Modelling strain hardening and steady state deformation of Al–Mg alloys

Abstract

A new approach to the modelling of work hardening during plastic deformation of pure fcc metals has recently been proposed by the present authors. The model is based on a statistical approach to the problem of athermal storage of dislocations. By combining the solution for the dislocation storage problem with models for dynamic recovery of network dislocations and sub-boundary structures, a general internal state variable description is obtained. In the present work this model is further developed by including the effects resulting from grain boundaries, elements in solid solution, and the presence of non-deformable precipitate particles. The result is a work hardening model and associated computer code, capable of providing the stress–strain behaviour for a given solid solution alloy under any combination of constant strain rate and temperature. The model has been applied to the problems of work hardening and flow stress saturation in Al–Mg alloys. It is demonstrated that the model predictions, in terms of microstructure evolution and associated strengthening, are in good agreement with experimental observations.