US4336305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic throw-away tips and process for producing the same
Assignee: Niterra Co Ltd
•
Filing: 1979-12-13
•
Granted: 1982-06-22
•
Expires: 1999-12-13
Abstract
Abstract A ceramic throw-away tip which comprises a hot-pressed sinter of Si 3 N 4 on the surface of which is a thin coating of at least one of Al 2 O 3 and AlON.
Inventors
- 👤 Hiroshi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:42
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B23; B23B; B23B27/00; B23B27/14; B23B27/148; C04B41/45; C04B41/50; C04B41/5025; C04B41/80; C04B41/81; C04B41/85; C04B41/87; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
34 words
A ceramic throw-away tip which comprises a hot-pressed sinter of Si 3 N 4 on the surface of which is a thin coating of at least one of Al 2 O 3 and AlON.
Claim 2
Dependent Claim
34 words
A ceramic throw-away tip which comprises a hot-pressed sinter of Si 3 N 4 on the surface of which is a thin coating of at least one of Al 2 O 3 and AlON.
Claim 3
Dependent Claim
16 words
The ceramic tip of claim 1, wherein said coating is about 3 to 20 μm thick.
Claim 4
Dependent Claim
27 words
The ceramic tip of claim 1, wherein said hot pressed sinter is hot pressed at about 1,650° to 1,800° C. and at least 200 kg/cm 2 pressure.
Claim 5
Dependent Claim
22 words
The ceramic tip of claim 1, wherein said coating is formed of particles having a particle size less than about 1 μm.
Claim 6
Dependent Claim
15 words
The ceramic tip of claim 1, wherein said coating is formed by chemical vapor deposition.
Claim 7
Dependent Claim
80 words
A process for producing ceramic throw-away tips which comprises forming a thin coating layer of at least one of Al 2 O 3 and AlON by chemical vapor deposition on a substratum of a throw-away tip which is produced by hot-pressing a mixture of a small amount of at least one sintering assistant selected from MgO, Y 2 O 3 , Ta 2 O 5 , ZrO 2 and Al 2 O 3 and an Si 3 N 4 powder.
Claim 8
Dependent Claim
80 words
A process for producing ceramic throw-away tips which comprises forming a thin coating layer of at least one of Al 2 O 3 and AlON by chemical vapor deposition on a substratum of a throw-away tip which is produced by hot-pressing a mixture of a small amount of at least one sintering assistant selected from MgO, Y 2 O 3 , Ta 2 O 5 , ZrO 2 and Al 2 O 3 and an Si 3 N 4 powder.
References Cited (Backward Citations)
US3914473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |