Rieko Nakano

Preparation of fine silicon nitride powders by vapor phase reaction of nitrogen containing organosilicon compound with ammonia

Fine amorphous silicon nitride powders were prepared by vapor phase reaction between nitrogen-containing, chloride-free organosilicon compound and NH3 at the production rate of-200g/h. Crystallization was carried out by heat treating the resulting amorphous powders in Ar atmosphere at 1500°C. High purity crystalline silicon nitride powders could be synthesized with metallic impurities Fe, Al, Ca 95wt%, respectively. Mechanical properties of hot-pressed silicon nitride from the resulting crystalline powders were comparable to hot-pressed bodies fabricated from high purity silicon nitride powders by imide decomposition and carbothermic reduction of silica.