Patent US4753904A successfully refreshed from Google Patents.
US4753904A
Expired / Lapsed
US
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Zirconia-modified alumina fiber
Assignee: EIDP Inc
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Filing: 1986-08-20
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Granted: 1988-06-28
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Expires: 2006-08-20
Abstract
Abstract Alumina fiber modified by stabilized zirconia has improved strength and strength retention after high temperature exposure.
Inventors
- 👤 Michael S. Wolfe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:28
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/06; D; D01; D01F; D01F9/00; D01F9/08; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C04B35/62236; C04B35/6225
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
80 words
A ceramic fiber of from 10 to 25 microns in diameter containing at least 60% by weight of alpha alumina, between 15 and 25% by weight of zirconia in the tetragonal phase, and from 0.4 to 12 mole %, based on zirconia, of a zirconia stabilizer, the zirconia having a grain size of less than 0.5 microns, said fiber having a normalized light transmittance of 19% or less as measured in an inert fluid having a refractive index of 1.72.
Claim 2
Dependent Claim
80 words
A ceramic fiber of from 10 to 25 microns in diameter containing at least 60% by weight of alpha alumina, between 15 and 25% by weight of zirconia in the tetragonal phase, and from 0.4 to 12 mole %, based on zirconia, of a zirconia stabilizer, the zirconia having a grain size of less than 0.5 microns, said fiber having a normalized light transmittance of 19% or less as measured in an inert fluid having a refractive index of 1.72.
Claim 3
Dependent Claim
12 words
The fiber of claim 1 containing about 20% by weight of zirconia.
Claim 4
Dependent Claim
11 words
The fiber of claim 1 wherein the zirconia stabilizer is yttria.
Claim 5
Dependent Claim
14 words
The fiber of claim 1 having a normalized light transmittance of 16% or less.
References Cited (Backward Citations)
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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) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |