JPH0422016A - Manufacture of compound superconductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for producing a compound-based conductor, and more specifically, to a method for producing a compound superconductor using a stabilizing material by diffusion of constituent elements, etc. The present invention relates to a method for manufacturing a compound superconducting conductor that prevents a decrease in electrical resistance.

(Prior art) As a superconducting conductor currently in practical use, Nb3S
Some are known to use compound-based superconductors such as n and Nb3 A1, or alloy-based superconductors such as Nb-Tj and Nb-Zr. Various places are researching the use of superconducting coils that can generate magnetic fields.

For example, a superconducting conductor using the above compound superconductor is manufactured by the method shown below.

That is, taking an Nb3Sn multi-superconducting wire as an example of a superconducting conductor, first, a large number of Nb core wires are embedded and integrated within a Cu--Sn alloy matrix. Next, this Cu
- The Sn alloy matrix is sequentially inserted into a Ta tube, etc., which will serve as a diffusion prevention layer, and a Cu tube, which will serve as a stabilizing material, and while they are integrated using a swaging machine, etc., the area is reduced to a predetermined outer diameter. After that, heat treatment is performed at the formation temperature of Nb3Sn to cause the Nb core wire to react with Sn in the Cu-Sn alloy matrix, and Nb is added to the outer circumferential side of the Nb core wire.
Form a b3Sn superconductor layer.

FIG. 9 shows a multi-superconducting wire manufactured in this way, in which a large number of Nb core wires 2 with Nb3Sn superconductor layers 1 formed on the outside are buried in a Cu-3n matrix 3. , a diffusion prevention layer 4 made of Ta or the like, and a stabilizing material layer 5 made of Cu are formed in this order on the outer periphery of the Cu-3n matrix 3 to form a multi-superconducting wire 6. Note that the stabilizing material layer 5 serves as a current path during the normal conduction transition of the Nb3 Sn superconductor layer 1, and prevents burnout and the like.

(Problem to be solved by the invention) By the way, C which becomes the stabilizing material 5 of such a superconducting wire 6
u is usually the residual resistance ratio (Re5idual Re-5
istictivity Ratio (hereinafter referred to as RI?
R)) or 200-3 (10,2
- If Sn in the 3n matrix 3 diffuses into the stabilizing material 5, the stabilizing material 5 will be contaminated with Sn, and its electrical resistance will increase significantly, and its function as a stabilizing material will be greatly reduced. There is a problem with putting it away.

The diffusion prevention layer 4 is provided to prevent the diffusion of Sn into the stabilizing material 5, or is not necessarily effective in preventing the diffusion of Sn into the stabilizing material 5 during heat treatment. C which is not sufficient and is a stabilizing material 5
Since properties such as elongation are significantly different between u and the material of the diffusion prevention layer 4, such as Ta, there may be difficulties in making the manufacturing process complicated, such as difficulty in uniformly applying wire drawing, etc. Ta.

The present invention has been made to address these problems, and is aimed at manufacturing a compound superconducting conductor that makes it possible to maintain the electrical resistance of the stabilizing material at a low level without providing a diffusion prevention layer made of Ta or the like. The purpose is to provide a method.

[Structure of the Invention] (Means for Solving the Problems) That is, the first method for manufacturing a compound superconductor in the present invention is to produce a Cu wire containing a compound superconductor material that reacts with heat treatment to form a compound superconductor. a step of embedding in a Cu-based matrix, a step of sequentially integrating a copper layer containing oxygen and a copper layer for a stabilizing material on the outside of the Cu-based matrix, and processing it into a desired conductor shape; a step of forming an oxide layer on the surface of the copper layer for stabilizing material of the structure, and applying the temperature at which the compound superconductor is formed in vacuum or in a non-oxidizing atmosphere to the structure on which the oxide layer is formed. The method is characterized in that it includes a step of performing heat treatment on the region.

The second method for manufacturing a compound superconductor includes a step of embedding a wire containing a compound superconductor material that reacts with heat treatment to form a compound superconductor in a Cu-based matrix; A step of forming an oxide layer, integrating a copper layer for stabilizing material through this oxide layer, and processing it into a desired conductor shape, and adding copper for stabilizing material of the integrated structure. A step of forming an oxide layer on the surface of the layer, and a step of subjecting the structure on which the oxide layer has been formed to heat treatment in a temperature range for forming the compound superconductor in a vacuum or a non-oxidizing atmosphere. It is characterized by

The compound superconductor material that reacts to form a compound superconductor through heat treatment used in the present invention is Nb3S.
Examples include Nb and Sn, which are the forming materials of n, and Nb and A1, which are the forming materials of Nb3Al. Furthermore, at least one of these compound superconductor materials is contained in a wire embedded in a Cu-based matrix, and the other is, for example, a C
Contained within a u-based matrix.

Further, the wire may be composed of both compound superconductor materials.

The specific structure of the Cu-based matrix filled with wires containing the compound superconductor material is such that one compound superconductor material, for example, a Cu-based alloy matrix containing Sn or A1, is filled with the other compound superconductor material. Examples include a material in which a wire of Nb is buried, or a wire in which a material containing Sn or AI is filled in a Nb tube is buried in a Cu-based matrix. Note that as the material for the Cu-based matrix, it is also possible to use a Cu-based alloy containing Ni or the like.

In the method for manufacturing a compound superconducting conductor of the present invention, a stabilizing material is first applied to a Cu-based matrix filled with wires containing the compound superconducting material described above, and then are integrated to form a structure that is a prototype of the compound superconducting conductor of the present invention.

■ Cu containing oxygen is placed outside the Cu-based matrix above.
The layers are integrated, and a Cu layer for a stabilizing material is integrated on the outside of this oxygen-containing Cu layer.

(2) An oxide layer is formed on the outside of the Cu-based matrix, and a Cu layer for a stabilizing material is integrated via this oxide layer.

The above-mentioned structure in the present invention may have any shape as long as the surface of the stabilizing material is in contact with oxygen gas. Various structures can be used, such as a linear body, a tape material in which a Cu-based matrix and a stabilizing material are laminated.

In addition, the oxygen-containing Cu in the above item (2) may be, for example, high-purity Cu containing oxygen in a range of about 0.08 to 1.0% by weight, or C in which oxide particles such as alumina are dispersed.
A u-based alloy or the like is used. As a method for incorporating oxygen into Cu, for example, after forming an oxide layer on the surface of a C0 member, heat treatment is performed at a temperature of about 600°C to 800°C in a vacuum to diffuse oxygen into Cu. A Cu-based alloy containing alumina or the like is produced by a hydrogen reduction method or the like. Further, as the Cu for the stabilizing material (1) and (2) above, pure copper having basically excellent conductivity is used.

In the present invention, after applying at least one of the above (1) and (2) and forming an oxide layer on the outer surface of the Cu layer for stabilizing material of the structure processed to the final size, the formation temperature of the compound superconductor used is Apply heat treatment to the area.

The above heat treatment is for reacting the compound superconductor material to form a compound superconductor.

In the manufacturing method of the present invention, the elements added to the Cu-based matrix by the heat treatment, such as the constituent elements of the compound superconductor, are diffused into the Cu layer for the stabilizing material. By combining oxygen in the Cu layer with oxygen diffused from the oxide layer formed on the surface of the Cu layer for stabilizing material, and in (2) above, the oxygen in the oxide layer formed on the surface of the Cu-based matrix It is formed on the surface of the Cu layer for the stabilizing material and captured by combining with oxygen diffused from the oxide layer distributed by processing into a desired shape. The oxides of these captured elements are arranged as a barrier layer between the oxygen-containing Cu layer and the Cu layer for stabilizing material in (1) above, and between the Cu-based matrix and Cu for stabilizing material in (2) above. .

The oxide layer formed on the surface of the Cu layer for stabilizing material is CuO
s Cu20 alone or a mixture of CuO and Cu2O, etc., for example, 1 to 12
It is formed by heat treatment for about 0 hours. Also, C
An oxide layer can be formed by forming a Cu oxide layer by VD, by chemically oxidizing it using a blackening agent, or by applying a paste-like paint containing a Cu oxide. I can do it.

If the oxide layer formed on the surface of the Cu layer for stabilizing material is too thin, for example less than 0.1μ, it will be difficult to supply enough oxygen, and the formation of a diffusion prevention layer using the metal oxide will be difficult. Or is it insufficient and low RRI? If the thickness of the oxide layer exceeds Iθμ for a wire diameter (outer diameter) of 1 mm, the amount of oxygen penetrating into the Cu for the stabilizing material will decrease. This increases the thickness of the diffusion prevention layer, reduces the volume of the stabilizing material due to oxidation, and may reduce the strength, RRR, and critical current density. Therefore, it is desirable to set the thickness of the Cu oxide layer while taking these balances into consideration.

In addition, the heat treatment conditions in the formation temperature range of compound superconductors are as follows:
LX In a vacuum of about 1O-3 Torr or less or in an inert gas atmosphere, for example, in the case of Nb3Sn, Nb5A is heated at 650°C to 770°C for 10 to 400 hours.
In this case, the temperature is 750°C to 950°C for about 1 to 100 hours.

Here, in the above (2), C
It is preferable to form an uneven shape on the interface between the U-based matrix and the Cu layer for stabilizing material, and then perform the above heat treatment. This is because by forming the above-mentioned uneven shape, the constituent elements of the compound superconductor are diffused over different distances from within the Cu-based matrix, and a barrier layer made of captured oxides is formed discontinuously. This makes it possible to maintain good heat conduction between the compound superconductor and the Cu layer for stabilizing material.

The uneven shape described above is obtained by roughening the outer surface of the inner member, such as an oxygen-containing Cu layer or a Cu-based matrix, using flat knurling, filing, etc., and then integrating Cu for the stabilizing material on top of it. It can be formed by

In addition, in the above (2), when forming an uneven shape on the boundary surface, it is preferable to use a material having a harderness than oxygen-containing Cu as the Cu for the stabilizing material. This makes it possible to sufficiently maintain the shape of the chevron groove formed by flat knurling or the like during the above-mentioned integration process. Furthermore, as the oxygen-containing C'u in such a case, it is advantageous to use the aforementioned Cu-based alloy in which oxide particles such as alumina are dispersed, so-called alumina dispersion-strengthened copper, etc. due to its high hardness. .

Further, by appropriately selecting conditions such as intermediate annealing, it is possible to impart a hardness difference between the Cus used.

Note that when the compound superconducting conductor obtained according to the present invention is applied to a product that can be heat treated, heat treatment in the above-mentioned compound superconductor formation temperature range may be performed during the assembly process of the product. For example, when forming a superconducting coil using the superconducting wire manufactured according to the present invention, the wire before heat treatment is wound onto a winding frame for the coil, and in this state, a compound superconductor and a diffusion prevention layer are formed. Heat treatment may also be performed for this purpose.

(Function) In the method for manufacturing a compound superconducting conductor of the present invention, Cu
After integrating a Cu layer containing oxygen on the outside of a Cu-based matrix, or after forming an oxide layer on the outside of a Cu-based matrix, a Cu layer for a stabilizing material is integrated. Here, if only the oxygen in the oxygen-containing Cu mentioned above or the oxygen in the oxide layer formed outside the Cu-based matrix is used, the constituent elements of the compound superconductor, etc. Diffusion into the stabilizer Cu cannot be sufficiently prevented. On the other hand, in the manufacturing method of the present invention, an oxide layer is further formed on the outside of the Cu layer for the stabilizing material, and oxygen diffused from this oxide layer is also used to form a compound superconductor such as Sn. The constituent elements and the like are captured as oxides and prevented from diffusing into the Cu layer for the stabilizing material. Thereby, it is possible to suppress an increase in the electrical resistance of the stabilizing material, and it is possible to improve the stability of the compound superconducting conductor.

In addition, by providing an uneven shape in the compound superconductor, differences tend to occur in the distance over which the constituent elements of the compound superconductor are diffused from within the Cu-based matrix. As a result, a barrier layer made of oxides such as constituent elements of the compound superconductor can be formed discontinuously, and good heat conduction can be maintained between the compound superconductor and the Cu layer for the stabilizing material. becomes possible.

(Example) Next, an example of the present invention will be described with reference to the drawings.

Example 1 First, as shown in FIG. 1(a), a cylindrical member made of a 12% by weight 5n-Cu alloy with an outer diameter of 50 rAmφ is prepared as a Cu-based matrix, and a large number of cylindrical members are arranged in the longitudinal direction of this Cu-8n matrix 11. A hole was opened, and the Nb core wire 12 was buried in each hole.

Next, as shown in FIG. 1(b), the Cu-8n matrix 11 with the Nb core wires 12 embedded therein is inserted into the Cu tube 13 containing 0.1% by weight of oxygen, and further stabilized. It was inserted into a Cu pipe 14 for materials, and was subjected to intermediate annealing while being integrated and subjected to surface reduction processing to a predetermined diameter.

Note that the oxygen-containing Cu tube 13 is heated at 300°C in the atmosphere.
After heat treatment for 20 hours to form a copper oxide layer on the surface, heat treatment was performed at 725°C in a vacuum of 3X 1O-6 Torr.
Oxygen is contained in Cu by performing heat treatment for 5 hours to diffuse oxygen. Also,
The Cu tube 14 for the stabilizing material was subjected to a softening heat treatment at 700° C. for 10 hours in a vacuum of 3×1 O −6 Torr.

Next, as shown in FIG. 1(C), the wire rod after the area reduction process is subjected to heat treatment at 300° C. for 50 hours in the atmosphere to coat the surface of the Cu tube 14 for stabilizing material with Cu. Oxide (Cu
An O+ Cu 20) layer 15 was formed.

After this, in a vacuum of 3x 1O-bTorr, 7
Heat treatment was performed at 00°C for 100 hours to cause the Nb core wire 12 to react with Sn in the Cu-8n matrix 11,
As shown in FIG. 1(d), Nb is placed on the outer periphery of the Nb core wire 12.
380 layers 16 were formed.

During this heat treatment, S in the Cu-8n matrix 11
n diffuses in the oxygen-containing Cu tube 13 or combines with oxygen contained in the Cu tube 13, and although the diffusion of Sn is suppressed to some extent, it further diffuses in the oxygen-containing Cu tube 13. Therefore, in this embodiment, in order to diffuse the oxygen in the Cu oxide layer 15 formed on the surface of the Cu tube 14 for stabilizing material into the Cu tube 14 for stabilizing material, the inside of the oxygen-containing Cu tube 13 is The diffused Sn is captured as an oxide, and a barrier layer 17 made of Sn oxide or the like is formed between the oxygen-containing Cu layer 13 and the stabilizer Cu layer 14. This prevents the stabilizer Cu layer 14 from being contaminated with Sn or the like.

RRI, which is the standard for the stability of compound superconducting wires obtained in this way? When we measured ρ (the same applies hereafter) at 20K just above the critical temperature, the RRR was 510 and ρ was l×
It was 10-9Ω·cm.

In addition, for comparison with the present invention, a compound superconducting wire formed by the same process except that an oxygen-containing Cu tube was not used and an oxide layer was not formed on the surface of the Cu tube for stabilizing material. The RRR of is 13 and ρ is 9X 10
It was -7Ω・cm.

From these results, it can be seen that the RRR of the compound superconducting wire according to the example of the present invention is improved by nearly 40 times, and a significant improvement in stability can be expected.

Furthermore, when these critical current densities were measured, the compound superconducting wire according to this example had a current density of 230 A/min at 15 Tesla.
Although no clear difference was observed between am2 and the conventional structure, the RRR measurement results above revealed that the purity of the stabilizing material could be maintained without using a diffusion prevention layer such as Ta. .

Example 2 Same as Example 1, except that the oxygen-containing Cu tube 13 in Example 1 above had chevron-shaped grooves 13a formed on the outer surface by flat knurling, as shown in FIGS. 2 and 3. A compound superconducting wire was fabricated using this process.

The cross section of the superconducting wire thus obtained was observed under a microscope. The observation results are schematically shown in FIG.

As is clear from the figure, the uneven shape 18 formed by the chevron-shaped groove 13a formed on the outer surface of the oxygen-containing Cu tube 13 is maintained at the interface between the oxygen-containing Cu layer 13 and the stabilizing material Cu layer 14. It was confirmed that a discontinuous barrier layer 19 made of Sn oxide or the like was formed on the valley side of the uneven shape 18.

Also, R1 of this compound superconducting wire? When R and ρ were measured, the same results as in Example 1 were obtained.

The compound superconducting wire according to the second embodiment has an oxygen-containing Cu layer 1
3 and the Cu layer 14 for stabilizing material, oxygen-containing Cu
Since the uneven shape 18 formed by the chevron-shaped groove 13a formed on the outer surface of the tube 13 exists, as shown in FIG.
There is a difference in the distance to the u-3n matrix 11 (Ω2
〉gl), this causes the valley side of the uneven shape 18 to contain oxygen.
Sn diffused into the Cu layer 13 is captured as an oxide, and a barrier layer 19 made of an oxide of Sn is formed discontinuously between the oxygen-containing Cu layer 13 and the stabilizer Cu layer 14. Ru.

In this way, the oxygen-containing Cu layer 13 and the stabilizing material Cu layer 1
By forming a barrier layer 19 made of Sn oxide or the like on the valley side of the uneven shape 18 provided at the interface with the uneven shape 18, the peak side of the uneven shape 18 becomes a path for current, and it is used as a stabilizing material. While preventing the Cu layer 14 from being contaminated with Sn or the like, it is possible to fully exhibit the function of the Cu layer 14 for the stabilizing material.

Example 3 A tubular member made of alumina dispersion-strengthened Cu was used as the oxygen-containing Cu tube in Example 1, and a chevron groove was formed on the outer surface of the alumina dispersion-strengthened Cu tube by flat knurling in the same manner as in Example 2. A compound superconducting wire was produced by the same steps as in Example 1 except that a wire formed with the following was used.

When the cross section of the superconducting wire thus obtained was observed under a microscope, it was confirmed that the uneven shape of the interface between the oxygen-containing Cu layer and the stabilizing Cu layer was more clearly maintained.

This is because alumina dispersion strengthened Cu has higher hardness than normal Cu (normal Cu has a Vickers hardness of Hvzoog-
40, whereas alumina dispersion-strengthened Cu has a Vickers hardness of Hv 2oog-120), so a chevron-shaped groove is formed on the outer surface of this alumina dispersion-strengthened Cu tube by flat knurling, and a soft This is because by covering the Cu tube for the stabilizing material, it becomes easier to embed the Cu for the stabilizing material in the valley side of the angular groove.

This creates a clear difference in the distance from the interface between the oxygen-containing Cu layer and the stabilizer Cu layer to the Cu-3n matrix, so the Sn oxide layer is formed on the valley side of the more uneven shape. This makes it easier to ensure a current path.

Further, by using alumina dispersion strengthened Cυ, there is also an advantage that heat treatment or the like for diffusing oxygen into the oxygen-containing Cu tube becomes unnecessary.

Example 4 After forming a chevron-shaped groove with flat knurling on the surface of the Cu-9n matrix in which the Nb core wire used in Example 1 was embedded, heat treatment was performed at 300°C for 30 hours in the air to improve the surface An oxide layer containing an oxide of Sn, an oxide of Cu, etc. was formed on the substrate.

Next, the Cu-3n matrix subjected to the above oxidation treatment was heated to 0.12% by weight. This was inserted into a Cu tube containing oxygen, and further inserted into a Cu tube for a stabilizing material, and while performing intermediate annealing, it was integrated and subjected to surface reduction processing to a predetermined diameter.

In addition, the above oxygen-containing Cu tube was heated at 300°C in the atmosphere at 2
After performing heat treatment for 0 hours to form a copper oxide layer on the surface, heat treatment was performed at 600° C. for 5 hours in a vacuum of 3×10-oTorr to diffuse oxygen. Naturally, since the heat treatment was performed at 600° C., the oxygen-containing Cu tube was softened. Further, the Cu tube for the stabilizing material was subjected to a softening heat treatment at 800° C. for 5 hours in a vacuum of 3×10−6 Torr. Since the Cu tube for the stabilizing material was subjected to a softening treatment at 800° C., its hardness was lower than that of the oxygen-containing Cu tube, that is, it was softer.

Thereafter, a surface oxidation treatment and a heat treatment in the compound superconductor production temperature range were performed under the same conditions as in Example 1 to produce a compound superconducting wire.

In this example, by changing the heat treatment conditions, etc., the hardness of Cu-8n matrix, oxygen-containing Cu, and stabilizer Cu was satisfied. Cu
Since each Cu is easily embedded in the chevron-shaped grooves formed on the surface of the -8n matrix, the interface between the oxygen-containing Cu layer and the stabilizer Cu layer and the interface between the Cu-8n matrix and the oxygen-containing 00 layer Excellent chevron grooves are formed on both surfaces.

When the cross section of the superconducting wire of this example was observed with a microscope, as shown in FIG.
1 and the oxygen-containing Cu layer 13, the Sn stabilizing material C
It was confirmed that differences in the diffusion distance to the u layer 14 were more likely to occur, and as a result, the Sn oxide distribution layer 2o was formed in the portion where the diffusion distance was short.

In addition, in the compound superconducting wire of this example, C
An oxide of Sn is formed on the surface of the u-3n matrix, and this oxide of Sn has become thinner due to surface reduction processing or is distributed in the long plane direction, so that S
This makes it easier to prevent diffusion of n.

When the RRR and ρ of the compound superconducting wire obtained in this way were measured, the RRR was 500, an improvement of nearly 25 times compared to the compound superconducting wire with the conventional structure, and ρ was LX
It was 10 −9 Ω·cm.

Example 5 First, as shown in FIG. 7(a), a Cu-3n made of a 12% by weight 5n-Cu alloy in which a large number of Nb core wires 12 were embedded.
On the surface of matrix 11,
After a heat treatment for several hours, Sn oxide and Cu are formed on the surface.
An oxide layer 21 containing an oxide or the like was formed.

Next, Cu-8n matrix 1 subjected to the above oxidation treatment
1 was inserted into the Cu tube 14 for stabilizing material, subjected to intermediate annealing, and then subjected to surface reduction processing to a predetermined diameter while being integrated.

The stabilizer Cu tube 14 was heat-treated in the same manner as in Example 4.

Next, as shown in FIG. 7(b), the wire rod after the area reduction process is subjected to heat treatment at 300° C. for 50 hours in the atmosphere to coat the surface of the Cu tube 14 for stabilizing material with Cu. Oxide (CuO
+Cu20) layer 22 was formed.

After this, in a vacuum of 3x 10-Torr, 70
Heat treatment was performed at 0°C for 100 hours, and the Nb core wire 12 and Cu
- react with Sn in the 8n matrix 11 to
As shown in Figure (c), Nb3S is placed on the outer periphery of the Nb core wire 12.
An n-layer 16 was formed.

During this heat treatment, S in the Cu-3n matrix 11
n tries to diffuse within Cu for the stabilizing material, or Cu-
Sn is captured as an oxide by the oxygen in the oxide layer 21 formed on the surface of the 3n matrix 11 and the oxygen diffused from the Cu oxide layer 22 formed on the surface of the Cu tube 14 for stabilizing material. , Cu layer 14 for stabilizing material and C
A barrier layer 23 made of a Sn oxide layer or the like is formed between the U-3N matrix 11 and the U-3N matrix 11. In addition, the oxide layer 21 containing Sn oxide, which is pre-formed on the surface of the Cu-3n matrix 11, has been made thinner by surface reduction processing or is distributed in the elongated direction, which prevents the diffusion of Sn. This makes it easier to prevent. These prevent the stabilizer Cu layer 14 from being contaminated with Sn or the like.

RI of the compound superconducting wire obtained in this way? When R and ρ were measured, RRR was 336 and ρ was 5×10-9Ω.
・It was C10.

Example 6 The Cu-5n matrix of Example 5 above was used, but the outer surface was formed with chevron-shaped grooves by flat knurling, and Example 5 was used except that an oxide layer was formed on the surface having the chevron-shaped grooves. A compound superconducting wire was fabricated using the same process.

The cross section of the superconducting wire thus obtained was observed under a microscope. The observation results are schematically shown in FIG. 8. As is clear from the figure, a Cu-3n matrix 1 is formed on the boundary surface between the Cu'-3n matrix 11 and the Cu layer 14 for the stabilizing material.
It was confirmed that the uneven shape formed by the chevron-shaped grooves 11a formed on the outer surface of the substrate 1 was maintained, and that a barrier layer 24 made of a discontinuous Sn oxide or the like was formed on the mountain side of the chevron-shaped grooves 11a.

Furthermore, when the RRR and ρ of this compound superconducting wire were measured, the same results as in Example 5 were obtained.

In the compound superconducting wire according to this example, since the chevron-shaped groove 11a exists at the interface between the Cu-8n matrix 11 and the Cu layer 14 for stabilizing material, a difference occurs in the diffusion distance of Sn, and Since the oxide layer of Sn or the like formed on the surface of the Cu-8n matrix 11 is thin or distributed in the longitudinal direction, Sn is captured as a discontinuous barrier layer 24.

[Effects of the Invention] As explained above, according to the present invention, since the impurity elements diffused into the stabilizing material are captured as oxides,
It becomes possible to provide a compound superconducting conductor with good reproducibility in which the electrical resistance of the stabilizing material is maintained low without providing a diffusion prevention layer made of Ta or the like.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the manufacturing process of one embodiment of the present invention, FIGS. 2 and 3 are views showing main parts of the manufacturing process of another embodiment of the invention, and FIG. A diagram schematically showing a cross section of a compound superconducting wire obtained in another example, FIG. 5 is a partially enlarged view thereof, and FIG. A diagram schematically showing a cross section,
FIG. 7 is a cross-sectional view showing the manufacturing process of still another example of the present invention, FIG. 8 is a view schematically showing a cross-section of a main part of a compound superconducting wire obtained according to still another example of the present invention, FIG. 9 is a cross-sectional view of a compound superconducting wire manufactured by a conventional method. 11...Cu-Sn alloy matrix, 12.
...Nb core wire, 13...Oxygen-containing Cu tube, lla, 13a...Chevron groove, 14...
Cu tube for stabilizing material, 15.2122...Oxide layer, 16...Nb3 Sn layer, 17.19.2
0.23.24...Barrier layer. Applicant: Toshiba Corporation

Claims (6)

[Claims] (1) A step of embedding a wire containing a compound superconductor material that reacts with heat treatment to form a compound superconductor in a Cu-based matrix, and a copper layer containing oxygen and a stabilizing material on the outside of the Cu-based matrix. a step of sequentially integrating the copper layer for use as a stabilizer and processing it into a desired conductor shape; a step of forming an oxide layer on the surface of the copper layer for the stabilizing material of the integrated structure; A method for manufacturing a compound superconducting conductor, comprising the step of subjecting a structure on which the layer is formed to heat treatment in a temperature range for forming the compound superconductor in vacuum or in a non-oxidizing atmosphere. (2) In the method for manufacturing a compound superconducting conductor according to claim 1, at least the interface between the oxygen-containing copper layer and the stabilizer copper layer and the interface between the Cu-based matrix and the oxygen-containing copper layer On the other hand, a method for producing a compound superconducting conductor, which includes a step of forming an uneven shape. (3) The method for manufacturing a compound superconducting conductor according to claim 2, wherein the hardness of the copper layer containing oxygen is greater than the hardness of the copper layer for stabilizing material. (4) The method for manufacturing a compound superconducting conductor according to any one of claims 1 to 3, comprising the step of forming an oxide layer on the surface of the Cu-based matrix. Production method. (5) embedding in a Cu-based matrix containing wires containing a compound superconductor material that reacts with heat treatment to form a compound superconductor; forming an oxide layer on the surface of the Cu-based matrix; A step of integrating the copper layer for stabilizing material via a material layer and processing it into a desired conductor shape, and forming an oxide layer on the surface of the copper layer for stabilizing material of the integrated structure. and a step of subjecting the structure on which the oxide layer is formed to heat treatment in a temperature range for forming the compound superconductor in vacuum or in a non-oxidizing atmosphere. Method. (6) The method for manufacturing a compound superconducting conductor according to claim 5, comprising the step of forming an uneven shape on the interface between the Cu-based matrix and the copper layer for a stabilizing material. Method.