Role of Dislocation Annihilation during Steady‐State Deformation

The relations between generation, glide, and annihilation of dislocations during plastic deformation are represented in terms of control theory. It is inferred that the rate of steady‐state deformation is proportional to the rate of dislocation annihilation and that annihilation is even rate‐controlling at least in certain ranges of temperature and strain rate. A model of annihilation‐controlled steady‐state deformation is proposed, which assumes that cell boundaries form barriers for dislocation glide and allows for local variation of the mean effective stress for glide according to the cellular dislocation structure. The model explains steady‐state deformation behaviour at low stresses. Modifications of the model necessary in the high stress range are discussed.