It was noted that recent progress in the dislocation-dynamics modelling of work-hardening had renewed interest in cross-slip, which could lead to dynamic recovery in face-centered cubic crystals. It was pointed out that neither continuum theory nor atomic modelling could reliably describe the reaction path and activation energy of cross-slip. Classical continuum theory and the concept of Volterra dislocations failed because, during nucleation, the effective Burgers vectors of the partials were not conserved and the specific atomic misfit energy changed. Atomistic modelling failed, because the ad hoc potentials used were unable to predict reliably the energies for atomic displacements far from equilibrium. However, it was possible to derive the stress conditions necessary for cross-slip to spread. An important contribution to the driving force resulted from the so-called Escaig stress, acting upon the edge components of the partials forming a dissociated screw dislocation, and changing their separation. Contrary to the usual assumption, the driving force was independent of whether the dislocation in the cross-slip plane was expanded or compressed.

The Cross-Slip Energy Unresolved. G.Schoeck: Philosophical Magazine Letters, 2009, 89[8], 505-15