In-Situ Synchrotron Profile Analysis after High-Pressure Torsion Deformation

The presence of hydrostatic pressure is a general, crucial characteristic of Severe Plastic Deformation methods for reaching the high strains and the introduction of the high amount of lattice defects, which are necessary to establish new grain boundaries. Insights into the processes during deformation and the influence of the hydrostatic pressure are necessary to help in better understanding the SPD-methods. A special experimental procedure was designed to simulate the hydrostatic pressure release:(HPT)-deformed Microstructure changes related to the release of hydrostatic pressure after high-pressure torsion deformation of Copper and Nickel were studied by freezing in the sample state before releasing the pressure. High resolution in-situ X-ray diffraction of the heating process was performed using synchrotron radiation in order to apply X-ray line profile analysis to analyze the pressure release. The result on Copper and Nickel show generally the influence of hydrostatic pressure on the mobility and interaction of deformations induced defects and the resulting mcirostructure