High pressure sintering of diamond-SiC composite

摘要: Sintered polycrystalline compacts in the system diamond-10–50 wt% SiC having average grain size of less than 1 μm were prepared at pressure 6 GPa and temperature between 1400 1600 °C. Knoop indentation hardness increased with diamond content sintering temperature, specimens a greater 40 obtained. It was found that small amount Al addition into starting diamond-SiC powder effective to improve relative density compacts. The formation graphite also suppressed by Al. Microstructure observation SEM TEM suggested segregated boundary promoted bonding grains. Thin microtwins observed grains, whereas fine wavy structures slightly different orientations or without addition.