Deformation of copper single crystals: Comparison of experimental results with crystal plasticity simulations

Abstract

A combined experimental and numerical study on deformation behaviour of single crystal copper is presented in this paper. High purity copper single crystals were fabricated and subjected to uniaxial compression loading at quasi-static strain rate. The stress-strain responses along four different crystallographic orientations were then extracted after determining the initial orientation by Laue Back-Refection technique. In order to study and compare the responses, a phenomenological crystal plasticity model was described and implemented in a crystal plasticity finite element based code. The key description of the model follows a generalized yield criterion that incorporates non-Schmid effects assuming cross-slip plays an important role on orientation dependence of the material. Using the model, the stress-strain responses of four different crystallographic orientations were investigated. Investigations were also carried out on the shape change of the deformed crystals along with lattice orientation mapping. Finally, details of slip activities of the deformed crystals were determined by comparing the orientation of slip lines with the theoretical traces of possible crystallographic planes. The identity of the experimentally determined active slip modes was matched with those determined by the simulations.