Influence of surface plastic deformation on the microstructure evolution of diffusion bonding interface of high Nb containing TiAl alloy

The surface plastic deformation was applied to high Nb containing TiAl alloy by means of shot peening, and the influence of the surface plastic deformation on the microstructure evolution of the diffusion bonding interface of high Nb containing TiAl alloy was studied. The results indicated that continuous α₂ phase formed in the bonding interface with surface plastic deformation, and the fraction of α₂ phase increased with the increasing deformation degree. Furthermore, the surface plastic deformation promotes the recrystallization in the subsequent annealing. The growth of the recrystallized grain reduced the fraction of α₂ phase when the plastic deformation is large enough, and the α₂ phase disappeared at last. Thus, the combined surface plastic deformation with recrystallization annealing improved the bonding quality of high Nb containing TiAl alloy.