JPS5846803B2 - Kagobutsuchiyodendosenno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a compound superconducting wire made of, for example, V3Ga wire.

In general, compound superconducting wires such as vanadium trigallium (V3Ga) wires are made of copper or
A gallium alloy material 1 is perforated, a bar-shaped vanadium material 2 is embedded in the hole, and the whole is wrapped and integrated with a sheath material 3 such as a copper material, and then this is cold drawn. After processing and intermediate annealing are repeated dozens of times to make the wire thin, it is manufactured by thermal diffusion treatment at 600 to 700° C. for several tens of hours.

However, it was necessary to perform the perforation of the steel/gallium alloy material 1 in accordance with the shape of the vanadium material 2, and high processing accuracy was required.

In addition, because the work hardening of the steel/gallium alloy material 1 is significant, it is necessary to perform the cold wire drawing process while interrupting the wire drawing process and performing intermediate annealing, which requires a large amount of work. It was inefficient as it took a lot of time.

By the way, among the materials constituting the above compound superconducting wire,
The higher the gallium concentration of the steel/gallium alloy material 1,
It is known that the rate of formation of a reaction phase with vanadium, the other material, is faster and that superconductivity is also excellent.

However, when the gallium concentration of the steel/gallium alloy material 1 exceeds 19% by weight, a problem arises in that cold processing of the superconducting wire is no longer possible, and warm or hot processing is required.

In addition, when warm or hot processing is performed in this way,
A problem arose in that an oxidized layer was likely to form at the interface between the steel/gallium alloy material 1 and the vanadium material 2, which inhibited the diffusion reaction.

Conventionally, it has been considered to produce a compound superconducting wire by pulverizing the steel/gallium alloy material 1 and the vanadium material 2, mixing them together, and embedding them in the sheath material 3.

However, when this is done, the surface area of the vanadium material, which is a metal with a high melting point, increases, making it easier to oxidize, and the uniform distribution of the vanadium material powder is also hindered, making it impossible to obtain good superconductivity. occured.

The present invention has been made in consideration of these circumstances, and its purpose is to make it possible to uniformly process a metal rod with a high melting point component even by cold working, for example, without requiring intermediate annealing treatment. The object of the present invention is to provide a highly practical method for manufacturing a compound superconducting wire that can easily manufacture a compound superconducting wire with good superconductivity.

Hereinafter, details of the present invention will be clarified with reference to an embodiment shown in the drawings.

First, a copper alloy with a low melting point component, which is one of the materials forming the compound superconducting wire, such as a copper-gallium alloy having a potassium concentration of 60% by weight, is pulverized to obtain a copper-gallium alloy powder.

On the other hand, vanadium, which is a metal with a high melting point as the other material forming the compound superconducting wire, is shaped into a rod to obtain a vanadium rod.

Then, as shown in the cross-sectional shape in the longitudinal direction in FIG.
The pre-recorded gallium alloy powder 6 is packed so as to fill the gap between the sheath material 4 and the sheath material 4.

Thereafter, the openings at both ends of the sheath material 40 are closed by the disc bodies 7, 7, respectively, and the sheath material 40 is integrated.

Thereafter, this integrated member is simply cold drawn, that is, without intermediate annealing (after drawing to make the wire thin, a thermal diffusion treatment is performed).

By this thermal diffusion treatment, a reactive phase of the image material is rapidly generated at the interface between the vanadium rod 5 and the copper-gallium alloy powder 6, and a vanadium 3 is alloyed with gallium, that is, a V3Ga superconducting wire is obtained.

Incidentally, the previously recorded gallium alloy powder 6 is melted into a continuous body after undergoing the above-mentioned thermal diffusion treatment.

As a result of actual measurements using the vanadium trigallium (V3Ga) superconducting wire produced in this way, it was found that vanadium trigallium (V3Ga) produced by the conventional method
It was confirmed that the wire exhibited a good critical current value equivalent to or better than that of superconducting wire.

As described above, according to the method of the present invention, a copper alloy with a low melting point component, such as a copper-gallium alloy, which is one material of a compound superconducting wire, is pulverized, and this copper-gallium alloy powder and a high-melting point component, which is the other material, are powdered. The component metal, for example, a vanadium rod made of vanadium, is wrapped and integrated with a sheath material made of copper or copper alloy, and this is wire-drawn, so that the mechanical properties of the sheath material and the low melting point of the powdered powder are The properties of the component copper alloy powder and the properties of the high-melting point component metal rod are well matched, and the pressing force is extremely uniformly distributed throughout, resulting in good elongation.

As a result, the thickness of the linear object becomes constant, and there is no discontinuity in the high melting point component metal rod.

Therefore, a compound superconducting wire having a high critical current value and exhibiting good superconductivity can be obtained.

Furthermore, since vanadium, which is a metal with a high melting point, is used as the rod-shaped body, a hard and brittle surface oxidation layer is hardly formed, unlike in conventional powdered vanadium.

Since it exhibits good elongation during the wire drawing process, it is diffused very uniformly and well throughout the composite superconducting wire by thermal diffusion treatment.

In other words, it is possible to sufficiently elongate vanadium, which is a metal with a high melting point that is generally difficult to spread, into a thin wire, and then thermally diffuse the thin wire to obtain a homogeneous and good compound superconducting wire.

Furthermore, it is possible to omit several tens of intermediate annealing treatments associated with drilling and cold working of the raw material in the conventional method, so that a compound superconducting wire can be obtained efficiently.

Further, since cold processing is possible, there is no limitation on the ratio of each component of the material used, and it is possible to provide a method for manufacturing a compound superconducting wire having excellent superconducting properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a superconducting wire obtained by conventional perforation, and FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention. 4... Sheath material, 5... Vanadium rod, 6... Copper-gallium alloy powder, 7...
・Disc body.

Claims (1)

[Claims] 1. When producing a compound superconducting wire made of a metal with a high melting point component and an alloy with a low melting point component including copper, a copper alloy powder obtained by pulverizing the alloy with a low melting point component including the steel, and the high melting point alloy A predetermined number of rod-shaped component metal rods are embedded and integrated inside a sheath material made of copper or copper alloy with both ends closed, and this integrated member is processed into a wire bow. A method for producing a compound superconducting wire, which comprises the steps of: and then subjecting it to a thermal diffusion treatment.