In situ X-ray synchrotron profile analysis during high pressure torsion of Ti

Abstract

X-Ray Line Profile Analysis is a powerful method to characterize the microstructure of deformed materials, especially when high energy and brilliant Synchrotron radiation enables investigations with high time and spatial resolution. Parameters like dislocation density, dislocation arrangement as well as scattering domain size and it’s distribution are parameters of a physical model of peak broadening, which can be applied to high quality diffraction measurements. A small high-pressure-torsion-machine was designed in order to perform in situ diffraction experiments during the deformation process at hydrostatic pressures up to 8, GPa in order to follow the strain as well as pressure induced microstructural characteristics of any material deformed. This was possible with the ideal design and equipment at the High-Energy-Materials-Science-beamline at PETRA III in Hamburg. Recent and First results of experiments on HPT-deformed Ti show that at 6 GPa the high pressure ω -phase is initiated only with additional shear deformation.