Static Recrystallization Behavior and Texture Evolution during Annealing in a Cold Rolling Beta Titanium Alloy Sheet

Abstract

In this study, the cold rolling microstructure and static recrystallization mechanism of the high strength titanium alloy Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe were systematically investigated. Results show that the cold rolling microstructure is mainly composed of the elongated deformed β grains containing micro-shear bands. After annealing at 815 °C for 2 min, the fine SRXed grains are observed, mainly concentrated in the micro-shear band, the grain boundary and the interior of the deformed grain. The sub-grain structure obtained by static recovery inside the deformed grain produces continuous SRX during the annealing treatment. Meanwhile, geometric and discontinued SRXed grains are also observed in the large deformed β grain and at the trigeminal grain boundaries, respectively. Many ultra-fine grains appear inside the micro-shear band, exhibiting a phenomenon of the micro-shear band assisting SRX. With the increase in the annealing holding time, the elongated β grains are significantly refined and the degree of recrystallization is continuously improved. In addition, the recrystallization behavior also results in a significant change in the fiber texture. With the extension of the annealing holding time, the rolling texture type evolves gradually, with the {111} γ-fiber texture to weak α-fiber, γ-fiber, and Goss-fiber.

Keywords

• titanium alloy
• cold rolling
• annealing treatment
• microstructure
• recrystallization
• texture