Chemical composition and ordering at the (111) antiphase boundary in the Ni3Al-based γ′ phase were studied by semi-grand canonical Monte Carlo simulations at temperatures from 700 to 1300K. The atomic interactions were modelled with an embedded-atom potential reproducing the relevant part of the Ni-Al phase diagram. In a certain range of bulk compositions and temperatures within the γ′ phase stability domain, the antiphase boundary undergoes a pre-wetting transformation by becoming a layer of disordered γ phase. The pre-wetting transformation line was mapped onto the bulk phase diagram allowing predictions of the antiphase boundary state under various thermochemical conditions.

Temperature Dependence of the Pre-Wetting Transition at the (111) Anti-Phase Boundary in Ni3Al: an Atomistic Study. Becker, C.A., Mishin, Y.: Modelling and Simulation in Materials Science and Engineering, 2010, 18[7], 074004