Effect of pre-deformation in the β phase field on the microstructure and texture of the α phase in a boron-added β-solidifying TiAl alloy

In this work, the effect of pre-deformation in the beta phase field on the microstructural characteristics of alpha phase in a Ti-40Al-8Nb-0.5B alloy (at. %) was investigated. The results showed that the morphology and crystallography of alpha phase were strongly influenced by the deformation. It was observed that if there was no deformation, alpha laths which formed strict Burgers orientation relationship with beta matrix are predominant (similar to 81% in number fraction). In contrast, the Burgers alpha laths are significantly reduced after compression in the beta phase field. Meanwhile, an abnormal double-fiber texture, < 11-20 > and < 10-10 >, is produced. After systematic analysis, we believe that the reduction of Burgers alpha is attributed to the heterogeneous nucleation of alpha phase at borides and the breakdown of the boride ribbons during deformation. Moreover, the formation of alpha texture is a synergetic consequence of beta texture and boride texture. (C) 2018 Elsevier B.V. All rights reserved.