Width and density of persistent slip bands as a consequence of deformationmesostructure

A system of persistent slip bands (PSBs) in a steady state cyclically defor med crystal is treated as a dynamic structure developed by a self-organizat ion process. The wave length of the dislocation structure formed in the ban ds represents the intrinsic length scale controlling the average width and density of PSBs. The model is described by the equation of motion for glide dislocations and the equations of elasto-plastic continuum. The basic assu mption is that the glide properties of dislocations in all active slip plan es of the PSB lamellae of localized shear are the same. The evaluated ratio of the wave length of the dislocation structure in PSBs to the average wid th of PSBs is compared with the measured values. The predicted proportional ity of the density of PSBs to the applied plastic strain amplitude is in ag reement with the observation.