US4844848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing Al2 O3 powder and products
Assignee: University of Florida
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Filing: 1985-02-25
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Granted: 1989-07-04
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Expires: 2005-02-25
Abstract
Abstract A composite made by milling Al 2 O 3 gel to a powder in the size range of from about 20 mesh to about 400 mesh, mixing said Al 2 O 3 gel powder with a reinforcement material consisting of SiC, SiO 2 , C, Al 2 O 3 , ZrO 2 , Si 2 N 4 , BN, B 4 O, Y 2 O 3 , TiC, TiB 2 , TiN and aluminosilicate, compressing and firing at an elevated temperature.
Inventors
- 👤 David E. Clark
- 👤 Kenneth W. Wistrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:20
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/71; C04B35/78; C04B35/80
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
52 words
A method of making a composite comprising milling Al 2 O 3 gel to a powder in the size range of from about 2% mesh to about 400 mesh, mixing said Al 2 O 3 gel powder with a reinforcement material, compressing and firing at an elevated temperature to form a composite.
Claim 2
Independent Claim
52 words
A method of making a composite comprising milling Al 2 O 3 gel to a powder in the size range of from about 2% mesh to about 400 mesh, mixing said Al 2 O 3 gel powder with a reinforcement material, compressing and firing at an elevated temperature to form a composite.
Claim 3
Dependent Claim
20 words
A method of claim 1 wherein the reinforcement material is selected from the group consisting of whiskers, fibers and powders.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the reinforcement is a refractory material.
Claim 5
Dependent Claim
50 words
The method of claim 3 wherein the refractory material is selected from the group consisting of SiC, SiO 2 , C, Al 2 O 3 , ZrO 2 , Si 3 N 4 , BN, B 4 C, Y 2 O 3 , TiC, TiB 2 , TiN and aluminosilicate.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein the elevated temperature is above 900° C.
Claim 7
Dependent Claim
28 words
An intermediate suitable for firing to produce a composite comprising a Al 2 O 3 gel powder with a reinforcement material distributed therein compressed in a preselected shape.
Claim 8
Dependent Claim
28 words
An intermediate suitable for firing to produce a composite comprising a Al 2 O 3 gel powder with a reinforcement material distributed therein compressed in a preselected shape.
Claim 9
Dependent Claim
21 words
An intermediate according to claim 6 wherein the reinforcement material is selected from the group consisting of whiskers, fibers and powders.
Claim 10
Dependent Claim
12 words
An intermediate according to claim 6 wherein the reinforcement material is refractory.
Claim 11
Dependent Claim
46 words
An intermediate according to claim 8 wherein the refractory material is selected from the group consisting of SiC, SiO 2 , C, Al 2 O 3 , ZrO 2 , Si 3 N 4 , BN, B 4 C, Y 2 O 3 , and aluminosilicate.
Claim 12
Independent Claim
48 words
A method of making a shaped refractory product comprising miling a refractory metal oxide gel to a powder of a size less than about 20 mesh, compressing said powder into the shape of a refractory product and firing at an elevated temperature to densify and coalesce said powder.
Claim 13
Independent Claim
48 words
A method of making a shaped refractory product comprising miling a refractory metal oxide gel to a powder of a size less than about 20 mesh, compressing said powder into the shape of a refractory product and firing at an elevated temperature to densify and coalesce said powder.
Claim 14
Dependent Claim
15 words
The method of claim 10 wherein the metal oxide is Al 2 O 3 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |