JPH09283812A - Manufacture of nb-ti superconducting multi-layer plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a superconducting multi-layer plate by depositing one or more layers formed by coating normal conductive metal material around a single layer of Nb-Ti alloy material covered by a sheet of Nb, Ta or the like, then after a heat process with a particular process rate and at a particular temperature, performing another heat process at a particular temperature and for a particular period, and repeating the cooling process at a particular process rate. SOLUTION: A single layer of Nb-Ti alloy material 1 covered with a sheet of Nb, Ta or the like, is inserted into a case 2 of normal conductive metal material, and the case 2 is weld-sealed, to obtain an Nb-Ti single-layer clad slab 4. The slab 4 is subjected to a surface reducing process including a heat process with a process rate of 30-98% and at 500-1000 deg.C for composite integration. Further, the slab 4 is subjected to another process with a process rate of 30-98% and at 600 deg.C or lower. Thereafter, a heat process at 300-450 deg.C and with a holding period of 1-168 hours and a cooling process with a process rate of 30-98% are alternately repeated 6 times or less, to form an Nb-Ti superconducting multi-layer plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes superconducting magnetism by utilizing excellent characteristics such as perfect diamagnetism, magnetic flux trap, and current carrying ability with high current density at zero electric resistance, which Nb-Ti alloy superconducting material has. TECHNICAL FIELD The present invention relates to a method for producing an Nb—Ti alloy superconducting multilayer plate capable of producing a superconducting multilayer plate having excellent ability as a shield, a superconducting permanent magnet, a superconducting conductive material, etc. at low cost and also capable of significantly improving the characteristics. It is a thing.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an Nb-Ti-based superconducting multilayer plate, a housing-shaped or cylindrical hollow body made of a highly conductive metal is coated with a sheet or foil of Nb, Ta or Nb-Ta alloy. At least one layer of the above-mentioned Nb-Ti alloy plate is filled so as to be alternately laminated with the above-mentioned plate of the high-conductivity metal, and the filling rate is set to 60% or more, and then the end is covered with the high-conductivity metal, and the inside is vacuumed Welded and sealed to form an integrated composite, and the integrated composite has a processing rate of 30 to 98%,
After hot working at a temperature of 500-1000 ° C, 300
Patented is a method of making a plate-shaped or box-shaped product by repeatedly performing heat treatment at a temperature of ~ 450 ° C for a holding time of 1 to 168 hours and cold working at a working rate of 30 to 98% six times or more. No. 1790043 "Nb-Ti based superconducting magnetic shield material and its manufacturing method", and "I. Itoh et a
L., Cryogenics, 35, 403 (1995) ”and the like.

The critical current density (Jc), which is one of the most important superconducting properties of Nb-Ti type alloys, is that α-Ti precipitates having an hcp structure are finely dispersed in a β phase having a bcc structure. It is known that by doing so, it can be greatly improved. The optimum heat treatment temperature for aging precipitation of α-Ti is said to be in the range of 300 to 450 ° C., and α-Ti phase is precipitated by performing heat treatment for a long time within this temperature range. If the temperature is higher than this, fine dispersion of the precipitate is impossible and the particles become coarse.
-Ti precipitates are said to decompose. Also, J
It is known that not only α-Ti precipitates but also dislocation networks and lattice defects are important for improving c. These are introduced into the crystal by cold working, but disappear in the temperature range where the β phase is recovered or recrystallized. As a method of appropriately mixing these dislocation networks and α-Ti precipitates, it has become known that Jc is greatly increased by repeating cold working at an appropriate working ratio and the above heat treatment several times. Came.

The following explanation is given as the reason why these materials improve Jc. When a superconducting current flows in a superconductor, a magnetic field is naturally generated, but Nb-T
In a type II superconductor such as an i-based alloy, in a magnetic field of Bc1 (lower critical magnetic field) or higher, the magnetic field enters a vortex-shaped bundle of quantum magnetic flux units and enters the superconductor. This is called a mixed state of the second type superconductor. Bc1 for Nb-Ti alloys
Is as low as several 10 G (Gauss), and all practical magnetic fields are B
It can be said that it penetrates into the superconductor beyond c1. Since the magnetic field at this time is orthogonal to the superconducting current, Lorentz force acts at right angles to both of them according to Fleming's law, and if there is no resistance force, magnetic flux flow will occur in an avalanche shape and electrical resistance will occur, causing heat generation. Therefore, the superconducting state instantly transits to the normal conducting state. This is called a quench. However, in this magnetic flux flow, the normal-conducting phase having an appropriate size and distribution density dispersed in the superconductor serves as a flow stopper (called pinning point) of the quantum magnetic flux vortex, and the superconducting state can be maintained. . If this can maintain a higher current density, it can be said to be a superconducting material with high Jc and excellent characteristics.

That is, in the case of Nb-Ti type alloys, it is generally recognized that the above-mentioned α-Ti precipitates, dislocation networks and lattice defects are pinning points. Further, it is said that the dislocation network and the lattice defects assist the movement of atoms forming the precipitation phase and serve as a driving force for the precipitation, and are important in a double sense. Therefore, as described above, in order to improve the characteristics, in the Nb-Ti based alloy, after the final solution treatment or recrystallization annealing, the cold working ratio (final solution treatment or recrystallization It is necessary to improve (NbTi thickness during crystallization / NbTi thickness in product).

However, in the conventional manufacturing method, considering the processing in the industrial rolling equipment, the processing ratio is limited to about 10 ² order. For example, when the NbTi sheet and the copper sheet both have a thickness of 3 mm when clad with 30 layers of NbTi, the outermost layer of copper is usually desired to have a thickness of about 10 times. 24
It becomes 0 mm. If hot rolling is applied at a processing rate of 50%,
The clad material thickness is 120 mm, and when the product thickness is 1 mm, the cold working ratio is only 120.

[0007]

Problems to be Solved by the Invention Patent No. 1790043
The Nb-Ti-based superconducting multilayer plate described in No. 1 requires a diffusion barrier layer which is a multiple of the number of Nb-Ti layers. Nb or Ta, which is the most suitable material as a barrier, is a rare metal and is extremely expensive. Due to the nature of the diffusion barrier, the required thickness is extremely small, depending on the manufacturing conditions. For example, the diffusion rate of Ti atoms in Nb at 350 ° C. is said to be 1.5 × 10 ⁻¹⁶ m / hr, and 100
hr Even if held at that temperature, 1.5 × 10 ^-13 m = 1.5 ×
It is much less than 10 ⁻³ angstrom and the distance between one atom. That is, it is sufficient that the barrier thickness is considerably small, the amount of Nb material is reduced, and the material cost should be reduced. However, the Nb or Ta sheet at the time of composite clad becomes more expensive as the thickness becomes foil-like and the processing cost rises. For example, in the case of Nb foil, depending on the width of the foil, when the thickness is 50 μm or less, the unit price per unit weight is several times to one digit higher than that of a sheet having 100 μm or more.

In the conventional manufacturing method, the barrier is inserted at the stage of assembling the multi-layered clad slab. Therefore, for example, when the copper ratio is about 2 and the number of NbTi layers is 30, the clad resulting from the restrictions of the rolling mill or the like. If the maximum thickness of the slab is about 300 mm, the thickness of the NbTi plate is about 3 mm, and the barrier thickness is many orders of magnitude larger than the thickness actually required in consideration of cost.

Further, in the above-mentioned Japanese Patent No. 1790043,
In order to obtain good metal bonding of both metal layers, the composite is subjected to hot working at a working rate of 30 to 98% and a temperature of 500 to 1000 ° C, but the metal softens at higher temperatures. It is easier to join. Therefore, α-Ti precipitates, dislocation networks and lattices, which are the most important factors for improving the Jc of NbTi superconducting materials, are required for the composite integration of the clad materials, that is, sufficient metallurgical bonding to be obtained at each metal interface. The defects had been heated to a temperature range where they could significantly reduce their role or even disappear.

That is, according to the above-mentioned Japanese Patent No. 1790043, the Nb-Ti alloy plate before being laminated in multiple layers is subjected to hot working and then cold working (mainly cold rolling). . At this time, dislocation networks and lattice defects introduced by rolling with a considerable working rate are accumulated in the structure. However, in the conventional method, hot working (mainly hot rolling) was then performed in order to obtain metal bonding of the composite material laminated in multiple layers, and heating at a temperature of 500 to 1000 ° C. at that time accumulated the charge. Dislocation networks and lattice defects were greatly reduced or even disappeared. Therefore, in the conventional method, before the multilayer clad process,
It was almost impossible to fully utilize the dislocation network and lattice defects introduced into the Nb-Ti based alloy structure, and only the components introduced afterward were utilized.

[0011]

[Means for Solving the Problems]

(1) First, as shown in FIG.
A sheet or foil 3 of Nb, Ta or Nb-Ta alloy is coated around the Nb-Ti based alloy material 1 of the layer, and also around it is coated with a normal conducting metal material 2. As this method, one layer of Nb-Ti based alloy material coated with a sheet or foil of Nb, Ta or Nb-Ta alloy is inserted into the casing 2 made of the normal conducting metal material, and the inside of the casing is evacuated. After that, they are welded and hermetically sealed to obtain a Nb-Ti single layer clad slab. This slab has a processing rate of 30-98% and a temperature of 500
Surface-reduction processing including hot processing at 1000 ° C is applied to form a composite integration. Examples of the surface-reduction processing method include hot, warm, and cold rolling, and hot, warm, and cold press forging. Also, methods such as HIP and CIP are effective.
Further, there is also a method in which the various processing methods are sequentially combined. After surface-reduction processing by these methods, as shown in FIG. 2, the content is Nb-Ti based alloy 1, the surface layer is normal conducting metal 2, and the layer 3 of Nb, Ta or Nb-Ta alloy is at their interface. An intervening clad plate 4 having a three-layer structure is formed. After removing impurities such as oxide scale, oil, and dirt existing on the outermost surface of the clad plate 4 and cleaning the clad plate 4, as shown in FIG. After being cut into a number and laminated in the plate thickness direction and inserted into the casing 2 made of normal conducting metal, the inside of the casing is evacuated and then welded and sealed to obtain a multilayer clad slab.
After subjecting the slab to processing at a processing rate of 30 to 98% and a temperature of 600 ° C or lower, heat treatment at a temperature of 300 to 450 ° C for a holding time of 1 to 168 hours and a processing rate of 30 to 98%.
The above cold working is alternately repeated 6 times or less to form a plate or foil, and the Nb-Ti-based superconducting multilayer plate 5 as shown in FIG. 3 is obtained. As the surface-reduction processing method, there is the above-mentioned method.

When the clad plate 4 having a three-layer structure is formed, the entire circumference is initially covered with the normal-conductivity metal, so that the whole circumference is covered with the normal-conductivity metal even after the surface reduction processing. Normally, except for the cut-off parts, for example, the sides of the plate are still covered with the normal-conducting metal, but they may be stacked as they are, or the end part (normally called the ear) made of only the normal-conducting metal is cut and removed. Either of them may be laminated after being formed. FIG. 1B shows a case where the ears are removed, but normally, this can effectively use the limited space in the housing.

Here, the normal-conducting metal layer is necessary as a partition material for ensuring the superconducting stability of the superconducting material of the present invention and for dividing the superconducting material into multiple layers, which is generally used. Examples thereof include high conductive metals such as Cu and Al or high resistance metals such as Cu-Ni alloys.
The division of the superconducting material is a method known as an effective means for reducing the hysteresis loss per unit volume, which is one of the main factors that occur in the superconductor and destroy the superconducting characteristics. Cu, Al when used in a static magnetic field (DC magnetic field) or in a fluctuating magnetic field with a small change rate
A high conductive metal such as Cu is preferable, and a high resistance metal such as a Cu—Ni alloy is preferable in a changing magnetic field (AC magnetic field or pulse magnetic field) having a large change rate. Under the former condition where the heat generation due to the eddy current generated in the normal conducting metal is small, the highly conductive metal helps stabilize the superconductivity, but under the latter condition where the eddy current problem becomes serious, the high resistance metal is desirable.

(2) Nb-T having a three-layer structure as in (1)
Making a single-layer clad plate, as shown in Fig. 4 (a),
After cutting the desired number of layers and stacking them in the plate thickness direction, and stacking the normal conducting metal plate 2 on the top and bottom surfaces, weld the ends of each stacking interface while keeping all the interfaces in vacuum and seal. Then, the surface is reduced again in the same manner as in (1) to make a composite integration, and an Nb-Ti based superconducting multilayer plate 5'as shown in FIG. 4 (b) is obtained. The processing methods for surface reduction and heat treatment are the same as in (1).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, as shown in FIG. 1 (a), a sheet of diffusion barrier metal to be inserted at the interface with respect to the plate thickness of one layer of Nb-Ti based alloy material at the start or It is possible to make the foil thickness ratio much smaller. That is, in the conventional method, as shown in FIG. 6, a plurality of Nb-Ti alloy plates and normal conductive metal plates, which have been reduced in surface thickness and have a reduced thickness, are alternately laminated, and a diffusion barrier metal of all the interfaces is formed. The multilayer laminate having the sheet or foil inserted therein has been inserted into a casing made of a normal conducting metal material. FIG.
The height restriction (thickness of the clad material) of the casing shown in (a) and FIG. 1 (b) is affected by the restriction on the equipment such as a rolling mill, and is the same in the present invention and the conventional method. Therefore, if the thickness of the diffusion barrier metal sheet or foil is the same, N
Since the thickness of the b-Ti alloy plate can be much larger in the present invention, when the final product is a multilayer plate having the same thickness and structure, diffusion is performed with respect to the Nb-Ti alloy layer having the same thickness. It is possible to reduce the barrier layer thickness by up to 2 digits,
It is possible to significantly reduce the amount of diffusion barrier metal material used without utilizing high-cost ultra-thin foil processing.

Further, according to the present invention, the clad process is carried out twice in the entire manufacturing process, and the first single-layer clad has a method as shown in FIGS. 1 (a) and 5 (a). Also 2
There is a method as shown in FIG. 1B and FIG. At the time of the first single-layer clad, as in the conventional method, in order to metallically bond the dissimilar metal layers, that is, the Nb-Ti alloy plate and the normal-conducting metal plate, and the diffusion barrier metal, metal It is necessary to perform hot working at 500 to 1000 ° C, preferably 600 to 1000 ° C. In this temperature range, α-Ti precipitates, dislocation networks, which are the most important factors for improving Jc of Nb-Ti superconducting materials,
Lattice defects had the risk of being significantly reduced or even disappeared, but in the present invention, since none of the above-mentioned important factors were introduced into the Nb-Ti structure at this stage, It can be said that there is almost no danger. Since the thickness of the Nb-Ti alloy plate is considerably large, only the hot working is required, and the cold working is not required, or even if it is, it is very small compared with the conventional method.

However, as can be easily seen from FIGS. 1 (b) and 4 (a), Cu and A are used in the second multi-layer cladding.
l, there is only an interface between normal-conducting metal layers such as Cu-Ni alloys, etc., and these are easy to perform good metal joining even by processing such as hot rolling at a significantly lower heating temperature than the first dissimilar metal interface. It is possible to obtain. That is, a temperature range of 600 ° C. or lower is sufficient. In this temperature range, Nb
There is little or no loss of α-Ti precipitates, dislocation networks, and lattice defects in —Ti alloys. Although the problem of coarsening of α-Ti precipitates that causes a decrease in Jc may occur, it is possible and avoidable to shorten the holding time of heating within a range that does not cause a problem. Therefore, the first and second
Most of the dislocation networks and lattice defects introduced by the processing such as cold rolling performed between the second cladding steps are superimposed on the cold rolling processing after the second multilayer cladding, and α-Ti by heat treatment is used. It is possible to use it for phase precipitation, and it is possible to bring about a great improvement in Jc.

[0018]

【Example】

(Embodiment 1) As shown in FIG. 1A, a Nb-Ti alloy plate 1 having a thickness of 50 mmt is entirely surrounded by N having a thickness of 0.1 mmt.
The b-sheet 3 was covered, inserted into a copper box 2 having a height of 100 mmt, and sealed by electron beam welding in vacuum to produce a single-layer clad material. The box was hot-rolled at 600 ° C. to 500 mmt and then cold-rolled to 3 mmt. The single layer clad plate 4 is shown in FIG.
As shown in (4), 20 rectangular plates having the same shape were cut and laminated, inserted into a copper box 2 having a height of 100 mmt, and sealed again by electron beam welding in vacuum to produce a multilayer clad material. The box was hot-rolled at 400 ° C. to 50 mmt, then cold-rolled and heat-treated for α-Ti phase precipitation to obtain a multilayer plate 5 having a thickness of 1 mmt as shown in FIG.

As a conventional method for comparison, a thickness of 5
A 0 mmt Nb-Ti alloy thick plate is hot rolled at 600 ° C to 25 mmt, and then cold rolled to 1.5 mmt, and the Nb-Ti alloy plate is cut into 20 rectangular plates of the same shape to obtain the same thickness. Then, the laminated body, which is formed by alternately laminating 19 shaped copper plates and inserting Nb sheets with a thickness of 0.1 mm at all interfaces, is inserted into a copper box with a thickness of 100 mm and sealed by electron beam welding in a vacuum. Then, a multilayer clad material was produced. After that, the thickness is 1mm with the same structure under the same conditions as above.
It was a multilayer board of t.

In order to compare the superconducting characteristics of both, "I. I
Toh et al., Cryogenics, 35, 403 (1995) ”(four-terminal method) was used to measure Jc in a magnetic field. Here, the applied magnetic field is applied in parallel to the Nb-Ti layer, and the applied current is the result when the applied current is perpendicular to the magnetic field and perpendicular to the rolling direction.

According to this, the Jc of the conventional method is 2.5 × 10 ³ A / mm ² at an applied magnetic field of 2T and 0.9 × 10 ³ A / mm ² at an applied magnetic field of 6T.
It was mm ^2. On the other hand, the Jc of the present invention is 2T and 4.
5 × 10 ³ A / mm ² , 6T 1.5 × 10 ³ A / mm ² , 2
It improved by 80% at T and about 70% at 6T.

Example 2 As shown in FIG. 4A, the Nb-Ti single-layer clad plate 4 having a thickness of 3 mmt was cut into 20 square plates having the same shape by the same method as in Example 1. After stacking a copper plate 2 having a thickness of 20 mmt on the top and bottom surfaces of the stacked layers, the edges around each interface were sealed by electron beam welding 6 in vacuum to produce a multilayer clad material. After that, FIG. 4 (b)
As shown in FIG. 5, a 1 mm thick multilayer plate 5'having the same structure as in Example 1 was obtained. When the Jc characteristics of this plate were measured by the same method as in Example 1, the Jc characteristics were almost the same.
Value.

(Embodiment 3) As shown in FIG. 1 (a), the entire circumference of a 50 mm thick Nb-Ti alloy plate 1 is covered with a 0.1 mm thick Nb sheet 3 to a thickness of 100 mmt. Was inserted into the copper box 2 and sealed by electron beam welding in vacuum to produce a single-layer clad material. The box was hot-rolled at 600 ° C. to 500 mmt and then cold-rolled to 3 mmt, and the single-layer clad plate was a square plate 20 of the same shape.
Cut into sheets, stack, and insert into a 100 mm thick copper box.
It was sealed again by electron beam welding in vacuum to produce a multilayer clad material. The box was hot-rolled at 400 ° C. to 50 mmt, and then cold-rolled and heat-treated for α-Ti phase precipitation were appropriately performed to 1 mmt. Nb-T at this time
The ratio of the thickness of the Nb barrier layer to the thickness of the i1 layer was about 0.2% as at the beginning. This is 1/33 of the thickness of the Nb barrier layer having the exact same structure prepared by the conventional method.
Met. In addition, since the price of both Nb sheets is the same, the cost related to the diffusion barrier has been reduced to almost 1/33. Further, the diffusion effect was not deteriorated due to the reduced barrier layer thickness.

[0024]

According to the present invention, Jc, which is one of the most important superconducting properties, can be greatly improved as compared with the conventional method, and an extremely great effect can be obtained from the aspects of both cost and property improvement. It is clear to have. In addition, regarding the use of diffusion barrier metal materials such as Nb, Ta, and Nb-Ta alloys, which are expensive metals, without changing the cost, 1
It has become possible to reduce orders of magnitude.

[Brief description of drawings]

FIG. 1 (a) is a single-layer clad slab prepared by inserting one layer of Nb-Ti based alloy sheet coated with a diffusion barrier metal sheet or foil into a casing made of normal conducting metal according to the present invention. , (B) is a multilayer clad slab according to the present invention, which is produced by inserting a plurality of single-layer clad plates into a casing made of a normal conductive metal.

FIG. 2 is a composite integrated single layer clad plate according to the present invention.

FIG. 3 is a composite integrated multilayer clad plate according to the present invention.

FIG. 4 (a) is a view showing that a plurality of single-layer clad plates according to the present invention are laminated in the thickness direction, a normal conducting metal plate is further laminated on the upper and lower surfaces thereof, and all the interfaces thereof are kept in vacuum. A multi-layer clad slab manufactured by welding and sealing the peripheral edges, and (b) is a multi-layer clad plate manufactured by composite-integrating the multi-layer clad slab in FIG. 4 (a) according to the present invention.

FIG. 5 (a) is a diagram showing a single layer of Nb—Ti alloy plate coated with a diffusion barrier metal sheet or foil and a normal conducting metal plate on both sides of the diffusion barrier metal sheet according to the present invention. The single-layer clad slab manufactured by welding and sealing the peripheral edges of the single-layer clad slab shown in FIG. 5 (a) according to the present invention. Layer clad plate.

FIG. 6 shows a laminated body obtained by alternately laminating a plurality of Nb—Ti alloy plates coated with a diffusion barrier metal sheet or foil and a plurality of normal conducting metal plates in a conventional method from a normal conducting metal. A multi-layer clad slab that is made by inserting it into an enclosure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Nb-Ti type | system | group alloy material 2 Normal conductive metal plate 3 Diffusion barrier metal sheet or foil 4 Single-layer clad plate integrated by processing FIG. 1 (a) 4'Processing FIG. 5 (a) and compounding Integrated single-layer clad plate 5 Multi-layer clad plate integrated by processing Fig. 1 (b) 5'Multi-layer clad plate integrated by processing Fig. 5 (b) 6 Welding location

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 21, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

Problems to be Solved by the Invention Patent No. 1790043
The Nb-Ti-based superconducting multilayer plate described in No. 1 requires a diffusion barrier layer which is a multiple of the number of Nb-Ti layers. Nb or Ta, which is the most suitable material as a barrier, is a rare metal and is extremely expensive. Due to the nature of the diffusion barrier, the required thickness is extremely small, depending on the manufacturing conditions. For example, the diffusion rate of Ti atoms in Nb at 350 ° C. is said to be 1.5 × 10 ⁻¹⁶ m / hr, and 100
Even if held at that temperature for 0 hr, 1.5 × 10 ^-13 m = 1.5
It is much less than the distance between one atom and × 10 ^-3 angstrom. That is, it is sufficient that the barrier thickness is considerably small, the amount of Nb material is reduced, and the material cost should be reduced. However, Nb during composite cladding
Alternatively, the Ta sheet becomes more expensive because the processing cost increases as the thickness becomes foil-like and becomes thinner. For example, in the case of Nb foil, depending on the width of the foil, when the thickness is 50 μm or less, the unit price per unit weight is several times to one digit higher than that of a sheet having 100 μm or more.

[Procedure amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction contents]

[0024]

According to the present invention, Jc, which is one of the most important superconducting properties, can be greatly improved as compared with the conventional method, and an extremely great effect can be obtained from the aspects of both cost and property improvement. It is clear to have. Further, regarding the use of a diffusion barrier metal material such as an expensive metal such as Nb, Ta, or Nb-Ta alloy, it has become possible to reduce the cost by one digit or more .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Reference Signs] 1 Nb-Ti alloy material 2 Normal-conducting metal plate 3 Diffusion barrier metal sheet or foil 4 Single-layer clad plate compositely integrated by processing FIG. 1 (a) 4 ′ FIG. 5 (a) A single-layer clad plate which is processed into a composite and integrated 5 A multi-layered clad plate which is processed into a composite and integrated in FIG. 1 (b) 5 ′ A composite clad plate which is processed into a composite and integrated in FIG. 4 (a) 6 welding points

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (2)

[Claims] 1. At least one Nb—Ti based alloy layer and at least one normal conductive metal layer are alternately laminated,
In the method for producing an Nb-Ti-based superconducting multilayer plate having a structure in which a barrier layer of Nb, Ta or an Nb-Ta alloy exists between the Nb-Ti-based alloy layer and the normal-conducting metal layer, Nb, Ta Alternatively, one layer of Nb-Ti based alloy material coated with a sheet or foil of Nb-Ta alloy is coated with a normal conducting metal material, and hot working is performed at a working rate of 30 to 98% and a temperature of 500 to 1000 ° C. After surface-reducing is performed to integrate the composite, at least one layer of the composite material is laminated and inserted into a case made of normal conducting metal, and then the case is evacuated and then the case is welded. After joining and sealing, the integrated composite is subjected to hot working at a working rate of 30 to 98% and a temperature of 600 ° C. or less, and then a heat treatment at a temperature of 300 to 450 ° C. for a holding time of 1 to 168 hours. , Processing rate is 30 ~
A process for producing a Nb-Ti-based superconducting multilayer plate, which comprises repeatedly performing cold working of 98% repeatedly 6 times or less to form a plate or foil. 2. At least one Nb—Ti based alloy layer and at least one normal conductive metal layer are alternately laminated,
In the method for producing an Nb-Ti-based superconducting multilayer plate having a structure in which a barrier layer of Nb, Ta or an Nb-Ta alloy exists between the Nb-Ti-based alloy layer and the normal-conducting metal layer, Nb, Ta Alternatively, one layer of Nb-Ti based alloy material coated with a sheet or foil of Nb-Ta alloy is coated with a normal conducting metal material, and hot working is performed at a working rate of 30 to 98% and a temperature of 500 to 1000 ° C. After performing surface reduction processing including, to make a composite integrated, at least one layer of the composite material is laminated, and the ends of the respective laminated interfaces are weld-bonded and sealed while keeping the laminated interfaces in a vacuum. After subjecting the composite to hot working at a working rate of 30 to 98% and a temperature of 600 ° C. or less, heat treatment at a temperature of 300 to 450 ° C. for a holding time of 1 to 168 hours and a working rate of 30 to 98%. Alternating cold work less than 6 times Applied returns a plate-like or foil-like, N
A manufacturing method characterized by obtaining a b-Ti-based superconducting multilayer plate.