EV31镁合金热压缩变形行为及热加工图

Hot compression deformation behavior and hot processing map of EV31 magnesium alloy

为研究EV31镁合金的热变形行为,采用Gleeble 3800型热模拟试验机对其在不同温度与应变速率下进行热压缩试验,计算得到了EV31镁合金的热变形激活能,构建了其流变应力本构方程和热加工图,并通过扫描电镜(SEM)及电子背散射衍射(EBSD)技术分析其热变形过程中的组织演变。结果表明:当真应变为0.4时,EV31镁合金适宜的热加工区间是变形温度为390~500℃及应变速率为0.01~0.1 s^(-1)的区域内。在500℃下压缩时,合金的动态再结晶比400℃更加充分,能得到晶粒细小、织构较弱的显微组织。

In order to study the hot deformation behavior of EV31 magnesium alloy,hot compression tests of the alloy were carried out at different temperatures and strain rates with a Gleeble 3800 thermo-mechanical simulator.The hot deformation activation energy of the EV31 magnesium alloy was calculated,the flow stress constitutive equation and hot processing map were constructed,and the microstructure evolution during the hot deformation process was analyzed by scanning electron microscopy(SEM)and electron back scattering diffraction(EBSD)technique.The results show that when the true strain is 0.4,the optimum hot processing range of the EV31 magnesium alloy is:the deformation temperature of 390-500℃and the strain rate of 0.01-0.1 s^(-1).When the alloy is compressed at 500℃,the dynamic recrystallization of the alloy is more sufficient than that at 400℃,and the microstructure with fine grains and weak texture can be obtained.