JPH0359911A - Aluminium stabilization superconductive wire rod - Google Patents

Abstract

PURPOSE:To obtain a superconductive wire rod having god workability and high tensile strength while making it lightweight and stable by arranging a reinforcing in high purity aluminium. CONSTITUTION:A superconductive wire coated with Al or Cu and a high-purity wire are combined while arranging reinforcing materials in the high-purity Al 4. Here, the high-purity Al 4 has an excellent property as compared with Cu under an extremely low temperature where a super conductive coil is operated. Accordingly, when the reinforcing materials are arranged in the high-purity Al 4, strength of a wire rod as a whole is increased so as to make it possible to be processed as a whole. Thereby, strength and workability of the wire rod as a whole can be improved so as to enable the superconductive coil to be wound with big tension when it is wound so that a stable coil to electromagnetic force and such at the time of excitation can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lightweight and stabilized AQ-stabilized superconducting wire.

[Conventional technology]

Conventional All-stabilized superconducting wires aimed at weight reduction and stabilization are made of Afl or AQ alloy at the center and Cu-coated superconducting wires are arranged around the outer periphery, as described in JP-A-49-107494. The method of
As described in Publication No. 3, Afi or AQ alloy is
A method is known in which the Q-coated superconducting wire is placed outside and subjected to area reduction processing. In addition, as a method to improve workability,
Japanese Patent No. 40286 discloses a manufacturing method in which a superconducting wire is coated with high-purity, high-tensile strength Afi containing alumina.

[Problem to be solved by the invention]

Generally, Cu and high purity A are used as stabilizing materials for superconducting alloy wires.
There are alloys such as Q and AQ alloys, and among the above materials, Cu is often used because it is relatively easy to process and manufacture. However, the thermal and electrical conductivity of pure AQ at extremely low temperatures is
It is several to several tens of times better than U, and its mass can be reduced to about 1/3 that of Cu.

Therefore, it is desirable to use pure Afl as a stabilizing material for superconductors, but since pure AQ is much softer than Cu, there is a large difference in deformation resistance, making it difficult to make into a wire, and the tensile strength is low. Therefore, there was a problem that the coil could not be wound with a large tension, and the coil would become unstable due to mechanical disturbance.

An object of the present invention is to eliminate the above-mentioned problems, to provide a superconducting wire material that is lightweight and stable, has good workability, and has high tensile strength.

[Means to solve the problem]

In order to achieve the above object, the present invention
This Afl-stabilized superconducting wire is a combination of a coated superconducting wire and a high-purity AM wire, in which a reinforcing material is arranged in the high-purity Afl.

[Effect]

High purity AQ is C at the extremely low temperatures where superconducting coils are operated.
It has superior properties compared to u. For example, 99.9
Compared to oxygen-free copper, which is generally used as a stabilizing material for superconducting wires, 99% pure AQ has a heat capacity of 0.91.
The thermal conductivity is 6.4 times, the electrical resistivity is 0.14 times under a 5T magnetic field, the cross-sectional area of the superconducting wire, and the shape of the superconducting coil.

Assuming the dimensions are the same, the Afl matrix superconducting coil has a stability margin about 40 times that of the conventional Cu matrix superconducting coil.

In this way, Afl is a thermally and electrically superior stabilizing material compared to Cu, but mechanically Afl is too soft and N
At present, the difference in deformation resistance with bTi is too large, and a high-performance Afl stabilized wire cannot be obtained. In addition, since high-purity Afl has a lower tension than Cu, it is not possible to wind a coil with a large tension, and when it is excited, it moves or deforms due to electromagnetic force, making it unstable as a coil.

- Therefore, in order to eliminate these drawbacks, Afl or Af which combines Cu-coated superconducting wire and high-purity Afl wire
In stabilized wire rods, it was found that a structure in which a reinforcing material is placed in high-purity AI2 is preferable from the viewpoint of plastic processing of the wire rod and coil deformation, and that a high-performance AI2 stabilized wire rod can be obtained. .

In other words, by placing a reinforcing material in high-purity AM,
The strength of the entire wire increases, making it possible to process it as a whole. The reinforcing material is made of materials such as Nb and Ta that are difficult to harden during processing and do not react with high-purity An during heat treatment that occurs during the manufacturing process.
, Ti, V, CuNi.

The effect is more effectively exhibited by using Ni, stainless steel, etc.

〔Example〕

Examples of the present invention will be described in detail below.

<Example 1> FIG. 1(a) is a schematic cross-sectional view of one superconducting wire of the present invention. Superconducting wire 1 is 1.9mm x 1.1mm
In the rectangular cross section of the wire, 3280 Nb-45 wt% Ti filaments 3 with a diameter of 20 μm are uniformly embedded in the Cu matrix 4-2.
, 8 an X 0 , 4 mn purity 99,999
A composite wire in which 50 Ta wires 5 each having a diameter of 63 μm are embedded in Afl4 with a high purity of 50% is placed at the center of the wire.

The manufacturing method of this wire rod is as shown in Fig. 1(b).
．． A hole is made in 999% pure AM4, 50 reinforcing Ta wires 5 are inserted into the hole, and processed until the two are in close contact.

Next, as shown in FIG. 1 (Q), this Ta wire-containing AQ
After placing the composite wire 6 concentrically in the center of the tube 7 and inserting the Cu-coated superconducting wire into the gap between the AQ composite wire 6 and the Cu tube 7,
After hydrostatic extrusion and wire drawing, and heat treatment at 375°C for 100 hours, the AQ stabilized superconducting wire 1 with rectangular reinforcing wires is passed through a rectangular die near the final dimension. was produced. Since the wire rod according to the present invention has a reinforcing wire arranged on pure AQ, the tension is about 2.4 times that of the conventional wire rod using only pure AQ, and it can be easily processed without losing stability. Ta.

<Example 2> FIG. 2(a) is a schematic cross-sectional view of another superconducting wire of the present invention. In other words, this wire has a Cu-coated NbT in the center.
It has a structure in which an i-superconducting alloy is placed, a composite material in which Ta wire 5 as a reinforcing material is embedded in pure A1114 is placed on the outer periphery, and a Cu layer is further placed on the outer periphery.

The manufacturing method of this wire rod is as shown in Fig. 2(b).
The coated NbTi superconducting wire 8 is inserted into the Cu tube and processed by wire drawing until it is brought into close contact.

Next, as shown in FIG. 2(c), a Ta wire as a reinforcing material is inserted into the high-purity Afl tube 4 and drawn to produce a single-core composite wire. Next, as shown in FIG. 2(d), a Cu tube 7 is used as the outermost layer, and the central part of the Cu tube is
The Cu-coated multi-core composite wire 9 shown in b) is placed concentrically with the Cu tube 7, and the AQ with Ta wire shown in FIG.
After inserting the single-fiber composite wire 10 between the outermost Cu tube 7, it is subjected to hydrostatic extrusion and wire drawing, and subjected to aging heat treatment, and then formed into a rectangular shape in the final stage, as shown in FIG. The wire rod shown in (a) was manufactured. Although the wire according to the present invention has an AQ layer on the outer periphery of the superconductor, even fine wires could be processed without breaking.

<Example 3> Next, using the same manufacturing method as Example 1 and Example 1, one wire rod was prepared for each of the two types without reinforcing material inserted into the high-purity Afl in the center.
A solenoid coil with an inner diameter of 100 mm was manufactured by winding the coil with 000 turns each.

At this time, the wire rod shown in Example 1 was able to be wound with a tension of about 12 kg/+nm2 because the reinforcing material was inserted, but with the wire rod made only of high purity AQ, a tension of only 5 kg/an2 could be applied.

Both coils were cooled to 4.2K with liquid He and then excited, but the current value at which superconductivity breaks in the coil wound in Example 1 and the coil made from wire without reinforcing material is 4. .2K.

980A and 750A at 6T, respectively
The coil with the reinforcing material inserted had a value about 1.3 times higher, indicating high stability.

Although three embodiments have been described above, the present invention is not limited thereto. For example, in addition to Ta as a reinforcing material, Nb, Tip V+ Ni+Cu,
Ni etc. may be used, and instead of Cu-coated superconducting wire, AQ
A similar effect can be obtained by using a coated superconducting wire.

〔Effect of the invention〕

The present invention can improve the strength and workability of the entire wire by adopting a structure in which a reinforcing material is arranged in high-purity AQ. Therefore, the superconducting coil can be wound with a large tension, and the coil can be made stable against electromagnetic force during excitation.

In addition, since AQ is used, the current density of the coil can be increased even if the matrix ratio is small, so the superconducting coil is small and lightweight, and is ideal for superconducting coils for magnetic levitation trains.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a superconducting wire according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view of a superconducting material according to another embodiment of the present invention. 1...Afl stabilized superconducting wire with reinforcing wire, 2...C
u matrix, 3...NbTi filament, 4...high

Claims (1)

[Claims] 1. An aluminum-stabilized superconducting wire material comprising a combination of an aluminum or copper coated superconducting wire and a high-purity aluminum wire, characterized in that a reinforcing material is arranged in the high-purity aluminum. wire. 2. The aluminum-stabilized superconducting wire according to claim 1, wherein the high-purity aluminum material provided with the reinforcing material is located at the center of the wire. 3. The aluminum stabilized superconducting wire according to claim 1, wherein the high-purity aluminum material provided with the reinforcing material is located on the outer periphery of the wire. 4. A superconducting coil characterized by using the aluminum stabilized superconducting wire according to claim 1, 2 or 3. 5. A superconducting wire in which aluminum is incorporated in the center of the cross-section of the wire and copper-coated NbTi ultrafine multifilamentary wires are formed on the outer periphery of the cross-section of the wire, characterized in that a reinforcing material is provided in the aluminum.