CUTTING TOOL BASED ON POLYCRYSTALLINE CUBIC BORON NITRIDE AND METHOD OF MANUFACTURING THEREOF (VERSIONS) Russian patent published in 2000 - IPC

FIELD: superhard materials. SUBSTANCE: cutting tool contains 50 to 85% of cubic boron nitride crystals joined together into polycrystalline block. Carrying phase mixed with polycrystalline cubic boron nitride contains 15 to 40% of refractory material, which is preferably titanium carbonitride or titanium-aluminum carbonitride. Initial composition also contains 4 to 10% of Co₂Al₉. Powders of mixtures of these ingredients are treated with ammonia at 1100 to 1250 C to considerably increase nitrogen level and reduce carbon level in carbonitride. Instead of these powders, coated particles such as those of cubic boron nitride coated by titanium carbonitride or by titanium carbonitride coated in turn by cobalt, aluminum, or cobalt aluminide. Cubic boron nitride can be partially substituted by hexagonal boron nitride. EFFECT: increased quality and reliability of tool. 16 cl, 2 dwg