Abstract: The mechanism governing the conservative climb of dipoles and a new dislocation dynamic model for single slip are proposed. Using this model, the formation of the carpet that is a planar array structure in the I stage of crystal hardening is predicted, in agreement with the experimental results. The present model takes into account not only the drift and climb mechanism of dipoles but also the three-dimensional movement of plus and mines mobile dislocations through slipping and cross-slipping. Besides, the ...