Formation of deformation substructures observed in ductile materials

Abstract

AbstractDeformation substructures control plastic, creep, fatigue and fracture properties of ductile crystalline solids. The key ingredient of a substructure is a spontaneously formed dislocation arrangement – dislocation structure. The present notes provide 5 different, complementary points of view which present the dislocation structure formation as a multi scale phenomenon: (i) The basic concepts of dislocation theory and plasticity of single crystals and polycrystals (Section 2). (ii) A ”gallery” of commented pictures of dislocation structures as seen by a transmission electron microscope (Section 3). (iii) Discrete dislocation dynamics (Section 4). (iv) An attempt to formulate statistics of dislocations as a transition from discrete dislocation dynamics to continuum crystal plasticity capable of modeling dislocation structure formation (Section 5). (v) Two continuous models of dislocation structure formation: one dimensional model simulating a formation of vein structure and its transformation into a ladder structure of a persistent slip band (Section 6.1), and a model of misoriented dislocation cells (Section 6.2).KeywordsSlip SystemSlip PlaneDislocation StructureCrystal PlasticityResolve Shear StressThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.