The activation energy for vacancy migration in [001] tilt boundaries in Ni under the action of homogeneous tensile stress in the presence of a grain-boundary dislocation was calculated with the help of atomistic computer simulation by the molecular-statics method using embedded-atom-method potentials. The Σ = 5 (θ = 36.9°) special boundary as well as the boundary with a misorientation angle of θ = 37.9° whose period contained 20 structural units of the Σ = 5 (θ = 36.9°) boundary and one structural unit of the Σ = 5 (θ = 53.1°) boundary simulating a grain-boundary dislocation were investigated. High applied stresses and long-range grain-boundary dislocation-induced stresses were shown to exert no significant effect upon the activation energy for vacancy migration. An analysis using calculated data on the energy for vacancy formation showed that, due to the internal stresses in ordered boundaries, the diffusion coefficient along grain boundaries could increase only slightly.

Activation Energy for Vacancy Migration in [001] Tilt Boundaries in Nickel. R.T.Murzaev, A.A.Nazarov: The Physics of Metals and Metallography, 2006, 101[1], 86-92