Patent US5424044A successfully refreshed from Google Patents.
US4548786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated carbide cutting tool insert
Assignee: Carboloy Inc
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Filing: 1983-04-28
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Granted: 1985-10-22
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Expires: 2003-04-28
Abstract
Abstract Cobalt cemented carbide cutting inserts are prepared for coating with a hard, wear-resistant coating by providing a cobalt enriched zone on a surface to be coated. Cobalt enrichment is effectuated by means of nitrogen gas contact with the carbide followed by a period of vacuum sintering during its sintering process of manufacture.
Inventors
- 👤 Warren C. Yohe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:12
CPC Classifications
C; C23; C23C; C23C10/00; C23C30/00; C23C30/005; B; B22; B22F; B22F2998/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
106 words
A process for providing a cobalt cemented carbide article with a cobalt-enriched zone comprising, in sequence; (a) heating a compressed composite mixture consisting essentially of tungsten carbide, cobalt and B-1 solid solution phase forming, carbide constituents in a furnace to provide a composite heated below the sintering temperature; (b) contacting said composite heated at a temperature in the range of 1200° C. to 1500° C. with nitrogen gas to nitride the B-1 phase; and (c) subjecting the composite having the nitrided B-1 phase to vacuum while the composite is heated at an elevated temperature below or about the sintering temperature to produce a cobalt-enriched surface zone.
Claim 2
Dependent Claim
106 words
A process for providing a cobalt cemented carbide article with a cobalt-enriched zone comprising, in sequence; (a) heating a compressed composite mixture consisting essentially of tungsten carbide, cobalt and B-1 solid solution phase forming, carbide constituents in a furnace to provide a composite heated below the sintering temperature; (b) contacting said composite heated at a temperature in the range of 1200° C. to 1500° C. with nitrogen gas to nitride the B-1 phase; and (c) subjecting the composite having the nitrided B-1 phase to vacuum while the composite is heated at an elevated temperature below or about the sintering temperature to produce a cobalt-enriched surface zone.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said nitrogen gas is below atmospheric pressure.
Claim 4
Dependent Claim
40 words
The process as recited in claim 2 wherein said nitrogen is introduced over an extended period of time, and thereafter the temperature of the composite is raised or lowered to its sintering temperature above about 1400° C. in a vacuum.
Claim 5
Dependent Claim
18 words
The composite made by the process of claim 3 which thereafter is coated with a hard, wear-resistant material.
Claim 6
Dependent Claim
15 words
The composite of claim 4 wherein the hard, wear-resistant material is a layer of TiN.
Claim 7
Dependent Claim
34 words
The composite as recited in claim 5 wherein a layer of TiC is deposited on the layer of TiN and a layer of Al 2 O 3 is deposited on the layer of TiC.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |