Textures in two phase intermetallic TiAl alloys after compression and extrusion

Polycrystalline cast alloys of composition Ti-48at%Al and Ti-46at%Al-1at%Cr-0,2at%Si consisting mainly of lamellar γ/α2-grains have been deformed in compression at room temperature and by rod extrusion at high temperatures. The textures of the γ-phase of the deformed specimens were measured and analyzed in terms of ODF's and inverse pole figures representing the tetragonal/triclinic crystal/specimen symmetry. The cast alloys possess a γ/α2 microstructure with unidirectionally aligned lamellae. After compression at room temperature as well as after hot extrusion a similar type of texture was observed namely a brass type {110)2-interfaces and 〈111〉 perpendicular to it). It can be explained in both cases by a strong tendency to plane strain deformation caused by the influence of the α2 lamellae on the slip and twinning modes in the γ-matrix.