AM60镁合金Johnson-Cook本构方程的修正及冲压有限元模拟  

Modification of Johnson-Cook Constitutive Equation and Stamping Finite Element Simulation of AM60 Magnesium Alloy

作　　者：刘泽成 郑小平(导师) 李红斌 田亚强 陈连生 LIU Zecheng;ZHENG Xiaoping;LI Hongbin;TIAN Yaqiang;CHEN Liansheng(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学冶金与能源学院,唐山063210

出　　处：《机械工程材料》2023年第3期85-91,共7页Materials For Mechanical Engineering

基　　金：河北省钢铁联合基金资助项目(E2017209121);河北省高等学科科学技术研究重点基金资助项目(ZD2018242)。

摘　　要：利用Gleeble-3500型热模拟机对AM60镁合金板进行热拉伸试验,研究了镁合金在变形温度200~350℃、应变速率0.01~0.1 s^(-1)下的热变形行为;对Johnson-Cook方程应变硬化部分进行修正并考虑应变速率和变形温度的耦合效应,基于热拉伸试验数据建立了修正Johnson-Cook本构方程,利用该方程进行冲压有限元模拟,并进行了试验验证。结果表明:AM60镁合金的流变应力与应变速率呈正相关,与变形温度呈负相关;采用修正Johnson-Cook本构模型预测得到AM60镁合金冲压真应力-真应变曲线与试验结果吻合较好,最大相对误差为18.28%,相比于未修正模型降低了57.61%;模拟得到200~350℃下冲压成形的筒形件成形良好,无表面缺陷,与试验结果一致。Gleeble-3500 thermal simulator was used to perform a hot tensile test on AM60 magnesium alloy plate,and the thermal deformation behavior of the magnesium alloy under deformation temperatures of 200-350℃and strain rates of 0.01-0.1 s^(-1) was studied.The strain hardening part of the Johnson-Cook equation was corrected and the coupling effect of strain rate and deformation temperature was considered;the modified Johnson-Cook constitutive equation was established with the hot tesile test data.The stamping finite element simulation was carried out by the equation,and the simulation was verified by tests.The results show that the rheological stress of AM60 magnesium alloy was positively correlated with the strain rate and negatively correlated with the deformation temperature.The stamping true stress-true strain curve of AM60 magnesium alloy predicted by the modified Johnson-Cook constitutive model was in good agreement with the test results,and the maximum relative error was 18.28%,which was 57.61%lower than that by the unmodified model.The barrel parts stamped at 200-350℃were well formed and had no surface defects by simulation,which was consistent with the test results.

关 键 词：AM60镁合金 热拉伸 Johnson-Cook本构方程 冲压模拟 

分 类 号：TG146.2[一般工业技术—材料科学与工程]