It was noted that the generation of double-kinks in sessile screw dislocation cores was a highly non-linear process, but was the rate-controlling step for plasticity at low temperatures. Double-kink generation in threefold screw dislocations in body-centered cubic crystals was studied here within the framework of the Peierls-Nabarro model; according to which partial dislocations were described by non-singular displacement fields. The kink geometry was modelled by dividing the dislocation into elemental slabs; each of which was assumed to have its own displacement field as calculated using the Peierls-Nabarro model under plane-strain conditions. Explicit expressions were obtained for the apparent activation energy and volume as a function of the applied stress.

A New Model for Dislocation Kink-Pair Activation at Low Temperatures based on the Peierls-Nabarro Concept. A.H.W.Ngan: Philosophical Magazine A, 1999, 79[7], 1697-720