Microstructural characterisation of nuclear grade graphite

Field emission and transmission electron microscopy are used to characterise the microstructure and morphology of baked carbon block and graphitized grades (from the same carbon block stock) of nuclear graphite. Quantitative analysis using Raman and energy dispersive spectroscopy (EDS) were used to investigate the decrease of crystallinity with graphitization and sample purity. Both baked carbon and graphitized nuclear graphites show no sensitivity of the Raman band shift to strain, consistent with strain accommodation by the porous structure.