Phase precipitation behavior during isothermal deformation in β-quenched near beta titanium alloy Ti-7333

Evolution of the α phase precipitation behavior and morphologies characteristics during isothermal deformation of a near β titanium alloy Ti-7Mo-3Al-3Nb-3Cr (Ti-7333) have been investigated using Transmission Electron Microscope (TEM) and Electron Backscattered Second Diffraction (EBSD). The results indicated that the fine and random α phase precipitated during the isothermal deformation. The morphologies of α phase precipitation during isothermal deformation are markedly different from those of the α phase during heat treatment. The volume fraction of α phase increases with the increasing of the true strain. Most of α phase precipitates in high-angle grain boundaries (HAGBs) and low-angle grain boundaries (LAGBs), while a small amount of spherical α phase precipitates in the grains. The crystallographic orientation of the spheroidal α phase is approximate where precipitate most in LAGBs and grains, otherwise different orientation relationship will be presented when the precipitation in grain boundaries (GBs). The α phase precipitation during isothermal deformation were affected by amount of dislocations.