The microstructure and hot tensile behaviors of the different heat-treated Ti2AlNb sheets were investigated by backscattered electron image (BSE), electron backscattering diffraction (EBSD), transmission electron microscope (TEM) and tensile tests. The grain sizes and contents of α2, B2/β and O phases were quantitatively studied. As the heating time increases at 970 °C, the mean grain size and content of α2-phase increased. The grain shapes and distributions of the O-phase lamellar grains were affected by the heat treatments. The plastic deformation promoted the O → B2/β phase transition and the globularization of O-phase lamellar grains at 970 °C. Calculated by the creep equation and the iso-stress method, the grain size exponent was μ=1.1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mu = 1.1$$\end{document} and the relationship between the material constants of B2/β and O phase was KO=1.14KB2/β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$K_{{\text{O}}} = 1.14K_{{{\text{B}}2/\upbeta }}$$\end{document}.

中文翻译：

---

各种热处理 Ti2AlNb 板材在 970 °C 时的显微组织和热流应力

通过背散射电子图像 (BSE)、电子背散射衍射 (EBSD)、透射电子显微镜 (TEM) 和拉伸试验研究了不同热处理 Ti2AlNb 薄板的显微组织和热拉伸行为。定量研究了α2、B2/β和O相的晶粒尺寸和含量。随着 970 °C 加热时间的增加，平均晶粒尺寸和 α2 相含量增加。O相层状晶粒的晶粒形状和分布受热处理的影响。塑性变形促进了 O → B2/β 相变和 O 相片状晶粒在 970 °C 的球化。由蠕变方程和等应力法计算，晶粒度指数为μ=1。