The importance of textures for determining the mechanical behaviour of intermetallics

In conventional metallurgy it is well accepted that preferred crystal orientations in a polycrystalline material can have significant effects in modifying properties, with notable examples found in γ-γ′ superalloy components and Fe(Si) transformer sheets. The same effects clearly should be obtained in intermetallics, but this aspect has hardly been considered until recently. The influence of textures will be examined in iron aluminide and in γtitanium aluminides. The first compound is highly elastically anisotropic and plastically relatively isotropic. The second compound is elastically more isotropic and shows severe plastic anisotropy, both as single phase γTiAl and in the more common two-phase (γ+α2) form. Control of texture and of its uniformity throughout a component can have a major effect on its response to mechanical stresses.