Effect of hydrogen on γ−phase transformation and texture evolution of a TiAl−based alloy deformed at elevated temperature

The effect of hydrogen on γ-phase transformation and texture evolution of a Ti-46Al-2V-1Cr-0.3Ni (in at%) alloy was investigated during deformed in the temperature range of 1100–1200 °C with a strain rate of 0.01 s⁻¹. Both the γ→α₂ and α₂→γ_lamella transformations occurred in the hydrogenated alloy, and the former was predominant, when it is deformed at 1150 °C/0.01 s⁻¹. γ→α₂ transformation occurred earlier than α₂→γ_lamella. Hydrogen-induced such transformation was mainly associated with hydrogen−promoted dislocation movement and hydrogen−decreased stacking faults energy. A sharp <111>−fiber texture was observed in the unhydrogenated alloy. That was significantly weakened in the hydrogenated alloy because of hydrogen−promoted lamellar decomposition and dynamic recrystallization. <110>− and <320>−fiber textures mainly associated with ∑3 and ∑27a which were increased by hydrogen can be only observed in the hydrogenated alloy. With increasing temperature, <110>− and <320>−fiber textures of the hydrogenated alloy was enhanced.