Atomistic simulation of dislocation core configurations in TiAl

Abstract

Dislocation core structures and γ surfaces in L1₀ TiAl were computed using embedded-atom interatomic potentials. The γ-surface studies for the (111) plane showed that no faults other than the antiphase boundary, superlattice intrinsic stacking fault and complex stacking fault appear to be stable on the close-packed plane of TiAl. Different possibilities of perfect superdislocation dissociation were examined on the basis of the dislocation core splitting configuration and separation between partials as revealed by atomistic computer simulation. Both ordinary and superdislocations in various orientations were studied with particular focus on the mechanisms of formation of nonplanar core configurations.