Claims
- 1. A method for making a polycrystalline cubic boron nitride cutting tool comprising the steps of:
- forming a mixture of cubic boron nitride crystals, a refractory material powder selected from the group consisting of titanium carbonitride and titanium aluminum carbonitride, a source of cobalt and a source of aluminum;
- treating at least a portion of the ingredients of the mixture with ammonia at a temperature in the range of from 1100.degree. to 1250.degree. C.; and
- subjecting the mixture to high temperature, high pressure conditions where cubic boron nitride is thermodynamically stable for a sufficient time for forming a polycrystalline body of cubic boron nitride containing a supporting phase formed from the titanium carbonitride or titanium aluminum carbonitride.
- 2. A method as recited in claim 1 wherein the source of cobalt and the source of aluminum comprise cobalt aluminide.
- 3. A method as recited in claim 1 wherein the cobalt aluminide comprises Co.sub.2 Al.sub.9.
- 4. A method as recited in claim 3 comprising the steps of:
- mixing the titanium carbonitride or titanium aluminum carbonitride powder and cobalt aluminide powder; and
- treating the titanium carbonitride or titanium aluminum carbonitride and cobalt aluminide mixture to a temperature of at least 1100.degree. C. in ammonia before mixing with cubic boron nitride crystals.
- 5. A method as recited in claim 1 wherein the entire mixture is treated with ammonia at a temperature of at least 1100.degree. C.
- 6. A method as recited in claim 1, wherein a portion of the polycrystalline cubic boron nitride is formed from hexagonal boron nitride contained in the mixture.
- 7. A method for making a polycrystalline cubic boron nitride cutting tool comprising the steps of:
- coating cubic boron nitride crystals with a layer of a material selected from the group consisting of titanium carbonitride and titanium aluminum carbonitride; and
- subjecting the coated cubic boron nitride crystals to high temperature, high pressure conditions where cubic boron nitride is thermodynamically stable for a sufficient time for forming a polycrystalline body of cubic boron nitride containing a supporting phase comprising the titanium carbonitride or titanium aluminum carbonitride.
- 8. A method as recited in claim 7 further comprising treating at least a portion of the ingredients of the mixture with ammonia at a temperature in the range of from 1100.degree. to 1250.degree. C.
- 9. A method as recited in claim 7 wherein the entire mixture is treated with ammonia at a temperature of at least 1100.degree. C.
- 10. A method for making a polycrystalline cubic boron nitride cutting tool comprising the steps of:
- coating particles with a layer of material selected from the group consisting of cobalt, aluminum, cobalt aluminide and combinations thereof, the particles being selected from the group consisting of cubic boron nitride crystals, titanium carbide powder, titanium carbonitride powder, titanium aluminum carbonitride powder and titanium nitride powder;
- mixing the coated particles for forming a mixture of cubic boron nitride crystals and powder selected from the group consisting of titanium carbide powder, titanium carbonitride powder, titanium aluminum carbonitride powder and titanium nitride powder; and
- subjecting the mixture to high temperature, high pressure conditions where cubic boron nitride is thermodynamically stable for a sufficient time for forming a polycrystalline body of cubic boron nitride containing a supporting phase comprising the refractory material and cobalt aluminide.
- 11. A method as recited in claim 10 further comprising treating at least a portion of the coated particles with ammonia at a temperature in the range of from 1100.degree. to 1250.degree. C.
- 12. A method for making a polycrystalline cubic boron nitride cutting tool comprising the steps of:
- forming a mixture of cubic boron nitride crystals, cobalt aluminide and a refractory material powder selected from the group consisting of titanium carbide, titanium nitride, titanium carbonitride and titanium aluminum carbonitride;
- treating the mixture with ammonia at a temperature in the range of from 1000.degree. to 1250.degree. C.; and
- subjecting the mixture to high temperature, high pressure conditions, where cubic boron nitride is thermodynamically stable for a sufficient time for forming a polycrystalline body of cubic boron nitride containing a supporting phase formed from the titanium carbide, titanium nitride, titanium carbonitride or titanium aluminum carbonitride, cobalt and aluminum.
- 13. A method as recited in claim 12 wherein the cobalt aluminide comprises Co.sub.2 Al.sub.9.
- 14. A method as recited in claim 12 wherein the entire mixture is treated with ammonia at a temperature of at least 1100.degree. C.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of patent application Ser. No. 08/440,773 filed May 15, 1995, now U.S. Pat. No. 5,639,285.
US Referenced Citations (17)
Divisions (1)
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Number |
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440773 |
May 1995 |
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