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 beta 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 a phase was restricted by CCHD, and the morphology of primary alpha phase nearly had no change with the deformation and temperature drop. In contrast, beta phase underwent more deformation and the grains tended to refine. This may be due to the dynamic recrystallization (DRX) of beta 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 eta-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.