Homogenization forging and deformation mechanism of near-β titanium alloy in α+β region
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract: The microstructures of a Ti-5Al-5Mo-5V-1Cr-1Fe alloy with a strain gradient from 0.1 to 1 were obtained by double-cone compression experiments. The deformation microstructures were analyzed by EBSD and TEM. The results show that the deformation mechanism is dynamic recovery when the strain is less than 0.42. In the strain range of 0.42-0.88, the deformation mechanism is dynamic recrystallization. When the strain exceeds 0.88, the deformation bands appear. The deformation mechanism map combined with the homogenization degree of the microstructure was constructed. The more homogeneous deformed microstructure was obtained at the strain of 0.6 and the temperature of 860 °C. The dynamic recrystallization forms new grains and reduces the size difference between the grains, which improves the homogenization degree of the microstructure.
Key words: near-β titanium alloy; hot deformation mechanism; dynamic recrystallization; homogenization degree; double-cone compression experiment