(1. 哈尔滨理工大学 材料科学与工程学院，哈尔滨 150040；
2. 哈尔滨工业大学(威海) 船舶工程学院，威海264209)
摘 要: 利用有限元方法对不同圆环压缩过程中的分流行为进行模拟研究，揭示铝合金圆环压缩过程中分流行为的产生机理，并利用罗德系数、J2应力偏量不变量等特征量对成形机理进行分析。结果表明：外侧施压时，随着高径比增大，难变形区明显扩大，向内侧流动的金属量逐渐减少，分流面位置明显左移；内侧施压时，随着摩擦因子增大，塑性区内应变类型由均一压缩类变为3种共存，此时向内侧流动的金属量增大，其流动分界面相对右移。
关键字: 铝合金；圆环压缩；分流行为；变形分区
（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
