Patent US5030592A successfully refreshed from Google Patents.
US5030592A
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US
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Highly dense cordierite and method of manufacturing same
Assignee: United States Department of the Air Force
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Filing: 1989-10-26
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Granted: 1991-07-09
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Expires: 2009-10-26
Abstract
Abstract Compositionally triphasic nanocomposite gel is made by mixing two or more sols of ceramic precursor oxides. Such gel is then dried and ground to a fine powder which is pressed into compact bodies. The compact bodies are thereafter fired in a sintering oven at from 1100 DEG C. to 1400 DEG C. and, aided by the heat of reaction of the two or more nono gel powders, the (heterogeneous) mixture of such powders crystallizes into a homogeneous crystalline ceramic of alpha -cordierite at up to 100% of theoretical density. Thus, novel method of manufacture and novel ceramic end-product are provided.
Inventors
- 👤 Sridhar Komarneni
- 👤 Ann M. Kazakos
- 👤 Rustum Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:45
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/90
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
33 words
A method for manufacture of cordierite precursor gel suitable for manufacture of dense cordierite bodies comprising, mixing at least two sols of nano ceramic precursor oxides to make a compositionally triphasic nanocomposite gel.
Claim 2
Independent Claim
33 words
A method for manufacture of cordierite precursor gel suitable for manufacture of dense cordierite bodies comprising, mixing at least two sols of nano ceramic precursor oxides to make a compositionally triphasic nanocomposite gel.
Claim 3
Independent Claim
59 words
A method for manufacture of dense cordierite bodies comprising, mixing at least two sols of nano ceramic precursor oxides to make a compositionally triphasic nanocomposite gel, suitable for manufacture of said bodies, drying said gel, grinding the so dried gel into powder, pressing said powder into a compact body and sintering said body into a ceramic of high density.
Claim 4
Independent Claim
59 words
A method for manufacture of dense cordierite bodies comprising, mixing at least two sols of nano ceramic precursor oxides to make a compositionally triphasic nanocomposite gel, suitable for manufacture of said bodies, drying said gel, grinding the so dried gel into powder, pressing said powder into a compact body and sintering said body into a ceramic of high density.
Claim 5
Dependent Claim
17 words
The method of claim 2 wherein said body is sintered at between 1100° C. to 1400° C.
Claim 6
Dependent Claim
17 words
The method of claim 2, wherein said body is sintered at between 1250° C. and 1350° C.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein three sols of said oxides are mixed to make said gel.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein at least one of said oxides is selected from the group consisting of silica, alumina and magnesia.
Claim 9
Dependent Claim
18 words
The method of claim 2 wherein the heat of reaction of said oxides contributes to the sintering thereof.
Claim 10
Dependent Claim
27 words
The method of claim 7 wherein said gel is of heterogeneous particles on a nanometer scale and is converted by sintering into a ceramic of homogeneous composition.
Claim 11
Dependent Claim
17 words
The method of claim 2 wherein said compact body is sintered into a ceramic of low porosity.
Claim 12
Dependent Claim
21 words
The method of claim 9 wherein said compact body is sintered, without sintering aids, into a ceramic 96% to 100% dense.
Claim 13
Dependent Claim
23 words
The method of claim 2 wherein said compact body is sintered into a ceramic having a density of between 2.480 to 2.512 g/cc.
Claim 14
Dependent Claim
26 words
The method of claim 2 wherein said gel is seeded with cordierite particles to accelerate the sintering of said compact body into a high density ceramic.
Claim 15
Dependent Claim
16 words
A high density cordierite body made from a compositionally triphasic nanocomposite gel of ceramic precursor oxides.
Claim 16
Dependent Claim
16 words
A high density cordierite body made from a compositionally triphasic nanocomposite gel of ceramic precursor oxides.
Claim 17
Dependent Claim
15 words
The cordierite body of claim 13 having low porosity and being free of sintering aids.
Claim 18
Dependent Claim
11 words
The cordierite body of claim 13 being 96 to 100% dense.
Claim 19
Dependent Claim
15 words
The cordierite body of claim 13 having a density of from 2.480 to 2.512 g/cc.
Claim 20
Dependent Claim
15 words
The cordierite body of claim 13 having a density of from 2.500 to 2.512 g/cc.
Claim 21
Dependent Claim
34 words
A high density cordierite body made from a compositionally triphasic nanocomposite gel which has been dried, ground and pressed into an article of desired shape and sintered at between 1100° C. and 1400° C.
Claim 22
Dependent Claim
34 words
A high density cordierite body made from a compositionally triphasic nanocomposite gel which has been dried, ground and pressed into an article of desired shape and sintered at between 1100° C. and 1400° C.
Claim 23
Dependent Claim
20 words
The cordierite body of claim 13 wherein said oxides are selected from the group consisting of silica, alumina and magnesia.
Claim 24
Dependent Claim
19 words
A compositionally triphasic nanocomposite cordierite gel having a mixture of at least two sols of nano ceramic precursor oxides.
Claim 25
Dependent Claim
19 words
A compositionally triphasic nanocomposite cordierite gel having a mixture of at least two sols of nano ceramic precursor oxides.
Claim 26
Dependent Claim
19 words
The gel of claim 20 wherein said oxides are selected from the group consisting of silica, alumina and magnesia.
Claim 27
Dependent Claim
15 words
The gel of claim 20 having triphasic gel particles sized between 1 to 20 nanometers.
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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) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |