Atomistic modeling methods with kinetic Monte Carlo simulations were combined in order to study self-diffusion in the intermetallic compound L10-TiAl. Atomic interactions in TiAl were modeled using an embedded-atom potential. The vacancy concentration in TiAl was obtained from a lattice gas model of non-interacting point defects. Molecular dynamics simulations were used to determine vacancy migration mechanisms in the compound. A set of representative vacancy jumps was identified and their rate constants were computed using the harmonic transition state theory with the reaction path established by the nudged elastic band method. The rate constants were used as input to kinetic Monte Carlo simulations performed at several temperatures and alloy compositions. Kinetic Monte Carlo simulations furnished the self-diffusion coefficients of Ti and Al, correlation factors and other diffusion characteristics. The results were in reasonable agreement with experimental data.

Atomistic Modeling of Diffusion in the TiAl Compound. Y.Mishin, I.V.Belova, G.E.Murch: Defect and Diffusion Forum, 2005, 237-240[1], 271-6