Gaye, A. (Université Paris-Est) | Bornert, M. (Université Paris-Est) | Lenoir, N. (Université Paris-Est) | Sab, K. (Université Paris-Est) | Dimanov, A. (École Polytechnique) | Bourcier, M. (École Polytechnique) | Héripré, E. (École Polytechnique) | Raphanel, J. (École Polytechnique) | Gharbi, H. (École Polytechnique) | Picard, D. (École Polytechnique) | Ludwig, W. (W. Ludwig)
The deformation of synthetic halite is investigated at the scale of its polycrystalline microstructure. Images recorded during compression test performed in the chamber of a scanning electron microscope on centimeter sized samples are analyzed by Digital Image Correlation techniques and reveal the combined contribution of crystal slip plasticity and grain boundary sliding (GBS) and opening. Specifically developed processing routines allow us to quantify the relative contributions of both mechanisms to the overall strain, and their dependences with temperature. These surface measurements are complemented by full 3D analyses based on synchrotron X-Ray absorption computed tomography on similar samples. The analysis of the CT volumes at various load levels by Digital Volume Correlation routines, confirms the complex localization of deformation at the scale of the microstructure. Transverse cracks at grain boundaries are also observed in the bulk of the material, as indirect signs of GBS.