US4973575A
Expired / Lapsed
US
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Preferential orientation of metal oxide superconducting materials by mechanical means
Assignee: ARCH DEVELOPMENT Corp ARGONNE NATIONAL LABORATORY 9700 SOUTH CASS AVENUE BUILDING 207 ARGONNE ILLINOIS 60439 A CORP OF ILLINOIS
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Filing: 1987-09-28
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Granted: 1990-11-27
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Expires: 2007-09-28
Abstract
Abstract A superconductor comprised of a polycrystalline metal oxide such as YBa 2 Cu 3 O 7-X (where 0<×<0.5) is capable of accommodating very large current densities. By aligning the two-dimensional Cu--O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the metal oxide material to accommodate high current densities. The orthorhombic crystalline particles have a tendency to lie down on one of the longer sides, i.e., on the a- or b-direction. Aligning the crystals in this orientation is accomplished by mechanical working of the material such as by extrusion, tape casting or slip casting, provided a single crystal powder is used as a starting material, to provide a highly oriented, e.g., approximately 90% of the crystal particles have a common orientation, superconducting matrix capable of supporting large current densities.
Inventors
- 👤 Donald W. Capone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:54
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; C; C30; C30B; C30B1/00; C30B1/12; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/225; C30B29/60; C30B29/605; C30B33/00; H10N60/20; H10N60/203; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/739; Y10S505/74; Y10S505/741
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
189 words
A method of forming a superconducting metal oxide with improved current carrying capacity wherein said superconducting metal oxide has a polycrystalline structure and is anisotropically superconducting having one or more longer crystal axes along which said metal oxide is superconducting, said method comprising the steps of: reducing the superconducting metal oxide of flake-like particles of single crystals by pressing the superconducting metal oxide into a compact form, heating the compacted superconducting metal oxide to a temperature on the order of its melting point for an extended period sufficient to induce large grain growth in the superconducting metal oxide, and reducing the superconducting metal oxide to a flake-like, powder form, wherein the metal oxide powder is comprised of particles of single crystals; mixing said particles of single crystals with a liquid to form a loose matrix of said particles; mechanically orienting said metal oxide single crystal particles along a preferential direction such that said one or more longer axes of each of said metal oxide crystals are in general alignment; and removing the liquid from the aligned metal oxide single crystal particles and sintering said metal oxide single crystal particles.
Claim 2
Independent Claim
189 words
A method of forming a superconducting metal oxide with improved current carrying capacity wherein said superconducting metal oxide has a polycrystalline structure and is anisotropically superconducting having one or more longer crystal axes along which said metal oxide is superconducting, said method comprising the steps of: reducing the superconducting metal oxide of flake-like particles of single crystals by pressing the superconducting metal oxide into a compact form, heating the compacted superconducting metal oxide to a temperature on the order of its melting point for an extended period sufficient to induce large grain growth in the superconducting metal oxide, and reducing the superconducting metal oxide to a flake-like, powder form, wherein the metal oxide powder is comprised of particles of single crystals; mixing said particles of single crystals with a liquid to form a loose matrix of said particles; mechanically orienting said metal oxide single crystal particles along a preferential direction such that said one or more longer axes of each of said metal oxide crystals are in general alignment; and removing the liquid from the aligned metal oxide single crystal particles and sintering said metal oxide single crystal particles.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein the step of orienting said metal oxide crystals along a preferential direction includes tape casting and the loose matrix of said metal oxide crystals onto a moving support member.
Claim 4
Dependent Claim
36 words
The method of claim 2 wherein the tape casting of the loose matrix of said metal oxide crystals includes passing the loose matrix across blade means for orienting the metal oxide crystals along a preferential direction.
Claim 5
Dependent Claim
45 words
The method of claim 1 wherein the step of orienting said metal oxide crystals along a preferential direction includes depositing the loose matrix of said metal oxide crystals into a plaster mold and allowing the thus deposited matrix to stand over a period of time.
Claim 6
Dependent Claim
27 words
The method of claim 4 wherein the plaster mold is shallow and the one or more shorter axes of the metal oxide crystals are oriented generally vertically.
Claim 7
Dependent Claim
35 words
The method of claim 1 wherein the step of orienting said metal oxide crystals along a preferential direction includes extruding the loose matrix of said metal oxide crystals in the form of a thin strip.
Claim 8
Dependent Claim
33 words
The method of claim 6 wherein the one or more shorter axes of the metal oxide crystals are oriented generally transverse to the direction the loose matrix of metal oxide crystals is extruded.
Claim 9
Dependent Claim
21 words
The method of claim 7 further comprising the step of depositing the extruded loose matrix of metal oxide as a wire.
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) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |