A theory for the dynamics of edge dislocation dipoles was presented which took account of dipole formation via the mutual trapping of mobile edge dislocations of opposite sign, of glide-induced dipole changes which led to the formation of narrower (stronger) dipoles, of glide-induced dipole decomposition and of glide-induced dipole annihilation. The approximate analytical results were in good agreement with earlier numerical results. The steady-state distribution of dipole widths was calculated by using a kinetic equation. The average dipole strength, and the cyclic anelastic strain which was accommodated by the reversible breathing of dipoles, were compared with experimental data. It was suggested that the results provided a starting point for the theory of dislocation patterning during fatigue. In order to explain the formation of highly ordered persistent slip bands which supported a large degree of irreversible plastic strain (dynamic equilibrium between dislocation generation and annihilation), 2 modifications of the theory were required. Thus, a stochastic approach was adopted in order to account for the stress and strain rate fluctuations that were caused by long-range dislocation interactions, and the mutual stabilization of dipoles in the dislocation-rich walls was considered in terms of an exhaustion factor for dipole decomposition.

The Dynamics of Dislocation Dipoles during Single Glide. P.Hähner: Scripta Materialia, 1996, 34[3], 435-41