Cyclic character of the evolution of the defect structure and the properties of metallic materials during megaplastic deformation

Abstract

The principle of nonequilibrium evolution thermodynamics is applied to describe the cyclic evo lution of the defect structures in metallic materials subjected to megaplastic (severe) plastic deformation. A unimodal distribution of defects over deformation induced dislocations and the grain boundaries that appear during dynamic recrystallization is considered as an initial model. It is shown that taking into account mem ory (inertia) effects during deformation induced restructuring transforms basic relations to the form charac teristic of wave equations with damping. In this case, a deformed system executes damped oscillations and gradually reaches stationary structural parameters.

Advanced Statistical Crystal Plasticity Model: Description of Copper Grain Structure Refinement during Equal Channel Angular Pressing

“…Following the classification provided in [22,23], grain refinement models can be classified into three main types: continuum models based on the macrophenomenological approach [24][25][26][27]; physically-based continuum models [28][29][30][31][32][33][34][35]; and multilevel crystal plasticity models. Recent decades have been marked by the appearance of some modifications of statistical [36][37][38][39][40][41], self-consistent [42][43][44][45][46][47] and direct crystal plasticity CMs [48][49][50][51][52][53], designed to take grain refinement into consideration.…”