Mg-Gd-Nd-Zr镁合金热变形过程中的动态再结晶研究  

Study on dynamic recrystallization of Mg-Gd-Nd-Zr magnesium alloy under hot deformation

作　　者：王鹏程 李家学 Wang Pengcheng;Li Jiaxue(Guangdong Technology College,Zhaoqing526100,China)

机构地区：[1]广东理工学院,广东肇庆526100

出　　处：《轻金属》2024年第8期38-42,47,共6页Light Metals

基　　金：广东省普通高校青年创新人才项目(2020KQNCX111,2022KQNCX129);广东理工学院科技项目(2021GKJZD003)。

摘　　要：通过Gleeble-3800热模拟试验机对Mg-Gd-Nd-Zr镁合金进行了热压缩试验,热压缩温度为350~500℃,应变速率为0.003~1 s^(-1),应变为0.7。通过光学显微镜和透射电镜,并基于加工硬化率,研究了合金热变形过程中的动态再结晶行为。研究结果表明,合金热变形过程中呈现出典型的动态再结晶特征,并表现出明显的温度和应变速率敏感性。热压缩温度的升高和应变速率的降低,有利于动态再结晶。再结晶包含晶界弓弯形核,连续动态再结晶和第二相诱发形核三种机制。随着变形速率的增大以及温度的降低,合金的动态再结晶临界应变增大,且临界应变模型为ε_(c)=3.061×10^(-6)×Z^(0.2482)。Using the Gleeble-3800 thermal simulated test machine,thermal compression tests on Mg-Gd-Nd-Zr magnesium alloys were performed at deformation temperatures ranging from 350℃to 500℃,with strain rates of 0.003~1 s^(-1)and strain of 0.7.Based on the work hardening rate,dynamic recrystallization of the alloy under hot deformation was investigated using optical microscopy and transmission electron microscopy.The results of this study show that the alloy exhibits typical dynamic recrystallization characteristics under hot deformation,with great sensitivity to temperature and strain rate.The increase in thermal compression temperature and the decrease in strain rate boost dynamic recrystallization.The recrystallization involves three mechanisms:bulging nucleation of grain boundary migration,continuous dynamic recrystallization and the second-phase induced nucleation.Then along with the increase of strain rate and the decrease of temperature,the critical strain of dynamic recrystallization of the alloy increases,and the established model of critical strain is ε_(c)=3.061×10^(-6)×Z^(0.2482).

关 键 词：Mg-Gd-Nd-Zr 加工硬化率 动态再结晶 临界应变 

分 类 号：TF125.22[冶金工程—粉末冶金]