Abstract: An article and method of manufacture of a (Bi,Pb)--Sr--Ca--Cu--O superconductor comprisingcalcinating powders of superconductor precursors of PbO, Bi.sub.2 O.sub.3, SrCO.sub.3 or SrO, CaCO.sub.3 or CaO in air to obtain a 2223 superconductor lump and second phases;crushing the lump into powder;molding the powder into a superconductor body;disposing the body within silver powder to form a composite;molding the composite;heat treating the composite to increase the bond strength of the silver powder; andworking the composite into a useable shape by rolling and drawing while applying intermediate and final heat treatments to obtain a final product.
Type:
Grant
Filed:
June 23, 1994
Date of Patent:
July 4, 1995
Assignees:
Korea Atomic Energy Research Institute, Korea Electric Power Corporation
Inventors:
Hee-Gyun Lee, Seon-Chil Kweon, Dong-Yeon Won, Gye-Won Hong
Abstract: A composite superconducting wire using ceramic superconductor material in which one or more elongated superconductor material are accommodated in one or more grooves formed on an elongated reinforcing member so that a long size superconductor wire can be provided. Various methods of producing such composite superconductor wire are also disclosed.
Abstract: A process for producing a composite oxide superconducting wire is disclosed, which comprises the steps of compacting material powder for an oxide superconductor in a noble metal pipe; heating the metal pipe filled with the material powder at a temperature ranging between an upper limit corresponding to the lowest melting point of any one of constituent components in the material powder and a lower limit which is lower by 100.degree. C. than said upper limit to sinter the material powder and cooling the product at a cooling velocity of less than 50.degree. C./min, and further including a series of wire-drawing, annealing and sintering steps. Furthermore, an intermediate layer of noble metal can be interposed between the oxide superconductor and the metal pipe.
Abstract: Improvement in a process for producing a sintered elongated article by the steps comprising filling a metal pipe with a material powder, carrying out plastic deformation of the metal pipe and then subjecting the material powder in deformed metal pipe to sintering. In the invention, the step of the plastic deformation includes at least one deformation satge carried out under a hot condition.
Abstract: This invention is related to the preparation of an elongate conductor having a silver sheath, and a core of an aligned polycrystalline oxide superconductor having the approximate formula Bi.sub.2-x Pb.sub.x Sr.sub.2-a L.sub.a+b Ca.sub.1-b Cu.sub.2 O.sub.y where y is from 7.5 to 8.5, and L is a lanthanide. A powder mixture is formed comprised of a first portion of a superconducting bismuth oxide compound that can be reaction-sintered to form the core oxide superconductor, and a second portion of oxides suitable for reacting with the first portion to form the core oxide superconductor. An elongate body is formed having a silver sheath, and a core of the mixture. The body is deformed to align the first portion, and heated to reaction-sinter the first and second portions to form the core oxide superconductor.
Abstract: Metal oxide superconductor powder precursors are prepared in an aerosol pyrolysis process. A solution of the metal cations is introduced into a furnace at 600.degree.-1000.degree. C. for 0.1 to 60 seconds. The process produces micron to submicron size powders without the usual loss of the lead stabilizer. The resulting powders have a narrow particle size distribution, a small grain size, and are readily converted to a superconducting composition upon subsequent heat treatment. The precursors are placed in a metal body deformed to form a wire or tape and heated to form a superconducting article. The fine powders permit a substantial reduction in heat treatment time, thus enabling a continuous processing of the powders into superconducting wire, tape or multifilamentary articles by the powder-in-tube process.
Type:
Grant
Filed:
October 30, 1992
Date of Patent:
March 7, 1995
Assignee:
Martin Marietta Energy Systems, Inc.
Inventors:
Donald M. Kroeger, Huey S. Hsu, Jorulf Brynestad
Abstract: Wire, bulk, film, etc. of a superconductive material is manufactured from a powdery precursor. The superconductive material has a superconductive crystal of 1223 phase and/or 1234 phase as a main component, and the powdery precursor comprises at least 1212 phase as a main component.
Abstract: A superconductor wire comprising an inner core and an outer ring covering the core, wherein one of the inner core and the outer ring comprises a sintered silver powder and the other of the inner core and the outer ring on the core comprises a sintered oxide superconductor powder.
Abstract: Disclosed herein is a method of preparing an oxide superconducting wire comprising the steps of coating a powder material for forming an oxide superconductor with a metal, performing deformation processing on the metal-coated powder material thereby obtaining a tape-type wire material, superposing a plurality of such tape-type wire materials, performing first heat treatment on the plurality of superposed tape-type wire materials while simultaneously diffusion-bonding the metallic coats to each other, then performing deformation processing on the plurality of superposed tape-type wire materials, and performing second heat treatment on the plurality of deformation-processed tape-type wire materials. Preferably the oxide superconductor to be obtained is a bismuth oxide superconductor having a 2223 composition in a composition of Bi--Sr--Ca--Cu or (Bi,Pb)--Sr--Ca--Cu, and the powder material consists of a superconducting phase, which is mainly composed of a 2212 phase, and non-superconducting phases.
Abstract: In order to prevent inflation of a metallic coating during heat treatment so that no ununiformity is caused in the critical current density in a method of preparing an oxide superconducting wire which is obtained by heat treating and sintering metal-coated raw material powder for an oxide superconductor, raw material powder (5) for an oxide superconductor is filled up in a metal billet (1), which in turn is degassed and sealed in the degassed state, elongated with application of hydrostatic extrusion, and then heat treated.
Abstract: An oxide superconducting material is coated with silver or an alloy thereof and shaped into a linear body, and the linear body is subjected to diameter reduction by means of groove roll rolling, a swaging machine and the like, and then differential speed rolling and heat treatment are repeatedly performed, whereby the linear body is shaped into a tape-shaped wire material. The microstructure control in the longitudinal direction is performed uniformly and efficiently, and a superconducting wire having a high c-axis orientation ratio and a large critical current density Jc at a service temperature is obtained.
Abstract: An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor.
Type:
Grant
Filed:
April 6, 1993
Date of Patent:
October 11, 1994
Assignee:
University of Chicago
Inventors:
Stephen E. Dorris, Roger B. Poeppel, Barton C. Prorok, Michael T. Lanagan, Victor A. Maroni
Abstract: A superconductive conductor or cable comprising a core, which comprises at least one string of a ceramic, superconductive material, and where the core is encapsulated by a metal cap. In order to manufacture a conductor or a cable with an encapsulation, and in which it is possible as well during the manufacturing process as under the operation to maintain a controlled atmosphere around the superconductive core, at least one layer of not sintered, ceramic powderous material is provided between the cap and the core, which material has a higher sintering temperature than the superconductive material in the core. The superconductive core may be sintered for formation of the superconductive ceramics by placing in the tubular metal cap a starting material in powderous form, and shaped as a core in the other ceramic powder material and subsequently forgeing the the metal cap with its content, preferably by swaging at an ambient temperature, which is below the sintering temperature of the core.
Type:
Grant
Filed:
October 23, 1990
Date of Patent:
June 14, 1994
Assignee:
Haldor Topsoe A/S
Inventors:
Ivar Primdahl Iversen, Hans J. Henriksen
Abstract: A process for producing a sintered ceramic wire, particularly a superconducting wire, by the steps of filling a metal pipe with a material powder of ceramic, wire drawing the metal pipe filled with the material powder by means of roller dies and then subjecting a composite of the metal pipe and the material powder to a heating operation to sinter the ceramic powder.