The effect of geometrically necessary dislocations on the flow stress of deformed crystals containing a heterogeneous dislocation distribution

摘要: Abstract In deformed crystals, long-range internal stresses develop during deformation as a consequence of the heterogeneity distribution dislocations which frequently form cell structure. The composite model describes these in natural manner terms elastic/plastic strain mismatch between hard walls and soft interiors. This is closely related to well-defined density so-called interface at hard–soft region interfaces. are geometrically necessary Ashby's terminology [M.F. Ashby, Phil. Mag. 21 (1970) 399]. According model, their main role provide stresses, for simultaneous compatible regions. do not, general, contribute flow stress. Hence, does not appear explicitly flow-stress equation. It shown that this strictly true single-slip deformation. case multiple slip, different situation prevails, since some one glide system can act like forest another slip system. analyzed more detail simple found interaction with interfacial makes only negligible contribution overall holds both bowing into out walls.