挤压AZ31镁合金的动态力学行为及本构模型  

Dynamic mechanical response and constitutive model of extruded AZ31 magnesium alloy

作　　者：李飞龙 肖罡 郭鹏程[2,3] 仪传明 刘晓红[4] LI Fei-long;XIAO Gang;GUO Peng-cheng;YI Chuan-ming;LIU Xiao-hong(Alnan Aluminum Co.,Ltd.,Nanning 530200,China;Collaborative Innovation Center of Engineering Technology,Jiangxi University of Applied Science,Nanchang 330100,China;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China;College of Mechanical Engineering,Jiujiang Vocational and Technical College,Jiujiang 332007,China)

机构地区：[1]南南铝业股份有限公司,广西南宁530200 [2]江西应用科技学院工程技术协同创新中心,江西南昌330100 [3]湖南大学汽车车身先进设计制造国家重点实验室,湖南长沙410082 [4]九江职业技术学院机械工程学院,江西九江332007

出　　处：《轻合金加工技术》2021年第10期51-55,共5页Light Alloy Fabrication Technology

基　　金：国家自然科学基金面上项目(52075159);中国博士后科学基金项目(2019M652755);国家金属材料近净成形工程技术研究中心开放基金项目(2020013);江西省教育厅科学技术研究项目(GJJ191277,GJJ191283)。

摘　　要：为构建挤压AZ31镁合金的动态力学本构模型,采用INSTRON液压伺服实验机和分离式霍普金森压杆对AZ31镁合金进行准静态和高速冲击压缩,加载应变速率分别为0.0015 s^(-1),880 s^(-1),1410 s^(-1),3430 s^(-1)和4820 s^(-1).结果表明:挤压AZ31镁合金在高速冲击载荷下具有明显的正应变速率敏感性,其流变应力明显比准静态载荷下的要高,屈服强度和极限强度均随应变速率的增加而增加。基于原始J-C方程,通过将应变速率硬化系数C修正为应变速率的线性函数,构建了挤压AZ31镁合金的修正J-C本构模型,本构拟合结果与实验结果基本吻合,能够较好地表征挤压AZ31镁合金的动态力学响应行为。To build a dynamic mechanical constitutive model for extruded AZ31 magnesium alloy,quasi-static and high-speed impact compressive tests were conducted using IN-STRON hydraulic servo machine and split Hopkinson pressure bar,the loading strain rates were 0.0015s^(-1),880 s^(-1),1410 s^(-1),3430 s^(-1)and 4820 s^(-1)respectively.The results show that the extruded AZ31 magnesium alloy exhibited an apparent positive strain rate sensitivity under high-speed impact load and its flow stress is obviously higher than that under quasi-static load.Both the yield strength and ultimate strength increased with the increase of the applied strain rate.Based on the original Johnson-Cook constitutive model,a modified Johnson-Cook constitutive model was constructed by modifying the strain rate hardening coef ficient C to a linear function with the applied strain rate.Constitutive fitting results were basically in agreement with the experimental results,which can accurately characterize the dynamic mechanical response behavior of the extmded AZ31 magnesium alloy.

关 键 词：AZ31镁合金 高速冲击 力学行为 本构建模 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TH142.3[金属学及工艺—金属材料]