National Research Institute for Metals

Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

The Furukawa Electric Co., Ltd.

Tokai University

National Research Institute

Kyoji Tachikawa

Kazumasa Togano

Hisashi Sekine

Hiroaki Kumakura

Kikuo Itoh

Yutaka Yamada

Satoru Murase

Toshihisa Asano

Takao Takeuchi

Yuji Yoshida

Kiyoshi Inoue

Mitsuo Sasaki

Yasuzo Tanaka

Hisaki Sakamoto

Yasuo Iijima

Yoshiaki Tanaka

Shoji Miyashita

Susumu Tsukamoto

Ei Nakamura

Hirosada Irie

Kaname Matsumoto

Hitoshi Wada

A superconductor wire comprising a plurality of Nb--Ti superconductor filaments embedded in a copper matrix made of a copper alloy other than a two element copper alloy selected from the group consisting of a Cu--Ni alloy, a Cu--Sn alloy and a Cu--Mn alloy, wherein the resistivity (Z) at room temperature of the copper matrix is 2.times.10.sup.-8 .OMEGA.m to 65.times.10.sup.-8 .OMEGA.m, and the distance between superconductor filaments is not less than 0.0625.times.1/.sqroot.Z nm. The superconductor wire has a high critical current density, a small AC loss and improved workability.

Superconductor wire

A process for producing a Ti-containing Nb.sub.3 Sn composite superconductor which comprises working a composite composed of a Cu matrix, a Sn core placed centrally of the matrix and Nb cores disposed around the Sn core and heat-treating the worked composite, said Sn core containing 0 to 30 atomic % of Ti and said Nb cores containing 0.1 to 5 atomic % of Ti on an average.

Process for producing Ti-containing Nb.sub.3 Sn composite superconductor

A powder having a predetermined composition is filled in a tube. The tube is drawn to obtain a wire and the wire is rolled to obtain a tape-like starting body. Then, a laser beam is irradiated on the part of the tape to heat and melt the part of the tape. The starting body is rapidly heated and then cooled, thereby the part of the starting body is melted and solidified to form a compound superconductor layer.

Method of manufacturing compound superconductors

A process for producing a superconducting compound tape or wire material, which comprises irradiating electron beams at an acceleration voltage of 5 to 150 KV on a starting tape or wire material consisting essentially of constituent elements of a superconducting compound, a compound between the constituent elements, and/or an alloy between the constituent elements at a power density, determined on the starting tape or wire material, of 1.times.10.sup.3 to 1.times.10.sup.7 W/cm.sup.2 while the starting tape or wire material is moved at a rate of 1 cm to 10 m/sec relative to the electron beams.

Process for producing superconducting compound tape or wire material by

An A-15 type superconductor compound having the composition A.sub.3 B composed of niobium (element A) and at least one element (B) selected from gallium, aluminum and germanium is produced by coating at least one element B on a substrate of niobium, heat-treating the coated niobium substrate at a temperature of 500.degree. to 2,000.degree. C. for 1 second to 300 hours to form intermetallic compounds of niobium and the coated element which are richer in element B than A-15 A.sub.3 B compound, and thereafter subjecting the substrate to the irradiation of high density energy beams such as electron beams or laser beams to form the A-15 type superconductor compound having the composition A.sub.3 B.

Process for production of A-15 type superconductor compound

A method of manufacturing a fine multifilamentary Nb-Ti based superconducting wire was disclosed, which comprises a first step of processing an alloy consisting essentially of 10 to 50 atomic % of niobium, 40 to 75 atomic % of titanium and no higher than 30 atomic % of least one element selected from a group consisting of hafnium, tantalum and tungsten to form an alloy wire, a second step of covering said alloy wire with a stabilizer, cold drawing the resultant wire, bundling a plurality of stabilizer-clad wires thus obtained, covering the bundle of wires with a stabilizer, and extruding and cold drawing the resultant bundled wire to thereby form a multifilamentary wire, and a third step of thermally treating the resultant multifilamentary wire at a temperature of 250.degree. to 600.degree. C. and drawing the resultant treated multifilamentary wire to a reduction rate of 30 to 99.9%. The third step is carried out more than once.

Method of manufacturing fine filamentary Nb-Ti based alloy

A process for producing a Nb.sub.3 Sn superconducting wire, which comprises preparing a composite from a copper alloy material containing 0.1 to 5 atomic percent in total of at least one element of Group IV of the periodic table selected from titanium, zirconium and hafnium, a tin material and a niobium material, processing the composite into a wire, tape or tube, and heat-treating the processed composite at a temperature of 400.degree. to 900.degree. C. to form a Nb.sub.3 Sn compound.

Process for producing NB.sub.3 SN superconducting wires

In a process for producing at least one Nb.sub.3 Sn superconductor which comprises drawing a composite composed of a core of niobium or a niobium alloy and a matrix of a copper-tin alloy and subjecting the drawn composite to reactive heat-treatment, thereby forming a layer of Nb.sub.3 Sn between the core and the matrix; the improvement wherein the copper-tin alloy contains 1 to 15 atomic percent of tin, and 0.1 to 8 atomic percent in total of at least one element selected from 0.1 to 8 atomic percent of titanium, 0.1 to 5 atomic percent of zirconium and 0.1 to 5 atomic percent of hafnium.

Process for producing Nb.sub.3 Sn superconductor

In a method for producing an Nb.sub.3 Sn superconductor which comprises elongating a composite composed of a core portion of an alloy containing niobium and a matrix portion of a copper-tin alloy, a copper-tin-aluminum alloy or a copper-tin-gallium alloy and heat-treating the elongated composite to form an Nb.sub.3 Sn layer between the core portion and the matrix portion; the improvement wherein the core portion of the composite is made of a niobium-titanium alloy containing 0.1 to 10 atomic percent of titanium.

Method for producing Nb.sub.3 Sn superconductors

In a method for producing a Nb.sub.3 Sn superconductor which comprises drawing a composite having a core of a Nb-Hf alloy containing 0.1 to 30 atomic % of Hf and a sheath containing Cu and Sn, and heat-treating the composite to form a Nb.sub.3 Sn layer between the core and the sheath; the improvement wherein the sheath is formed of pure Cu, a Cu-Sn alloy containing not more than 6 atomic % of Sn, a Cu-Ga alloy containing not more than 20 atomic % of Ga, a Cu-Al alloy containing not more than 20 atomic % of Al, a Cu-Ga-Sn alloy containing not more than 6 atomic % of Sn and not more than 20 atomic % of Ga, or a Cu-Al-Sn alloy containing not more than 6 atomic % of Sn and not more than 20 atomic % of Al; and after the drawing, a Sn film is coated on the surface of the sheath, and then the product having a Sn film coated thereon is heat-treated.

In a method of producing a superconducting Nb.sub.3 Sn wire which comprises passing a wire or tape of a niobium-base alloy through a molten metal bath containing tin and then heat-treating it to form a Nb.sub.3 Sn compound layer on the surface of said wire or tape, the improvement wherein said niobium-base alloy is an alloy comprising niobium and 0.1 to 30 atomic percent of hafnium, and said molten metal bath is a molten bath of pure tin or a tin-base alloy consisting of tin, from 0.1 to 70 atomic percent of one element of Group IIIb of the periodic table selected from the group consisting of gallium, indium, and aluminum, and from 0.1 to 70 atomic percent of one element of Group Ib of the periodic table selected from the group consisting of copper and silver, the total amount of the element of Group IIIb and the element of Group Ib not exceeding 70 atomic percent.

Method for producing superconducting Nb.sub.3 Sn wires

A method for producing a V.sub.3 Al superconductor which comprises making a composite composed of a sheath portion of a copper alloy containing 1 to 15 atomic percent of germanium, 1 to 15 atomic percent of silicon or 2 to 25 atomic percent of gallium and surrounded by the sheath portion, at least one core portion of a vanadium-aluminum alloy containing 0.5 to 20 atomic percent of aluminum; elongating the composite; and then heat-treating the elongated composite thereby to form a V.sub.3 (Al, Ge), V.sub.3 (Al, Si) or V.sub.3 (Al, Ga) layer between the sheath portion and the core portion.

Method for producing superconductors

In a method for producing V.sub.3 Ga superconductors which comprises forming a composite of a core portion and a sheath portion surrounding said core portion, said sheath portion being composed of a gallium-containing alloy selected from the group consisting of copper-gallium and copper-silver-gallium alloys, and said core portion being composed of a vanadium metal, elongating said composite, and heat-treating the resulting elongated composite to form a V.sub.3 Ga layer between said sheath and core portions; the improvement wherein the gallium-containing alloy has a gallium content of 0.1 to 30 atomic percent and additionally contains at least one metal selected from the group consisting of 0.05 to 5 atomic percent of magnesium, 0.5 to 10 atomic percent of aluminum, 0.1 to 10 atomic percent of cerium and 0.05 to 10 atomic percent of sodium, and the vanadium metal is a vanadium alloy containing 0.1 to 15 atomic percent of gallium.

In a method for producing Nb.sub.3 Sn superconductors which comprises forming a composite consisting of a core portion and a sheath portion surrounding said core portion, said sheath portion being composed of a Cu-Sn alloy, and said core portion being composed of a Nb metal; elongating said composite; and heat-treating the resulting elongated composite to form an Nb.sub.3 Sn layer between said sheath and core portions; the improvement wherein the Cu-Sn alloy contains 1 to 20 atomic percent of Sn and the Nb metal is an Nb alloy containing 0.1 to 30 atomic percent of Hf.

Method for producing Nb.sub.3 Sn superconductor

A superconductor including V.sub.3 Ga is produced by making a composite of a vanadium core metal, a continuous portion of aluminum surrounding the vandium core metal or forming a second core, and a copper, silver or copper-silver alloy containing gallium, fabricating the composite to the desired shape, and heat-treating the shaped composite. The vanadium core may contain titanium, zirconium or hafnium, and the continuous portion of aluminum may contain copper or zirconium.

Growing community of inventors

Tokyo, Japan

Kyoji Tachikawa