AZ31镁合金挤压-剪切变形损伤研究  

Damage study of AZ31 magnesium alloy in extrusion-shear deformation

作　　者：周洁 吴任东[1] 袁朝龙[1] 焦玮[1] ZHOU Jie;WU Ren-dong;YUAN Chao-long;JIAO Wei(Key Laboratory for Advanced Materials Processing Technology,Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学先进成形制造教育部重点实验室

出　　处：《塑性工程学报》2020年第1期123-130,共8页Journal of Plasticity Engineering

摘　　要：以宽幅AZ31镁合金板材为研究对象,采用有限元软件DEFORM-2D对镁合金的挤压-剪切变形过程进行数值模拟。基于Normalized C&L断裂准则,研究了镁合金在挤压-剪切变形过程中损伤积累及分布情况,分别从模具结构和工艺参数的角度进行模拟分析。模拟结果表明,坯料损伤值随着模具拐角数目的增加而快速增长,最大损伤区主要集中在板材下表面。通过添加背压及增大模具内拐角区圆角半径可以有效地降低损伤值,改善坯料内部损伤分布。增大坯料与模具之间的摩擦能够促使大损伤区逐渐向坯料头部集中,从而提高材料利用率。而挤压温度和挤压速度对坯料损伤值的影响不大。The wide AZ31 magnesium alloy sheet was taken as the object,and finite element software DEFORM-2D was used to simulate the extrusion-shear process of magnesium alloy. Based on the Normalized C&L fracture criterion,the damage accumulation and distribution of magnesium alloy in extrusion-shear deformation process were studied,and the simulation analysis was carried out in aspect of die structure and process parameter,respectively. The simulation results show that the damage value increases rapidly with the increase of number of die corners,and the maximum damage zone is mainly concentrated on the bottom surface of the sheet. By adding back pressure and increasing the fillet radius of die inner corner,the damage value can be effectively reduced,and the damage distribution inside of the billet can be optimized. Increasing the friction between billets and dies can cause the server damage zone move to the billet head gradually,thereby the material utilization is improved. While,extrusion velocity and extrusion temperature have little effect on damage value of billet.

关 键 词：挤压-剪切 数值模拟 AZ31镁合金 损伤分析 

分 类 号：TG111.91[金属学及工艺—物理冶金]