US4431431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbide coated silicon nitride cutting tools
Assignee: Verizon Laboratories Inc
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Filing: 1982-05-20
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Granted: 1984-02-14
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Expires: 2002-05-20
Abstract
Abstract Cutting tools and cutting tool inserts having improved mechanical and chemical wear resistance under demanding conditions of machining speed, temperature, or workpiece hardness comprise a silicon nitride substrate body having at least one hard, adherent coating layer of a refractory metal carbide. The silicon nitride substrate body consists essentially of a first phase of silicon nitride and a refractory second phase comprising silicon nitride and an effective amount of a densification aid selected from the group consisting of silicon dioxide, aluminum oxide, magnesium oxide, yttrium oxide, hafnium oxide, zirconium oxide, the lanthanide rare earth oxides, and mixtures thereof.
Inventors
- 👤 Vinod K. Sarin
- 👤 Sergej-Tomislav Buljan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:42
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; C04B41/85; C04B41/87; B; B23; B23B; B23B27/00; B23B27/14; B23B27/148; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B41/45; C04B41/50; C04B41/5025; C04B41/5053; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
84 words
A coated ceramic cutting tool comprising a densified silicon nitride substrate body having at least one adherent coating layer; said substrate body consisting essentially of a first phase of silicon nitride and a refractory second phase comprising silicon nitride and an effective amount of a densification aid selected from the group consisting of silicon dioxide, aluminum oxide, magnesium oxide, yttrium oxide, hafnium oxide, zirconium oxide, the lanthanide rare earth oxides, and mixtures thereof; said adherent coating layer consisting essentially of a refractory metal carbide.
Claim 2
Dependent Claim
84 words
A coated ceramic cutting tool comprising a densified silicon nitride substrate body having at least one adherent coating layer; said substrate body consisting essentially of a first phase of silicon nitride and a refractory second phase comprising silicon nitride and an effective amount of a densification aid selected from the group consisting of silicon dioxide, aluminum oxide, magnesium oxide, yttrium oxide, hafnium oxide, zirconium oxide, the lanthanide rare earth oxides, and mixtures thereof; said adherent coating layer consisting essentially of a refractory metal carbide.
Claim 3
Dependent Claim
41 words
A coated ceramic cutting tool in accordance with claim 1 wherein said adherent coating layer is selected from the group consisting of titanium carbide, vanadium carbide, chromium carbide, zirconium carbide, niobium carbide, molybdenum carbide, hafnium carbide, tantalum carbide, and tungsten carbide.
Claim 4
Dependent Claim
21 words
A coated ceramic cutting tool in accordance with claim 2 wherein said adherent coating layer is titanium carbide or hafnium carbide.
Claim 5
Dependent Claim
26 words
A coated ceramic cutting tool in accordance with claim 1 wherein said adherent coating layer is of a thickness between about 0.1 microns and 10 microns.
Claim 6
Dependent Claim
26 words
A coated ceramic cutting tool in accordance with claim 4 wherein said adherent coating layer is of a thickness between about 1.0 and about 10 microns.
Claim 7
Dependent Claim
32 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is present in an amount of between about 1 and about 25 weight percent of said substrate body.
Claim 8
Dependent Claim
32 words
A coated ceramic cutting tool in accordance with claim 6 wherein said densification aid is present in an amount of between about 1 and about 5 weight percent of said substrate body.
Claim 9
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 7 wherein said densification aid is silicon dioxide.
Claim 10
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is magnesium oxide.
Claim 11
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is aluminum oxide.
Claim 12
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is yttrium oxide.
Claim 13
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is hafnium oxide.
Claim 14
Dependent Claim
17 words
A coated ceramic cutting tool in accordance with claim 1 wherein said densification aid is zirconium oxide.
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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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |