Abstract: In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or Nb—Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

Abstract: A method for producing an at least two-part structure, such as a semifinished product for a superconducting wire is provided. A first structure and a second structure are separately produced, and the first structure and the second structure are then inserted one into the other. The first structure and the second structure are respectively produced in layers by selective laser melting or selective electron beam melting of a powder. The method produces two-part structures for semifinished products of superconducting wires.

Abstract: In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or Nb—Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

Abstract: A new heat treatment for Internal-Tin Nb3Sn strands is described. The heat treatment uses Nausite membranes to decrease the volume fraction of the ? phase and therefore minimize its liquefaction—ultimately resulting in better connected Nb3Sn. The heat treatment requires only one stage aside from the final Nb3Sn reaction stage. This heat treatment enables an increase in critical current density (at 16 T) of 28%.

Abstract: In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or Nb—Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

Abstract: The present invention relates to a precursor (1) for production of a high-temperature superconductor (HTS) in ribbon form, comprising a metallic substrate (10) in ribbon form having a first ribbon side (11) and a second ribbon side (12), wherein, on the first ribbon side (11), (a) the substrate (10) has a defined texture as template for crystallographically aligned growth of a buffer layer or an HTS layer and (b) an exposed surface of the substrate (10) is present or one or more layers (20,30) are present that are selected from the group consisting of: buffer precursor layer, pyrolyzed buffer precursor layer, buffer layer, HTS precursor layer, pyrolyzed HTS buffer precursor layer and pyrolyzed and further consolidated HTS buffer precursor layer, and, on the second ribbon side (12), at least one ceramic barrier layer (40) that protects the substrate (10) against oxidation or a precursor which is converted to such a layer during the HTS crystallization annealing or the pyrolysis is present, wherein, when one or

Abstract: Disclosed herein are superconducting wires. The superconducting wires can comprise a metallic matrix and at least one continuous subelement embedded in the matrix. Each subelement can comprise a non-superconducting core, a superconducting layer coaxially disposed around the non-superconducting core, and a barrier layer coaxially disposed around the superconducting layer. The superconducting layer can comprise a plurality of Nb3Sn grains stabilized by metal oxide particulates disposed therein. The Nb3Sn grains can have an average grain size of from 5 nm to 90 nm (for example, from 15 nm to 30 nm). The superconducting wire can have a high-field critical current density (Jc) of at least 5,000 A/mm2 at a temperature of 4.2 K in a magnetic field of 12 T. Also described are superconducting wire precursors that can be heat treated to prepare superconducting wires, as well as methods of making superconducting wires.

Abstract: The present disclosure provides three-dimensional (3D) objects, 3D printing processes, as well as methods, apparatuses and systems for the production of a 3D object. Methods, apparatuses and systems of the present disclosure may reduce or eliminate the need for auxiliary supports. The present disclosure provides three dimensional (3D) objects printed utilizing the printing processes, methods, apparatuses and systems described herein.

Abstract: A semi-finished wire (1) for a Nb3Sn superconducting wire (45) has a multiplicity of elements containing Nb packed against each other (6). The elements containing Nb (6) each have a rod containing Nb (7) and an enclosure containing Cu (8) surrounding the latter. The semi-finished wire also has a structure containing Sn (5) and a matrix containing Cu (4) in which the structure containing Sn (5) is disposed and on and/or in which the elements containing Nb (6) are disposed. The enclosures containing Cu (8) of the elements containing Nb (6), contain Sn. The semi-finished wire is suitable for manufacturing an Nb3Sn superconducting wire with which further improved superconducting current-carrying capacity is achieved.

Abstract: A precursor for a Nb3Sn superconductor wire to be manufactured by the internal diffusion method, includes a plurality of Nb-based single core wires, each of which includes a Nb-based core coated with a Cu-based coating including a Cu-based matrix, a plurality of Sn-based single core wires, each of which includes a Sn-based core coated with a Cu-based coating including a Cu-based matrix; and a cylindrical diffusion barrier including Ta or Nb, in which the plurality of Nb-based single core wires and the plurality of Sn-based single core wires are regularly disposed, wherein the plurality of Nb-based single core wires include Nb-based single core wires having a Cu/Nb ratio of 0.4 or more, wherein the Cu/Nb ratio is a cross sectional area ratio of the Cu-based coating to the Nb-based core.

Abstract: A method of producing a Nb3Sn superconducting wire rod includes forming a wire rod comprising Nb, Sn and Cu, and having a mole ratio of the Sn expressed as ax+b(1?x), where 0.25?x?0.8, 0.3?a?0.4 and 0.02?b?0.1, and x and 1?x are prescribed as a mole ratio of the Nb and a mole ratio of the Cu, respectively, to a total of a mole number of the Nb and a mole number of the Cu, and heating the wire rod to produce Nb3Sn from the Sn and the Nb. By the heating of the wire rod, a Cu—Sn alloy is produced from the Sn and the Cu, concurrently with the Nb3Sn produced from the Sn and the Nb.

Abstract: A precursor for a Nb3Sn superconductor wire to be manufactured by the internal diffusion method. The precursor includes Nb-based single core wires, Sn-based single core wires, and a cylindrical diffusion barrier made of Ta or Nb. Each Nb-based single core wire includes a Nb-based core coated with a Cu-based coating made of a Cu-based matrix. Each Sn-based single core wire includes a Sn-based core coated with a Cu-based coating made of a Cu-based matrix. The Nb-based single core wires and the Sn-based single core wires are regularly disposed in the diffusion barrier. The Nb-based single core wires includes at least two kinds of Nb-based single core wires having different Cu/Nb ratios and the Cu/Nb ratio is a cross sectional area ratio of the Cu-based coating to the Nb-based core.

Abstract: A precursor for a Nb3Sn superconductor wire is configured to be manufactured by the internal Sn diffusion method. The precursor includes a Cu tube including a barrier layer at an inner surface thereof. The barrier layer includes a metal selected from the group consisting of Ta, Ta-alloy, Nb and Nb-alloy. A plurality of Sn single cores are disposed in the Cu tube. Each of the Sn single cores includes Sn or Sn-alloy. A plurality of Nb single cores are also disposed in the Cu tube. Each of the Nb single cores includes Nb or Nb-alloy. The Sn single cores and the Nb single cores are arranged in the Cu tube such that the Sn single cores are not adjacent to each other.

Abstract: A precursor for fabricating a Nb3Sn superconducting wire by an internal Sn process includes one or a plurality of stabilizing copper portions collectively disposed in the center, each stabilizing copper portion being provided with a diffusion barrier layer in the periphery thereof, and a superconducting matrix portion disposed so as to surround the one or the plurality of stabilizing copper portions, the superconducting matrix portion including a Nb or Nb-based alloy core and a Sn or Sn-based alloy core embedded in a Cu or Cu-based alloy matrix.

Abstract: The invention relates to a composite (1), comprising a Cu—Sn bronze matrix (2) and filaments (3) surrounded by the bronze matrix (2), wherein the filaments (3) contain niobium (?Nb) or a Nb alloy, characterized in that the filaments (3) contain between 0.3% and 20% of volume of copper (?Cu) substructures (4), which are distributed within the Nb or the Nb alloy. The composite can be used to produce a superconducting element with the bronze route which has an improved critical current density.

Abstract: A precursor for manufacturing a Nb3Sn superconducting wire according to the present invention includes a mono-element wire including a Sn or Sn-based alloy core disposed at the, a Cu or Cu-based alloy matrix and a plurality of Nb or Nb-based alloy filaments surrounding the Sn or Sn-based alloy core, and a diffusion barrier layer and a stabilizing copper layer surrounding the Cu or Cu-based alloy matrix. In a final shape after a reduction process, the average diameter of the Nb or Nb-based alloy filaments is set to 5 ?m to 30 ?m, and the average distance between the Sn or Sn-based alloy core and the Nb or Nb-based alloy filaments nearest the Sn or Sn-based alloy core is set to 100 ?m or less.

Abstract: Critical current densities of internal tin wire having values of at least 2000 A/mm2 at temperature of 4.2 K and in magnetic field of 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; and barrier thickness relative to the filament thickness; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.

Abstract: A method for manufacturing a powder-metallurgy processed Nb3Sn superconducting wire is provided. In the method, a sheath made of Nb or a Nb alloy is filled with a raw material powder containing Sn. The sheath filled with the raw material powder is subjected to diameter reduction to form a wire. The wire is heat-treated to form a superconducting phase at the internal surface of the sheath. The raw material powder is prepared by adding a Sn powder to a Cu—Sn alloy powder or a Cu—Sn intermetallic compound powder, and is compacted under isotropic pressure.

Abstract: A superconducting material useful for forming electrolytic devices is made by establishing multiple niobium or tantalum components in a primary billet of a ductile material; working the primary billet through a series of reduction steps to form the niobium or tantalum components into elongated elements; cutting and restacking the resulting elongated elements with a porous confining layer to form a secondary billet, working the secondary billet through a series of reduction steps including twisting and final rolling to thin ribbon cross-sections with greater than 5:1 Aspect Ratios; cutting the resulting elongated billet into sections; and leaching the core and sheath at least in part.

Abstract: A method for producing a superconductive element, in particular a multifilament wire, starting from a composite (1) comprising a bronze matrix containing Cu and Sn, in which at least one elongated structure containing Nb or an Nb alloy, in particular NbTa, is embedded, whereby in a first step the composite is extruded at a temperature between 300° C. and 750° C.

Abstract: A method for producing a superconductive element, in particular a multifilament wire, starting from a composite (1) comprising a bronze matrix containing Cu and Sn, in which at least one elongated structure containing Nb or an Nb alloy, in particular NbTa, is embedded, whereby in a first step the composite is extruded at a temperature between 300° C. and 750° C.

Abstract: A method for producing an Nb3Sn superconductive wire material using a powder process is provided, in which a powdered raw material is filled in a sheath made of Nb or an Nb-based alloy, and the above sheath is subjected to diameter reduction to form a wire, followed by heat treatment to form a superconducting layer at the interface between the sheath and the filled powder. The above powdered raw material contains powdered Sn, powdered Cu, and a powdered alloy or a powdered intermetallic compound, which is formed from Sn and at least one metal selected from the group consisting of Ti, Zr, Hf, V, and Ta.

Abstract: Disclosed is a manufacturing method of an Nb3Sn superconductive wire using a powder technique, the method including the steps of: filling, as a raw powder, an intermetallic compound powder obtained from a metallic powder containing at least one metallic powder selected from Ta powder and Nb powder, and Sn powder, or a mixture of the metallic powder and the Sn powder into a sheath made of Nb or an Nb based alloy; performing a diameter-reduction process on the sheath to form a wire; heat treating the wire; and, forming a superconductive layer on the interface between the sheath and the powder, wherein at least one of the metallic powders selected from the Ta powder and the Nb powder is obtained by aggregating fine particles (primary) in shape of coral to form secondary particles.

Abstract: Critical current densities of internal tin wire having values of at least 2000 at temperature of 4.2 K and in magnetic field of 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; and barrier thickness relative to the filament thickness; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.

Abstract: Critical current densities of internal tin wire to the range of 3000 A/mm2 at temperature of 4.2 K and in magnetic field 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; barrier thickness relative to the filament thickness; additions of a dopant such as Ti or Ta to the Nb3Sn; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.

Abstract: A composite multi-core wire rod in which a plurality of Al alloy wires containing 15 at % to 40 at % of Ge are arranged in Nb matrix at a core diameter of 2 ?m to 20 ?m is subjected to heating for at least five hours at a temperature ranging from 1300° C. to 1600° C.; and additionally heating at a temperature ranging from 650° C. to 900° C.

Abstract: A multi-filament superconducting wire in which the filaments comprise zirconia-stabilized ultra-fine grain Nb3Sn. The superconducting wire is formed by wire-drawing a preform comprising a metallic matrix and at least one niobium alloy rod having zirconium and oxygen in solid solution and heat treating the drawn wire in the presence of tin to yield at least one continuous filament comprising ultra-fine grain Nb3Sn having semi-coherent ZrO2 precipitates disposed therein. The ZrO2 precipitates serve to stabilize the ultra-fine grain microstructure of the Nb3Sn at temperatures up to 1100° C. and allows Nb3Sn to maintain the ultra-fine grain microstructure when heat treated at temperatures that are greater than those previously used. By using higher temperatures to form Nb3Sn, the time required for heat treatment can be significantly reduced.

Abstract: A precursor for manufacturing a Nb3Sn superconducting wire according to the present invention includes a mono-element wire including a Sn or Sn-based alloy core disposed at the, a Cu or Cu-based alloy matrix and a plurality of Nb or Nb-based alloy filaments surrounding the Sn or Sn-based alloy core, and a diffusion barrier layer and a stabilizing copper layer surrounding the Cu or Cu-based alloy matrix. In a final shape after a reduction process, the average diameter of the Nb or Nb-based alloy filaments is set to 5 ?m to 30 ?m, and the average distance between the Sn or Sn-based alloy core and the Nb or Nb-based alloy filaments nearest the Sn or Sn-based alloy core is set to 100 ?m or less.

Abstract: A superconducting material useful for forming electrolytic devices is made by establishing multiple niobium or tantalum components in a primary billet of a ductile material; working the primary billet through a series of reduction steps to form the niobium or tantalum components into elongated elements; cutting and restacking the resulting elongated elements with a porous confining layer to form a secondary billet, working the secondary billet through a series of reduction steps including twisting and final rolling to thin ribbon cross-sections with greater than 5:1 Aspect Ratios; cutting the resulting elongated billet into sections; and leaching the core and sheath at least in part.

Abstract: A superfine multi-core Nb3Al superconductive wire is produced by getting a Nb3Al superconductive wire ready which was obtained by subjecting a precursor wire having a superfine multi-core structure in which a plurality of Nb/Al complex cores are embedded in Nb, Ta, a Nb based dilute alloy, or a Ta based dilute alloy as the matrix to a rapid heating and quenching treatment comprising rapidly heating to a temperature range near 2,000° C. in 2 seconds, (A) coating the Nb3Al superconductive wire with Cu or Ag as the stabilizing material; then (B) subjecting to a hot isostatic press (HIP) process for 10 minutes or more in a inert gas environment with a pressure of 40 atmospheres or more; and then (C) subjecting heat treatment for 1–200 hours in temperature range of 680–850° C.

Abstract: A method for producing a superconductor having a high copper to superconductor composition (Cu/SC) ratio by cross-sectional area. An assembly is prepared formed of one or more fine filaments of a superconductor composition or of a precursor component for a superconductor alloy composition, which filaments are embedded in a copper-based matrix. The assembly is electroplated with copper to increase the Cu/filament ratio in the resulting product, and thereby increase the said Cu/SC ratio to improve the stability of the final superconductor.

Abstract: A niobium-based superconductor is manufactured by establishing multiple niobium components in a billet of a ductile metal, working the composite billet through a series of reduction steps to form the niobium components into elongated elements, each niobium element having a thickness on the order of 1 to 25 microns, surrounding the billet prior to the last reduction step with a porous confining layer of an acid resistant metal, immersing the confined billet in an acid or a high temperature liquid metal to remove the ductile metal from between the niobium elements while the niobium elements remain confined by said porous layer, exposing the confined mass of niobium elements to a material capable of reacting with Nb to form a superconductor.

Abstract: An Nb3Sn-based superconductive wire which, when used in a superconductive magnet, manifests sufficient strength also against force along the radius direction in operating the magnet and reveals little deterioration in properties due to mechanical strain ascribable to the force along the radius direction is provided. An Nb3Sn-based superconductive wire comprising a bronze/filament aggregate obtained by placing a lot of niobium (Nb) or niobium alloy filaments in a copper (Cu)-tin (Sn)-based alloy matrix, wherein said niobium or niobium alloy filament constituting the bronze/filament aggregate 3? is a composite filament 5 obtained by combining with a filament reinforcing material having mechanical strength under temperature not more than room temperature after thermal treatment for producing an Nb3Sn-based superconductive compound, larger than the mechanical strength of the niobium or niobium alloy.

Abstract: By rapidly heating a precursor wire having a multifilamentary structure in which multiple composite cores in which a composite compound of an Nb—Ga compound and Nb is embedded in Nb are embedded in Nb, Ta, Nb-base alloy or Ta-base alloy as a matrix material to a temperature range of 1400 to 2100° C. in 2 seconds, quenching the precursor wire at a rate of 5000° C./second or larger, and subjecting the precursor wire to additional heat treatment at a temperature range of 600 to 850° C. for 1 to 400 hours, a superconducting wire having a multifilamentary structure in which multiple composite cores in which a composite compound containing Nb3Ga of a stoichiometric composition embedded in Nb are embedded in Nb, Ta, Nb-base alloy or Ta-base alloy as a matrix material is obtained.

Abstract: A high-performance Nb3Al extra-fine multifilamentary superconducting wire is produced simply and inexpensively through the improvement of critical values, Tc, Hc2 and Jc, without the addition of third elements such as Ge, Si and Cu. A first rapid heating and quenching treatment is applied to an Nb/Al composite wire having an atomic ratio of Al to Nb from 1:2.5 to 1:3.5 and having an extra-fine multifilamentary structure to form a BCC alloy phase comprising Nb with Al supersaturatedly dissolved therein wherein the treatment comprises heating the composite wire up to a temperature not lower than 1900° C. within two seconds and then introducing it into a molten metal at a temperature not higher than 400° C. to rapidly quench it.

Abstract: A Nb3Al superconducting wire and method for fabricating the same wherein Nb and Al powders in combination, or Nb—Al alloy powders are encapsulated in a metal tube, preferably copper or copper-alloy (e.g., CuNi), and the resultant composite is processed by conventional means to fine wire. Multifilamentary composites are produced by rebundling of the powder-filled wires into metal tubes followed by conventional processing to wire of a desired size. It is required for the use of Nb and Al powders in combination that the Nb and Al powder particle size be less than 100 nm. In the use of Nb—Al alloy powders, it is preferred, but not required, that the powder particle size be similarly of a nanometer scale. The use of nanometer-scale powders is beneficial to wire fabrication, allowing the production of long wire piece-lengths. At final wire size, the wires produced by practice of the present invention are heat treated at temperatures below the melting point of copper (1083° C.

Abstract: A Cu-containing Nb3Al multifilamentary superconductive wire having a multifilamentary (superfine multi-core structure that a large number of micro-complex cores each obtained by complexing a Cu—Al alloy containing Cu in an amount of more than 0.2 at. % and at most 10 at. % in Nb are embedded in Nb, Ta, an Nb alloy or a Ta alloy as a matrix, wherein in the micro-complex cores, an A15 phase compound structure is formed by rapid heating at a temperature of 1,700° C. or more for 2 seconds or less and quenching to approximately room temperature, and further additionally heat-treated at a temperature of 650 to 900° C. This superconductive wire has high Jc in a low magnetic field, can be applied to all magnetic fields of 29 T or less, and is excellent in Jc characteristics in a high magnetic field in comparison with an Nb3Al wire.

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: A tin alloy bath with controlled iron content is used for coating a niobium-base substrate with tin in a manufacturing process for triniobium tin superconductor. One hundred twenty-five parts per million by weight or less of iron is used in tin alloy baths to increase the reaction kinetics of the formation of the superconductor material.

Abstract: A method of forming a superconducting joint between the Nb.sub.3 Sn layer of a superconducting tape and a superconducting NbTi wire through use of a Pb-Bi bath, joint securing arrangement and mold around the joint.

Abstract: Object of the present invention is to obtain a Nb.sub.3 Al group superconductor having a high critical current density under a whole range of magnetic field from low to high such as 20 T level, manufacturing methods thereof, a Nb.sub.3 Al group superconducting precursory composition, and a magnet for high magnetic field. In a process for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, the object of the present invention can be achieved.

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: In a method for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, A Nb.sub.3 Al group superconductor can be achieved.

Abstract: A method to provide large sheets of Nb.sub.3 Sn superconducting material suitable for use as a superconducting gradient shield in a magnetic resonance imaging system magnet by heating an anodized Nb-1 Zr sheet, tin dipping and reacting the sheet, and subsequently quenching the sheet in a purged atmosphere to provide an improved time constant and lowered Jc heating when used in a superconducting magnetic field.

Abstract: Foils used to manufacture superconductor materials can effectively be cleaned by heat treatment prior to anodization and further processing steps. The heat treatment can be in conjunction with other cleaning processes or separate.

Abstract: The solid-liquid diffusion process used to form triniobium tin superconductor is improved by oxidizing the tin coated niobium substrate with an oxide layer on the surface of the tin coat after tin dipping. The oxide layer can be added to the tin coat by passing the tin coated niobium substrate through an oxidizing chamber before the reaction anneal step, by adding oxygen to the reaction anneal furnace with argon or helium, by adding oxygen to the cooling tower immediately after the tin dipping process, or by controlling the exit temperature of the tin coated substrate from the tin dip in room atmosphere conditions.

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 of manufacturing an Nb.sub.3 Al superconducting wire includes a step of forming a wire by a jelly-roll process, a first thermal step of heating the obtained wire at a temperature of 500.degree. to 700.degree. C. for at least 10 hours for diffusing Al in Nb while suppressing formation of Nb.sub.3 Al, and a second thermal step of heating the wire, after the first thermal step, at a temperature of 800.degree. to 1050.degree. C. for about 0.01 to 10 hours, thereby forming Nb.sub.3 Al. In the jelly-roll process, a sheet of Nb and a sheet of Al are lap-wound on a copper core. The material obtained by such lap winding is inserted in a copper pipe, and then subjected to drawing. The drawn wire is cut to obtain a plurality of segments. The plurality of segments are bundled and charged in a copper pipe, and then subjected to drawing. The resulting drawn wire is subjected to the first and second thermal steps.

Abstract: A process for preparing a superconducting wire having improved superconducting characteristics in shortened period of time at a reduced cost, which comprises the steps of forming a plurality of holes in each of Cu base metal plates, stuffing the plates in a supporting container to form a stacked body of the plates with their holes aligned with each other, stuffing a superconductor or a material convertible into a superconductor by a heat treatment into the resulting through-holes of the stacked body, evacuating and sealing the supporting container to form a composite billet, and processing the composite billet in a usual manner to give a superconducting wire.

Abstract: A method for making triniobium tin foil is disclosed where the niobium-based foil with an oxide layer is passed continuously at a set speed into an enclosed chamber. The enclosed chamber has an inert atmosphere which is substantially oxygen free. Upon entering the chamber, the foil passes through a decomposition anneal furnace, a low temperature tin dip, and then a high temperature reaction anneal furnace before exiting the chamber as triniobium tin foil.