Microstructure of diamond–SiC nanocomposites determined by X-ray line profile analysis

Diamond composites with nanosize diamond crystals and nanosize SiC matrix were obtained at 8 GPa and temperatures varied between 1800 and 2000 °C. Multiple Whole Profile fitting method applied to X-ray diffractograms of sintered composites provided information on crystallite size and population of dislocations. When the temperature was increased at a constant pressure, it led to a growth of crystallite sizes in both phases and reduced population of dislocations. Porosity was limiting hardness of the specimens indicating importance of sample preparation prior to sintering nanosize diamond powders.