Modeling of large strain hardening during grain refinement

Strain hardening was modeled at large strains taking into account the geometrically necessary dislocations (GNDs) with the help of a recent grain refinement model. The GND density was studied experimentally with orientation imagining for oxygen-free high-conductivity copper deformed in equal channel angular pressing and in simple shear to the same equivalent strain. The results show that the GND density can be predicted fairly well by the model in accord with experiments, and also affects stage IV hardening. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.