B2 phase precipitation behavior in high-Nb TiAl alloy under lower temperature and shorter time with compression stress

The high Nb-TiAl alloy is subjected to lower temperature and shorter time hot compression treatment in this study, and it is found that the B2 phase precipitated from the metastable phase. The analysis shows that under the action of stress and temperature, due to the different diffusion velocity of Ti, Al and Nb atoms, the diffusion of Ti and Nb atoms is slower and the diffusion of Al atom is faster, which leads to the enrichment of Ti and Nb atoms and formation B2 phase. In the whole process, stress can promote the movement of dislocations, thereby accelerating the diffusion of atoms.