Predominantly two kinds of antiphase boundaries form in Al5Ti3, which was an Al-rich ordered derivative of the γ-TiAl (L10) phase. This phase could be viewed as a periodic arrangement of lean rhombs and squares on the Ti-rich (002) planes of the tetragonal L10. Energies of the two types of antiphase boundaries were varied in a Monte Carlo simulation by suitably changing the pair interaction parameters. Antiphase boundaries of both types form boundaries of Al5Ti3 antiphase domains, which coarsen with time. An important observation in this regard was that mostly facetted antiphase boundaries formed at lower ageing temperatures, whereas curved antiphase boundaries appeared to form at relatively higher ageing temperatures. The present findings suggested that there exists a critical temperature, akin to the roughening transition temperature for crystals, that marks the transition from facetted to curved antiphase boundaries.

Monte Carlo Simulation of Antiphase Boundaries and Growth of Antiphase Domains in Al5Ti3 Phase in Al-Rich γ-TiAl Intermetallics. U.D.Kulkarni, S.Hata, T.Nakano, M.Mitsuhara, K.Ikeda, H.Nakashima: Philosophical Magazine, 2011, 91[22], 3068-78