Three-dimensional X-ray diffraction (3DXRD) is a novel technique aimed at quick and non-destructive characterization of the individual elements within millimetre- to centimetre-sized specimens. It is based on two principles: the use of highly penetrating hard X-rays from a synchrotron source (X-ray energies above 30 keV) and the application of ‘tomographic” reconstruction algorithms for the analysis of the diffraction data. This chapter outlines the 3DXRD methodology with the focus on characterizing grains and orientations. The chapter is organized as follows. The 3DXRD setup is presented and 3DXRD strategies discussed. Then, the standard modes of operation are presented in more detail with emphasis on reconstruction principles and providing selected examples of use. Next, a novel method called diffraction contrast tomography is proposed — this is related to 3DXRD in the same way as bright-field and dark-field images are in transmission electron microscopy. Finally, the mathematics underlying the 3DXRD diffraction geometry and the representation of the crystallographic orientation are summarized.
Keywords: 3DXRD, X-rays, tomographic reconstruction, reconstruction algorithms, bright-field images, dark-field images, crystallographic orientation