JPS63278309A - Manufacture of superconductive coil - Google Patents

Abstract

PURPOSE:To enable the easy manufacturing of a superconductive coil which is high in its critical temperature and its critical current density, by forming a mask with a spiral opening on a substrate and next projecting powder formed of at least either an oxide superconductor or elements which compose the oxide superconductor and next performing heat treatment. CONSTITUTION:A mask 2 with a spiral opening 2a is formed on a substrate, and a spray gun 3 is used to apply raw material powder, containing elements which compose an oxide superconductor, on the substrate 1, so that a laminate made of raw material slurry is formed on the substrate 1. Next this laminate is provided with heat treatment. Since a shape and a size of a superconductive coil can be determined from those of the opening of the mask formed on the substrate, a superconductive coil of desired shape and size can be freely and easily manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a superconducting coil that can be used, for example, as a magnet coil for a nuclear magnetic resonance imaging device, a particle accelerator, or the like.

(Prior art and its problems) Recently, the critical temperature at which the normal conducting state transitions to the superconducting state (
Various oxide-based superconductors exhibiting extremely high values of Tc) are being discovered. Since such oxide superconductors have a higher critical temperature than conventional alloy-based or intermetallic compound-based superconductors, they are considered to be extremely promising superconducting materials for practical use.

However, the oxide superconductors currently available are generally in the form of blocks, and an effective method for producing long wires, which is essential for manufacturing superconducting coils, has not yet been developed. This is the current situation.

(Means for Solving the Problems) In the present invention, a mask having a spiral or spiral opening is formed on a substrate, and then an oxide superconductor and an element constituting the oxide superconductor are formed on the substrate. The solution was to thermally spray a powder made of at least one of the containing materials and then heat treat it.

The present invention will be explained in detail below.

In this invention, a raw material powder is first prepared. The raw material powder used includes powders containing elements constituting the oxide superconductor, specifically alkaline earth metal element powders,
A mixed powder made of powder of a Group Ma element of the periodic table, copper oxide powder, etc. is used. Here, the alkaline earth metal element powders include Be, Sr, Mg, Ba,
Carbonate powder, oxide powder, chloride powder of each element of Ra,
Compound powders such as sulfide powders and fluoride powders, or alloy powders are used. In addition, as powders of elements of group ma of the periodic table, Sc, Y, La, Ce, Pr
, Nd.

Pro, Sm, Eu, Gd, Tb, Dy,
Ho, Er, 'I'm.'

Compound powders or alloy powders such as carbonate powders, oxide powders, chloride powders, sulfide powders, and fluoride powders of the elements Yb and Lu are used. Furthermore, examples of oxide powders include Cuo and CusO.

Copper oxide powders such as Cu, Os, and CL1403 are used.

The mixing ratio of these powders is such that the resulting oxide superconductor is AxByCuOz (where A is Sc).

Represents group ma elements of the periodic table such as Y, La, Yb, etc., and B
represents an alkaline earth metal element such as Be, Sr, Ba, etc. ), it is desirable that x, y, and z be determined within the following ranges.

0.1≦X≦2. 0.1≦y≦3. l≦2≦8 Then, a raw material powder is prepared from each of these powders. In preparing this raw material powder, one type each of an alkaline earth metal element powder and a powder of an element of group 1 [a of the periodic table] is prepared. Alternatively, 2 pieces each may be selected from the alkaline earth metal element powder or the Group Ma element powder of the periodic table.
You may select more than one species. In the former case, for example, La-
It becomes possible to prepare a raw material powder that is a raw material for a 5r-Cu-0 based superconductor, and in the latter case, for example, Ba-5
It becomes possible to prepare raw material powder for superconductors such as r-Cu-0 series and La-Y-Cu-0 series.

On the other hand, a disk-shaped base l as shown in FIG. 2 is prepared.

It is desirable that at least the surface layer of the base body 1 is made of a heat-resistant material that can withstand the heat during the thermal spraying process described below. The heat-resistant material is not particularly limited, but high-melting point metals such as tungsten and nichrome having a melting point of 1500° C. or higher, or heat-resistant ceramics such as alumina sintered bodies are preferably used.

Next, a disk-shaped mask 2 having a spiral opening 2a is provided on such a base 1. As a material for forming this mask 2, a material substantially similar to that for forming the surface layer of the base 1 described above is suitably used. Further, the size and depth of the opening 2a of this mask 2 are determined depending on the dimensions of the superconducting coil to be obtained.

Next, the base body with such a mask 2 applied! The above-mentioned raw material powder is thermally sprayed on top. For this thermal spraying, for example, a thermal spray pistol as shown in FIG. 1 can be used. The thermal spray pistol 3 of this example uses oxygen-acetylene mixed gas, oxygen-
An inner pipe 3a that supplies combustion gas such as propane mixed gas to the nozzle tip, and an outer pipe that is provided concentrically on the outside of this inner pipe 3a and that transports the raw material powder to the nozzle tip using a carrier gas such as nitrogen gas or air. It consists of a tube 3b.

In this thermal spraying pistol 3, raw material powder is supplied into the outer tube 3b from a raw material supply port 3c provided in the middle of the outer tube 3b, and then sent to the nozzle tip by a carrier gas. At the tip of this nozzle, the raw material powder is transferred to the inner tube 3a.
One flame of combustion gas supplied from the gas is heated to a high temperature and melted or semi-molten to form a raw material slurry.
This raw material slurry is ejected from the nozzle and is sprayed onto the mask 2.
and onto the substrate i through the opening 2a of the mask 2. In this way, a spiral-shaped stacked body made of raw materials in accordance with the shape of the opening 2a of the mask 2 is formed on the base 1.

Next, the thus obtained laminate is heat treated.

This heat treatment is desirably carried out in an oxidizing atmosphere, and the conditions are: a treatment temperature of about 800 to 1100°C;
The processing time is approximately 300 hours. Through such heat treatment, the above-mentioned laminate loses Ba, Sr inside it.
, alkaline earth metal elements such as Be, and Sc, Y, L
The elements of the ULA group of the periodic table, such as Yb and Yb, the copper element, and oxygen react with each other to form a layered perovskite-type oxide superconductor, that is, a superconducting coil 4 as shown in FIG.

Such a superconducting coil 4 is formed from an oxide superconductor of a system consisting of an alkaline earth metal element, a group A element of the periodic table, a copper element, and oxygen. It exhibits high critical temperature and critical current density. Therefore, this superconducting coil 4 can be suitably used as a magnet coil for a nuclear magnetic resonance imaging device, a particle accelerator, or the like.

In this method, the above-mentioned stabilization measures for the superconducting coil 4 can be easily taken.

That is, in the thermal spraying process of thermally spraying raw material powder to obtain a laminate, before and after obtaining the laminate, a normal conductor powder such as copper or aluminum is sprayed instead of the raw material powder, thereby forming a superconductor made of raw material powder. Stabilization can be easily achieved by sandwiching the laminate between laminates made of normal conductors to form a sandwich structure.

According to this method, a mask 2 having a spiral opening 2a is provided on a substrate l, and then a raw material powder containing elements constituting an oxide superconductor is thermally sprayed onto the substrate l using a thermal spray pistol 3. Then, a laminate made of the raw material slurry was formed on the substrate l, and then this laminate was heat-treated.
The superconducting coil 4, which is a spiral superconductor, can be easily manufactured. Further, according to this method, the shape and size of the superconducting coil 4 can be adjusted by adjusting the shape and size of the opening 2 of the mask 2 applied to the base 1.
Since it can be determined by the shape and size of a, a superconducting coil of a desired shape and size can be manufactured freely and easily.

In the above examples, a powder containing elements constituting an oxide superconductor was used as the raw material powder, but a powder consisting of a superconductor that already exhibits superconducting properties, or a mixture of a powder consisting of this superconductor and the above elemental powder is used. Powder may also be used. In these cases, the heat treatment conditions for the laminate obtained from the raw material powder can be relaxed or omitted, and a superconducting coil can be easily obtained.

Furthermore, in the above embodiments, a disk-shaped substrate is used as the substrate l, but a cylindrical substrate as shown in FIG. 4, for example, may also be used. In this case, a metal tape (mask) 5 is spirally wound around the outer peripheral surface of the cylindrical base 1, or the cylindrical base 1 is inserted inside the spirally wound metal tape 5. A mask is applied onto the substrate l. Here, when winding the metal tape 5 in a spiral shape as a mask, it is wound with appropriate winding intervals so that the winding density is sparse. According to this, the opening 2a of the mask 2 can be formed in a spiral shape on the outer peripheral surface of the cylindrical base 1.

Then, by thermally spraying the raw material slurry onto the substrate 1 provided with such a mask 2 and then subjecting it to heat treatment, it is possible to manufacture, for example, a spiral superconducting coil 6 as shown in FIG. 5.

Furthermore, in the above embodiment, the gas flame from the thermal spray pistol 3 was used to thermally spray the raw material powder, but the thermal spraying method is not limited to such a thermospray method, and plasma flames from a plasma torch may also be used. good. When a plasma flame is used, the spraying temperature can be raised compared to a gas flame, so a superconducting coil can be easily obtained even from a raw material powder with a high melting point.

(Effects of the Invention) As explained above, according to the present invention, after applying a mask having a spiral or spiral opening on a base,
Since a powder made of at least one of the oxide superconductor and a material containing elements constituting the oxide superconductor is sprayed onto the substrate, it is easy to produce a superconducting coil that exhibits an extremely high critical temperature and critical current density. can be manufactured.

Further, according to the present invention, the shape and size of the superconducting coil can be determined by the shape and size of the opening in the mask formed on the base, so it is possible to freely and easily create the superconducting coil in the desired shape and size. can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a manufacturing apparatus suitably used in carrying out the present invention, and FIG. 2 is a schematic configuration diagram showing an example of a substrate and a mask used in the first embodiment of the present invention. FIG. 3 is a schematic configuration diagram showing an example of a superconducting coil manufactured according to the first embodiment of the present invention, and FIG.
The figure is a schematic configuration diagram showing an example of a base and a mask used in the second embodiment of the present invention, and FIG. 5 is a schematic configuration diagram showing an example of a superconducting coil manufactured according to the second embodiment of the invention. be. l...Base, 2...Mask, 2a...Opening, 3...
...Thermal spray pistol, 4...Superconducting coil (spiral),
5... Metal tape (mask), 6... Superconducting coil (spiral).

Claims (1)

[Claims] After applying a mask having spiral or spiral openings on the substrate, a powder consisting of at least one of an oxide superconductor and a material containing an element constituting the oxide superconductor is thermally sprayed onto the substrate, and then A method for manufacturing a superconducting coil, characterized by heat treatment.