Strip projection methods established that the formation of antiphase boundaries was the initial stage of a periodic-to-quasiperiodic transformation in superlattices, and the Al5Ti3-to-quasiperiodic superlattice transformation which was observed in Al-rich γ-TiAl intermetallics was a classic example of such a transition. The energy of the relevant antiphase boundaries was therefore expected to play an important role in the occurrence of the transition. The present 2-dimensional Monte Carlo simulations showed that a change in the antiphase boundary energy, accomplished by suitably altering the pair interaction energies, could explain the diffraction effects observed in alloys which exhibited this transition. The results of the simulations reproduced salient features of the atomic arrangements in imperfectly ordered quasi-periodic and near-quasiperiodic structures.

Role of the Antiphase-Boundary Energy in Periodic-to-Quasiperiodic Superlattice Transitions - a Monte Carlo Simulation of Ordering in Al-Rich γ-TiAl. U.D.Kulkarni: Philosophical Magazine A, 2002, 82[5], 1017-32