Abstract: A ceramic composite containing less than 90% of a single phase silicon aluminum oxynitride and titanium nitride in an amount of up to about 10% by weight. Also disclosed are silicon nitride containing compositions for forming the composite and methods of producing the composite from the composition.

Abstract: Disclosed is a 35 to 45 volume percent silicon carbide whisker reinforced ceramic composite containing alumina and from about 5 to 21 volume percent zirconia which is used to make hard cutting tools having excellent toughness and hardness. Also disclosed are methods of producing the same.

Abstract: Boron nitride-boron nitride composite bodies may be produced by combining pure boron nitride fibers with partially nitrided fibers consisting essentially of B, N, O, and H, and hot pressing the composite at elevated temperatures and pressure. The partially nitrided material serves as a source of matrix material for the boron nitride fibers, and when fiber orientation is properly controlled, bodies of extremely high strength may be obtained. Densities in excess of 1.5 g./cc. may be obtained, in a one-step process which overcomes difficulties inherent in multiple-step nitriding and re-nitriding processes.