Texture evolution of the gamma- and the alpha/alpha2-phase during hot rolling of gamma-TiAl based alloys

Abstract

Multiple hot rolling experiments were performed in the upper area of the α+γ phase field of the γ-TiAl based alloy Ti46Al9Nb (in atomic percent). The texture evolution for both the γ- and the α/α2-phase has been investigated by X-ray diffraction. In the γ-phase textures comparable to those known from fcc-metals evolve. The texture components and fibers were separated and described with respect to the lower symmetry of the L10-structure. Computer simulations of the deformation texture evolution allow to attribute specific texture components to the predominant activity of ordinary dislocations, super dislocations and twinning, respectively. The accompanying recrystallization appears to be orientation dependent. In the α/α2-phase transversal and basal type textures similar to those found after hot rolling of two-phase titanium based alloys have been identified. Based on the literature about titanium-based alloys specific orientations were correlated with characteristic slip activity. The underlying mechanisms of texture evolution and orientation dependent recrystallization are discussed for both phases.