Microstructure and texture evolution of a near β titanium alloy Ti-7333 during continuous cooling hot deformation

The microstructure and texture evolution during continuous cooling hot deformation (CCHD)in a near β titanium alloy, named Ti-7Mo-3Nb-3Cr-3Al (Ti-7333), were investigated by using the electron backscattered diffraction (EBSD). The results indicate that the precipitation of secondary α phase was restricted by CCHD, and the morphology of primary α phase nearly had no change with the deformation and temperature drop. In contrast, β phase underwent more deformation and the grains tended to refine. This may be due to the dynamic recrystallization (DRX)of β phase, including continuous dynamic recrystallization (CDRX)and discontinuous dynamic recrystallization (DDRX). In addition, the textures of {110} <110>, {225} <520> and {115} <123> transformed to {100} <110> and {001} <100> during CCHD. Among these, the ƞ-fiber component of {001} <100> was the dominant deformation texture in the deformed Ti-7333 alloy. Finally, continuous cooling has an important effect on the work hardening and softening during CCHD, contributing to the different flow behaviors at different cooling rates.