Towards a theory of cooperative deformation processes: The case of flow in optimally superplastic and nanostructured materials

Low stress, high homologous temperature deformation is analysed initially at the level of phenomenology. It is shown that high temperature creep can be deduced as a special case of the analysis for optimal structural superplasticity. Subsequently, an atomistic analysis for grain/interphase boundary sliding is developed to a mesoscopic scale. It is suggested that this mechanism is the rate controlling process during optimally superplastic flow as well as the deformation of nanostructured materials. Possible areas for future research are touched upon.