The microstructural morphology of transformed α induced by <111> β fiber texture in a dissimilar inertia friction weld between near-α and α+β titanium alloys

The microstructure and texture features of the dissimilar inertia friction welded (IFW) joint of Ti65 titanium alloy to TC25G titanium alloy were characterized. The β textures in dynamic recrystallization zone (DRZ) produced by severe hot shear deformation were dominated by the bcc D₂ (11-2)[111] shear texture for both the Ti65 and the TC25G alloys. The variant selection occurred during the β α phase transformation at the final cooling stage, in which higher fraction of α variants with misorientation of [−10 5 5 3]/63.26° formed. The triangular configuration structures were frequently observed in the interior of the β grains in DRZ, which was resulted from the variant selection occurring in microregion. The formation of triangular configurations was also favored naturally by the <111>_bcc β fiber texture.