Based on the existing experimental results of dynamic deformation at room temperature [1], a high-temperature dynamic test and a few supplementary microstructure observations by using an optical microscope were performed. Based on these experimental results, a thermal-activation-based dynamic constitutive model was proposed to describe the temperature-dependent dynamic deformation of an extruded AZ31B magnesium alloy. In the proposed model, both dislocation slipping and twinning were taken as shear movements with fixed shear planes and directions but with different thermodynamic features. Then, the total flow stress was divided into two parts, i.e., non-thermally and thermally activated ones. In addition, the effects of applied strain, strain rate, and temperature on the dynamic deformation of the extruded AZ31B magnesium alloy were incorporated into the proposed constitutive model. It is demonstrated that the flow stresses predicted by the proposed model show good agreement with the experimental results.

基于室温下动态变形的现有实验结果[1]，进行了高温动态测试和使用光学显微镜的一些补充显微组织观察。基于这些实验结果，提出了一种基于热活化的动态本构模型来描述挤压型AZ31B镁合金的温度相关动态变形。在提出的模型中，位错滑移和孪生都被视为具有固定剪切平面和方向但具有不同热力学特征的剪切运动。然后，将总流应力分为两个部分，即非热激活部分和热激活部分。此外，施加的应变，应变率，温度和温度对挤压的AZ31B镁合金动态变形的影响被纳入了本构模型。结果表明，该模型预测的流动应力与实验结果吻合良好。