Abstract: Methods for implementing production of an oxide superconductor joined member, excellent in electric current transmission performance, without a need of going through particularly complex steps, are provided. When joining together oxide superconductors by use of a solder composed of an oxide superconducting material, a finally solidified portion of the solder is positioned in a region where a transmission path of electric current flowing between oxide superconductor base materials as joined together is not obstructed by, for example, disposing the solder on a face of the oxide superconductor base materials, other than butting surfaces of the oxide superconductor base materials, so as to straddle both the base materials like bridge-building. Current flow is also not obstructed by, for example, shaping junction faces of the oxide superconductor base materials such that at least portions of the butting surfaces thereof are in the shape of sloped open faces, parting from each other.

Abstract: A process for producing an ultrafine multifilamentary superconducting Nb3(Al,Ge) wire capable of generating a high critical current density comprising: preparing a composite core material comprising an A1—(2-30)at. % Ge alloy (where at. % represents % by atomic) 1 &mgr;m or less in thickness uniformly incorporated into a Nb matrix at a volume ratio in a range of 1:2.5 to 1:3.5 and forming a composite therewith; fabricating a composite wire having an ultrafine multifilamentary structure by embedding several tens to several millions of the resulting composite core materials in a cylindrical matrix material containing Nb; forming a A15-phase filament having a lower order in crystallinity inside the composite wire by a rapid heating and quenching treatment comprising rapidly heating to a temperature of 1,700° C.

Abstract: The method of preparing an NB.sub.3 Al superconducting wire comprises the steps of passing an Nb/Al composite wire consisting of an Nb metal or an Nb alloy and an Al metal or an Al alloy through a furnace for heating the same from the room temperature to a prescribed temperature, subsequently passing the same through the furnace for holding the same at the prescribed temperature, and subsequently passing the same through a cooling part for cooling the same from the prescribed temperature to the room temperature, and these steps are continuously carried out by continuously moving the wire. According to the present invention, it is possible to obtain an Nb.sub.3 Al superconducting wire having homogeneous characteristics along its overall width with a high critical current density.

Abstract: A method is described which increases the critical current of triniobium tin by bonding thermal contraction control layers to the triniobium tin superconducting articles at a process temperature to form a composite, and subsequently cooling the composite to a test temperature.

Abstract: A method for producing a superconductor by partial inter diffusion of layers of metal under a diffusion heat treatment to provide a ductile beta phase alloy, along with undiffused metal layers to permit ease of extrusion and drawing to fine layer thickness. At some point in the reduction the layers are further diffused to give an alloy superconducting product which is optimal for the high field (5-9 T) of interest in contact with a non-superconducting layer. This optimal diffusion is preferably accomplished after a sufficient reduction such that the individual metal layers are 2.5-15 microns thick.

Abstract: A Type II superconducting alloy which is superconducting at a predetermined high magnetic field is prepared by creating a composite having a periodic arrangement of at least two transition metals so as to provide numerous interfaces between the different transition metals including niobium, titanium, zirconium, vanadium, hafnium, and tantalum, and alloys thereof. The combination of transition metals is such that one of the metals will serve as a second phase when the layers are subjected to temperatures which would produce a two-phase equilibrium state from a solid solution alloy of the transition metals. The composite is mechanically reduced and heated to cause interdiffusion of the transition metals to form ductile superconducting alloy zones at the interfaces of the transition metals.

Abstract: Artifical pinning centers are provided in normal metal layers adjacent to a type II superconductor layer produced by reacting two normal metal layers. The transverse thicknesses of the final superconductor and normal metal layers are less than about 1000 A.degree.. Planar layers of metal which are to provide a multilayer wire whose layers are parallel. A plurality of the multilayer wires are combined to produce a multifilament superconductor, the layers in all the individual wires being parallel to each other.

Abstract: A superconductor which is superconducting of a predetermined high field and low temperature is formed by combining a plurality of metal bodies to form a composite structure. The metal bodies are selected from transition metals such as niobium, tantalum, zirconium, hafnium and vanadium, and alloys of such metals, alternate bodies being formed of ductile alloys of the metals which are not superconducting at the predetermined high field. The alternate bodies of transition metals are reacted to form a ductile superconducting ternary alloy zone at the interfaces of these bodies. The extent of the reaction is limited so as to maintain areas of transition metal and transition metal alloys which are not superconducting at the high field. The composite structure is reduced sufficiently that each non superconducting zone is less than 1000A.degree. thick and serves as an artificial pinning site for each adjacent superconducting zone.

Abstract: In a preferred form of the invention, a superconductor is produced by the steps of combining a plurality of layers of metal sheets to form a composite structure. The sheets are pure transition metals--niobium, titanium, zirconium, or vanadium, alternate sheets being formed of different transition metals. The resulting composite structure is mechanically reduced sufficiently so that each transition metal sheet is less than 1000 .ANG. thick. In the course of reduction, the composite is subjected to sufficient temperatures for sufficient times such that the transition metal layers are partially reacted to form a ductile superconducting material between the transition metal layers. Approximately one half by volume of the transition metal layers remain unreacted. These unreacted layers afford efficient flux pinning within the composite when the layers are reduced to the <1000.ANG. final size. In other embodiments, powders and filaments can be used instead of initial layers.

Abstract: A method for producing a superconductor includes the steps of combining a plurality of metal bodies to form a composite structure, metal bodies being selected from transition metals such as niobium, tantalum, titanium, zirconium, hafnium and vanadium, alternate bodies being formed of different transition metals to form triplets. The transition metals are reacted to form a ductile superconducting ternary alloy at the interfaces of these triplets of metals. The extent of the reaction is limited so as to maintain areas of pure or nearly pure transition metal along with the superconducting ternary alloy in at least one of each triplet of transition metals.

Abstract: In the present invention, a superconductor is produced by the steps of wrapping a plurality of layers of metal sheets around a support to form a composite structure. The sheets are pure transition metals-13 niobium, titanium, zirconium, or vanadium, for example--alternate sheets being formed of different transition metals. The support may be composed of any ductile metal. The resulting composite structure is mechanically reduced sufficiently so that each transition metal sheet is less than 1000 .ANG. thick. In the course of reduction, the composite is subjected to sufficient temperatures for sufficient times such that the transition metal layers are partially reacted to form a ductile superconducting material between the transition metal layers. Approximately one half by volume of the transition metal layers remain unreacted. These unreacted layers afford efficient flux pinning within the composite when the layers are reduced to the <1000 .ANG. final size.

Abstract: In one embodiment this invention provides a process for decreasing the resistivity of an electrical conductor.The process involves the application of high temperature and an external field to a conductor to induce a current flow and physicochemical transition in the conducting matrix.

Abstract: A superconductive wire having an elongated flexible sheath bent into a nonlinear shape and formed with an inwardly extending longitudinal formations which can be grooves. A sintered body of a ceramic superconductive materials fills the sheath and conforms to the shape, the body having formations complementarily interfitting with the formations of the sheath. At least one of the grooves can be formed with a channel through which a cooling medium can be circulated or the grooves can receive a conductive strand or a support rod.

Abstract: A glass-clad wire of ceramic superconductive material is produced by filling a glass-lined metal cylinder with a powder of superconductive material, sealing the cylinder ends and drawing the filled, sealed cylinder through dies of progressively smaller size until a predetermined wire size is achieved. The formed wire is then heat treated to assure necessary crystallinity in the superconductor material. Removal of the outer metal coating leaves a glass-clad superconductor wire.

Abstract: A wire of ceramic superconductive material is produced by filling a metal tube with a powder of superconductive material, sealing the tube ends and drawing the filled, sealed tube through dies of progressively smaller size until a predetermined wire size is achieved and then heat treating the drawn wire to assure necessary crystallinity in the superconductor material.