EBSD for microstructure and property characterization of the SiC-coating in TRISO fuel particles

Tristructural-isotropic (TRISO)-coated particle fuel is being developed for use in the Next Generation Nuclear Plant. The reliable and precise characterization of the microstructure and properties of the SiC layer in the TRISO particle is essential for optimizing processing parameters to ensure reproducibility and performance of the coatings. Electron backscatter diffraction (EBSD) is a time-efficient analytical tool for obtaining a wealth of information on the SiC layer. In this study, we report the application of EBSD to the analysis of the SiC layer in a TRISO particle. The SiC layer identified as 3C–SiC with an average elastic stiffness of ∼402 GPa was mainly composed of random boundaries with a small fraction of low-Σ CSLBs. A few large grains, which were generally associated with local strains and tended to be columnar with the long axis oriented approximately along the TRISO particle radial direction, were observed in the SiC layer with an increased population from the IPyC–SiC to the SiC–OPyC interfaces.