The 3-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 model potentials, fitted to the elastic and structural properties of Ni, were used for the simulations. New 2- and 3-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 in the cross-slip process were studied. The core structures of the constrictions were diffuse, as opposed to a Stroh point constriction. The 2 constrictions which were formed by cross-slip onto a {111} cross plane had significantly different energy profiles, again at variance with the classical Stroh continuum theory. This suggested that self-stress forces and atomistics dominated the energetics of cross-slip, and 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. The cross-slip energies which were estimated for Cu and Ni were in reasonable agreement with experimental data. The cross-slip energy exhibited a significantly weaker dependence upon the Escaig stress, when compared with elasticity calculations. The activation volume for the cross-slip process 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 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