X-ray microbeam diffraction studies of large strain dislocation substructure formation in OFHC copper

This paper presents results of x-ray microbeam diffraction assessment of the development of dislocation substructure in OFHC copper. Polychromatic synchrotron x-radiation was used to study samples with four strain histories: virgin specimens, 50% effective strain in compression, 100% effective strain in torsion, and 50% compressive prestrain followed by 50% torsion using a very narrow beam (approximately 20μm diameter). The microstructures of the specimens were mapped with transmission Laue patterns from an array of positions spaced 10μm apart. The resulting Laue patterns were assessed in terms of both the degree of substructure formation and the nature of the distributed microstructure.