Identification of different deformation mechanisms and the nature of transitions between them

Abstract
Several formulations have been proposed linking strain accumulation with time, stress temperature and microstructural features of a given material. More detailed approaches have considered distinctive mechanisms of deformation and their predominating influence in specific regimes. The importance of identifying the boundaries of these regimes is demonstrated. Their distinguishing features are emphasised and shown to have important consequences. Transitions between different regimes however may not be sharp. The nature of the transition between deformation occurring by lattice dislocation movement and by the stress directed diffusion of vacancies is analysed and its practical implications are considered.