Full elastic strain tensor mapping of polycrystalline Cr coated Zr nuclear claddings with high resolution Diffraction Microstructure Imaging

In order to enhance the oxidation resistance of nuclear Zr based fuel cladding tubes, PVD Cr coatings are one of the most advanced concepts. These coatings exhibit complex interactions at the interface between Cr and the Zr substrate, mostly driven by the micro-mechanical state. In this context, being able to access non-destructively to the local strain field is of prime interest. Following previous micro-diffraction Laue and DAXM mappings on an as-deposited microstructure, we need to further refine the knowledge of the mechanical state with a multimodal approach. In this scope, scanning-3DXRD and DFXM imaging techniques would allow to derive full elastic strain tensor maps, respectively over large representative slices through the interface, and on finer 3D maps of individual Zr grains – in both cases with optimal resolution (10-1 µm spatially and 10-5 in strain). The resulting dataset will also provide an opportunity to compare the performances of each technique.