摩擦条件对铝合金挤压变形流动行为影响.PDFVIP

第 18 卷第 11 期 中国有色金属学报 2008 年 11 月 Vol.18 No.11 The Chinese Journal of Nonferrous Metals Nov. 2008 文章编号：1004-0609(2008)11-2014-06 摩擦条件对铝合金挤压变形流动行为的影响 1 1 2 李 峰 ，刘晓晶，苑世剑 (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 材料科学与工程学院，哈尔滨 150001) 摘 要：通过有限元模拟和实验，对不同摩擦挤压过程中铝合金变形流动行为的机理进行分析，并利用罗德系数 和应力偏量不变量(J2)等特征量进行变形分区。结果表明：采用积极摩擦可使挤压时的“死区”缺陷完全消失， 且塑性区内材料的应变类型由 3 种变为均一的拉伸类变化，显著地提高了挤压过程中坯料横断面上金属流速的均 匀性，更利于金属的挤出成形。 关键词：挤压；摩擦条件；数值模拟；应变类型；金属流动行为 中图分类号：TG 376 文献标识码：A Effect of friction condition on flow behavior of aluminum alloys during extrusion 1 1 2 LI Feng , LIU Xiao-jing , YUAN Shi-jian (1. School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China; 2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China) Abstract: The mechanical mechanism of the flow behavior of aluminum alloys during extrusion process with active friction was investigated by numerical simulations and experiments. The characteristic quantities such as the second invariant of the Lode parameter (μ) and deviatoric stress tensor (J2) were employed for the division of deformation area. The results show that when extruded with active friction, no metal flow interface forms at the container bottom, the dead metal zone completely disappears, the deformation types of the metal in the plastic deformation area change from three