The three-dimensional cross-slipped core structures of (a/2)[110] screw dislocations in model face-centered cubic structures were simulated by using lattice statics within the embedded-atom formalism. Two parametric embedded-atom method potentials, fitted to the elastic and structural properties of Ni, were used for the simulations. Newly reported two-dimensional and three-dimensional Green's function techniques were used to relax the boundary forces in the simulations. The core structures and energetics of the constrictions which occurred during the cross-slip process were studied. The core structures of the constrictions were diffuse; unlike the point constrictions envisaged by Stroh. The two constrictions which were formed by cross-slip onto a cross {111} plane had significantly different energy profiles; again contrary to the classical continuum theory of Stroh. This suggested that self-stress forces and atomistics dominated the energetics of the cross-slip process. The far-field elastic-energy contribution to cross-slip appeared to be minimal. However, the Shockley partial separation distances near to the constrictions - as well as the variation in cross-slip energy with stacking-fault energy - were in reasonable agreement with continuum predictions. Cross-slip energies which were estimated for Cu and Ni, using these calculations, revealed a reasonable agreement with experimental data. The cross-slip energy exhibited a significantly weaker dependence upon the Escaig stress, as compared with elasticity calculations. The activation volume for cross-slip was estimated to be of the order of 20b3 at an applied Escaig stress of 0.001μ in Cu. This was an order of magnitude lower than expected from experimental estimates and continuum predictions.

Atomistic Simulation of Cross-Slip Processes in Model FCC Structures. S.Rao, T.A.Parthasarathy, C.Woodward: Philosophical Magazine A, 1999, 79[5], 1167-92