BEHAVIOR OF DISSOCIATED DISLOCATIONS WITH SESSILE CORES

The behaviour of dislocations dissociated into two partials, dislocati ons which are not freely mobile on the plane of dissociation has been studied in the frame of a model where the frictional force is describe d by a simple Peierls-Nabarro potential. In addition to the dislocatio ns exhibiting the equilibrium separation of the partial dislocations, the metastable partial separations are also considered. To study the d ynamics of dislocation processes, including the effect of the applied stress, a stochastic model based on the Monte Carlo method has been de veloped. Changes in the dislocation width distribution, caused by ther mally activated jumps between dislocation states with differing width of dissociation, have been investigated for several starting configura tions of the simulated dislocation ensemble.