(1. 哈爾濱理工大學 材料科學與工程學院，哈爾濱 150040；
2. 哈爾濱工業(yè)大學(威海) 船舶工程學院，威海264209)
摘 要: 利用有限元方法對不同圓環(huán)壓縮過程中的分流行為進行模擬研究，揭示鋁合金圓環(huán)壓縮過程中分流行為的產(chǎn)生機理，并利用羅德系數(shù)、J2應力偏量不變量等特征量對成形機理進行分析。結(jié)果表明：外側(cè)施壓時，隨著高徑比增大，難變形區(qū)明顯擴大，向內(nèi)側(cè)流動的金屬量逐漸減少，分流面位置明顯左移；內(nèi)側(cè)施壓時，隨著摩擦因子增大，塑性區(qū)內(nèi)應變類型由均一壓縮類變?yōu)?種共存，此時向內(nèi)側(cè)流動的金屬量增大，其流動分界面相對右移。
關(guān)鍵字: 鋁合金；圓環(huán)壓縮；分流行為；變形分區(qū)
（1. College of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China; 2. School of Naval Architecture, Harbin Institute of Technology at Weihai, Weihai 264209, China）
Abstract:The mechanism of aluminium alloy diffluence behaviour was studied during the ring compression. The FEM simulations of ring compression under different deformation conditions were carried out. The plastic forming mechanism was investigated based on the Lode parameter and J2 invariant of stress deviator. The results show that when the pressure is added on the external side, the metal flowing towards the internal hole decreases with increasing ratio of height to diameter, and the hard deforming zones expand and the diffluence surface shifts towards the left. When the pressure is added on the internal side, the metal flowing towards the internal hole increases with increasing friction factor, the diffluence surface shifts towards the right and the strain in the plastic area changes from the single compression mode into three coexistent modes.
Key words: aluminium alloy; ring compression; diffluence behaviour; deformation division
