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US4465778A
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Sinterable fluorite oxide ceramics
Assignee: NATIONAL RESEARCH DEVELOPMENT Corp 66-74 VICTORIA STREET LONDON SW1 ENGLAND A BRITISH CORP
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Filing: 1983-01-14
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Granted: 1984-08-14
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Expires: 2003-01-14
Abstract
Abstract Zirconia ZrO 2 , ceria CeO 2 or thoria ThO 2 may be rendered ionically conductive; a typical composition is ZrO 2 +12 mol % CaO. This is sintered in the solid state as a 40 nm powder using as a sintering additive 0.1 mol % MgO at 1450 C. for 4 hours; a density 98% of the theoretical is achieved. For other fluorite oxide compositions, MgO is also useful as a sintering additive but in different proportions.
Inventors
- 👤 Richard J. Brook
- 👤 Suxing Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:28
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C01; C01F; C01F15/00; C01G; C01G25/00; C01G25/02; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; C04B35/50; C04B35/51; H; H01; H01M; H01M8/00; H01M8/10; H01M8/12; H01M8/124; H01M8/1246; C01P; C01P2002/00; C01P2002/50; C01P2002/52; C01P2004/00; C01P2004/60; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/10; C01P2006/80; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
40 words
A composition of fluorite oxide sinterable in the solid state, comprising a fluorite oxide, which may be partly or fully stabilised, characterised in that it contains 0.05 to 0.15 mole % MgO and substantially no Al 2 O 3 .
Claim 2
Dependent Claim
40 words
A composition of fluorite oxide sinterable in the solid state, comprising a fluorite oxide, which may be partly or fully stabilised, characterised in that it contains 0.05 to 0.15 mole % MgO and substantially no Al 2 O 3 .
Claim 3
Dependent Claim
19 words
A composition according to claim 1, wherein the particle size of the fluorite oxide does not exceed 1 micron.
Claim 4
Dependent Claim
16 words
A composition according to claim 2, wherein the said particle size does not exceed 0.4 micron.
Claim 5
Dependent Claim
16 words
A composition according to claim 3, wherein the said particle size does not exceed 0.1 micron.
Claim 6
Dependent Claim
42 words
A composition according to claim 1, wherein the fluorite oxide is chosen from the group consisting of ZrO 2 (which may include HfO 2 ), CeO 2 and ThO 2 , and a single-phase solid solution between at least two oxides thereof.
Claim 7
Dependent Claim
23 words
A composition according to claim 5, wherein the fluorite oxide is ZrO 2 further comprising from 6 to 16 mol % of CaO.
Claim 8
Dependent Claim
17 words
A composition according to claim 6, wherein the CaO content is from 10 to 14 mol %.
Claim 9
Dependent Claim
15 words
A composition according to claim 1, wherein the MgO content is from 0.08-0.12 mole %.
Claim 10
Dependent Claim
50 words
A composition of fluorite oxide sinterable in the solid state wherein the fluorite oxide is ZrO 2 (which may include HfO 2 ) further comprising from 2 to 12 mole % Y 2 O 3 , 0.2 to 1.0 mole % MgO and substantially no Al 2 O 3 .
Claim 11
Dependent Claim
50 words
A composition of fluorite oxide sinterable in the solid state wherein the fluorite oxide is ZrO 2 (which may include HfO 2 ) further comprising from 2 to 12 mole % Y 2 O 3 , 0.2 to 1.0 mole % MgO and substantially no Al 2 O 3 .
Claim 12
Dependent Claim
31 words
A composition according to claim 9, wherein the Y 2 O 3 content is from 6 to 10 mol % and the MgO content is from 0.2 to 0.5 mol %.
Claim 13
Dependent Claim
17 words
A composition according to claim 9, wherein the MgO content is from 0.4 to 1.0 mol %.
Claim 14
Dependent Claim
18 words
A composition according to claim 11, wherein the Y 2 O 3 content is substantially 5 mol %.
Claim 15
Dependent Claim
44 words
A method of making a ceramic body from a composition according to claim 1, comprising sintering a shaped body of the composition at a temperature below which any liquid forms until the density of the sintered composition is at least 96% of theoretical density.
Claim 16
Dependent Claim
34 words
A method according to claim 13, wherein the sintering is performed under a condition selected from the group consisting of an atmosphere of gas soluble in the fluorite oxide, and an atmosphere of air.
Claim 17
Dependent Claim
32 words
A method according to claim 13, wherein the sintering temperature is above 1,600° C. and not more than 1,800° C. and wherein the duration of the sintering is at least 5 minutes.
Claim 18
Dependent Claim
32 words
A method according to claim 13, wherein the sintering temperature is at least 1,400° C. and up to 1,600° C. and wherein the duration of the sintering is at least 1 hour.
Claim 19
Dependent Claim
12 words
A sintered fluorite oxide body of the composition according to claim 1.
Claim 20
Dependent Claim
44 words
A method of making a ceramic body from a composition according to claim 9, comprising sintering a shaped body of the composition at a temperature below which any liquid forms until the density of the sintered composition is at least 96% of theoretical density.
Claim 21
Dependent Claim
31 words
A method according to claim 18, wherein the sintering is performed under a condition selected from the group consisting of an atmosphere of gas soluble in the fluorite oxide, and air.
Claim 22
Dependent Claim
32 words
A method according to claim 18, wherein the sintering temperature is above 1,600° C. and not more than 1,800° C. and wherein the duration of the sintering is at least 5 minutes.
Claim 23
Dependent Claim
31 words
A method according claim 18, wherein the sintering temperature is at least 1,400° C. and up to 1,600° C. and wherein the duration of the sintering is at least 1 hour.
Claim 24
Dependent Claim
12 words
A sintered fluorite oxide body of the composition according to claim 9.
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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |