Description of creep with allowance for dislocation multiplication and transformations

Abstract

The previously developed approach to the description of plastic deformation is applied in this work to an analysis of creep. Plastic deformation is considered as the evolution of a dislocation ensemble including dislocation transformations and processes of generation and annihilation of dislocations. On the assumption of a spatially uniform distribution of dislocations, we obtained a set of first-order differential equations that describe the time dependence of the amount of plastic deformation and the densities of dislocations of various types. It is shown that the approach developed permits one to describe the entire evolution of the time dependence of deformation, including various stages of creep and transitions between them. We also analyze how the shape of creep curves is affected by changes in the parameters that characterize dislocation transformations and the operation of dislocation sources.