Chapter 79 White Beam Microdiffraction and Dislocations Gradients

Abstract

Publisher Summary This chapter describes how X-ray micro-diffraction is influenced by the number, kind, and organization of dislocations. Particular attention is placed on micro-Laue diffraction where polychromatic X-rays are diffracted into characteristic Laue patterns that are sensitive to the dislocation content and arrangement. Micro-Laue diffraction and related techniques are important for measurements where defect distributions need to be measured with good 2D and 3D spatial resolution. Diffraction is considered for various stages of plastic deformation. X-ray micro-diffraction provides a powerful tool for the study of plastic deformation in materials. Plastic deformation introduces geometrically necessary dislocations and dislocation walls that produce elongated diffraction streaks. The streaks can be used to estimate the dislocation density tensor. For single slip deformation, the predominant slip system can be identified because of its distinctly different streaking of the Laue patterns. For multiple slip deformation, the components of the dislocation density tensor may be determined. The influence of various dislocation structures on the orientation space and white beam diffraction is summarized in the chapter.