WO2016194225A1

WO2016194225A1 - Superconducting wire rod and method for manufacturing same

Info

Publication number: WO2016194225A1
Application number: PCT/JP2015/066358
Authority: WO
Inventors: 英次坂本; 寺前　俊哉; 田中　秀樹; 和也西; 孝明鈴木; 一宗児玉
Original assignee: 株式会社日立製作所
Priority date: 2015-06-05
Filing date: 2015-06-05
Publication date: 2016-12-08

Abstract

To provide a superconducting wire rod, which has a high critical current density, and is capable of achieving size reduction and cost reduction. This superconducting wire rod includes a plurality of bar-like composite bodies 6, and in each of the bar-like composite bodies 6, two or more bonded bodies are formed, each of said bonded bodies having a first layer 1a, 1b containing a first metal as a main component, and a second layer 2a, which is bonded to the first layer 1a, 1b with a diffusion layer 4, 12 therebetween, and which contains a second metal as a main component.

Description

Superconducting wire and method for manufacturing the same

The present invention relates to a superconducting wire and a manufacturing method thereof.

The superconducting magnet is applied to, for example, an MRI (Magnetic Resonance Imaging) apparatus used for examination in a hospital. Since the MRI apparatus is large in size and heavy in weight, downsizing is required in consideration of the convenience of securing an installation room in the hospital. In addition, since the MRI apparatus is expensive to manufacture, cost reduction is also required. For this reason, realization of a superconducting magnet that can be reduced in size and cost is required.

As a method for reducing the size of the superconducting magnet, there is a method of improving the critical current density (Jc [A / mm ² ]) of the superconducting wire used for the superconducting magnet. The larger the critical current density, the smaller the superconducting wire can be realized for the same current to flow.

As a technique for increasing the current density of a superconducting wire, production of a superconducting electric material by a diffusion method can be mentioned. The diffusion method is a method of forming a diffusion layer by diffusing a metal by performing heat treatment after drawing a wire containing a plurality of metals into an elongated shape. Since the material structure obtained by the diffusion method is dense and easily transmits electricity, the critical current density can be increased.

For example, Patent Document 1 discloses a rod-like composite in which boron (B) is arranged in the center and a magnesium tube (hereinafter referred to as Mg tube) containing aluminum (Al) and zinc (Zn) is installed on the outer periphery thereof. A method is disclosed in which a plurality of metal pipes are processed into a long length and then heat-treated. In this method, the powder containing boron (B) filled in the rod-shaped composite is uniformly moved in the metal tube, so that nonuniformity of the powder density is reduced and further heat treatment is performed thereafter. (Mg) and boron (B) diffuse to produce magnesium diboride (MgB ₂ ), and a wire having high superconducting properties can be obtained.

In Patent Document 2, boron (B) is arranged at the center, an Mg tube containing silver (Ag) is installed on the outer periphery thereof, a rod-shaped composite is prepared, and this is heat-treated. It describes that magnesium (Mg) diffuses sideways into boron (B) at the interface between them, making it possible to produce a magnesium diboride (MgB ₂ ) superconducting wire.

Japanese Patent No. 5517866 US2010 / 0093546

However, even with the techniques described in Patent Documents 1 and 2, improvement of the critical current density in the superconducting wire is not always sufficient.

Therefore, an object of the present invention is to provide a superconducting wire that can have a higher critical current density, and can be reduced in size and cost, and a method for manufacturing the same.

A preferred embodiment of the superconducting wire according to the present invention is a superconducting wire including a plurality of rod-shaped composites, wherein the rod-shaped composite includes a first layer mainly composed of a first metal, and the first layer. Two or more joined bodies having a second layer mainly composed of a second metal joined to the layer through a diffusion layer are formed.

As a preferred embodiment of the method for producing a superconducting wire according to the present invention, the first layer mainly composed of the first metal and the second layer mainly composed of the second metal are bonded to these surfaces. Are arranged so that two or more are formed to form a rod-like composite, and a structure in which a plurality of the rod-like composites are arranged is drawn and then heat-treated.

According to the present invention, it is possible to realize a superconducting wire that has a high critical current density and can be reduced in size and cost.

1 is a cross-sectional view of a superconducting wire according to Example 1. FIG. It is sectional drawing which shows the state before the wire drawing of the superconducting wire 20A of Example 1. FIG. It is sectional drawing which shows the state before heat processing of the rod-shaped composite_body | complex of Example 1, and after heat processing. It is sectional drawing which shows the state before the drawing process of the superconducting wire of Example 2. FIG. It is sectional drawing which shows the state before the drawing process of the superconducting wire of Example 3. 6 is a cross-sectional view of a superconducting wire of Example 3. FIG.

Hereinafter, a superconducting wire according to Example 1 of the present invention and a manufacturing method thereof will be described with reference to FIGS. FIGS. 1 and 2 and FIGS. 4 to 6 each show an enlarged view on the right side. FIG. 1 is a cross-sectional view of the superconducting wire according to the first embodiment.

As shown in FIG. 1, the superconducting wire 20 has a plurality of rod-like composites 6 provided inside the outer tube 7. In the example shown in FIG. 1, six rod-like composites 6 are provided, and between each of the rod-like composites 6, a filling layer 10 that fills a region between each bar-like composite 6 and the outer peripheral tube 7 is formed. Yes.

As shown in the enlarged view of FIG. 1, the rod-shaped composite body 20 is provided with a center layer 1a mainly composed of a first metal at the center, and the second metal is placed outside the center layer 1a. An annular layer 2 a as a main body is provided so as to be joined to the center layer 1 a via the first diffusion layer 4. On the outside of the annular layer 2a, an annular layer 1b mainly composed of a first metal is provided so as to be joined to the annular layer 2a via the second diffusion layer 12.

An annular barrier layer 5 is provided on the outer periphery of the annular layer 1b so as to be in contact with the annular layer 1b.

In the present specification, “consisting mainly of metal A” means containing 50% or more of metal A.

The first diffusion layer 4 and the second diffusion layer 12 are formed by bringing a layer mainly composed of the first metal and a layer mainly composed of the second metal into contact with each other to perform heat treatment. This is a layer obtained by diffusing the second metal. In the configuration of Example 1, as shown in FIG. 1, two joined bodies each having a diffusion layer are formed in one rod-shaped composite body 6. That is, it is interposed between a layer mainly composed of a first metal (hereinafter referred to as a first layer) and a layer mainly composed of a second metal (hereinafter referred to as a second layer). Therefore, the amount of current contributing to superconductivity should be doubled compared to a structure in which only one diffusion layer is formed for each rod-shaped composite. And the critical current density can be improved.

Further, as shown in FIG. 1, in the rod-shaped composite body 6, the joined body having the center layer 1a, the first diffusion layer 4, and the annular layer 2a, the annular layer 2a, the second diffusion layer 12, and the annular layer 1b. Are joined so as to share the annular layer 2a.

Thus, by providing the first layer and the second layer alternately and continuously via the diffusion layer, the ratio of the diffusion layer to the cross-sectional area of the superconducting wire 20 can be improved. Therefore, it is preferable because the critical current density can be increased accordingly.

The diffusion layer is not particularly limited as long as superconductivity can be obtained, but a layer mainly composed of magnesium diboride (hereinafter referred to as MgB ₂ ) can be preferably used.
MgB ₂ is a so-called high temperature superconducting material having a critical temperature Tc as high as 39K compared to niobium titanium (NbTi) (critical temperature; Tc = 9.8K) and niobium tin (Ni ₃ Sn) (critical temperature; Tc = 18K). Known as.

The high-temperature superconducting material has a large temperature margin that can maintain the superconducting state by cooling with, for example, liquid helium (boiling point 4.2 K) or refrigerator cooling, and thus has high thermal stability and may simplify the cooling equipment. Further, MgB ₂ has a possibility that a helium-free, small, light, and low-cost superconducting magnet can be realized because the magnetic flux creep is several times slower than that of the oxide-based superconducting material.

Note that the first diffusion layer 4 and the second 12 are not necessarily limited to MgB ₂ , and for example, niobium titanium (NbTi) or niobium tin (Ni ₃ Sn) described above can also be applied. The constituent material of each layer other than the diffusion layer is appropriately selected depending on the type of the diffusion layer, and details thereof will be described later.

In Example 1, a joined body having the center layer 1a, the first diffusion layer 4, and the annular layer 2a, and a joined body having the annular layer 2a, the second diffusion layer 12, and the annular layer 1b are: Although the configuration in which the annular layer 2a is shared and adjacent is shown, the superconducting wire of the embodiment is not necessarily limited to such a configuration. For example, another layer other than the second diffusion layer 12 is interposed between the annular layer 2a and the annular layer 1b, and the second layer is formed on the outer periphery of the annular layer 1b so as to be in contact therewith. May be.

Moreover, in Example 1, although the diffusion layer interposed between the 1st layer and the 2nd layer was shown in each rod-shaped composite body 6A, the structure shown by 2 layers was shown. May be provided in three or more layers in each rod-shaped composite body 6A. As the number of diffusion layers contained in the rod-shaped composite increases, the critical current density can be improved, and a superconducting wire having superior superconducting properties can be obtained.

In addition, as shown in FIG. 1, the shape of each rod-shaped composite 6 is preferably a hexagon, but may be other polygons such as a quadrangle, or may be a circle.

Next, the manufacturing process of the superconducting wire shown in FIG. 1 will be described with reference to FIGS. First, the case where the 1st metal which comprises the center layer 1a of the cyclic | annular composite body 6 is formed using powdery bodies, such as a compact, is demonstrated to an example.

In the following description, for example, “first metal 1a” and “first metal 1b” are both the first metal 1 or an alloy containing the first metal 1, and “second metal 2a”. "Is the second metal 2 or an alloy containing the second metal 2, and" third metal 3 "is the third metal 3 or an alloy containing the third metal 3, and in the following description These are simply indicated as "first metal 1a", "first metal 1b", "second metal 2a", and "third metal 3".

First, a tubular second metal 2a is prepared. Next, the tubular second metal 2a is filled with the powdery first metal 1a, and using a predetermined jig, pressure is applied to the powdered first metal 1a to form a shaped body. .

Next, a tubular barrier layer 5 having an outer diameter larger than that of the second metal 2a is prepared, and this barrier layer 5 is disposed on the outer periphery of the second metal 2a. Next, a powdery first metal 1b is filled between the second metal 2a and the barrier layer 5, and pressure is applied to the powder using a predetermined jig to form a shaped body. By putting them into the space of the tubular third metal 3, a rod-shaped composite before drawing is completed.

Next, the rod-shaped composite before drawing is drawn by extrusion or drawing. At that time, the rod-shaped composite body 6A having a predetermined cross-sectional shape can be manufactured by using a die having a required processing shape, for example, a hexagonal shape, in the wire drawing process. Thereafter, annealing is performed in an inert atmosphere in order to remove strain that has been hardened by wire drawing.

The superconducting wire 20A before drawing is completed by putting a plurality of the rod-like composites 6A into the space of the tubular outer tube 7 and putting the fourth metal 8 in the center.

As shown in FIG. 2, the shape of each rod-shaped composite body 6A and the fourth metal 8 is preferably a hexagon, but may be other polygons such as a rectangle, or may be a circle.

The barrier layer 5 is placed in the space of the third metal 3 in advance, and after the powdery first metal 1a and the tubular second metal 2a are placed inside, the tubular second metal 2a is placed. The rod-shaped composite 6A may be manufactured by filling the powdery first metal 1b between the metal 2a and the barrier layer 5 and applying pressure to the powder using a predetermined jig to form a shaped body.

FIG. 2 is a cross-sectional view showing a state of the superconducting wire 20A of Example 1 before drawing. As shown in FIG. 2, the superconducting wire 20A is a multi-core wire having a plurality of rod-shaped composite bodies 6A, and has a space 9 in an area excluding the rod-shaped composite bodies 6A and the fourth metal 8 in the outer peripheral tube 7. is doing.

The rod-shaped composite body 6A is provided with a first metal 1a at the center, a second metal 2a at the outer periphery thereof, and a first metal 1b at the outer periphery thereof. That is, the first metal 1a and the second metal 2a, and the second metal 2a and the first metal 1b are provided in contact with each other at the joint surface 16 and the joint surface 17, respectively.

A barrier layer 5 is provided on the outer periphery of the powdery first metal 1b, and a tubular third metal 3 is provided on the outermost periphery of the rod-shaped composite 6A.

After that, the superconducting wire 20A before drawing is elongated by drawing. At this time, the third metal 3 and the fourth metal 8 arranged in the superconducting wire 6 </ b> A move to the space 9 due to plastic deformation during wire drawing. During wire drawing, intermediate annealing in an inert atmosphere may be performed in the middle of the drawing.

After completion of the wire drawing process, the superconducting wire 20A is heated to a temperature equal to or higher than the melting point of the first metal 1a, the first metal 1b, and the second metal 2a, whichever has a lower melting point, and the first metal 1a The second metal 2a, the second metal 2a, and the first metal 1b are diffused to form the first diffusion layer 4 and the second diffusion layer 12 having superconducting properties as shown in FIG. At this time, the third metal 3 and the fourth metal 8 become a filling layer 10 which is an integral mixture by heat treatment and fills the space 9. Thereby, the superconducting wire 20 shown in FIG. 3 is completed.

1 to 3, the third metal 3, the fourth metal 8, and the filling layer 10 are described with different names, but all may be made of the same material.

After the diffusion layer is formed by heat treatment, a defect due to a space such as Kirkendall void may occur at the position where the diffused metal exists. For this reason, it is preferable to pressurize the superconducting wire after the formation of the diffusion layer by heat treatment. Thereby, the space volume generated after the formation of the diffusion layer can be reduced, or such a space can be eliminated. For this reason, the superconducting wire 20 which has the dense rod-shaped composite body 6 without the defect in the

layers

1a and 1b mainly composed of the first metal and the layer 2a mainly composed of the second metal can be obtained.

The constituent materials of each layer when forming the MgB ₂ layer as the first diffusion layer 4 and the second diffusion layer 12 will be described by taking as an example the case of using a powdery body as the first metal 1a constituting the center layer 1a. To do.

When the first metal 1a is a powdery body such as a green compact, for example, boron (B) or an alloy powder containing boron (B) can be used as the first metal 1a.

As the second metal 2a, magnesium (Mg) or a tubular body of an alloy containing magnesium (Mg) can be used. In the case where the first metal 1a is a powdery body, the second metal 2a is preferably a tubular body from the viewpoint of manufacturing convenience.
However, even when the first metal 1a is a powder, the second metal 2a may be a powder. For example, Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same is used. It may be a powder, or may be a powder of magnesium (Mg) or an alloy containing magnesium (Mg).

When Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same is used as the second metal 2a, the particle size is 1 nm to 100 nm, and the second metal 2a is formed by a mechanical milling method (MM method). Compared with the case of using untreated Mg-B metal powder. For this reason, it is possible to further increase the density of the first diffusion layer 4 and the second diffusion layer 12 formed after the heat treatment. By increasing the density, it becomes easier to pass the current, and the critical current density can be improved.

As the first metal 1b, for example, boron (B) or an alloy powder containing boron (B) can be used.

When the first metal 1a, the first metal 1b, and the second metal 2a are powdery, in addition to the main component described above, a carbide such as silicon carbide (SiC) is appropriately mixed. You may let them.

The barrier layer 5 is not particularly limited as long as it is a metal material having low reactivity with the first metal and the second metal. As the barrier layer 5, for example, iron (Fe), niobium (Nb), copper (Cu), titanium (Ti), nickel (Ni), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (Mo) ) And vanadium (V) selected from the group consisting of one or two or more metals or alloys containing each metal can be used.

As the third metal 3, it is preferable to use a metal material having low reactivity with the first metal and the second metal and having excellent thermal conductivity. As the third metal 3, for example, a tubular body of copper (Cu) or an alloy containing copper (Cu) can be used.

As the fourth metal 8, it is preferable to use a metal material having low reactivity with the first metal and the second metal and having excellent thermal conductivity. As the fourth metal 8, for example, a metal molded body or powdered body of copper (Cu) or an alloy containing copper (Cu), or an alloy containing iron (Fe) or iron (Fe) can be used.

Although it does not specifically limit as the outer periphery pipe | tube 7, For example, iron (Fe), niobium (Nb), copper (Cu), titanium (Ti), nickel (Ni), aluminum (Al), tantalum (Ta), tungsten ( A tubular body of one or two or more metals or alloys selected from the group consisting of W), molybdenum (Mo), and vanadium (V) can be used.

The structure of each layer of the superconducting wire 20 shown in FIG. 1 manufactured using the above materials as the constituent material of each layer will be described.
As the first diffusion layer 4 and the second diffusion layer 12, MgB ₂ is formed as a layer having superconducting characteristics.

The center layer 1a mainly composed of the first metal is a layer mainly composed of boron (B) or an alloy containing boron (B).
The annular layer 2a mainly composed of the second metal is mainly composed of magnesium (Mg) or an alloy containing magnesium (Mg), Mg—B formed by a mechanical milling method (MM method), or an alloy containing this. Is a layer. As described above, the particle diameter of Mg—B formed by the mechanical milling method (MM method) or an alloy including the same is 1 nm to 100 nm.

The annular layer 1b mainly composed of the first metal is a layer mainly composed of boron (B) or an alloy containing boron (B).

The barrier layer 5 includes iron (Fe), niobium (Nb), copper (Cu), titanium (Ti), nickel (Ni), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (Mo) and It is a layer mainly composed of one or more metals or alloys selected from the group consisting of vanadium (V).

As described above, the filling layer 10 is a mixture of the third metal 3 and the fourth metal 8 of the rod-shaped composite body 6A before wire drawing, and for example, copper (Cu) or an alloy containing copper (Cu). Or a layer mainly composed of iron (Fe) or an alloy containing iron (Fe).

In addition, the constituent material of the outer peripheral tube 7 is the same as the constituent material described in the manufacturing method.

The shape of each rod-like composite 6 and the fourth metal 8 is preferably a hexagon, but may be other polygons such as a rectangle or a circle.

In the present embodiment, an example in which two joint surfaces between the first layer and the second layer are formed in each rod-like composite 6A has been described. As another example, it is also possible to increase the number of first layers or second layers formed in each rod-shaped composite body 6A, and to have three or more joint surfaces thereof. Since the number of diffusion layers formed after the heat treatment increases due to the increase of the joint surfaces, the critical current density can be increased accordingly.

In the present embodiment, the first metal 1a, the second metal 2a, and the first metal are formed so that the

joint surfaces

16 and 17 between the first layer and the second layer are continuously formed. Although 1b is arranged, these joint surfaces do not necessarily have to be formed continuously. For example, a layer mainly composed of the second metal is provided so that another layer between the second metal 2a and the first metal 1b is interposed and in contact with the outer periphery of the first metal 1b. A second layer) may be formed.

However, by continuously forming the joint surface between the first layer and the second layer, the proportion of the diffusion layer per 20 cross-sectional areas of the superconducting wire can be improved. This is preferable because the density can be increased.

Next, regarding the manufacturing process of the superconducting wire shown in FIG. 1, the second metal constituting the annular layer 2a provided on the outer periphery of the center layer 1a of the rod-shaped composite 6 is used by using a powdery material such as a green compact. The case of forming will be described as an example.

First, a rod-shaped first metal 1a and a tubular first metal 1b having a diameter larger than that of the rod-shaped first metal 1a are prepared, and the rod-shaped first metal 1a is placed in the space of the first metal 1b. insert. Then, the gap between the rod-shaped first metal 1a and the tubular first metal 1b is filled with the powdered second metal 2a, and pressure is applied to the powder using a predetermined jig, and the shaped body. And

Next, a tubular barrier layer 5 having an outer diameter larger than that of the tubular first metal 1b is prepared, and this barrier layer 5 is disposed on the outer periphery of the first metal 1b. By putting these into the space of the tubular third metal 3, a rod-shaped composite before drawing is completed. The rod-shaped composite body before wire drawing formed in this way is subjected to wire drawing by extrusion or drawing like the above-described manufacturing method, and then annealed in an inert atmosphere to produce a rod-shaped composite 6A. To do.

In addition, after putting the barrier layer 5 in the space of the third metal 3 in advance and putting the rod-shaped first metal 1a and the tubular first metal 1b inside thereof, the rod-shaped first metal A rod-shaped composite 6A may be manufactured by filling a powdery second metal 2a between 1a and the tubular first metal 1b.

Note that the drawing process and heat treatment of the superconducting wire 20A are the same as in the above-described manufacturing method in the case of using a powdery body as the first metal 1a, and the description thereof is omitted.

Regarding the constituent material of each layer when forming the MgB ₂ layer as the first diffusion layer 4 and the second diffusion layer 12, the case where a powdery body is used as the second metal 2a constituting the annular layer 2a is taken as an example. explain.

When the second metal 2a is made into a powdery body such as a green compact, for example, magnesium (Mg) or an alloy containing magnesium (Mg) can be used as the rod-shaped first metal 1a.

In addition, when the 2nd metal 2a is a powdery body, it is preferable that the 1st metal 1a is a rod-shaped body from a viewpoint of the convenience of manufacture. However, even when the second metal 2a is a powder, the first metal 1a may be a powder, such as Mg-B formed by a mechanical milling method (MM method) or an alloy containing the same. It may be a powder, or may be a powder of magnesium (Mg) or an alloy containing magnesium (Mg).

As the second metal 2a, boron (B) or an alloy powder containing boron (B) can be used.

As the first metal 1b, a tubular body of magnesium (Mg) or an alloy containing magnesium (Mg) can be used. In addition, when the 2nd metal 2a is a powdery body, it is preferable from a viewpoint of the convenience of manufacture that the 1st metal 1b is a tubular body. However, even when the second metal 2a is a powder, the first metal 1b may be a powder, for example, Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same. It may be a powder, or may be a powder of magnesium (Mg) or an alloy containing magnesium (Mg).

For the barrier layer 5, the third metal 3, the fourth metal 8, and the outer tube 7, it is possible to use the same constituent materials as when the powdery body is used as the first metal 1 a.

In addition, like the manufacturing method when using a powdery body as the first metal 1a, the first metal 1a, the first metal 1b, and the second metal 2a have a powdery body, In addition to the main components described above, carbides such as SiC may be appropriately mixed.

The configuration of each layer of the superconducting wire 12 shown in FIG. 1 manufactured using the above-described materials as the constituent material of each layer will be described.
As in the case where a powder is used as the first metal 1a, MgB ₂ is formed as the first diffusion layer 4 and the second diffusion layer 12 as a layer having superconducting characteristics.

The central layer 1a mainly composed of the first metal is composed mainly of magnesium (Mg) or an alloy containing magnesium (Mg), Mg—B formed by a mechanical milling method (MM method), or an alloy containing this. Is a layer.
The annular layer 2a mainly composed of the second metal is a layer mainly composed of boron (B) or an alloy containing boron (B).
The annular layer 1b mainly composed of the first metal is composed mainly of magnesium (Mg) or an alloy containing magnesium (Mg), Mg—B formed by a mechanical milling method (MM method), or an alloy containing this. Is a layer.

In the central layer 1a and the annular layer 2a, the particle diameter of Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same is 1 nm to 100 nm as described above.

Other constituent materials of the barrier layer 5, the outer peripheral tube 7, and the filling layer 10 are the same as those in the case of using a powdery body as the first metal 1a, and the description thereof is omitted.

In the above-described manufacturing method, the case where the first metal 1a or the second metal 2a is a powdery body such as a green compact has been described as an example. However, the present invention is not necessarily limited to such a form. . For example, any of the first metal 1a, the second metal 2a, and the first metal 1b may be formed of a rod-like body or a tubular body. Moreover, you may comprise any of the 1st metal 1a, the 2nd metal 2a, and the 1st metal 1b with a powdery body.

Hereinafter, a method of manufacturing the superconducting wire of Example 2 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a state of the superconducting wire of Example 2 before drawing.

Example 2 is different from Example 1 in that a plurality of rod-shaped composite bodies 6A and a fourth metal 8 are installed in the outer peripheral pipe 7, and then the outer peripheral pipe 7, the bar-shaped composite bodies 6A and the fourth metal 8 are disposed. The sixth metal 11 is placed in a region between the structure 15 and the structure 15.

The sixth metal 11 is a metal molded body having a shape along the region between the outer peripheral tube 7 and the structure 15. Although it does not specifically limit as the 6th metal 11, For example, the alloy containing copper (Cu) or copper (Cu) can be used.

As the sixth metal 11, it is possible to fill a region between the outer peripheral tube 7 and the structure 15 by using a plurality of metal rods, but the shape along the outer shape of the space 9 It is preferable to use a metal molded body.

In Example 2, the structure 15 in the state shown in FIG. 4 is drawn together with the sixth metal 11 and the outer tube 7 and further heat-treated. Thereby, after the heat treatment, the first diffusion layer 4 and the second diffusion layer 12 are formed in the rod-shaped composite body 6, and the region between the rod-shaped composite bodies 6 in the outer tube 7 3 is formed, and the filling layer 10 which is a mixture of the fourth metal 8 and the sixth metal 11 in the center is formed, and the superconducting wire 20 is obtained.

In addition, the manufacturing method of Example 2 is the same as that of Example 1 except the point which uses the 6th metal 11, and the description is abbreviate | omitted. Moreover, the structure of the superconducting wire obtained by the manufacturing method of Example 2 is the same as that of the superconducting wire of Example 1 shown in FIG.

In Example 2, before the wire drawing process, the space 9 in the outer peripheral tube 7 is filled, whereby the barrier layer breakage of the rod-shaped composite body 6A during the wire drawing process can be prevented, and manufacturing is performed with higher yield. Can do.

Hereinafter, the superconducting wire of Example 3 and the manufacturing method thereof will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing a state of the superconducting wire of Example 3 before drawing. FIG. 6 is a cross-sectional view of the superconducting wire of Example 3. That is, FIG. 6 is a cross-sectional view of the superconducting wire of the finished product after the wire drawing and heat treatment.

The third embodiment is different from the first embodiment in that the outer periphery of the structure 15 in which the plurality of rod-shaped composite bodies 6A and the fourth metal 8 are installed on the outer peripheral surface of the structure 15 in a state before wire drawing. It is the point which has installed the outer periphery pipe | tube 7 which has the inner periphery shape which follows.

In Example 3, as shown in FIG. 5, an area corresponding to the space 9 in FIG. 1 is filled with the outer peripheral tube 7. The outer peripheral tube 7 having the shape shown in FIG. 5 can be formed by plastic working such as drawing or extruding. The constituent material of the outer tube 7 can be the same as that of the outer tube 7 of the first embodiment.

And the superconducting wire 20 shown in FIG. 6 is obtained by drawing the structure 15 shown in FIG. That is, after the heat treatment, the first diffusion layer 4 and the second diffusion layer 12 are formed in the rod-shaped composite body 6, and the region between the rod-shaped composite bodies 6 in the outer peripheral tube 7 is in the third region. The filling layer 10 which is a mixture of the metal 3 and the fourth metal 8 at the center is formed, and the superconducting wire 20 is obtained.

The manufacturing method of Example 3 is the same as that of Example 1 except that the outer peripheral tube 7 having an inner peripheral shape along the outer peripheral surface of the structure 15 is installed on the outer periphery of the structure 15 before the wire drawing. Yes, the description is omitted. Moreover, the superconducting wire 20 obtained by the manufacturing method of Example 3 is the same as Example 1 except that the region between the rod-like composites 6 is joined by the outer peripheral tube 7 described above, and the description thereof is omitted. Is omitted.

According to Example 3, the space area between the outer peripheral tube 7 and the rod-shaped composite body 6A can be reduced by using the above-described form as the outer peripheral tube 7. For this reason, the barrier layer tearing of the rod-shaped composite body 6A at the time of wire drawing can be prevented, and it can be manufactured with higher yield. Moreover, since the process of installing the sixth metal 11 which is a metal molded body in the space 9 is not required before the drawing of the superconducting wire as in the second embodiment, it is manufactured in a shorter amount of time. Is possible.

1a ... center layer (first metal), 1b ... annular layer (first metal), 2a ... annular layer (second metal), 3 ... third metal, 4 ... first diffusion layer, 12 ... 2nd diffusion layer, 5 ... barrier layer, 6 ... rod-shaped composite, 6A ... rod-shaped composite before wire drawing, 7 ... outer peripheral tube, 8 ... fourth metal, 9 ... space, 10 ... filling layer, 11 ... the sixth metal,
DESCRIPTION OF SYMBOLS 15 ... Structure, 16, 17 ... Joint surface, 20 ... Superconducting wire, 20A ... Superconducting wire before wire drawing

Claims

A superconducting wire containing a plurality of rod-shaped composites,
The rod-shaped composite has a first layer mainly composed of a first metal and a second layer mainly composed of a second metal bonded to the first layer via a diffusion layer. A superconducting wire comprising two or more bodies.
The rod-shaped composite body is provided with a second metal annular layer as the second layer outside the first metal center layer as the first layer provided at the center,
A first metal annular layer as the first layer is further provided outside the second metal annular layer,
A barrier layer mainly composed of one kind or two or more kinds of metals or alloys is provided outside the laminate having the first metal center layer, the second metal ring layer, and the further first metal ring layer. The superconducting wire according to claim 1, wherein:
2. The superconducting wire according to claim 1, wherein the superconducting wire has two or more combinations of adjacent joints sharing the first layer or the second layer.
The first metal center layer is a layer mainly composed of boron (B) or an alloy containing boron (B),
The second metal annular layer is a layer mainly composed of magnesium (Mg) or an alloy containing magnesium (Mg), Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same.
The first metal annular layer is a layer mainly composed of boron (B) or an alloy containing boron (B),
The barrier layer includes iron (Fe), niobium (Nb), copper (Cu), titanium (Ti), nickel (Ni), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (Mo) and The superconducting wire according to claim 2, wherein the superconducting wire is a layer mainly composed of one or more metals or alloys selected from the group consisting of vanadium (V).
The first metal center layer is a layer mainly composed of magnesium (Mg) or an alloy containing magnesium (Mg), Mg-B formed by a mechanical milling method (MM method) or an alloy containing the same.
The second metal annular layer is a layer mainly composed of boron (B) or an alloy containing boron (B),
The first metal annular layer is a layer mainly composed of magnesium (Mg) or an alloy containing magnesium (Mg), Mg—B formed by a mechanical milling method (MM method) or an alloy containing the same.
The barrier layer includes iron (Fe), niobium (Nb), copper (Cu), titanium (Ti), nickel (Ni), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (Mo) and The superconducting wire according to claim 2, wherein the superconducting wire is a layer mainly composed of one or more metals or alloys selected from the group consisting of vanadium (V).
The superconducting wire according to claim 4, wherein a particle diameter of Mg-B formed by the mechanical milling method (MM method) or an alloy containing the Mg-B is 1 nm to 100 nm.
The superconducting wire according to claim 5, wherein the Mg-B formed by the mechanical milling method (MM method) or an alloy containing the Mg-B has a particle size of 1 nm to 100 nm.
The superconducting wire according to claim 1, wherein a plurality of the rod-shaped composites are joined together by an outer tube.
The superconducting wire according to claim 1, wherein the diffusion layer is a layer mainly composed of magnesium diboride (MgB 2 ).
The first layer mainly composed of the first metal and the second layer mainly composed of the second metal are arranged so that two or more of these joint surfaces are formed to form a rod-shaped composite,
A method for producing a superconducting wire, characterized by subjecting a structure in which a plurality of the bar-shaped composite bodies are arranged to a heat treatment after wire drawing.
11. The rod-like composite is formed by arranging the second layer and the first layer alternately and in contact with each other outside the first layer arranged in the center. The manufacturing method of the superconducting wire described in 1.
The method for producing a superconducting wire according to claim 10, wherein the structure in which a plurality of the rod-shaped composite bodies are arranged is heat-treated and then pressurized.
After the metal molded body having a shape conforming to the outer shape of the region is installed in a region between the structure in which a plurality of the rod-shaped composite bodies are arranged and the outer tube, the structure is formed together with the metal molded body and the outer tube. The method of manufacturing a superconducting wire according to claim 10, wherein the body is drawn.
After the outer peripheral tube having an inner peripheral shape along the outer peripheral surface of the structure in which a plurality of the rod-shaped composite bodies are arranged is installed on the outer periphery of the structure, the structure is drawn together with the outer peripheral tube. The method for producing a superconducting wire according to claim 10.
The method for manufacturing a superconducting wire according to claim 14, wherein the outer peripheral tube is formed by drawing or extruding.