Precipitation behavior of B2 phase in (Nb, W) alloyed TiAl-based alloy during low temperature hot deformation

The precipitation behavior of B2 phase in Ti–44Al–4Nb–1W–0.1B alloy with metastable α phase during low temperature hot deformation is studied. The experimental results show that the B2 phase is precipitated under 300 MPa heat treatment at different temperatures, and the precipitation content of B2 increases first and then decreases with the increase of temperature. Detailed analysis shows that the B2 phase is precipitated from the metastable α phase. The segregation of Nb and W elements and the lack of Al elements caused the precipitation of B2 phase. The difference in diffusion rate between the elements in the alloy results in the segregation of Nb and W elements. Under the action of stress, the tangled concentration of dislocations also provides conditions for the deposition of Nb and W elements. In addition, the interdiffusion between elements results in the absence of Al element.