US4810339A
Expired / Lapsed
US
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Preparing superconducting ceramic materials
Assignee: Chloride Silent Power Ltd
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Filing: 1988-07-15
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Granted: 1989-03-07
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Expires: 2008-07-15
Abstract
Abstract Superconducting ceramic material is prepared by mixing desired oxide powders, calcining them, forming a slurry of the calcined powders with a carrier liquid, depositing a layer of the ceramic from the slurry by electrophoretic deposition and then drying the layer. The layer should then be sintered to increase densification. Typical powders are oxides of Y, Ba and Cu in molar proportions 1:2:3 respectively.
Inventors
- 👤 Stephen N. Heavens
- 👤 Ivor W. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:46
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/4521; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0352; H10N60/0576; Y; Y10; Y10S; Y10S505/00; Y10S505/80; Y10S505/815; Y10S505/818
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
91 words
A method of preparing a superconducting ceramic material comprising the steps of mixing together predetermined proportions of selected oxide powders, calcining the mixed powders to produce a ceramic powder having a desired phase for superconductivity, and forming the powder as a ceramic mass, wherein the forming step comprises preparing a slurry containing the ceramic powder suspended in a carrier liquid, depositing a layer of the ceramic material from the slurry by electrophoretic deposition and then drying the deposited ceramic material to drive off the carrier liquid to form the ceramic mass.
Claim 2
Independent Claim
91 words
A method of preparing a superconducting ceramic material comprising the steps of mixing together predetermined proportions of selected oxide powders, calcining the mixed powders to produce a ceramic powder having a desired phase for superconductivity, and forming the powder as a ceramic mass, wherein the forming step comprises preparing a slurry containing the ceramic powder suspended in a carrier liquid, depositing a layer of the ceramic material from the slurry by electrophoretic deposition and then drying the deposited ceramic material to drive off the carrier liquid to form the ceramic mass.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 1, including the additional step of sintering the ceramic mass to increase its densification.
Claim 4
Dependent Claim
14 words
A method as claimed in claim 1, wherein the carrier liquid is non aqueous.
Claim 5
Dependent Claim
14 words
A method as claimed in claim 1, wherein the carrier liquid is amyl alcohol.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 1, wherein the ceramic powder is dry milled prior to use in preparing the slurry.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 5, wherein the powder is dry milled for at least two hours.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 1, wherein the slurry is milled for at least five hours prior to use in electrophoretic deposition.
Claim 9
Dependent Claim
42 words
A method as claimed in claim 1, wherein the electrophoretic deposition is conducted by applying an electric field between mutually positive and negative electrodes immersed in the slurry, with the electrode on which deposition is to take place being the negative electrode.
Claim 10
Dependent Claim
14 words
A method as claimed in claim 1, wherein the layer is deposited on nickel.
Claim 11
Dependent Claim
21 words
A method as claimed in claim 1, wherein the layer is deposited as a thin coating adhering to a metal substrate.
Claim 12
Dependent Claim
16 words
A method as claimed in claim 10, wherein the coating is 30 to 150 microns thick.
Claim 13
Dependent Claim
19 words
A method as claimed in claim 1, wherein the selected oxide powders are oxides of Y, Ba and Cu.
Claim 14
Dependent Claim
20 words
A method as claimed in claim 12, wherein the oxide powders are yttrium oxide, barium hydroxide hydrate and cupric oxide.
Claim 15
Dependent Claim
17 words
A method as claimed in claim 13, wherein the powders are mixed in molar proportions 1:2:3 respectively.
Claim 16
Independent Claim
20 words
A method as claimed in claims 1, wherein the selected oxide powders are oxides of bismuth, strontium, calcium and copper.
Claim 17
Dependent Claim
28 words
A method as claimed in claim 15, wherein the oxide powders are bismuth oxide, strontium hydroxide octahydrate, calcium carbonate and cupric oxide mixed in molar proportions 2:2.3:0.7:2 respectively.
Claim 18
Independent Claim
19 words
A method as claimed in claims 1, wherein the selected oxide powders are oxides of lanthanum, strontium and copper.
Claim 19
Dependent Claim
26 words
A method as claimed in claim 17, wherein the oxide powders are lanthanum oxide, strontium hydroxide octahydrate and cupric oxide mixed in molar proportions 1.8:0.2:1 respectively.
Claim 20
Dependent Claim
19 words
A method as claimed in claim 1, wherein the selected oxide powders are oxides of lanthanum, strontium and niobium.
Claim 21
Dependent Claim
26 words
A method as claimed in claim 19, wherein the oxide powders are lanthanum oxide, strontium hydroxide octahydrate and niobium oxide mixed in molar proportions 2:1:5 respectively.
References Cited (Backward Citations)
US4079192A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |