Deformation and Phase Transformation of Disordered α Phase in the (α plus γ) Two-Phase Region of a High-Nb TiAl Alloy

In this paper, the deformation and phase transformation of disordered alpha phase in the (alpha + gamma) two-phase region in as-forged Ti-44Al-8Nb-(W, B, Y) alloy were investigated by hot-compression and hot-packed rolling. The detailed microstructural evolution demonstrated that the deformed microstructure was significantly affected by the deformation conditions, and the microstructure differences were mainly due to the use of a lower temperature and strain rate. Finer alpha grains were formed by the continuous dynamic recrystallization of alpha lamellae and alpha grains distributed around lamellar colonies. Moreover, the grooved gamma grains formed by the phase transformation from alpha lamellae during hot rolling cooperated with and decomposed alpha lamellae. A microstructure evolution model was built for the TiAl alloy at 1250 degrees C during hot rolling.

Automated summary

This paper investigated the deformation and phase transformation of disordered alpha phase in the (alpha + gamma) two-phase region in the Ti-44Al-8Nb-(W, B, Y) alloy. The microstructural evolution was found to be significantly affected by the deformation conditions, primarily the lower temperature and strain rate. A microstructure evolution model for the alloy at 1250 degrees C during hot rolling was established.