PROCESS FOR PRODUCING BORON NITRIDE HAVING AMORPHOUS STRUCTURE Russian patent published in 1994 - IPC

FIELD: manufacture of abrasive materials. SUBSTANCE: this process prescribes preparing paste from hexagonal or turbostratic boron nitride and catalyst, that is, water to be taken in amount of 8 to 20 % by mass of boron nitride, placing starting materials in platinum cylinder, fitting lid on and sealing latter, placing whole in high-pressure press, heating whole from room temperature to point of 1700 to 1950 C during 3 to 5 min, stepping up pressure from atmospheric one to about 70 to 80 kbar during 5 min, allowing boron nitride to completely melt down, discontinuing heating, and relieving pressure to atmospheric one during 3 to 7 min. Resultant product is compact stuff whose color ranges from white to brown-blank and particle size varies from 0.01 to 1.0 mm. It can leave scratches on diamond surface. Amorphous boron nitride yield makes up 94 to 98 % of theoretical one. EFFECT: more sophisticated technique. 2 cl