PREPARATION OF SILICON NITRIDE-TITANIUM NITRIDE AND TITANIUM-TITANIUM NITRIDE COMPOSITES FROM (CH3)(3)SINHTICL3-COATED SI3N4 AND TI PARTICLES

[(Trimethylsilyl)amino]titanium trichloride, (CH3)(3)-SiNHTiCI3, was isolated as a red-orange crystalline solid in 58% yield from the reaction of TiCl4 with [(CH3)(3)Si]2NH in 1:1 molar ratio in dichloromethane at -78 degrees C. Pyrolysis of (CH3)(3)SiNHTiCI3 at 600 degrees C furnished titanium nitride. This precursor is suitable for the preparation of composites and was employed to prepare Si3N4-TiN and Ti-TiN powders by adding Si3N4 particles or titanium powders to a solution of (CH3)(3)SiNHTiCI3 in dichloromethane, drying and pyrolyzing the resulting solid. This precursor also has been used as a binder to prepare Si3N4-TiN and Ti-TiN bodies. High-resolution transmission electron microscopic studies of the Si3N4-TiN composite showed that titanium nitride is concentrated on the surface of the Si3N4 particles.