Dynamic recrystallization behavior of β grains in hot deformed Ti-6Mo-5 V-3Al-2Fe alloy

High temperature compression tests were carried out on Ti-6Mo-5 V-3Al-2Fe alloy. EBSD and TEM analysis were performed on alpha + beta phase and beta phase to study the microstructure and dynamic recrystallization mechanism. The results show that the dynamic recrystallization of the alloy is difficult to occur during hot deformation in the alpha + beta phase region because of the existence of alpha phase. A little amount of dynamic recrystallizated beta grains can be formed when the deformation temperature is below beta-transus. When the deformation temperature is 760 ?, and the strain rate is greater than 0.005 s(-1), the recrystallized grains are formed along the primary beta grain boundary under the influence of discontinuous dynamic recrystallization mechanism, and the primary beta grains are not significantly refined. When the deformation temperature is 710 ? and 760 ?, the average beta grain size is the smallest at the strain rate of 0.05 s(-1). When the deformation temperature is above beta-transus, the dynamic recrystallization can occur relatively easy, and a large amount of dynamic recrystallizated beta grains can be observed. When the deformation temperature is 810 celcius and the strain rate is 0.005 s(-1), the beta grains exhibit the smallest size difference and the minimum average size of 20.53 mu m. The recrystallization mechanism of the alloy is the mixed behavior of continuous dynamic recrystallization and discontinuous dynamic recrystallization.