A model for dynamic strain aging was proposed. It was written as a local constitutive formulation but could easily be extended to account for spatial interactions. The model was obtained by embedding accepted ‘slow’ time scale formulations for dislocation dynamics and aging kinetics in a multiple time scales dynamic system. dislocation and solute dynamics were coupled at the ‘fast’ time scale pertaining to dynamic aging. Features of jerky flow described by standard models such as the negative strain rate sensitivity of the flow stress and critical strains for the occurrence of the Portevin-Le Chatelier effect were retrieved. In addition, negative strain rate sensitivity of the threshold stress for instability was predicted.

Dynamic Strain Aging - a Coupled Dislocation-Solute Dynamic Model. C.Fressengeas, A.J.Beaudoin, M.Lebyodkin, L.P.Kubin, Y.Estrin: Materials Science and Engineering A, 2005, 400-401, 226-30