JPS58212012A - Method of producing compound superconductive conductor - 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] It is related to

When manufacturing, for example, Nb3Sn IM using the conventional superconducting superconducting wire in situ method, the
1 (After twisting the composite wire 3 of Nb J and Cu2,
The outer periphery is covered with an 8N4F hot-deposit bed, which is then subjected to diffusion heat treatment at a high temperature of 600 to 800°C to
This was to form a compound superconducting wire of sSn.

However, when using this method, uneven voids are formed due to the surface of the strands, so the subsequent Sn adhesion layer cannot be made uniform, resulting in thick layer portions and thin layer portions. Therefore, the above-mentioned diffusion heat treatment cannot be performed uniformly, and the Sn in the thick layer remains in an undiffused state, and when Sn and Cu are dissolved in solid solution, they are dissolved sequentially starting from the portions that are close to Cu.
The undiffused residual Sn forms a solid solution with the Sn-type Cu in the OS and other thick layer parts, forming a SnCu alloy with a large Sn weight. At the same time, these low-melting-point pots sag in the direction of gravity during diffusion heat treatment, which deforms the conductor size after the diffusion reaction, making it impossible to move around a homogeneous material as a winding. As mentioned above, due to the dripping of the t-melting point metal, a diffusion dyed id was formed in that part.

In addition, in the case of twisted wires made of round wires as shown in Figure 1, the outer periphery of the cable is not smooth, so when the cable is bent, the stress is not uniform and is concentrated in one part, resulting in non-uniform strain. The superconducting compound would have minute cracks and the critical current value would drop.The present invention is the result of intensive research aimed at improving this drawback. We have discovered a manufacturing method that can equalize the outer diameter size and alleviate stress concentration. In other words, the uninvented method is to cut out at least some of the elements constituting the superconducting compound, compress the other elements← until →γ disappears, and form an aggregate or mounted state in which no gap is formed. This method is characterized by heating an aggregate consisting of a desired number of strands of filaments, which are preformed into a cross-sectional shape and made of the above-mentioned ten thousand elements, to a temperature for forming a compound.

An example of the uninvented method will be explained with figures and surfaces. , as shown in Fig. 2, when forming Nb3Sn powder, a composite line 3 of Nb1 and Cu2, which are the 10,000 elements that make up Nb3Sn.
A plurality of cable wires pre-plated with the other element, Sn4, are twisted together on the outer periphery of the wire, and the voids between the purple #R are eliminated by pulling with a die, roller die, or Turk's rad roll, and the outer circumferential surface is The N of the present invention was prepared by compressing the material until it became smooth, making it into an aggregate, and then performing a circulation heat treatment.
It is a super-transparent compound of b5SH.

FIG. 3 shows another example of the method of the present invention.9f) Nb
The outer periphery of a composite 'M3 of 1 and Cu 2 was pre-plated with 5n4f, and the outer shape of the purple pole was formed into a rectangular shape, and a superconducting metal of the Nb 3 S n compound of the present invention was fabricated in the same manner as described above.

In the invention, the outer periphery of the aggregate may be covered with a glass tube or the like before performing the diffusion heat treatment step, or the aggregates that have been edged may be joined together. ':'1 Next, embodiments of the present invention will be explained.

Example Copper powder was blended with pananum powder at a concentration of 35 ai%, and the compacted product was melted in an arc melting furnace to form an ingot with a diameter of 30 mm. This ingo.

The round wire was cold-worked into a wire of 0.3 maφ, and this round wire was plated with Ga to a thickness of 15 μm. Using these 7 Mesogi wires and a twisting die, the exterior is completely smooth? Day (
0.9, mφ). Thereafter, after preheating at 300° C. for 25 hours, a diffusion heat treatment was performed at 600° C. for 50 hours to obtain a V sGa superconductor according to the present invention.

In addition, in order to compare with the uninvented method, a comparative example VaGa compound Asahikame 4M was obtained in the same manner as in the above example except that the smooth body was not applied.

The resulting combination by an uninvented method? I examined the appearance of the superconducting wire (uninvented product) and the superconducting wire produced by comparative example dispersion (specifically soft series product), and found that the first product was smooth and beautiful. In the case of the product, the metal was distributed non-uniformly along the strands.The critical current value was added to 4゜2 and 12T for the non-invention product and the proportional yield product.Results is as shown in the first column.

As described above in Table 1, according to the method of the present invention, the elements required for the diffusion reaction, ie, the conductive compound tS, are uniformly thickened on the surface of the green leaves, so that the amount of t¥1. It does not cause deformation of the conductor shape of the reaction, and can be used to remove damaged glands. In addition, since the elevation of the assembly due to the confusion is flat, the stress does not concentrate even when the song is processed, and this makes it possible to create a monme that is ni ni ni ni na na monme. have not yet.

FIG. 2 is a perspective view of a conducting wire; FIG.

l... niobium, 2... punishment, 3... compound lucidity, 4... tin.

Applicant's agent: Accountant: Suzue Takehikosai Figure 1

Claims (1)

[Claims] A circle of elements constituting a superconducting compound A desired number of strands coated with at least one element and containing the other element are combined and compressed until the voids between the layers are almost eliminated. A compound superelectronic wire is formed by heating an assembly consisting of a desired number of strands, which are preformed in a cross-sectional shape without voids, coated with the above-mentioned 10,000 elements, and containing other elements, to a compound formation temperature. Manufacturing method of 4 machines.