DEVELOPMENT AND APPLICATION OF THE DISLOCATION MODEL FOR ANALYSIS OF THE MICROSTRUCTURE EVOLUTION AND DEFORMATION BEHAVIOR OF METALS SUBJECTED TO SEVERE PLASTIC DEFORMATION

The upgraded Estrin-Toth model is presented to describe the deformation behavior of the materials subjected to severe plastic deformation. The model has been applied toward study of tension of the as-received Cu samples and the samples after the 1 st , 4 th , and 8 th equal channel angular pressing passes. The dislocation density evolution in the two phases, namely in the bound- aries of fragments/cell blocks and interiors, is studied. The evolution of the concentration of vacan- cies that formed during deformation, annihilation of dislocations during their non-conservative motion and generation of dislocations during multiple cross slip are considered. As a result, pecu- liarities of the microstructure evolution, causes of achieving high values of the vacancy concentra- tions and dislocation densities are revealed. Features of the deformation behavior of the consid- ered samples are explained.