US4411672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing composite of diamond and cemented tungsten carbide
Assignee: Individual
•
Filing: 1981-07-21
•
Granted: 1983-10-25
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Expires: 2001-07-21
Abstract
Abstract A composite of diamond and cemented tungsten carbide is produced by placing pulverized diamond in adjacency with a tungsten carbide/cobalt composition. The two materials are separated by a metallic material positioned therebetween which material has a melting point, when so utilized, lower than the eutectic point of the tungsten carbide/cobalt composition. The assembly is heated at a temperature high enough to permit melting of the metallic material and in a pressure-temperature region of the carbon phase diagram where diamond is thermodynamically stable but which temperature is insufficient to cause substantial melting of the tungsten carbide/cobalt composition. In this way, a controlled amount of metal is introduced into the pulverized diamond to promote bonding thereof.
Inventors
- 👤 Hiroshi Ishizuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:20
CPC Classifications
C; C22; C22C; C22C26/00; B; B22; B22F; B22F7/00; B22F7/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
149 words
A method for producing a composite of diamond and cemented tungsten carbide, which method comprises: placing a layer consisting of pulverized diamond adjacent to a sintered tungsten carbide-cobalt support, said pulverized diamond and support being separated from each other by a second metallic material, said second metallic material having a melting point, when so utilized, below the eutectic point of said sintered tungsten carbide-cobalt support; heating said assembly to a temperature sufficiently high to cause the second metal to melt but not high enough to effect co-melting of the tungsten carbide and cobalt, said heating being effected in a pressure-temperature region of the carbon phase diagram where diamond is thermodynamically stable, and maintaining said temperature in said temperature-pressure region to join the diamond particles to each other and to join the diamond particles to said sintered tungsten carbide-cobalt support; and recovering a composite of diamond and cemented tungsten carbide.
Claim 2
Independent Claim
149 words
A method for producing a composite of diamond and cemented tungsten carbide, which method comprises: placing a layer consisting of pulverized diamond adjacent to a sintered tungsten carbide-cobalt support, said pulverized diamond and support being separated from each other by a second metallic material, said second metallic material having a melting point, when so utilized, below the eutectic point of said sintered tungsten carbide-cobalt support; heating said assembly to a temperature sufficiently high to cause the second metal to melt but not high enough to effect co-melting of the tungsten carbide and cobalt, said heating being effected in a pressure-temperature region of the carbon phase diagram where diamond is thermodynamically stable, and maintaining said temperature in said temperature-pressure region to join the diamond particles to each other and to join the diamond particles to said sintered tungsten carbide-cobalt support; and recovering a composite of diamond and cemented tungsten carbide.
Claim 3
Dependent Claim
17 words
A method as recited in claim 1, in which said second metallic material comprises a cobalt-based alloy.
Claim 4
Dependent Claim
17 words
A method as recited in claim 1, in which said second metallic material comprises a nickel-based alloy.
Claim 5
Dependent Claim
20 words
A method as recited in claim 1, in which said second metallic material consists essentially of cobalt, nickel and iron.
Claim 6
Dependent Claim
19 words
A method as recited in claim 3, in which said second metallic material consists essentially of nickel and iron.
Claim 7
Dependent Claim
19 words
A method as recited in claim 3, in which said second metallic material consists essentially of cobalt and iron.
Claim 8
Dependent Claim
26 words
A method as recited in claim 1, in which said heating is effected in the presence of a metallic additive capable of forming a stable carbide.
Claim 9
Dependent Claim
23 words
A method as recited in claim 7, in which said metallic additive is selected from the group consisting of chromium, titanium and tantalum.
Claim 10
Dependent Claim
28 words
A method as recited in claim 1, in which said composition of tungsten carbide and cobalt is hard sintered prior to placement in adjacency with the pulverized diamond.
Claim 11
Dependent Claim
28 words
A method as recited in claim 1, in which said composition of tungsten carbide and cobalt is soft sintered prior to placement in adjacency with the pulverized diamond.
References Cited (Backward Citations)
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Cited
US4063909A
Cited
US4215999A
Cited
US4219339A
Cited
US4225322A
Cited
US4268276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |