Silicon nitride-silicon carbide nanocomposites prepared by water processing of commercially available powders

摘要

Dispersion of nano-sized silicon carbide powders in silicon nitride was examined. Zeta potential was measured over a range of pH values and the aqueous dispersion of nano-sized silicon carbide powders in silicon nitride matrix was optimised. Ultrafine silicon carbide, 30-200 nm, which had agglomerated in organic media leading to a degradation in strength, was well disperse and acted to reinforce silicon niride matrix material. Densification of these mano- composites was also examined. They were densified to 98-99/100 theoretical density by hot pressing, gas pressure sintering and pressureless sintering.