JPH03151205A - Manufacture for ceramic superconductive body - Google Patents

Abstract

PURPOSE:To enable formation of a long-sized ceramic superconductive body, by a method wherein a reinforced metallic sheet obtained by reinforcing a stabilized metal superior in thermal and electric conductivity with a heat- resistant high-strength metallic material is used for one metallic sheet out of the two metallic sheets constituting a composite. CONSTITUTION:A stabilized metallic sheet 1 is fed at a fixed speed through an uncoiler 5, over which a ceramic superconductive substance 4 is fed in a stratified state quantitatively through a hopper 6 arranged upward. Then the stratified ceramic superconductive substance 4 is made into a composite body 8 by feeding a reinforced metallic sheet 3 obtained by reinforcing a stabilized metal with a heat-resistant high-strength metallic material onto the stratified ceramic superconductive substance 4 from an uncoiler 15 through a guide roll 7. It is made into a composite material 10 by rolling with a rolling roll 9 and wound up round a coiler 11. Then sintering, feed of oxygen and regulation of crystalline structure are performed by heat-treating the same and the same is made into a ceramic superconductive body. With this construction, an excellent and long-sized ceramic superconductive body is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a ceramic superconductor with excellent mechanical and electrical properties suitable for use as a conductor in magnets, coils, current leads, current limiters, cables, etc. Relating to a manufacturing method.

[Conventional technology and its issues]

In recent years, La-Ba-Cu-0 has shown superconductivity at liquid nitrogen temperatures.
system, La-3r-Cu-0 system, Y-Ba-Cu-0 system,
B i -3r-Ca-Cu-0 system, Tl-Ba-Ca
Ceramic superconductors such as the -Cu-0 series have been discovered, and their application to magnets and the like is being actively studied.

By the way, since the above-mentioned ceramic superconductor is brittle, in order to process it into a wire etc., a metal tube is filled with a raw material that can be made into a ceramic superconductor and stretched.The obtained wire is then heat-treated. By doing so, a ceramic superconductor is manufactured.

The ceramic superconductor thus obtained is a conductor in which the outer periphery of the ceramic superconductor layer is coated with a metal layer, and this metal layer not only reinforces the internal ceramic superconductor layer but also provides cooling during use. It also functions as a medium and as a current bypass in the event of a quench accident.

However, the metal layer used is a metal with excellent thermal and electrical conductivity such as Ag, and the heat treatment is
Because the process is carried out at a high temperature of 1000°C for a long period of time, the metal layer of the resulting 44 ceramic superelectric bodies softens and its reinforcing effect decreases. There is a problem in that the ceramic superconductor layer is easily stretched and deformed, causing distortion and cracks in the internal ceramic superconductor layer, resulting in a decrease in properties such as critical current density (Jc).

Furthermore, as mentioned above, the raw material that can be used as a ceramic superconductor is filled into a metal tube or stretched between metal plates, making it difficult to manufacture a long body and resulting in poor productivity.

[Means to solve problems]

The present invention was made as a result of intensive research in view of the above situation, and its purpose is to provide a method for manufacturing 44 long ceramic superelectric bodies with excellent mechanical and electrical properties. Specifically, the present invention involves continuously supplying a ceramic superconductor or its precursor in a layered manner onto a traveling metal sheet, further covering it with another metal sheet to form a composite, and adding the following to the composite: A method for manufacturing a ceramic superelectric 44 body as it is or by subjecting it to a desired elongation process and then subjecting it to a predetermined heat treatment, the method comprising: at least one metal sheet of the two metal sheets constituting the composite body; The invention is characterized by the use of a reinforced metal sheet in which a stabilized metal with excellent thermal and electrical conductivity is reinforced with a heat-resistant, high-strength metal material.

Ceramic superconductor or its precursor used in the method of the present invention (hereinafter abbreviated as ceramic superconductor)
In addition to the various types of ceramic superconductors that are widely used as described above, intermediates from raw materials that can be made into ceramic superconductors, which are precursors of the above-mentioned ceramic superconductors, to synthesis into ceramic superconductors, For example, a mixture or coprecipitated mixture of the constituent elements of the ceramic superconductor, an oxygen-deficient composite oxide, or an alloy of the above constituent elements can be used, and these precursors can be converted into the ceramic superconductor by heat treatment in an oxygen-containing atmosphere. It is something that reacts.

In the method of the present invention, the stabilized metal sheet constituting the reinforced metal sheet includes Ag, Au, and Cu.

Ir%Pd, PL, or their alloys are used. Among them, Ag or Ag alloys have good oxygen permeability, so oxygen can be sufficiently supplied to the ceramic superconductor in the heat treatment process, and a high Jc can be obtained. Since it has high conductivity, it has excellent quench resistance and is suitable because it can increase the amount of current applied. In addition, Ni, Cr, Mo, W, or their alloys are suitable as the heat-resistant, high-strength metal material for reinforcing the stabilizing metal sheet, and any shape such as sheet or linear can be used. .

Next, an example of the structure of the reinforced metal sheet will be explained with reference to the drawings.

FIG. 1 is a cross-sectional view of a reinforced metal sheet,
1 is a stabilized metal sheet, and 2 is a heat-resistant high-strength metal material.

The opening in Figure A is a composite of one or two thin, heat-resistant, high-strength metal sheets 2 inside a stabilizing metal sheet 1. In this case, if a perforated sheet (Fig. A) or a net-like sheet (Fig. This is preferable since the oxygen permeability of the material is not inhibited. Also, Figure 1/
% is a composite of three thin, narrow heat-resistant, high-strength metal sheets 2 placed side by side at intervals in 1 (stabilized metal sheet); 2 are arranged in the longitudinal direction in a composite manner, and both have good oxygen permeability. In the above, it is preferable to plate the heat-resistant, high-strength metal material with a noble metal such as Pt, as this improves the adhesion with the stabilizing metal.

Such reinforced metal sheets are manufactured by conform extrusion, cold or hot welding, or the like.

The method of the present invention will be specifically explained below with reference to the drawings.

FIG. 3 is a process explanatory diagram showing one embodiment of the method of the present invention. In the figure, 3 is a reinforced metal sheet, and 4 is a ceramic superconducting material.

The stabilized metal sheet 1 was fed at a constant rate from the unfiller 5, and the laminated superconducting material 4 was quantitatively fed in a layered manner from the hopper 〇 placed above. A reinforced metal sheet 3 having a cross-sectional structure as shown in FIG. body 8
is rolled with a rolling roll 9 to produce a composite material IO, which is wound around a coiler 11.

In addition to the above-mentioned rolling process, any processing method such as extrusion, rolling, drawing, swaging, etc. can be applied to the stretching process of the composite body.

Therefore, the composite material after the above-mentioned stretching process is
The ceramic superconducting material is heated at a temperature of 00 to 1000°C to react and sinter into a lamic superconductor, supplying oxygen to the sintered body, adjusting the crystal structure, etc., and making the ceramic superconductor. Manufactured in the body.

Cross section 14 of the composite material produced in the intermediate step of the method of the present invention
An example is shown in Figure 4, Ill. 2. The one shown in Figure A has a structure in which a ceramic superconductor layer is sandwiched and rolled between a reinforced metal sheet 3 made by reinforcing a stabilized metal sheet +-i and a stabilized metal sheet L with a heat-resistant high-strength metal sheet 2. . The structure shown in the second example has a structure in which a ceramic superconductor layer 3 is sandwiched and rolled between two reinforced metal sheets 3 in which a stabilized metal sheet 1 is reinforced with a rod-shaped heat-resistant high-strength metal material 2. Also, what is shown in Figures C and 2 is one in which one or more grooves are provided in the upper part of the reinforced metal sheet 3, the grooves are filled with ceramic superconductors, and a stabilizing metal sheet is placed over the grooves and rolled. It is.

In the above, by using the reinforced metal sheet 1- provided with a plurality of grooves, it is possible to manufacture a multicore superconducting wire, and by laminating a plurality of sheets, it is possible to further increase the number of cores.

[Effect]

In the method of the present invention, the Igoraminox superconducting material is continuously supplied to the traveling metal sheet 1-, and the metal sheet is placed over the ceramic superconducting material 1,- to form a composite. Lamin shoes. , an inductive conductor can be manufactured.

In addition, since the above ceramic superconducting material is "c"), at least one of the two metal sheets is a reinforced metal sheet in which the stabilized metal sheet l- is reinforced with a heat-resistant high-strength metal material. Even after heat treatment, the ceramic superconducting body maintains high strength, and the inner ceramic superconductor layer is not damaged by external bending strain, impact, tension, etc., and is stable with the ceramic superconductor layer. The heat-resistant, high-strength metal sheet also alleviates the difference in thermal expansion between the heat-resistant and high-strength metal sheet, thereby preventing cracks from occurring due to thermal strain during heat treatment.

If the heat-resistant high-strength metal sheet used for the above-mentioned reinforced metal sheet is made breathable by making holes, oxygen permeation inside the reinforced metal sheet 1- will be improved during heat treatment. [Example] The present invention will now be explained in more detail with reference to Example U.

Embodiment 1 A ceramic superelectric body JLH11-1 was manufactured in accordance with the example shown in Fig. 3 (62+1). B1xSrs CaCu5O on stabilized metal substrate.

A calcined powder having a composition of is quantitatively supplied from a hopper, and a hole of 0.21≠ is drilled on the calcined powder with a hole coverage ratio of 30%.
A composite was made by continuously covering the L sheet with a reinforced metal sheet which was sandwiched and pressed between two Ag sheets each having a width of 4.5 its and a thickness of 0.5 mm. Next, this composite was rolled with a rolling roll to form a composite material having a width of 6°21111111 and a thickness of 2.01 as shown in FIG.

However, the above composite material was subjected to 850'' C2OH heat treatment in the atmosphere to produce a ceramic superconductor.

Example 2 Fourteen ceramic superelectric bodies were manufactured in the same manner as in Example 1 except that a non-perforated Ni sheet was used as the reinforced metal sheet.

Example 3 SU of 0, 2 mm ■φ plated with Au in an Ag sheet with a width of 6 mm and a thickness of 1° and 2 mm manufactured by the conform method.
The same pre-fired powder used in Example 1 was heated and melted on a reinforced metal sheet reinforced by arranging five S wires horizontally at equal intervals, and the same pre-fired powder as used in Example 1 was continuously supplied in a layered manner to solidify. The above-mentioned reinforced metal sheet made by reinforcing the above-mentioned Ag sheet with SUS wire is placed on the solidified layer to form a composite, and this composite is rolled, wound, and heat-treated in the same manner as in Example 1 to obtain a width. 7.14 ceramic superelectric bodies having a thickness of 2-2 were manufactured.

Example 4 In Example 1, a SUS net having the same shape as shown in the opening of Figure 2 and having a width of 8 l and a thickness of 0.2 m was sandwiched between Ag sheets and pressure-bonded to the composite metal sheet, and one side of this pressure-welded body was A
4 grooves with a width of 11 Ill and a depth of 0.5 w Iwr on the g sheet.
A reinforced metal sheet having the same shape as shown in FIG. A ceramic superstructure was formed in the same manner as in Example 1, except that a stabilized metal sheet made of Ag with 8 layers and a thickness of 2 m + 1 was placed on the calcined powder, and the dimensions of the composite material after rolling were 121 III in width and 2 mm in thickness. 14 electric bodies were manufactured.

Comparative Example 1 In Example 1, the reinforced metal sheet was replaced with radial 4.
44 ceramic superelectric bodies were manufactured in the same manner as in Example 1, except that a stabilized metal sheet made of Ag and having a thickness of 5 mm was used.

Comparative Example 2 In Example 3, a width of 6 m was used instead of the reinforced metal sheet.
Fourteen ceramic superelectric bodies were manufactured in the same manner as in Example 3, except that a stabilized metal sheet made of Ag and having a thickness of 1.2 m was used.

Each ceramic superelectric 14 obtained in this way
Tc and Jc were measured for the body.

In the above, Jc was measured in liquid N2 without a magnetic field. The results are shown in Table 1.

Table 1 *Reinforcement material for reinforced metal sheets.

As is clear from Table 1, the products produced by the method of the present invention had high values of Tc and Jc. Among these, Jc of Example 2 was a slightly lower value because the Ni sheet of the reinforcing material had no holes, so oxygen was not sufficiently supplied during the heat treatment.

Furthermore, the reason why Jc of Example 3 showed a high value is because the density of the ceramic superconductor layer was improved because the ceramic superconductor material was supplied in a molten state.

On the other hand, the comparative method product (Comparative Example 1.2) did not use a reinforced metal sheet, so both Jc
had a low value.

When the ceramic superconductor layer of the comparative method product was observed by SEM, many cracks and voids were observed. This is due to thermal distortion occurring in the ceramic superconductor layer due to the difference in thermal expansion during heat treatment, or because the stabilizing metal sheet is softened by heat treatment and tension is applied to the ceramic superconductor layer during handling. be. In particular, in Comparative Example 2, the stabilizing metal sheet was softened because the ceramic superconducting material was supplied in a molten state, and it is thought that the ceramic superconducting material in the inner layer also cracked when the composite material was wound up.

〔effect〕

As described above, according to the method of the present invention, a long ceramic superconductor having excellent superconducting properties and mechanical strength can be obtained, and a remarkable effect can be achieved on the T-beam.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing an example of a reinforced metal sheet, Part 2 A-C is a plan view showing an example of a heat-resistant high-strength metal sheet; The figure is a process explanatory diagram showing one embodiment of the method of the present invention.
4-Ceramic superconducting material, 8-・-composite, 10-
Composite material.

Claims (1)

[Claims] A ceramic superconductor or its precursor is continuously supplied in a layer on a running metal sheet, and another metal sheet is placed on top of it to form a composite, and the composite is subjected to a stretching process as is or as desired. A method for producing a ceramic superconductor by subjecting at least one of the two metal sheets constituting the composite to thermal and electrical conductivity. A method for manufacturing a ceramic superconductor, characterized by using a reinforced metal sheet in which an excellent stabilized metal sheet is reinforced with a heat-resistant, high-strength metal material.