JPH02187003A - Superconducting coil manufacturing method - 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] [Industrial Application Field] The present invention relates to a method for manufacturing a superconducting coil constructed using an oxide ceramic superconducting material, and particularly relates to a method for manufacturing a superconducting coil constructed using an oxide ceramic superconducting material, and in particular, a method for manufacturing a superconducting coil constructed by using an oxide ceramic superconducting material. The present invention relates to a method for manufacturing a superconducting coil including a sintered body.

[Prior Art] When attempting to manufacture a superconducting coil using a sintered body obtained by sintering ceramic raw material powder, first, a plurality of ring-shaped sintered bodies having superconducting properties are prepared. These sintered bodies are in a state in which ceramic raw material powder of a component system that provides superconducting properties is sintered. Each ring-shaped sintered body is partially cut off to form a C-shape having both ends. These C-shaped sintered bodies are stacked in an appropriate number with an appropriate insulating layer in between, and each sintered body is stacked in such a way that the superconducting portion forms a coil shape. are connected with their end faces butted against each other. Thereafter, a desired superconducting coil is obtained by heat treatment.

Another method is to cut a sheet-like sintered body having superconducting properties into a spiral shape to form a superconducting coil.

[Problems to be Solved by the Invention] However, the sintered body used in the superconducting coil obtained by the above-mentioned conventional method has no crystal orientation;
Therefore, sufficient current cannot be passed to generate a strong magnetic field.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a superconducting coil that improves the crystal orientation in the current direction of the coil, thereby allowing a large current to flow.

[Means for Solving the Problems] The present invention is directed to a method of manufacturing a superconducting coil comprising a sintered body obtained by sintering ceramic raw material powder of a component system that imparts superconducting properties, In order to solve the above technical problem, the present invention is characterized by comprising a step of forming a molten zone in the sintered body by condensed heating and moving the molten zone in the direction of current flow in the coil.

The superconducting coil obtained by this invention is, for example,
A plurality of the sintered bodies each having a C-shape with a ring partially cut out are fused and connected with their respective end faces abutted against each other, thereby giving a coil-like shape. There are cases. In this case, the step of forming and moving the molten zone may be performed before melting and connecting the plurality of C-shaped sintered bodies, or conversely, may be performed after melting and connecting the plurality of C-shaped sintered bodies. Furthermore, it may be implemented to also serve as fusion connection.

[Operations and Effects of the Invention] In the present invention, - a molten zone is formed by condensed heating on the sintered body obtained once, and the molten zone is The direction of solidification that occurs after the coil passes through can be made to match the current direction of the coil. Therefore, it is possible to improve the crystal orientation in the current direction of the coil. Therefore, a large current can be passed through the obtained superconducting coil, and therefore a high magnetic field can be generated.

Originally, coils using oxide ceramic superconducting materials take advantage of their superconductivity to operate in liquid nitrogen, for example.
The characteristics and objectives of this invention were to be able to generate no heat, to flow a large current, and to generate a high magnetic field.According to this invention, these objectives can be advantageously achieved, and as a result, various superconducting It is possible to operate magnet-applied equipment at, for example, liquid nitrogen temperature.

In addition, in the method according to the present invention, when a plurality of sintered bodies are fused and connected to form a coil shape, the step of forming and moving a molten zone involves melting the plurality of sintered bodies into a coil shape. It is more preferable to carry out the process after the connection or in a manner that also serves as fusion connection. This is because the molten zone can be passed through the fusion-connected part in the same way as in other parts, making it possible to obtain a superconducting coil that has uniformly high crystal orientation throughout the coil-shaped superconducting part. It is from.

[Embodiment] An embodiment of the present invention is shown in FIGS. 1 to 4.

FIG. 1 and FIG. 2 show a ring-shaped sintered body 1 obtained by sintering ceramic raw material powder of a component system that provides superconducting properties. In order to obtain such a ring-shaped sintered body 1, specifically, Bi20, , S rco, ,
CaC0,, CuO, Bi:Sr:Ca:Cu-2
:2:1:2 ratio, this mixture was sintered twice at 800°C for 12 hours, and then sintered at 860°C for 96 hours.
The powder is sintered under conditions of 1 hour, then crushed, and the powder is
After filling a ring-shaped mold jig with a diameter of 0 Qmm, an inner diameter of 90 mm, and a thickness of 3 mm and press-molding, sintering was performed at 870° C. for 24 hours. In this way, a ring-shaped sintered body 1 is obtained.

Next, as shown in FIGS. 1 and 2, while the ring-shaped sintered body 1 is held by the stopper 9, the ring-shaped sintered body 1 is A part of the ring-shaped sintered body 1 was heated by condensing light to form a floating molten zone 4 in the ring-shaped sintered body 1. Then, this molten zone 4 was moved in the circumferential direction of the ring-shaped sintered body 1 at a speed of 3 mm/h, as shown by the broken line 5 in FIG. The movement of the melted zone 4 was terminated when it completed one revolution. Note that the melting zone 4 may be rotated multiple times.

Next, as shown in FIG. 3, a portion including the start end and end end of movement of the molten zone 4 was cut out by a length of 10 mm on the outer peripheral side to obtain a C-shaped sintered body 1a. The C-shaped sintered body 1a has opposing end faces 6°6.

Ten C-shaped sintered bodies 1a as described above are produced, and as shown in FIG. The C-shaped sintered bodies 1a were arranged in a series of coil shapes. At this time, between the layers of the stacked C-shaped sintered bodies 1a, there is a 0-thickness layer made of, for example, fiber-reinforced plastic having the same shape as the sintered bodies 1a.
An insulating plate 7 with a thickness of 5 mm was inserted.

When electrodes (not shown) were formed at both ends of the coil portion of the thus obtained superconducting coil 8, which was made up of a plurality of C-shaped sintered bodies 1a extending in a coil shape, and a current was applied, up to 200 A. flow, and a magnetic field of 400 gauss was generated.

As a comparative example, without the formation and movement of the melt zone,
A coil of the same size and shape made using a C-shaped sintered body made only by sintering could only conduct a current of up to 35 A and generate a magnetic field of only 65 gauss.

In the embodiments described above, the step of forming and moving the molten zone 4 was carried out before the plurality of C-shaped sintered bodies 1a were fused together. This may be carried out after a plurality of C-shaped sintered bodies are fused and connected to form a coil shape. This thing,
To explain with reference to FIG. 4, the C-shaped sintered body 1a is
First, the respective end surfaces 6 are fused and connected with each other in a state of abutting each other, and then a molten zone is formed by, for example, irradiating a laser beam from the outer circumferential side and condensed heating, and this molten zone is shaped into a spiral. In other words, it may be moved in the direction in which the coil is energized. Similarly, when a plurality of C-shaped sintered bodies are connected in a coil shape and temporarily fixed, and a molten zone is formed and moved, the plurality of C-shaped sintered bodies are connected to each other. Melt bonding may also be performed at the same time.

[Brief explanation of the drawing]

1 to 4 are for explaining one embodiment of the present invention, and in FIG. 1, a molten zone 4 is formed in a ring-shaped sintered body 1 by condensed heating using a laser beam 3. FIG. 2 is a front view of the ring-shaped sintered body 1 showing the state in which
FIG. 3 is a plan view of the ring-shaped sintered body 1 showing the same state; FIG. 3 is a plan view of the C-shaped sintered body 1a obtained from the ring-shaped sintered body 1; FIG. , is a perspective view showing a superconducting coil 8 obtained in this example. In the figure, 1 is a ring-shaped sintered body, 1a is a C-shaped sintered body, 3 is a laser beam, 4 is a molten zone, 6 is an end surface, and 8 is a superconducting coil.

Claims (5)

[Claims] (1) A method for manufacturing a superconducting coil comprising a sintered body obtained by sintering a ceramic raw material powder having a component system that imparts superconductivity, comprising: forming a molten zone in the sintered body by condensed heating; A method for manufacturing a superconducting coil, comprising the step of moving a molten zone in the direction of current flow in the coil. (2) The superconducting coil is formed by melting and connecting a plurality of C-shaped sintered bodies with their respective end faces abutting each other to form a coil-like structure. The method for manufacturing a superconducting coil according to claim 1, wherein the superconducting coil has a given shape. (3) The method for manufacturing a superconducting coil according to claim 2, wherein the step of forming and moving the molten zone is performed before melting and connecting the plurality of C-shaped sintered bodies. (4) The method for manufacturing a superconducting coil according to claim 2, wherein the step of forming and moving the molten zone is performed after fusion-connecting the plurality of C-shaped sintered bodies. (5) The method for manufacturing a superconducting coil according to claim 2, wherein the step of forming and moving the molten body also serves to melt and connect the plurality of C-shaped sintered bodies.