TEM characterization of domain boundaries in a Ti–46Al–1Cr–0.2Si alloy

Abstract The microstructure of a Ti–46Al–1Cr–0.2Si alloy was investigated by transmission electron microscopy (TEM). It is characterized by a duplex structure consisting of a two-phase γ/α 2 lamellar microstructure and single-phase γ grains. In the single-phase γ areas there exist 60°, 120° and 180° domain boundaries. In the lamellar structure the γ and α 2 phases obey the relationships: (0 0 0 1) α 2 //{1 1 1} γ with 〈1 1 2 0〉 α 2 //〈110〉 γ . The mechanism of formation of the ordered domains is discussed.