US4855265A
Expired / Lapsed
US
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High temperature low thermal expansion ceramic
Assignee: Corning Inc
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Filing: 1988-04-04
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Granted: 1989-08-08
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Expires: 2008-04-04
Abstract
Abstract This invention relates to the high temperature stabilization of aluminum titanate and aluminum titanate-mullite compositions by the addition of iron oxide. It has been found that iron oxide concentrations greater than 5 weight percent and as high as approximately 25 weight percent have a stabilization effect at high temperatures on aluminum titanates. The resultant ceramic body is further enhanced by the addition of from 0.1 to 5 weight percent rare earth oxide.
Inventors
- 👤 John P. Day
- 👤 Robert J. Locker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:10
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/49; C04B35/16; C04B35/18; C04B35/46; C04B35/462; C04B35/478
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
77 words
A sintered ceramic article containing iron-aluminum titanate solid solution and mullite as the predominant crystal phases with a minor amount of a rare earth metal oxide crystal phases, said article exhibiting grain boundary and intracrystalline microcracking and consisting essentially, expressed in terms of weight percent on the oxide basis, of 1.5-20% SiO 2 , 225-25% Fe 2 O 3 , 35-75% Al 2 O 3 , 10-40% TiO 2 , and 0.1-5% RE 2 O 3 .
Claim 2
Dependent Claim
77 words
A sintered ceramic article containing iron-aluminum titanate solid solution and mullite as the predominant crystal phases with a minor amount of a rare earth metal oxide crystal phases, said article exhibiting grain boundary and intracrystalline microcracking and consisting essentially, expressed in terms of weight percent on the oxide basis, of 1.5-20% SiO 2 , 225-25% Fe 2 O 3 , 35-75% Al 2 O 3 , 10-40% TiO 2 , and 0.1-5% RE 2 O 3 .
Claim 3
Dependent Claim
42 words
A sintered ceramic article according to claim 1 wherein said crystal phases, expressed in terms of volume percent, consist essentially of about 25-90% iron-aluminum titanate solid solution and about 5-70% mullite with the rare earth metal oxide comprising up to the remainder.
Claim 4
Dependent Claim
35 words
A sintered ceramic body as in claim 2 wherein said solid solution consists essentially of, by weight percent, 30 to 75 percent alumina, 20 to 65 percent titania, and >5 to 25 percent iron oxide.
Claim 5
Dependent Claim
55 words
A sintered ceramic body as in claim 3 wherein said solid solution is stable to within less than 20 percent of a total stoichiometric decomposition, wherein said decomposition products are Al 2 O 3 , Fe 2 O 3 , and TiO 2 , within the temperature range between approximately 1000° C. to 1300° C.
Claim 6
Dependent Claim
38 words
A sintered ceramic body as in claim 1 wherein said rare earth oxide is selected from the group consisting essentially of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, ytterbium, yttrium, scandium, and/or a combination thereof.
Claim 7
Dependent Claim
27 words
A sintered ceramic body as in claim 1 wherein said body exhibits a coefficient of thermal expansion between -25×10 -7 /°C. and 25×10 -7 /°C. (25°-800° C.).
Claim 8
Dependent Claim
26 words
A sintered ceramic body as in claim 1 wherein said body exhibits a four point bend MOR in the range from 1000 psi to 9000 psi.
Claim 9
Dependent Claim
26 words
A sintered ceramic body as in claim 1 wherein said body exhibits a coefficient of thermal cycling growth of less than 200×10 -4 percent per cycle.
Claim 10
Dependent Claim
14 words
A sintered ceramic body as in claim 1 wherein said body is a honeycomb.
Claim 11
Dependent Claim
31 words
A sintered ceramic body consisting essentially of, by weight percent, 50 to 75 percent iron-aluminum titanate solid solution, 20 to 50 percent mullite, and 0.1 to 5 percent rate earth oxide.
Claim 12
Dependent Claim
31 words
A sintered ceramic body consisting essentially of, by weight percent, 50 to 75 percent iron-aluminum titanate solid solution, 20 to 50 percent mullite, and 0.1 to 5 percent rate earth oxide.
Claim 13
Dependent Claim
35 words
A sintered ceramic body as in claim 10 wherein the solid solution consists essentially of, by weight percent, 35 to 50 percent alumina, 40 to 42 percent titania, and 8 to 25 percent iron oxide.
Claim 14
Dependent Claim
35 words
A sintered ceramic body as in claim 10 wherein the solid solution consists essentialy of, by weight percent, 35 to 50 percent alumina, 40 to 42 percent titania, and 15 to 25 percent iron oxide.
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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |