摘要
采用数值模拟和实验,深入分析了积极摩擦挤压过程中金属变形流动行为的力学机理,利用应力偏张量第二不变量J2、Lode系数μ等特征量对挤压过程进行了变形分区.结果表明:积极摩擦挤压时简底不出现分流的现象,“死区”缺陷完全消失,处于塑性区内材料的应变类型由三种变为均一的拉伸类,且显著改善了成形过程中金属变形和流动的均匀性,利于金属的挤出成形及制品质量的提高.
Numerical simulations and experiments were employed to investigate the mechanical mechanism of the extrusion process with active friction. The characteristic quantities such as the second invariant of the deviatoric stress tensor (J2) and Lode parameter (#) were employed for the division of deformation area. The results show that when extruded with active friction, no metal flow interface formed at the container bottom, the dead metal zone completely disappeared, the deformation types of the metal in the plastic deformation area changed from three types to a type of tension, and the homogeneity of the deformation as well as metal flow are greatly improved, which will be helpful for extrudin~ and promoting the quality of extrudates.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第2期199-204,共6页
Acta Metallurgica Sinica
基金
国家重点基础研究发展计划资助项目5131903ZT2~~
关键词
挤压
摩擦
数值模拟
extrusion, friction, numerical simulation