JPH02429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a Nb ₃ Sn-based or V ₃ Ga-based compound superconductor.

BACKGROUND ART Compound superconductors in which Nb ₃ Sn or V ₃ Ga is embedded in a normal conducting metal such as Cu have been put into practical use. These superconductors, such as Nb ₃ Sn, are manufactured by a method called the bronze method. That is, in this bronze method, the weight ratio of Sn is 13.5.
% or less of Cu-Sn alloy, a large number of through holes are drilled in the billet, and Nb rods are inserted into these through holes.
This method forms a Nb ₃ Sn layer at the interface between Nb and the Cu-Sn alloy by subsequently subjecting the billet to forming processes such as extrusion and drawing, and heat treatment.

This manufacturing method has the advantage of being able to manufacture large wire rods depending on the billet size, but
As the Sn concentration in a Cu-Sn alloy increases, segregation tends to occur in the alloy, and Cu ₄ Sn compounds, which are intermetallic compounds at high temperatures, precipitate, making the billet non-uniform and reducing workability. It has the disadvantage that it decreases. For this reason, in this manufacturing method, it is actually necessary to use a Cu-Sn alloy with a Sn concentration of 10% or less in consideration of workability, homogeneity, etc., and when the Sn concentration is low, heat treatment is required. Sometimes, only about 25% or less of the Nb rod reacts, and therefore the Nb ₃ Sn layer produced is small, making it impossible to obtain a superconductor with excellent current characteristics.

An object of the present invention is to provide a method for manufacturing a compound superconductor that does not impair workability or homogeneity even when the Sn or Ga concentration is 10% or more and has excellent current characteristics.

That is, in the present invention, by injecting a Cu-Sn-based or Cu-Ga-based molten metal with a Sn or Ga concentration of 10 to 30% by weight through an inert gas.
A Cu-Sn-based or Cu-Ga-based alloy is created, and a Nb-based or V-based metal and a Cu-Sn-based, Cu-Ga-based, or
Nb ₃ Sn-based or V ₃ Ga
The present invention relates to a method for producing a compound superconductor, characterized in that a compound superconductor is produced, and a compound superconductor obtained by the method.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 shows a crucible 1 used in an embodiment of the present invention.
is shown, and the lower part of this crucible 1 has an air outlet 2 downward.
A cylindrical blow-off portion 2 having a diameter A is provided.
A gas supply cylinder 4 is attached to this crucible 1 so as to cover approximately half of the crucible and the blowing part 2.
This gas supply tube 4 is provided with a gas supply port 4B on the side wall, and a gas injection port 4A that aligns with the blow-off port 2A and opens downward at the bottom. A high-speed rotation roll 5 that rotates at high speed clockwise in FIG. 1 is arranged below the gas injection port 4A.

First, a Cu-Sn molten metal 3 with a Sn weight ratio of 20% is prepared, and this molten metal 3 is poured into the crucible 1, and an inert gas,
For example, argon gas 7 is supplied at high pressure, and the molten metal 3 is injected onto the high-speed rotating roll 5 from the blow-off port 2A and the gas injection port 4A to rapidly cool it. In this way, molten metal 3
When sprayed onto the roll 5, a Cu-Sn alloy tape 6 having a Sn weight ratio of 20% can be obtained.
In this example, a Cu-Sn alloy tape 6 having a width of 20 mm and a thickness of 80 μm was prepared.

The obtained alloy tape 6 is laminated with a plurality of Nb tapes interposed therebetween, that is, for example, as shown in FIG.
Thirty layers of Nb tape 8 are sandwiched between two pieces of alloy tape 6 in a sandwich pattern, and this laminate is stacked with Nb tube 9 whose inner dimensions are 8 mm, width is 21 mm, and wall thickness is 0.3 mm. Cu tube 1 of 9mm, width 22mm, wall thickness 2.5mm
It is arranged in a Cu-Nb composite pipe 11 composed of 0 and 0. Then, this Cu-Nb composite tube 11 was repeatedly subjected to rolling processing and softening annealing treatment to create a tape with a thickness of 0.35 mm, and this tape was further heat-treated at 680°C for 100 hours to form a Nb tape 8. Nb ₃ Sn on the surface
It is possible to form a Nb ₃ Sn compound superconductor.

When a bias magnetic field was applied to this Nb ₃ Sn compound superconductor at 4.2 K and its critical current characteristics were measured, characteristic curve A shown in FIG. 3 was obtained. For comparison, curve B shows the critical current characteristics of a Nb ₃ Sn compound superconductor produced by a conventional manufacturing method. As is clear from FIG. 3, the Nb ₃ Sn compound superconductor produced by the method of the present invention has excellent superconducting properties.

Example 2 Using the apparatus used in the above embodiment, a Cu-Ga alloy tape (width 20 mm,
80μm thick) was made, and a V tape with a width of 20mm and a thickness of 80μm was sandwiched between two pieces of this alloy tape.
The layers are laminated, and this laminate has an inner dimension of 8 mm in height,
Ta tube with a width of 21 mm and a wall thickness of 0.3 mm and an inner dimension of height 9
mm, width 22mm, wall thickness 2.5mm Cu tube
- Placed in a Ta composite tube, and repeated rolling and softening annealing treatments in the same manner as in the above embodiments to reduce the thickness.
A 0.35mm tape was made. On the resulting tape
Heat treatment was performed at 600° C. for 80 hours to form V ₃ Ga on the surface of the V tape, creating a V ₃ Ga compound superconductor.

The critical current characteristics of the obtained V ₃ Ga compound superconductor were measured under the same conditions as in Example 1 above.
It showed extremely good superconducting properties.

Example 3 Similar to the above embodiment, in weight ratio
Sn is 30%, width and thickness are 30mm and 100μm respectively
A Cu-Sn alloy tape was prepared, and this alloy tape was spirally wound around a Nb-1wt ⁰ /oZr rod with a diameter of 1.8 mm to obtain a composite rod with a diameter of 2.8 mm. Approximately 470 of these composite rods were then assembled into a tube with an outer diameter of 72 mm and an inner diameter of 68 mm, each with a Ta pipe inside to be used as a diffusion barrier.
A composite billet is formed by packing it into a pure Cu container with a diameter of 80 mm, an inner diameter of 72 mm, and a length of 200 mm, and one end of this billet is sealed by electron beam welding.
Hot extrusion was performed at 600°C to obtain a linear body with an outer diameter of 16 mm. This linear body is then subjected to cold wire drawing and intermediate annealing heat treatment many times to form a wire rod with a final wire diameter of 0.2 mm, and this wire rod is heat treated at 650°C for 50 hours. By this method, a composite multi-core Nb ₃ Sn compound wire was fabricated.

When a bias magnetic field was applied to this compound wire at 4.2 K and its critical current characteristics were measured, it showed extremely good superconducting characteristics.

Embodiment 4 FIG. 4 shows another embodiment of the apparatus, in which 1' indicates a crucible. This crucible 1' is provided with an air outlet 2' at its lower part. A gas supply chamber 4' is provided below this outlet 2', and this gas supply chamber 4' has a molten metal inlet 4'B and an injection port aligned with the outlet 2' on its upper and lower walls. 4'A is provided. Further, a water tank 12 is provided below the injection port 4'A.

First, Cu-Sn with a Sn weight ratio of 20% is melted in the melting furnace 13.
A molten metal 14 is created, and this molten metal 14 is put into the crucible 1'.
At the same time, argon gas 7 is supplied at high pressure into the gas supply chamber 4' through the gas supply pipe 16, and the molten metal 14 is poured into the water in the water tank 12 at high speed from the outlet 2' and the injection port 4'A. Spray and quench. When the molten metal 14 is injected into the water tank 12 in this manner, Cu-Sn alloy powder 15 having a Sn weight ratio of 20% and a particle size of 3 to 30 μm can be produced.

The obtained alloy powder 15 was mixed with a Sn weight ratio of 8%,
As shown in FIG.
Filled with Nb rod 18 with a length of 130 mm (filling density 68
%) to create a composite billet 19, and after sealing one end of this billet 19 by electron beam welding, this billet 19 was hot extruded at 550°C and coated with a Cu-Sn alloy with an outer diameter of 18 mm. A composite Nb rod was prepared, and the oxide scale formed on the surface of the Nb rod was ground and removed, and the wire was drawn. After that, the 19 wire-drawn composite Nb rods were reassembled into Cu-Sn wire with an outer diameter of 80 mm, an inner diameter of 72 mm, a length of 200 mm, and a Sn weight ratio of 8%.
Filled into a container and hot extruded, the oxidized scale portion on the surface was removed and wire drawn to obtain a composite wire miscellaneous material.
A composite wire was created by removing the oxide scale portion and performing wire drawing treatment three times in total. After repeatedly performing diameter reduction processing and softening annealing treatment on the obtained composite wire, a Nb tube with an outer diameter of 16.0 mm and an inner diameter of 14.8 mm, and an oxygen-free copper tube with an outer diameter of 19.5 mm and an inner diameter of 16.5 mm. Pitzchi 30
After further twisting of mm, the final wire diameter is 1mm.
By creating a composite multi-core Nb ₃ Sn compound wire and heat-treating this wire at 680℃ for 100 hours,
A Nb ₃ Sn compound wire was obtained.

When a bias magnetic field was applied to this compound wire at 4.2K and its critical current characteristics were measured, it showed good superconducting characteristics similar to the above example.

In the present invention, Nb or V includes Al, Mg, Mn,
Adding metal elements that improve superconducting properties such as Ga, Hf, Ta, and Zr, or adding metal elements such as Ga, Hf, Ta, and Zr to Cu-Sn and Cu-Ga.
It is preferable to add metal elements that improve the properties of Al, Ga, In, Mg, Mn, Pb, Sn, etc. Furthermore, elements that are not harmful to superconducting properties are added to Nb, V, Cu-Sn, or Cu-Ga. May be added.

Furthermore, the method of disposing the Cu-Sn or Cu-Ga alloy and the structure of the compound superconductor are not limited to the above-mentioned embodiments, and various modifications can be made without detracting from the features of the present invention. do not have.

As explained below, according to the manufacturing method of the present invention, Cu-Sn-based or Cu-Ga-based molten metal having a Sn or Ga concentration of 10 to 30% by weight is injected through an inert gas. The process of creating a tape-shaped or powdered Cu-Sn-based or Cu-Ga-based alloy is performed by converting this tape-shaped Cu-Sn-based or Cu-Ga-based alloy into a tape-shaped or rod-shaped Nb-based or V-based metal. In combination with Cu-based or Cu-Sn-based or Cu
- a step of inserting into a container made of any of the Ga-based alloys, and then a step of subjecting this container to cross-sectional reduction processing and heat treatment to create a tape or wire of a Nb ₃ Sn or V ₃ Ga compound superconductor; By providing _a large amount of _{Nb 3} Sn or V ₃ Ga, it is possible to obtain a compound superconductor with excellent critical current characteristics.
Since the amount of is large, a high current density can be obtained. Since the method of the present invention produces a compound superconductor by combining the above-mentioned alloy with a low-concentration alloy of this type prepared by a conventional method, there is no deterioration in workability, and since the compound superconductor has a concentration gradient, Superconductors can be easily manufactured.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view of the apparatus used in the method of the present invention, Figure 2 is a perspective view showing the tape-shaped alloy produced by the apparatus of Figure 1 placed in a Cu container together with Nb tape, and Figure 3. is a diagram showing the critical current characteristics of a compound superconductor obtained by the method of the present invention and a compound superconductor obtained by a conventional method, FIG. 4 is a schematic cross-sectional view of an apparatus used in another embodiment of the present invention, and FIG. The alloy powder obtained by the apparatus shown in Fig. 4 has a low Sn concentration.
FIG. 3 is a cross-sectional view showing a state in which a Cu-Sn alloy container is filled. 1, 1'... Crucible, 2... Blower part, 2'... Blower outlet, 3, 14... Molten metal, 4... Gas supply tube, 4'
...Gas supply chamber, 4A, 4'A...Gas injection port,
5... High-speed rotating roller, 6... Tape-shaped alloy, 7
...Argon gas, 8...Nb tape, 9...Nb
Pipe, 10...Cu pipe, 11...Cu-Nb composite pipe, 1
2...water tank, 13...melting furnace, 15...alloy powder,
16... Gas supply pipe, 17... Alloy container, 18
...Nb rod, 19...composite billet.

Claims (1)

[Claims] 1 Cu whose Sn concentration is 10 to 30% by weight
- A step of creating a tape-shaped or powdered Cu-Sn-based alloy by injecting a Sn-based molten metal through an inert gas;
In combination with tape-shaped or rod-shaped Nb-based metal,
A process of inserting this into a container made of either a Cu-based alloy or a CU-Sn-based alloy obtained by a conventional method, and then subjecting this container to cross-sectional reduction processing and heat treatment to form a Nb ₃ Sn compound superconductor tape. A method for manufacturing a compound superconductor, comprising: or a step of creating a wire. 2 Cu with a Ga concentration of 10 to 30% by weight
- A process of creating a tape-shaped or powdered Cu-Ga-based alloy by injecting Ga-based molten metal through an inert gas;
The process of combining a tape-shaped or rod-shaped V-based metal and inserting it into a container made of either a Cu-based metal or a Cu-Ga-based alloy obtained by a conventional method.Then, this container is subjected to cross-section reduction processing and heat treatment processing. 1. A method for producing a compound superconductor, comprising the steps of: producing a tape or wire of a V ₃ Ga compound superconductor.