Theoretical and experimental studies of dislocation phenomena in the initial stages of plastic deformation (yield drop, incubation period) were reviewed. The role of dislocations in the loss of plastic stability and the localization of deformation during high-temperature tests at constant stress and constant strain-rate was analyzed. It was established that the appearance of the localized mode corresponded to the onset of the yield drop in stress-strain curves, and of the incubation period in creep curves. The use of the macroscopic parameters of high-temperature stress-strain curves, and analysis of a basic dislocation glide equation, showed that nucleation and the development of shear at high temperatures were governed by the dynamic properties of dislocations. Deformation localization was cause by conservation, in all subsequent stages of deformation, of the inhomogeneities in glide distribution which were formed in the initial stages.

Role of Dislocations in the High-Temperature Super-Localization of Plastic Deformation. G.V.Berezhkova, V.Sustek: Kristallografiya, 1997, 42[2], 368-82 (Crystallography Reports, 1997, 42[2], 327-40)