Stresses to bow edge dislocation segments out of di-/multipolar edge dislocation bundles

Abstract

In deformed crystalline materials, edge dislocation segments bowing out of di-/multipolar edge dislocation bundles and walls are frequently observed. In the present work, a simple estimate is given of the stress that must be applied in order to detach such bowing-out edge dislocation segments from the bundles. Instead of dealing with this problem in its whole complexity, a strongly simplified situation is considered in which the bowing-out segments interact with only one closely neighbouring edge dislocation of the same or of the opposite sign. In the calculations, only the elastic interaction between the two dislocations and the restoring force acting on the bowing-out dislocation segment due to the line tension are considered. The calculations were performed for different combinations of dislocation segment lengths and spacings of the glide planes on which the two dislocations considered lie. The results obtained for the detachment stresses are compared and discussed.