AZ31B镁合金电流辅助拉伸的多场耦合分析  

Multi-physical field coupled analysis of electric current assisted tension of AZ31B magnesium alloy

作　　者：石文[1] 董湘怀[1] SHI Wen;DONG Xiang-huai(Institute of Forming Technology and Equipment,Shanghai Jiao Tong University,Shanghai 200030,China)

机构地区：[1]上海交通大学塑性成形技术与装备研究院

出　　处：《塑性工程学报》2019年第6期106-113,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51635005;51775335)

摘　　要：为了探讨电流对材料成形性能的影响,建立了考虑温度影响的AZ31B镁合金流动应力模型及电场-温度场-变形场三场耦合有限元模型,分析了AZ31B镁合金板料在电流辅助拉伸变形中电流、温度和应变速率分布的关系,模拟了电流辅助拉伸和等温拉伸变形直至破裂的过程,研究了电流、温度和应变速率分布随拉伸变形的演化规律,并建立了AZ31B破裂应变与Z参数的关系式。结果表明:通电拉伸试样伸长率较等温拉伸时降低,这是由于通电拉伸时试样内温度分布不均导致变形局部化,但两者的破裂应变基本一致,该变形局部化对断面收缩率几乎没有影响,采用断面收缩率评价通电拉伸时材料的塑性更为合理。To investigate the effect of current on the forming performance of material,a flow stress model of AZ31B magnesium alloy considering the influence of temperature and a finite element model coupling electric field,temperature field and deformation field were established;the relationships among the current,temperature and strain rate distribution in electric current assisted tension deformation of AZ31B magnesium alloy sheet were analyzed,and the processes of electric current assisted tension deformation and isothermal tensile deformation until fracture were simulated;the evolution law of current,temperature and strain rate distribution with tensile deformation was studied,and the relationship between fracture strain and Z parameter of AZ31B magnesium alloy was established.The results show that the elongation of the electric current assisted tensile sample is lower than that of isothermal tensile sample,which is caused by the localized deformation due to the uneven distribution of temperature within the sample during electric current assisted tension.The localization of deformation has little effect on the shrinkage of fracture surface,and it is more reasonable to use the shrinkage of fracture surface to evaluate the plasticity of the material in electric current assisted tension.

关 键 词：AZ31B镁合金 电塑性 流动应力 破裂应变 多场耦合模拟 

分 类 号：TG306[金属学及工艺—金属压力加工]