Texture evolution during β→O→α2 and β→α2 and phase transformations in a Ti3Al-Nb alloy

The alloy Ti-24Al-11Nb was hot rolled in the beta phase field at 1523 K by 80% and water quenched. The material was then aged at 773 K, 873 K and 1173 K for various lengths of time leading to the formation of the O phase and the alpha(2) phase, either directly from the beta or via beta to O phase transformation. The O phase shows a "tweed" microstructure while the transformed alpha(2) phase displays the typical plate like features. The texture of the a, phase whether formed directly or indirectly from the beta phase, due to a final ageing treatment at 1173 K, is rather strong and non-basal type. By contrast, the alpha(2) texture of the 873 K aged material is weak and again non-basal type, but it differs significantly from the texture of the 1173 K aged material. (C) 2004 Elsevier B.V. All rights reserved.