Effects of Recrystallization on the Microstructure and Mechanical Properties of Cold-Rolled Ti-B20 Alloy

The static recrystallization behaviour and microstructure evolution of cold rolled (CR) Ti-B20 alloy with high strength during annealing were investigated using electron back-scattered diffraction and x-ray diffraction methods. Results suggest that the deformation bands and grain boundaries in the CR Ti-B20 alloy became a preferred nucleation position of recrystallized grains, which led to the formation of an uneven microstructure at the initial stage of annealing. After a given annealing time, the nucleation and growth rate of recrystallized grains accelerated with increasing annealing temperature. The relationship among the volume fraction of recrystallized grains, annealing temperature and annealing time can be described by the Johnson–Mehl–Avrami–Kolmogorov equations X800=1-exp(-0.00011∗t1.64\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( {X_{800} = 1 - \exp ( - {0}{\text{.00011}}\, * \,t^{1.64} } \right)$$\end{document} and X820=1-exp(-0.00009∗t1.98)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_{820} = 1 - \exp ( - {0}{\text{.00009}}\, * \,t^{1.98} )$$\end{document}. For the CR sheet specimens, a typical cold texture was formed, such as γ-fiber components of {111} < 110 > and {111} < 112 > textures. When complete recrystallization occurs for the CR sheet, the texture component primarily consists of {112} < 021 > for the CR sheet annealed at 800 and 820 °C.