Deformation Behavior and Dynamic Recrystallization of Ti–22Al–25Nb Alloy at 750–990 °C

Ti–22Al–25Nb is a representative of Ti₂AlNb alloys with excellent comprehensive properties, which has great application prospects in the aerospace field. Herein, high-temperature tensile plastic deformation behavior and dynamic recrystallization process of Ti–22Al–25Nb alloy are researched during 750–990 °C. From 750 to 870 °C, plasticity is gradually improved with temperature increasing, and the fracture mode is crack aggregation. From 900 to 930 °C, the content of B2 phase increases and plasticity is significantly improved because crack along the grain is suppressed by combined precipitation of three phases B2 + O + α₂ at grain boundaries with large areas. From 960 to 990 °C, the alloy is mainly composed of B2 phase and has best plastic deformation performance. Fully dynamic recrystallization of B2 phase happens at 990 °C. Texture strength is strengthened by intense plastic deformation, but it is weakened by dynamic recrystallization subsequently.