摘要
为了研究Mg-11Gd-4Y-1.5Zn合金的热变形行为,通过热压缩试验获得了不同变形条件下该类合金材料的真实应力-真实应变曲线,并基于动态材料模型和MURTY失稳判据构建了可描述Mg-11Gd-4Y-1.5Zn合金可成形性的三维热加工图。三维热加工图显示,合金材料在高应变速率下大多发生了流变失稳,仅在较窄的温度区间具有良好的可成形性,并且随着成形温度的升高和应变速率的减小呈现功率耗散系数增大、流变失稳现象减少的规律,初步确定了该种合金材料的可加工成形参数区间。基于得出的三维热加工图,使用DEFORM-3D有限元软件开展了等温平面应变模锻数值模拟,以对材料在3组不同参数下的可成形性进行预测。模拟结果显示,材料在420℃/0.1 mm·s^(-1)和450℃/0.1 mm·s^(-1)工艺参数下的变形未发生破坏,但在370℃/1 mm·s^(-1)工艺参数下却发生了流变失稳。与数值模拟参数一致的平面应变模锻成形工艺试验结果表明,试样微观组织观察结果与数值模拟基本吻合,验证了所建立三维热加工图的正确性,确定了Mg-11Gd-4Y-1.5Zn合金的最佳成形工艺参数区间为:温度410~500℃、速度0.01~0.15 mm·s^(-1)。
To study the hot deformation behavior of Mg-11Gd-4Y-1.5Zn alloy,true stress-true strain curves under different deformation conditions of this alloy were obtained through hot compression experiments,and the 3D hot processing map which can describe the form-ability of Mg-11Gd-4Y-1.5Zn alloy was constructed based on dynamic material model and the MURTY instability criterion.The 3D hot processing map shows that the alloy material undergoes plastic instability at high strain rates in most cases,and has good formability only in a narrow temperature range.The power dissipation coefficient increases and the flow instability phenomenon decreases as the forming temperature increases and the strain rate decreases,and the ranges of formability parameters of the alloy material are determined initially.Based on the obtained 3D hot processing map,numerical simulation of isothermal plane strain die forging was conducted using the DE-FORM-3D finite element software to predict the formability of the material with three different sets of parameters.The simulation results show that the material undergoes safe deformation with process parameters of 420℃/0.1 mm·s^(-1) and 450℃/0.01 mm·s^(-1),but rheo-logical instability occurs with process parameters of 370℃/1 mm·s^(-1).The experimental results of the plane strain die forging process with the same parameters as numerical simulation show that the microstructure observation results of the sample are basically consistent with the numerical simulation,which verifies the correctness of the established 3D hot processing map.The optimal forming process pa-rameter range for Mg-11Gd-4Y-1.5Zn alloy is determined to be the temperature of 410-500℃and the velocity of 0.01-0.15 mm·s^(-1).
作者
曾健
赵涵博
李明
董杰
ZENG Jian;ZHAO Han-bo;LI Ming;DONG Jie(National Engineering Research Center of Light Alloy Net Forming,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Luoyang Institute of Special Materials Research,Luoyang 471023,China;Southwest Technology and Engineering Research Institute,Chongqing 400039,China)
出处
《塑性工程学报》
北大核心
2025年第8期187-194,共8页
Journal of Plasticity Engineering
基金
国防基础科研项目(JCKY2023209C001)。
关键词
镁合金
热变形行为
热加工图
可成形性
magnesium alloy
hot deformation behavior
hot processing map
formability
作者简介
第一作者/通信作者:曾健,男,1992年生,博士,助理研究员,主要从事轻合金精密成形技术及装备研究,E-mail:jianzeng@sjtu.edu.cn。
