Kinetics of antiphase domain boundaries during an L12 order-disorder phase transformation: A Monte Carlo simulation

Abstract

Abstract The formation of the L12 phase in an A3B intermetallic solid solution has been investigated by Monte Carlo simulation. The ordering is modelled with a simple atomic exchange mechanism based on a fcc Ising model with appropriate values for the pairwise atomic interactions. It is shown that the ordering kinetics occurs on two time scales: nucleation and growth of ordered domains and the annealing of antiphase boundaries between the domains. The model is applied to the L12 ordered Ni3Al phase under various irradiation conditions. It is demonstrated that the migration and annihilation of antiphase boundaries largely determine the time evolution of the L12 phase.