JP2557063B2 - Superconducting wire manufacturing method - Google Patents

Description

The present invention relates to a superconducting magnet coil, a superconducting wire used for power transportation, and the like, and relates to a superconducting wire using an oxide-based superconductor as a superconductor.

“Prior Art” Recently, various oxide-based superconducting materials exhibiting a high critical temperature (Tc) at which a transition from a normal conducting state to a superconducting state is higher than liquid nitrogen temperature are being discovered. And, among the conventional superconductors made of this kind of superconducting material, Y-Ba-Cu-O
System, so-called AB-Cu-O system such as La-Sr-Cu-O system (however, A represents a group IIIa metal element of the periodic table such as Y, La, Ce, Yb and Sc, and B represents In order to produce a superconducting material (which represents an alkaline earth metal element such as Ba or Sr), the compound powder of the group IIIa metal element, the compound powder of the alkaline earth metal element, and the copper oxide powder are mixed. The mixed powder thus obtained is molded into a predetermined shape and further heat-treated to obtain a superconducting material.

Attempts have also been made to wire oxide superconductors such as the AB-Cu-O superconductors into wire rods. As a method for producing a superconducting wire using such an oxide superconducting material, for example, a metal seal such as copper is filled with a powder of the oxide superconducting material or its raw material powder, and then wire drawing is performed. A method of manufacturing a superconducting wire has been attempted.

"Problems to be solved by the invention" However, in such a superconducting wire, since it is difficult to mix the raw material powder of the superconductor completely uniformly, even if a heat treatment is performed, the crystal parts in which each part is completely uniform are obtained. When a long superconducting wire is manufactured without a structure, it is not possible to generate a superconductor with a uniform crystal structure in a continuous state over the entire superconducting wire. There was a problem that the wire could not be manufactured.

Further, since the inside of the superconducting wire is made of brittle ceramics, there is a problem that the mechanical strength is low.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a long long conductive wire having excellent superconducting properties and high mechanical strength.

"Means for Solving Problems" A method for manufacturing a superconducting wire according to the present invention is
O type (however, A represents a group IIIa metal element of the periodic table such as Y, La and Ce, and B represents an alkaline earth metal element such as Ba and Sr)
A method for manufacturing a superconducting wire comprising the superconductor according to claim 1, wherein the copper alloy wire contains the A element, the copper alloy wire contains the B element, and the copper alloy contains the A element and the B element. A wire, a metal wire having an oxide layer formed on the surface thereof, a metal wire in which particles of copper oxide are dispersed, a copper alloy wire containing the above-described A element in which particles of copper oxide are dispersed, and particles of copper oxide. A plurality of dispersed copper alloy wires containing the element B, metal wires containing the element A having an oxide layer formed on the surface, and metal wires containing the element B having an oxide layer formed on the surface And bundling the respective lines so that all the elements constituting the AB-Cu-O-based oxide are included in a plurality of lines adjacent to each other to form a superconducting segment element conductor, and at least one of At least one normal conductor consisting of a superconducting segment element conductor and a metallic normal conductor. An electrically conductor segments collectively, and the superconducting wire is subjected to wire drawing, then a means of solving problems to produce a superconducting wire is subjected to a heat treatment to the superconducting wire.

[Operation] In this method for producing a superconducting wire, all the elements constituting the AB-Cu-O-based oxide are bundled into a plurality of copper alloy wires or metal wires adjacent to each other to form a superconducting segment element conductor, At least one superconducting segment element conductor and at least one normal conducting segment conductor composed of a metallic normal conductor are gathered, subjected to wire drawing to form a superconducting element wire, and then subjected to heat treatment to obtain a superconducting segment element conductor. The contact portion reacts in a state where the respective wires are in close contact with each other, and an oxide superconductor having a uniform crystal structure is generated in the contact portion in a continuous state over the entire superconducting wire.

Further, the metal wire portion and the normal-conducting segment conductor remaining in the central portion of each of the wires enhance the mechanical strength of the oxide superconductor and act as a stabilizing material.

"Example" Hereinafter, a method for manufacturing a superconducting wire according to the present invention will be described with reference to Y-Ba-Cu.
An example applied to the method of manufacturing an —O-based superconducting wire will be described in detail.

In the method for manufacturing a superconducting wire of this example, first, as shown in FIG. 1, a plurality of Y—Cu alloy wires 1, a plurality of Ba—Cu alloy wires 2, and a plurality of CuO dispersed copper wires 3 are bundled together. To form the superconducting segment element conductor 4. The number of these wires used is not particularly limited, but it is necessary that these wires are assembled so that all the elements that constitute the Y-Ba-Cu-O-based superconductor are adjacent to each other.

Next, two superconducting segment element conductors 4 and a normal conducting segment conductor 6 formed by bundling a plurality of copper wires 5 together.
The two are assembled as shown in FIG. 2 to form a superconducting element wire 7. The normal conductive segment conductor 6 may be formed by bundling a plurality of copper wires 5 as shown in FIG.
Alternatively, an integral member formed into a desired shape such as a fan-shaped cross section may be used. The material of the normal conducting segment conductor is, in addition to copper, silver, gold, platinum, aluminum, copper alloy, silver alloy,
Various metal materials such as stainless steel, copper-silver clad, and copper-gold clad can be used. The numbers of the superconducting segment element conductors 4 and the normal conducting segment conductors 6 are not limited, but it is desirable that the superconducting segment element conductors 4 and the normal conducting segment conductors 6 are assembled so as to be adjacent to each other, as shown in FIG. .

Next, the superconducting wire 7 is shaped and drawn. By this forming / drawing process, the superconducting element wire 7 is formed into a wire rod in which four segments each having a fan-shaped cross section are assembled and joined in a circular cross section.

Next, heat treatment is applied to the superconducting wire that has been formed and drawn. This heat treatment condition is 1 to 100 at a temperature of 800 to 1000 ° C.
Time is suitable. In this example, the method of the present invention is applied to a superconducting wire including a Y-Ba-Cu-O-based superconductor, and Y-Ba-Cu is used as the superconductor.
When manufacturing a superconducting wire including an A-Ba-Cu-O-based superconductor other than -O, it is necessary to appropriately set the heat treatment conditions. By this heat treatment, each wire in each superconducting segment element conductor 4, that is, each wire of the Y—Cu alloy wire 1, the Ba—Cu alloy wire 2, and the CuO-dispersed copper wire 3 is brought into close contact with each other at a contact portion. Occurs, and a Y-Ba-Cu-O-based superconductor having a uniform crystal structure is generated continuously over the entire length of the superconducting element wire 7.

By the above operation, as shown in FIG. 3, Y-Ba-
A superconducting wire 9 having a circular cross section, which is composed of two superconducting segment conductors 8 including Cu—O based superconductors and two normal conducting segment conductors 6, is manufactured.

Although the superconducting wire 9 has a circular cross section in this example,
The cross-sectional shape of the superconducting wire 9 is not limited to this, and may be formed to have a rectangular cross section, for example.

Further, in this example, a plurality of superconducting segment element conductors 4 and normal conducting segment conductors 6 are assembled and subjected to molding and wire drawing as they are. However, the assembly of each segment is housed in a metal sheath such as copper. The wire drawing process may be applied to this.

According to the method of manufacturing a superconducting wire according to this example, Y-Ba-
The superconducting segment element conductors 4 are created by assembling the respective wires so that all the elements constituting the Cu-O-based superconductor are included in a plurality of copper alloy wires or copper wires that are adjacent to each other. 4 and two normal-conducting segment conductors 6 formed by bundling copper wires 5 into a superconducting element wire 7. The superconducting element wire 7 is formed and drawn, and then heat-treated. The contact portion reacts with each wire in the element conductor 4 in close contact with each other, and a Y-Ba-Cu-O-based superconductor having a uniform crystal structure is formed in the contact portion continuously over the entire length. Therefore, the superconducting wire 9 having excellent superconducting characteristics can be manufactured.

Further, the normal conducting segment conductor 6 and the superconducting segment conductor 8 provided in close contact with the superconducting segment conductor 8
The unreacted metal wire portion remaining inside is the above Y-Ba-Cu-O.
Superconducting wire with high mechanical strength that can reinforce the superconductors 9
Can be manufactured.

[Production example]

Based on the method of the present invention, a superconducting wire comprising a Y-Ba-Cu-O-based superconductor was manufactured.

A Y-Cu alloy wire having a diameter of 1 mm containing 15% of yttrium, a Ba-Cu alloy wire having a diameter of 1 mm containing 30% of barium, and a copper wire having a diameter of 1 mm in which CuO was dispersed by 45% were prepared. Next, these wires were bundled in an array as shown in FIG. 1 to obtain a superconducting segment element conductor. On the other hand, copper wires having a diameter of 1 mm were bundled in the same manner as the superconducting segment element conductor to form a normal conducting segment conductor. Next, two superconducting segment element conductors and two normal conducting segment conductors were assembled into the state shown in FIG. 2 to form a superconducting element wire. Next, this superconducting element wire is subjected to wire drawing processing, drawn into a wire having a diameter of 0.5 mm, and then subjected to heat treatment at 500 to 900 ° C. for 10 to 20 hours, and has the same structure as that shown in FIG. Manufactured superconducting wire.

As a result, a long superconducting wire having a good superconducting property of critical temperature of 95K was obtained, and the mechanical strength of the obtained superconducting wire was improved as compared with the conventional one.

"Effect of the invention" According to the method for manufacturing a superconducting wire according to this example, AB-
A superconducting segment element conductor is prepared by assembling each element so that all the elements constituting the Cu-O-based superconductor are included in a plurality of copper alloy wires or copper wires that are adjacent to each other. , Two normal conducting segment conductors consisting of normal conductors are gathered to form a superconducting element wire, and this superconducting element wire is subjected to forming / drawing processing and then heat treatment, so
The superconducting segment reacts in the contact portion of each wire in the element conductor in close contact with each other, and the contact portion has a uniform crystal structure AB.
A —Cu—O-based superconductor can be continuously formed over the entire length, and a superconducting wire having excellent superconducting properties can be manufactured.

Further, the normal-conducting segment conductor provided in close contact with the superconducting segment conductor and the unreacted metal wire portion remaining in the superconducting segment conductor can reinforce the Y-Ba-Cu-O-based superconductor and mechanically A superconducting wire with high strength can be manufactured.

[Brief description of drawings]

1 to 3 are views for explaining an example of the method of the present invention. FIG. 1 is a cross-sectional view showing a superconducting segment element conductor, and FIG. 2 is a cross section showing a state of forming superconducting element wires. A plan view and FIG. 3 are cross-sectional views showing a superconducting wire. 1 ... Y-Cu alloy wire, 2 ... Ba-Cu alloy wire, 3 ... CuO
Dispersed copper wire, 4 ... Superconducting segment conductor, 6 ... Normal conducting segment conductor, 7 ... Superconducting element wire, 8 ... Superconducting segment conductor, 9 ... Superconducting wire.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shoichi Hasegawa 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Cable Co., Ltd. (72) Inventor Hiroshi Yamanouchi 1-1-5, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd.

Claims (2)

(57) [Claims] 1. A-B-Cu-O system (wherein A represents a group IIIa metal element of the periodic table such as Y, La and Ce, and B represents an alkaline earth metal element such as Ba and Sr. ) A method for producing a superconducting wire comprising a superconductor, comprising: a copper alloy wire containing the A element, a copper alloy wire containing the B element, and the A element and the B element. A copper alloy wire, a metal wire in which particles of copper oxide are dispersed, a metal wire in which an oxide layer is formed on the surface, a copper alloy wire containing the above element A in which copper oxide is dispersed, and copper oxide are dispersed. And a copper alloy wire containing the above B element and the above A having an oxide layer formed on the surface thereof.
A plurality of metal wires containing the element and metal wires containing the element B having an oxide layer formed on the surface thereof are selected,
A superconducting segment element conductor is formed by bundling the respective wires so that all the elements constituting the —Cu—O-based oxide are included in a plurality of mutually adjoining lines, and at least one of the superconducting segment element conductors and a metal At least 1 consisting of a normal conductor
A method for producing a superconducting wire, which comprises gathering two normal conducting segment conductors, subjecting them to wire drawing processing to form a superconducting element wire, and then subjecting this superconducting element wire to a heat treatment. 2. The method for producing a superconducting wire according to claim 1, wherein a wire rod in which a part of oxygen contained in the superconducting segment element conductor is replaced with halogen is used.