METHOD FOR PRODUCTION OF HEAT-RESISTANT, SUPERHARD COMPOSITE MATERIAL ON THE BASIS OF MODIFIED DIAMOND AND CUBIC BORON NITRIDE POWDERS

摘要

The invention is related to the field of production of superhard composite diamond materials and is intended for manufacture of dressing, shape-forming and edge cutting tools. The method comprises annealing of powders of diamond and cubic boron nitride in a protective atmosphere, in vapour of silicon-containing compounds followed by sintering of the blend produced under conditions of high pressures and temperatures; in accordance with the invention, diamond powder is annealed at a temperature of 850-1000°C during 1-4 hours; after annealing, silicon quantity on diamond powder grains is within 8-30% by mass of initial mass of diamond powder; cubic boron nitride powder is annealed at a temperature of 850-1000°C during 1-2 hours, after annealing, silicon quantity on cubic boron nitride powder grains is within 8-15% by mass of initial mass of cubic boron nitride powder; grain size in diamond and cubic boron nitride powders is within 1-40 μm, the ratio of diamond powder mass to cubic boron nitride powder mass in the blend is within 1:1 to 5:1, and blend sintering at high pressures and temperatures is performed at a pressure range of 5.0-6.0 GPa at a temperature of 1650-2000°C during 30-60 s. To improve sintering behaviour of the material, amorphous boron powder in an amount of 0.5-1.5% by mass and/or aluminium powder in an amount of 1-5% by mass is added to the blend of diamond and cubic boron nitride powders. The use of the present invention makes it possible to decrease the cost of the superhard material production process and to improve physico-mechanical and cutting properties of tools based thereon.