JPH0133885B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a superconducting composite wire, in particular a core material made of a brittle material such as a compound superconducting wire, and a metal outer layer material on the periphery of the core material. The present invention relates to a method of manufacturing a superconducting composite wire that can suppress strain applied to a core material to a low level when extrusion coating the superconducting composite wire.

[Prior Art] Conventionally, methods for manufacturing metal composite wires include an extrusion method in which an outer layer material is extruded and coated on the periphery of a core material, and an outer layer material (plate shape) is rolled and welded on the periphery of a core material to form a wire rod. Well-known methods include a clad rolling method for forming a wire, a wire drawing method for preparing a billet-shaped composite base material and subjecting it to wire drawing, and a plating method.

Extrusion methods, rolling methods, and wire drawing methods, excluding the metsuki method, are
Both have the disadvantage that large strains are applied to the core material during the manufacturing and coating process, causing plastic deformation of the core material. Therefore, in these manufacturing methods,
For example, when a brittle material with low tensile strength such as a compound superconducting wire is used as a core material, the amount of strain applied to the core material becomes a problem, which significantly limits manufacturing conditions.

On the other hand, in the plating method, as described above, the amount of strain applied to the core material does not pose a problem, but there is a limit to the thickness of the coating. For this reason, it is usually applied only to thin objects, and cannot be applied, for example, to cases where a considerable thickness of aluminum is coated on the circumference of a compound superconducting wire as a stabilizing material. In addition, in the plating method, the metal structure coated by plating becomes a cast structure, so in order to improve this, it is generally necessary to perform a wire drawing process, which causes the problem that the manufacturing process becomes extremely complicated depending on the product. There is.

[Problems to be Solved by the Invention] In view of the above-mentioned points, the present invention provides a method for suppressing strain applied to the core material when extrusion coating a metal outer layer material on the periphery of the core material of a compound-based superconducting wire. The purpose of the present invention is to provide a method for manufacturing a superconducting composite wire that can be manufactured using a superconducting composite wire.

[Means for Solving the Problems] The gist of the present invention is to extrude the outer layer material onto the periphery of the core material of a compound-based superconducting wire via an intermediate material having lower deformation resistance than the core material and the metal outer layer material. The present invention provides a method for manufacturing a superconducting composite wire characterized by coating the wire.

Here, if the intermediate material is melted and supplied between the core material and the outer layer material that is being extruded around the core material, low strain extrusion coating processing on the core material can be more easily achieved.

Furthermore, in the above case, if the outer layer material is heated to a temperature higher than the melting point of the intermediate material and then extruded, a sound adhesive structure between the outer layer material and the intermediate material can be easily constructed.

Furthermore, when the intermediate material is solder and the outer layer material is aluminum, it is possible to easily obtain an aluminum-stabilized superconducting wire with a sound structure while maintaining the quality of the compound-based superconducting wire that is the core material.

When the core material is a compound-based superconducting wire as mentioned above, it is necessary to keep the strain applied to the core material to a particularly low level, but the adhesive structure between the core material and the outer layer material also has the electrical and It needs to be sound and strong in terms of ensuring mechanical properties. Here,
Low-strain extrusion processing, which aims not to place too much stress on the core material, and general extrusion processing, which emphasizes adhesive strength between the core material and the core material, can be said to be extrusion processing based on mutually contradictory requirements. By extruding and covering the outer layer material in the shape of a pipe at intervals, and supplying molten solder into the space between the core material and the outer layer material, the strain applied to the core material can be significantly suppressed. In addition, the molten solder described above can also make the bonding structure between the core material and the outer layer material sound and strong. If the outer layer material is simply extruded into a pipe shape, there is a problem with the adhesive structure, but by using molten solder, a sound adhesive structure can be easily constructed. Here, in order to make the adhesive structure constructed using molten solder more reliable and to eliminate or reduce defects due to poor adhesion, the outer layer material is heated to a temperature higher than the melting point of the intermediate material solder and then pressed. It is better to release it.

When supplying molten solder, it is a very efficient manufacturing method to pour the molten solder into the gap between the core material and the outer layer material. In this case, it is preferable to employ a downward extrusion method as the extrusion method.

Performing extrusion processing at a higher temperature than necessary
This may form or encourage the formation of an unfavorable alloy layer at the adhesion interface of the core material, intermediate material, and outer layer material, respectively, and there is a concern that the electrical and mechanical properties of the superconducting composite wire will deteriorate. Therefore, for this reason, it is important to set various conditions such as extrusion temperature, extrusion speed, and cooling to appropriate values in advance during extrusion.

[Example] Hereinafter, an example of the method for manufacturing a superconducting composite wire of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a cross section of an aluminum stabilized superconducting wire manufactured according to the method of the present invention, in which an aluminum outer layer material 3 is placed on the periphery of a core material 1 of the compound superconducting wire via an intermediate material 2 of solder. It will be covered.
As the intermediate material 2, a solder having a lower deformation resistance and a lower melting point than the core material 1 and the outer layer material 2 is selected and used.

FIG. 2 shows the manufacturing method of the composite wire 4, in which a core material 1 of a compound-based superconducting wire prepared in advance is introduced from above the extruder at a constant speed through the nipple 5 and die 6 of the extruder, while aluminum The outer layer material 2 is supplied under pressure to the circumference of the core material 1 through the limited space between the nipple 5 and the die 6, and is then passed through the space to the pipes at intervals on the circumference of the core material 1. It is extruded into a shape. Furthermore, an intermediate material 2 of molten solder is supplied onto the circumference of the core material 1 through the nipple 5, and the distance between the core material 1 and the outer layer material 3 which is being extruded into a pipe shape is increased. It is poured in to fill it up. In this way, the aluminum stabilized superconducting wire is discharged from the bottom of the extruder. 4 indicates the superconducting composite wire 4.

In this case, if the aluminum outer layer material 3 is heated to a temperature higher than the melting temperature of the intermediate material 2 and then extruded, it becomes easier to form a coating with the intermediate material 2 by pouring the molten solder, and the intermediate material 2 and the outer layer material 3 are It also makes the adhesion between the two easier and stronger.

In this embodiment, the core material 1 is a single wire with a circular cross section, and the cross section of the superconducting composite wire with respect to the core material 1 is concentric. can be used as a core material to construct a concentric elliptical superconducting composite wire, or to construct a stranded wire 7
It is also possible to use it as a core material. In addition, 8
indicates a superconducting composite wire.

Since the basic technology of the present invention is metal extrusion, the core material and the outer layer material that is the raw material for the extrusion are limited to metal materials, but the intermediate material is not necessarily limited to metal materials. As for the intermediate material, an appropriate material is selected and used in consideration of the properties required for the product as well as the materials of the core material and outer layer material.

[Effects of the Invention] According to the method for manufacturing a superconducting composite wire of the present invention, the outer layer is formed on the periphery of the core material of a compound superconducting wire via an intermediate material having a lower deformation resistance than the core material and the metal outer layer material. Since the material is extruded and coated, when a metal outer layer material is extruded and coated on the circumference of the core material, the strain applied to the core material due to plastic deformation of the outer layer material is absorbed by the intermediate material. This makes it possible to easily keep it low. That is, low distortion extrusion coating processing becomes easily possible. Therefore, according to the method of the present invention, it is possible to easily coat a compound-based superconducting wire with metal, which requires keeping the strain particularly low, and as a result, it is possible to produce a superconducting composite wire with a high quality and sound coating structure. can be obtained easily.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a superconducting composite wire manufactured according to the method of the present invention, FIG.
The figures are cross-sectional views of other superconducting composite wires manufactured based on the method of the present invention. 1: Compound superconducting wire, 2: Intermediate material, 3: Outer layer material, 4, 8: Superconducting composite wire, 5: Nipple,
6: Dice, 7: Stranded wire.

Claims (1)

[Scope of Claims] 1. A superconductor characterized in that the outer layer material is extruded and coated on the periphery of the core material of a compound-based superconducting wire via an intermediate material having lower deformation resistance than the core material and the metal outer layer material. Method of manufacturing composite wire. 2. A method for manufacturing a superconducting composite wire according to claim 1, characterized in that the intermediate material is melted and supplied between the core material and the outer layer material that is being extruded around the core material. 3. A method for manufacturing a superconducting composite wire according to claim 1 or 2, characterized in that the outer layer material is heated to a temperature higher than the melting point of the intermediate material and then extruded. 4. The method for manufacturing a superconducting composite wire according to claim 1, 2 or 3, wherein the intermediate material is solder and the outer layer material is aluminum.