàn)證的方法研究ECAEE-SC過程中工業(yè)純鋁的塑性變形行為。結(jié)果表明：ECAEE-SC工藝具有復(fù)合劇烈塑性變形的效果，球形轉(zhuǎn)角和膨脹通道為兩個(gè)主要變形區(qū)域；擠壓過程中材料處于理想的壓應(yīng)力狀態(tài)，坯料單道次ECAEE-SC變形累積等效應(yīng)變量約為3.5，整體變形均勻性良好，擠壓效率大幅提高。擠壓實(shí)驗(yàn)與有限元模擬結(jié)果相一致，擠出坯料外形完整且宏觀無裂紋，坯料顯微硬度平均值從初始36.6 HV增加至70.2 HV，力學(xué)性能得到顯著改善。
關(guān)鍵字: 球形分流；等通道球形轉(zhuǎn)角膨脹擠壓；復(fù)合劇烈塑性變形；變形行為；顯微硬度
（1. School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou 221018, China;
2. School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China;
3. State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, Xuzhou 221004, China）
Abstract:The concepts of “spherical split flow” and “expansion extrusion” were introduced to conventional ECAP and a novel process entitled equal channel angular expansion extrusion with spherical cavity (ECAEE-SC) was proposed. The plastic deformation behavior of commercially pure aluminum during ECAEE-SC process was investigated using finite element simulation and experimental validations. The results show that ECAEE-SC process is capable of combining some efficient severe plastic deformation (SPD) methods, the spherical die corner and expansion channel are the two main deformation zones. In ECAEE-SC process, the material is in an ideal compressive state. After a single pass of extrusion, the accumulated effective strain in the billet is about 3.5 with good deformation uniformity, demonstrating a considerable increase in the extrusion efficiency. Moreover, the extrusion experiment is consistent with the finite element simulation results. The extruded billet is free of macro crack with intact shape, and the microhardness increases from 36.6 HV to 70.2 HV. Therefore, the mechanical properties of the billet are greatly improved.
Key words: spherical split flow; equal channel angular expansion extrusion with spherical cavity; severe plastic deformation; deformation behaviors; microhardness
