COMPUTER-SIMULATION OF (100) DISLOCATION CORE STRUCTURE IN NIAL

A detailed study of the structure of (100) dislocations in NiAl is pre sented. Atomistic computer simulation is carried out with embedded ato m interatomic potentials and the results are analysed using invariants of the strain tensor in the dislocation core region. No dislocation d issociation is observed in the simulations. The spreading of the cores in various crystallographic planes is identified and correlated with the strain fields given by anisotropic elasticity theory. Although the relaxed structures are closely related to those given by elasticity, non-elastic effects, originating mainly from the discrete nature of th e lattice, are evident. Among them, asymmetries of the twinning-antitw inning type are found.