US4396724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic composition
Assignee: Carboloy Inc
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Filing: 1981-05-26
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Granted: 1983-08-02
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Expires: 2001-05-26
Abstract
Abstract Improved ceramic compositions useful for cutting tools and the like are described. They are composed of an essentially homogeneous admixture of sintered powders of an aluminum oxide base material with other refractories including zirconium oxide, titanium oxide, hafnium oxide, titanium nitride, zirconium nitride, and tungsten or molybdenum carbide. In addition to their common and improved properties of hardness and strength, many of these compositions may be made by simple cold-pressing and sintering procedures. This avoids the known drawbacks of conventional hot press production.
Inventors
- 👤 Stephen J. Burden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:16
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
47 words
In a ceramic composition comprising an essentially homogeneous admixture of sintered powders of an aluminum oxide base refractory material, the improvement wherein said composition additionally contains zirconium oxide and tungsten carbide in an amount sufficient to enhance wear resistance while permitting said powder to undergo pressureless sintering.
Claim 2
Dependent Claim
47 words
In a ceramic composition comprising an essentially homogeneous admixture of sintered powders of an aluminum oxide base refractory material, the improvement wherein said composition additionally contains zirconium oxide and tungsten carbide in an amount sufficient to enhance wear resistance while permitting said powder to undergo pressureless sintering.
Claim 3
Dependent Claim
12 words
The composition of claim 1 wherein the composition also includes titanium nitride.
Claim 4
Dependent Claim
33 words
The composition of claim 2, wherein the zirconium oxide is present in an amount from 1 to 30% and titanium nitride is present in an amount from 1 to 30% by total weight.
Claim 5
Dependent Claim
19 words
The composition of claim 3, further including titanium oxide in an amount from 1 to 15% by total weight.
Claim 6
Dependent Claim
19 words
The composition of claim 1, wherein the tungsten carbide is present in amounts up to 5% by total weight.
Claim 7
Dependent Claim
13 words
The composition of claim 1, wherein the powders are cold-pressed and then sintered.
Claim 8
Dependent Claim
12 words
The composition of claim 1 wherein the composition also includes zirconium nitride.
Claim 9
Dependent Claim
19 words
The composition of claim 2, wherein the titanium nitride is present in from 15 to 30% by total weight.
Claim 10
Dependent Claim
58 words
In a ceramic composition comprising an essentially homogeneous admixture of sintered powders of an aluminum oxide base refractory material, the improvement wherein said composition additionally contains zirconium oxide, tungsten carbide, and titanium nitride, the aluminum oxide comprising from 67-87%, the zirconium oxide comprising 10-15%, the titanium nitride comprising 1-15% and the tungsten carbide comprising 2-3% by total weight.
Claim 11
Dependent Claim
58 words
In a ceramic composition comprising an essentially homogeneous admixture of sintered powders of an aluminum oxide base refractory material, the improvement wherein said composition additionally contains zirconium oxide, tungsten carbide, and titanium nitride, the aluminum oxide comprising from 67-87%, the zirconium oxide comprising 10-15%, the titanium nitride comprising 1-15% and the tungsten carbide comprising 2-3% by total weight.
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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) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |