METHOD OF PRODUCTION OF SUPERHARD COMPOSITE MATERIAL ON BASE OF CUBIC BORON NITRIDE FOR CUTTING AND COMPOSITE MATERIAL Russian patent published in 2000 - IPC

FIELD: cutting tools working in continuous or intermittent cutting mode in cutting hardened steels, hard alloys and cast iron. SUBSTANCE: powder of cubic boron nitride and/or powder of boron nitride with borid or nitride coated titanium is first wetted in ethyl alcohol, then it is granulated and premolded at pressure of 1•10⁴-2•10⁴ kgf/sq.cm; briquette thus obtained is placed in heater and washer is laid on its end face; washer is molded from mixture of natural graphite and hexagonal boron nitride; aluminum gasket is laid on inner surface of washer; container is subjected to evacuation for 1 to 2 h, after which aluminium gasket and washer are laid on other end face of container which is placed in high-pressure matrix and is compressed to pressure corresponding to thermodynamic stability of cubic boron nitride; briquette is heated by passing an electric current at constant power for 12 to 120 s till current intensity drops by 2 to 10 % of rated magnitude, after which heating is disconnected and briquette is held under pressure for 10 to 180 s; then pressure is reduced to atmospheric level and composite material blank is withdrawn. Composite material contains powder of cubic boron nitride and/or fraction of 5/1 mcm of powder of cubic boron nitride with boride or nitride coated titanium at content of titanium of up to 25%. EFFECT: enhanced stability of properties of material at minimized rejects. 11 cl, 6 ex