Synthesis of dense silicon-based ceramics at low temperatures

THE conventional preparation of advanced ceramic parts based on silicon carbide or nitride involves pressureless sintering, hot pressing or hot isostatic pressing of appropriate ceramic starting powders1. Owing to the covalent nature of the Si–C and Si–N bonds and hence the low diffusion coefficients in SiC and Si3N4, high sintering temperatures and the addition of sintering aids are normally used to enhance densification. During densification,...