Preparation of silicon carbide/nitride particulate nanocomposites with oxides or nitrides

Highly homogeneous silicon carbide/nitride nanosized powders and their composites with oxides as sintering aids or titanium and aluminium nitrides were prepared by evaporation of raw materials in nitrogen plasma flow and by chemical deposition of oxides onto nanosized particles. The average particle size of the silicon carbide/nitride nanopowders with oxides and nitrides are determined by concentration of particles in the plasma, by cooling rate and the ratio of components. The typical average size of the nanocomposites is in the range of 30-60 nm, but the particle size distribution is bimodal. The microstructure of particles depends on the formation or condensation temperature of the components in the gas flow as well as on the preparation route. The surface characteristics of the nanoparticles prepared by the plasma technique are similar to pure silicon nitride. Combining both preparations route leads to the formation of nanoparticles with surface characteristics similar to alumina.