In-Situ Study of Dynamic Structural Rearrangements During Stress Relaxation

Abstract

Abstract We have conducted in-situ, real-time x-ray diffraction experiments to probe the dynamic structural changes occurring in copper during loading and then on relaxation. The 331 KαI, KαII peaks were used to monitor the development of elastic strains during loading, and their response during relaxation. The peak width was studied to better understand the structural changes that occur during loading, and more importantly on relaxation, since it is these structural rearrangements that reduce the overall strain in the system and allow the stress to relax. The results revealed that the structure is highly mobile immediately following the start of stress relaxation. The mobility decreases with time, scales with the magnitude of the applied strain and is highly dependent upon the applied strain rate. In addition, it was apparent that the KαI and KαII peaks do not respond in the same way to the elastic strains and that they also show different structural rearrangements. This suggests an in homogeneous distribution of displacements within the sample.