JP2010153090A - Tape shape substrate for superconductive wire rod, its manufacturing method, and superconductive wire rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superconductive wire rod substrate from which a low-cost superconductive wire rod without variations in quality and having no deterioration in characteristics can be obtained, its manufacturing method, and a superconductive wire rod. <P>SOLUTION: The superconductive wire rod substrate is equipped with a tape-shape substrate and a metal plated layer of a thickness 0.1-5 μm which is formed by grinding the surface of the tape-shape substrate and formed on single side or both sides of the tape-shape substrate. The surface of the metal plated layer is applied with a mirror face rolling and heat treatment, and the surface roughness Ra of the metal plated layer is 10 nm or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a superconducting wire rod-shaped substrate, a method for producing the same, and a superconducting wire including the superconducting wire tape-shaped substrate.

  Conventionally, as a high-temperature superconducting wire using a non-oriented metal substrate (for example, a metal substrate made of Hastelloy (trademark)), an intermediate layer is formed on a metal substrate by using an IBAD (ion beam assisted vapor deposition) method. An oxide superconducting layer such as YBCO formed thereon is known. (For example, refer to Patent Document 1).

  As described above, the surface of a non-oriented metal substrate used for a substrate (so-called IBAD substrate) having an intermediate layer formed on the surface by the IBAD method is required to have high performance (high smoothness, high flatness), and rolling. A non-oriented metal substrate having a surface roughness Ra of several nanometers is manufactured by optimizing the process and high-precision mechanical polishing.

  In such a conventional method for producing a non-oriented metal base material, surface layer defects scattered in the non-oriented metal material, surface defects caused by transfer of galling scratches on the surface layer and rolling roll after solution heat treatment, and the like are caused in the intermediate layer and It had an influence on the crystal growth of the superconducting layer, and became a factor of local deterioration of superconducting characteristics. The defects generated in the rolling process of the non-oriented metal material are inherent in the surface of the non-oriented metal substrate and the surface layer, and it is difficult to confirm and delete the defects. As a result, 1) variation in the quality of the non-oriented metal substrate, 2) characteristic deterioration of the superconducting wire mainly due to local defects in the non-oriented metal substrate, and 3) a problem that a low-cost superconducting wire cannot be obtained. was there. Each issue will be discussed below.

1) Problem of variation in quality of non-oriented metal substrate The surface property of a non-oriented metal substrate is required to have a surface roughness Ra of several nm. This evaluation is measured by AFM (Atomic Force Microscope), and the measurement range is defined by surface measurement within a range of 10 μm square to 100 μm square. For this reason, the defects inherent in the surface layer of the non-oriented metal substrate and the defects scattered on the surface cannot be directly observed, and it is impossible to guarantee the entire surface quality. Furthermore, these defects are not in the shape and size that can be visually confirmed, and there are many problems in the reproducibility of the sensitivity setting and the quality determination in the confirmation with the optical device.

2) Degradation of critical current characteristics of superconducting wires due mainly to local defects in non-oriented metal substrates To produce high-conductivity superconducting wires such as Y-based superconducting wires, an intermediate layer is formed on the substrate surface. It is required to epitaxially grow a Gd—Zr oxide layer or an oxide layer such as CeO ₂ . At this time, if the defects included in the surface layer of the non-oriented metal base material are scattered, the crystal growth to the superconducting layer is inhibited, the local defect point exists, and the problem of deterioration of the critical current value characteristic arises.

3) Cost of superconducting wire With conventional manufacturing methods, the location of defects in non-oriented metal substrates and the effect on superconducting performance cannot be accurately grasped. There was a problem of lowering the yield. This is a big problem in producing a low-cost superconducting wire.
Japanese Patent Laid-Open No. 04-329867

  The present invention is made under the circumstances as described above, does not cause variations in quality, does not cause deterioration of characteristics, and can obtain a low-cost superconducting wire, a manufacturing method thereof, And it aims at providing a superconducting wire.

  In order to solve the above problems, a first aspect of the present invention comprises a tape-shaped substrate and a metal plating layer having a thickness of 0.1 μm to 5 μm formed on one or both surfaces of the tape-shaped substrate. The surface of the tape-like substrate is polished, the surface of the metal plating layer is subjected to at least mirror finish rolling and heat treatment, and the surface roughness Ra of the metal plating layer is 10 nm or less. A tape-like substrate for a superconducting wire is provided.

  By subjecting the surface of the metal plating layer to precise polishing, the surface roughness Ra of the metal plating layer can be set to 5 nm or less.

  As the metal plating layer, a layer containing at least one selected from the group consisting of Ni, W, Mo, V, Ag, Au, Cr, Cu, Sn, and P can be used.

  As the tape-shaped substrate, 1 to 80 atomic% of W, Mo, Cr, V, Fe, Cu, Nb, Ta, Ti, Si, Al, B, and C are included. Ni alloy can be used.

  The second aspect of the present invention includes a step of forming a tape-shaped substrate by rolling, a heat treatment step for recovering the spreadability of the tape-shaped substrate, a step of polishing the surface of the tape-shaped substrate, There is provided a method for producing a tape-like substrate for a superconducting wire comprising a step of forming a metal plating layer on the surface of the tape-like substrate and a step of performing mirror finish rolling on the surface of the metal plating layer.

  In the heat treatment step for recovering the spreadability of the tape-shaped substrate, the tape-shaped substrate is 750 ° C. to 1150 ° C. in a mixed gas atmosphere containing 0.5 to 5 vol. It is desirable to carry out by holding for 3 minutes or more.

  A step of performing a heat treatment for improving flatness may be further provided after the mirror finish rolling. In the heat treatment for improving the flatness, the tape-shaped substrate is held at 750 ° C. to 850 ° C. for 10 seconds or more in a mixed gas atmosphere containing 0.5 to 5 vol. It is desirable to do so.

  As the metal plating layer, a layer containing at least one selected from the group consisting of Ni, W, Mo, V, Ag, Au, Cr, Cu, Sn, and P can be used.

  The metal plating layer is preferably formed to a thickness of 0.1 μm to 30 μm by wet plating.

  The tape-shaped substrate is at least one selected from the group consisting of 1 to 80 atomic% W, Mo, Cr, V, Fe, Cu, Nb, Ta, Ti, Si, Si, Al, B, and C. Ni-based alloys containing can be used.

  It is desirable that the surface roughness Ra of the metal plating layer is 5 to 10 nm by a finish rolling process of the surface of the metal plating layer.

  The step of forming the tape-shaped base material by rolling is desirably performed within a range of 50% to 80% of the rolling process rate, whereby the 0.2% proof stress of the tape-shaped base material for superconducting wire is 1 GPa or more. can do.

  A step of polishing the surface of the tape-shaped substrate can be further included before the step of forming the tape-shaped substrate by rolling.

  Moreover, the process of carrying out the mirror surface finish rolling can further comprise the process of carrying out the precision grinding | polishing of the surface of the said metal plating layer. Note that the surface roughness Ra of the metal plating layer can be reduced to 5 nm or less by precision polishing.

  According to a third aspect of the present invention, there is provided a superconducting wire characterized by forming a superconducting layer directly or via an intermediate layer on the surface of the tape-like base material for a superconducting wire described above.

  According to the present invention, it is possible to provide a substrate for a superconducting wire, a method for manufacturing the same, and a superconducting wire capable of obtaining a low-cost superconducting wire without quality variation and without causing deterioration of characteristics. .

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic diagram showing a cross-sectional structure of a metal substrate for a superconducting wire according to an embodiment of the present invention. The metal substrate for a superconducting wire according to this embodiment includes a tape-like base material 1 and a metal plating layer 2 formed on the surface of the tape-like base material 1.

  The tape-shaped substrate 1 is desirably a Ni alloy. Examples of the Ni alloy include an Ni alloy containing at least one selected from the group consisting of W, Mo, Cr, V, Fe, Cu, Nb, Ta, Ti, Si, Si, Al, B, and C. I can do it. The addition amount of these additive elements is desirably 1 to 80 atomic%.

  Specific examples of the Ni alloy include Hastelloy (trademark), Inconel (trademark), and stainless steel.

  The metal plating layer 2 is preferably made of a metal material containing at least one selected from the group consisting of Ni, W, Mo, V, Ag, Au, Cr, Cu, Sn, and P. The film thickness of the metal plating layer 2 is 0.1 μm to 5 μm. If the thickness of the metal plating layer 2 is less than 0.1 μm, it is affected by defects contained in the underlying surface layer, and crystal growth up to the superconducting layer is hindered, local defect points exist, and the critical current value characteristic is degraded. If the thickness exceeds 5 μm, the metal plating cost increases, which is not preferable economically.

  The metal plating layer 2 may be, for example, Ni—Ag—Cu—Sn plating, Ni—W alloy plating, or Ni—WP plating. Further, the metal plating layer may have a structure of two or more layers. In addition, the metal plating layer is not limited to one side of the tape-shaped substrate 1 and may be provided on both sides.

  In the metal substrate for a superconducting wire according to the present embodiment, the surface roughness Ra of the metal plating layer is 10 nm or less. If the surface roughness Ra of the metal plating layer exceeds 10 nm, the smoothness of the intermediate layer will be affected, the precision polishing cost and precision polishing quality performed after mirror finish rolling and heat treatment will decrease, and the subsequent film formation cost will increase. It is not preferable economically and in quality.

  The surface roughness Ra is the arithmetic average roughness Ra in the “amplitude average parameter in the height direction” of the surface roughness parameter defined in JIS B 0601-2001.

  Such a surface roughness can be obtained by forming a metal plating layer on the surface of the tape-shaped substrate 1 and rolling and polishing the surface of the metal plating layer.

  According to the metal substrate for a superconducting wire according to the present embodiment, since the metal plating layer 2 is formed on the surface of the tape-like base material 1, the unevenness locally present on the surface of the tape-like base material 1 is a metal plating layer. 2 to prevent material defects of the tape-like substrate 1 from appearing on the surface. Moreover, since it is covered with a uniform and extremely thin plating layer, a uniform and highly smooth substrate surface can be obtained by subsequent rolling and polishing.

  The metal substrate for a superconducting wire described above can be manufactured by the process shown in FIG.

  First, at the start of the process, a tape-shaped substrate made of a Ni alloy is prepared. The tape-shaped substrate can be obtained with a predetermined size by rolling and slitting the material. In addition, you may perform rough grinding | polishing of the surface (one side or both sides) before rolling.

  Next, mechanical polishing is performed on the surface (one side or both sides) of the tape-like substrate. By this mechanical polishing, roll surface galling in the subsequent rolling process can be prevented, and the background level of the material can be unified.

  In addition, you may perform the heat processing (BA process: Bright annealing process) for recovering the extensibility (elongation) of a base material before this mechanical polishing. The BA treatment is performed by holding the tape-like substrate at 750 ° C. to 1150 ° C. for 3 minutes or more in a mixed gas atmosphere containing 0.5 to 5 vol.% Hydrogen with respect to the argon gas.

  Next, a metal plating layer by wet plating is applied to the tape-like substrate surface (one side or both sides). The plating may be matte plating or gloss plating, and is not necessarily limited to wet plating, and dry plating can also be applied. Further, for example, a film of Ag having a thickness of several nm may be formed by sputtering, and then a NiW alloy, for example, may be laminated to a thickness of several μm by wet plating. Alternatively, a plurality of layers can be formed by dry plating and wet plating, respectively.

  Further, by using a dry plating method, a refractory metal such as Ta or Nb is formed to a thickness of 0.1 nm to several nm, and an excessive amount of tape-like substrate and metal plating layer and between different metal plating layers are excessive. It is also possible to prevent diffusion.

  The metal plating layer preferably has a thickness of 0.1 μm to fill the unevenness locally present on the surface of the tape-like substrate, and considering the reduction of the film thickness due to subsequent rolling and polishing. 30 μm, more preferably 1 μm to 10 μm.

  Thereafter, mirror finish rolling is performed on the tape-like substrate on which the metal plating layer has been applied. The mirror finish rolling is preferably performed using, for example, a 12-stage or 20-stage rolling roll so that the surface roughness Ra is 5 to 10 nm in a range of a rolling rate of 50% to 80%.

  In addition, when selecting thin conditions (0.5 micrometer or less) by the film thickness of a metal plating layer, a metal plating layer can also be formed into a film by making the tape base material surface equivalent to a mirror surface surface by mirror rolling beforehand. Finally, heat treatment (TA treatment: tension annealing treatment) for restoring flatness is performed. TA treatment can be performed by holding the tape-shaped substrate at 750 ° C. to 850 ° C. for 10 seconds or more in a mixed gas atmosphere containing 0.5 to 5 vol.

  In some cases, finish mirror polishing is performed after the TA treatment. As a polishing method, mechanical polishing, electrolytic polishing, chemical polishing, or a combination thereof can be employed.

  In mechanical polishing, the abrasive grains are preferably diamond grains or oxide grains, especially aluminum oxide, cerium oxide, chromium oxide, zirconium oxide, iron oxide, etc., and the solution (polishing liquid) is water, surfactants, oils, An organic solvent or a mixture thereof, or a solution in which water is mixed with an acid such as formic acid, acetic acid or nitric acid, or an alkali such as sodium hydroxide in water, is particularly desirable.

  In chemical polishing, the polishing liquid is a chemical solution that chemically reacts with the substrate surface, such as nitric acid, sulfuric acid, formic acid, acetic acid, hydrochloric acid, hydrofluoric acid, chromic acid, hydrogen peroxide, oxalic acid, tetraphosphoric acid, glacial acetic acid, etc. Or a mixed solution thereof, and a solution obtained by further mixing an accelerator such as saturated alcohol or sulfonic acid with the mixed solution.

  In chemical mechanical polishing, the abrasive grains may be the above-mentioned mechanically polished grains, and a polishing solution (slurry) containing a chemical polishing solution is used there.

  In electrolytic polishing, a substrate is immersed in an electrolytic solution, and the substrate surface is polished by an electrolytic reaction by energizing the substrate as an anode. This electrolytic solution may be an acid or an alkali, and nitric acid, phosphoric acid, chromic acid, hydrogen peroxide, potassium hydroxide, potassium cyanide and the like are particularly desirable.

  As described above, a tape-like base material that maintains high performance (high smoothness, high flatness) is made possible by a manufacturing method with a short rolling process history. In the plating process, the range of manufacturing conditions is up to about 500 mm. Is promising for cost reduction.

  An intermediate layer is then formed on the tape-shaped substrate, and a superconducting layer is formed on the intermediate layer, whereby a superconducting wire is obtained.

  Examples of the present invention are shown below, but the present invention is not limited to these examples.

Example 1
(Direct material polishing + wet Ni plating method + cold rolling + mirror rolling finish + TA heat treatment)
Both sides of a metal tape (BA material: surface roughness Ra 50-100 μm) made of Hastelloy (Trademark: Ni-16Cr-15.6Mo-6Fe-4W-2Co) with a thickness of 0.3 mm x width 75 mm x length 350 m are machined. The surface roughness Ra was modified to about 30 nm by polishing, and a matte Ni plating was formed on one side of the polished surface to a thickness of 3 μm to obtain a composite substrate.

  This tape base material is manufactured with a 12-stage rolling mill having a roll diameter of Φ15 mm, and a tape base material having a length of 0.1 mmt × 75 mm width × 1050 m is manufactured. Ra mirror finish of 8 nm.

Next, in order to improve the flatness of the tape substrate, a tension of 3 kgf / mm ² was applied under the condition of holding at 790 ° C. for 20 seconds, and heat treatment was performed in an atmosphere of a mixed gas of argon gas and hydrogen.

  The tape base material thus heat-treated was roll-rolled, and further slitted with a finished size to finish a tape having a thickness of 100 μm and a width of 10 mm × 1050 m × 6. At this time, the thickness of the Ni layer on the surface layer of the tape was about 1 μm. This secured a processing rate of 60% or more in the rolling process.

  The Ni layer, which is the surface layer of the tape, is polished to a surface roughness Ra of 1.5 nm in a subsequent precision polishing step. At this time, the thickness of about 0.5 μm is deleted by precision polishing. This precision polishing may be any method of electrolytic polishing, mechanical polishing, and chemical polishing. In this case, since the surface layer before precision polishing is uniform, an effect of reducing precision polishing cost can be obtained.

  Further, by making the thickness of the surface layer of the tape base material about 1/100 or less of the total thickness, it was possible to make almost non-magnetic.

As a result of measuring the surface roughness of 10 μm square by using an atomic force microscope (AFM) for samples taken from both ends of this finished tape, Ra = 8.2 and 8.8 nm in average at both ends. Ra <9 nm at all measurement points.

  Moreover, when the tension test was done at room temperature, 0.2% yield strength was 1.5 GPa. Therefore, a high-strength, non-magnetic, high-performance metal tape substrate could be manufactured.

IBAD process On the tape substrate obtained as described above, an IBAD method is used to form a Gd-Zr oxide intermediate layer (GZO) with a thickness of about 1 μm. The CeO ₂ oxide intermediate layer was formed to a thickness of about 400 nm by the position method.

  Further, a YBCO superconductor was deposited on the intermediate layer to a thickness of about 1 μm by the PLD method. Then, silver was vapor-deposited to a thickness of about 10 μm on the upper surface of the Y-based superconductor using a high frequency sputtering apparatus to form an electrode layer.

  The critical current was measured using the four-terminal method in a state where 50 m of the superconducting wire thus obtained was immersed in liquid nitrogen. At this time, the measurement was performed with a 1 m pitch and a voltage terminal of 1.2 m. The current-carrying characteristics of the superconducting wire were defined as 1 μV / cm, 220 A or more was confirmed at all measurement positions of the critical current value, and the minimum-maximum difference was 16 A.

Example 2
(Material cold rolling + BA heat treatment + Material polishing + Cold rolling + Wet Ni plating method + Cold rolling + Mirror finish + TA heat treatment)
A material made of Hastelloy (Trademark: Ni-16Cr-15.6Mo-6Fe-4W-2Co) 0.5 mmt x 75 mm width x 210 m (BA material: surface roughness Ra 50-100 μm) was cooled to a thickness of 0.3 mm. The surface roughness Ra of both surfaces is improved to about 30 nm by performing hot rolling (BA treatment: light annealing) to recover the spreadability (elongation) of the base material by rolling. Furthermore, it was rolled to a sheet thickness of 0.2 mm by a 12-high rolling mill having a roll diameter of Φ15 mm, and the surface of the non-oriented metal material was modified to a rolled surface.

  Next, matte Ni alloy plating was applied to one side of the rolled surface to a thickness of 1.5 μm to obtain a composite substrate.

  A tape base material of 0.1 mmt × 75 mm width × 1050 m was produced with a 12-stage rolling mill having a roll diameter of Φ15 mm, and the surface roughness of the tape base material surface was determined by Ra at the final finishing step of the rolling. The mirror finish was 8 nm.

  Next, in order to improve the flatness of the tape substrate, a tension of 3 kgf / mm 2 was applied under a condition of 790 ° C. × 20 seconds, and heat treatment was performed in a mixed gas atmosphere of argon gas and hydrogen.

  This tape base material was finished into a tape having a thickness of 100 μm and a width of 10 mm × 1050 m × 6 by slitting in a roll rolling process and a finished size. The thickness of the Ni layer of the surface material at this time was 0.7 μm. As a result, the total processing rate of the rolling process was secured at 80%.

  Thereafter, the Ni layer as the metal plating layer was subjected to a precision polishing process by electropolishing, and finished to a surface roughness Ra of 1.5 nm. At this time, a thickness of about 0.3 μm is removed by precision polishing. This precision polishing may be either mechanical polishing or chemical polishing in addition to electrolytic polishing. In addition, since the surface layer before precision grinding | polishing is uniform by mirror surface finish rolling and TA process, precision grinding | polishing cost is reduced.

  Further, by making the thickness of the metal plating layer on the surface of the tape base material to be about 1/140 or less of the total thickness, almost non-magnetization is possible.

  About the sample extract | collected from the both ends of the finished tape-shaped base material obtained as mentioned above, as a result of measuring the surface roughness of a 10 micrometer square with an atomic force microscope (AFM), Ra is averaged by 10 places at both ends. = 8.5, 9.1 nm, and Ra <10 nm at all measurement points.

  Moreover, when the tension test was done at room temperature, 0.2% yield strength was 1.4 GPa. Therefore, a high-strength, non-magnetic, high-performance metal tape substrate could be manufactured.

IBAD process A Gd-Zr oxide intermediate layer (GZO) is formed to a thickness of about 1 μm on the tape base material obtained as described above by using the IBAD method, and further, CeO is formed thereon by the PLD method. _{A two-} oxide intermediate layer was formed to a thickness of about 500 nm.

  Further, a YBCO superconductor was deposited on the intermediate layer to a thickness of about 1 μm by the PLD method. Then, silver was vapor-deposited to a thickness of about 10 μm on the upper surface of the Y-based superconductor using a high frequency sputtering apparatus to form an electrode layer.

  The critical current was measured using the four-terminal method in a state where 50 m of the superconducting wire thus obtained was immersed in liquid nitrogen. At this time, the measurement was performed with a 1 m pitch and a voltage terminal of 1.2 m. The energization characteristic of the superconducting wire was defined as 1 μV / cm, and 240 A or more was confirmed at all measurement positions of the critical current value, and the minimum-maximum difference was 13 A.

Example 3
(Direct material polishing + wet Ni plating method + cold rolling + mirror rolling finish + TA heat treatment)
Both sides of a metal tape (BA material: surface roughness Ra 50-100 μm) made of Hastelloy (Trademark: Ni-16Cr-15.6Mo-6Fe-4W-2Co) with a thickness of 0.3 mm x width 75 mm x length 350 m are machined. The surface roughness Ra was modified to about 30 nm by polishing, and a matte Ni plating was formed on one side of the polished surface to a thickness of 2 μm to obtain a composite substrate.

  This tape base material is manufactured with a 12-stage rolling mill having a roll diameter of Φ15 mm, and a tape base material having a length of 0.1 mmt × 75 mm width × 1050 m is manufactured. Ra mirror finish of 8 nm.

Next, in order to improve the flatness of the tape substrate, a tension of 3 kgf / mm ² was applied under the condition of holding at 790 ° C. for 20 seconds, and heat treatment was performed in an atmosphere of a mixed gas of argon gas and hydrogen.

  The tape base material thus heat-treated was roll-rolled, and further slitted with a finished size to finish a tape having a thickness of 100 μm and a width of 10 mm × 1050 m × 6. At this time, the thickness of the Ni layer on the surface layer of the tape was about 0.7 μm. This secured a processing rate of 60% or more in the rolling process.

  As a result of measuring the surface roughness of 10 μm square by using an atomic force microscope (AFM) for samples taken from both ends of this finished tape, Ra = 8.2 and 8.8 nm in average at both ends. Ra <9 nm at all measurement points.

  Moreover, when the tension test was done at room temperature, 0.2% yield strength was 1.5 GPa. Therefore, a high-strength, non-magnetic, high-performance metal tape substrate could be manufactured.

IBAD process A Gd-Zr oxide intermediate layer (GZO) is formed to a thickness of about 1 μm on the tape base material obtained as described above by using the IBAD method, and further, CeO is formed thereon by the PLD method. _{A two-} oxide intermediate layer was formed to a thickness of about 500 nm.

  Further, a YBCO superconductor was deposited on the intermediate layer to a thickness of about 1 μm by the PLD method. Then, silver was vapor-deposited to a thickness of about 10 μm on the upper surface of the Y-based superconductor using a high frequency sputtering apparatus to form an electrode layer.

  The critical current was measured using the four-terminal method in a state in which 50 m of the superconducting wire thus obtained was immersed in liquid nitrogen. At this time, the measurement was performed with a 1 m pitch and a voltage terminal of 1.2 m. The current-carrying characteristics of the superconducting wire were defined as 1 μV / cm, and at least 205 A was confirmed at all measurement positions of the critical current value. The minimum-maximum difference was 12 A.

Table 1 below collectively shows the characteristics of the tape base materials according to Example 1, Example 2, and Example 3 described above. In addition, about the board | substrate characteristic Ra in Table 1, about Example 1, 2 which implemented precision grinding | polishing, it is the substrate surface roughness before performing precision grinding | polishing.

  From Table 1 above, the tape-like base material for superconducting wires obtained in Example 1, Example 2, and Example 3 in which the Ni plating layer was formed on the surface of the base material had the surface roughness before performing precision polishing. Less than 9 nm or less than 10 nm, and σ 0.2% (yield strength) is as high as 1.5 GPa and 1.4 GPa, respectively, and the number of places where the property is reduced per 50 m of superconducting wire is 0, and it has excellent characteristics. .

  On the other hand, in the conventional example in which the Ni plating layer is not formed on the surface of the base material, there are many characteristic deterioration portions per 50 m of the superconducting wire, and a high performance superconducting wire could not be obtained.

Sectional drawing which shows the tape-shaped base material which concerns on one Embodiment of this invention. The figure which shows the process which manufactures the tape-shaped base material which concerns on one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tape-like base material, 2 ... Metal plating layer.

Claims (16)

  It comprises a tape-like substrate and a metal plating layer having a thickness of 0.1 μm to 5 μm formed on one or both sides of the tape-like substrate, and the surface of the tape-like substrate is polished, The surface of the metal plating layer is subjected to at least mirror finish rolling and heat treatment, and the surface roughness Ra of the metal plating layer is 10 nm or less.   The tape-shaped substrate for a superconducting wire according to claim 1, wherein the surface of the metal plating layer is subjected to precision polishing so that the surface roughness Ra of the metal plating layer is 5 nm or less.   The superconducting wire according to claim 1, wherein the metal plating layer includes at least one selected from the group consisting of Ni, W, Mo, V, Ag, Au, Cr, Cu, Sn, and P. Tape-like substrate.   The tape-shaped substrate contains at least one selected from the group consisting of 1 to 80 atomic% of W, Mo, Cr, V, Fe, Cu, Nb, Ta, Ti, Si, Al, B, and C. The tape-shaped substrate for a superconducting wire according to claim 1, wherein the tape-shaped substrate is a Ni alloy.   A step of forming a tape-like substrate by rolling, a step of polishing the surface of the tape-like substrate, a step of forming a metal plating layer on the surface of the tape-like substrate, and mirror finish rolling on the surface of the metal plating layer And a method for producing a tape-like base material for a superconducting wire.   In the heat treatment step for recovering the spreadability of the tape-shaped substrate, the tape-shaped substrate is 750 ° C. to 1150 ° C. in a mixed gas atmosphere containing 0.5 to 5 vol. It is holding for 3 minutes or more, The manufacturing method of the tape-shaped base material for superconducting wires of Claim 5 characterized by the above-mentioned.   The method for producing a tape-like substrate for a superconducting wire according to claim 5, further comprising a step of performing a heat treatment for improving flatness after the mirror finish rolling. The heat treatment for improving the flatness, the tape-shaped substrate, the argon gas to in a mixed gas atmosphere containing hydrogen of ^0.5~5vol.%, The tension of 1kgf / mm ² ~10kgf / mm 2 The method for producing a tape-like base material for a superconducting wire according to claim 7, wherein the tape is held at 750 ° C. to 850 ° C. for 10 seconds or longer in a state in which is added.   The superconducting wire according to claim 5, wherein the metal plating layer contains at least one selected from the group consisting of Ni, W, Mo, V, Ag, Au, Cr, Cu, Sn, and P. For producing a tape-shaped base material for use.   The said metal plating layer is formed in the thickness of 0.1-30 micrometers by wet plating, The manufacturing method of the tape-shaped base material for superconducting wires of Claim 5 characterized by the above-mentioned.   The tape-shaped substrate contains at least one selected from the group consisting of 1 to 80 atomic% of W, Mo, Cr, V, Fe, Cu, Nb, Ta, Ti, Si, Al, B, and C. It is a Ni-based alloy, The manufacturing method of the tape-shaped base material for superconducting wires of Claim 5 characterized by the above-mentioned.   The method for producing a tape-like substrate for a superconducting wire according to claim 5, wherein the surface rolling Ra of the surface of the metal plating layer has a surface roughness Ra of 10 nm or less.   The method for producing a tape-shaped substrate for a superconducting wire according to claim 5, wherein the step of forming the tape-shaped substrate by rolling is performed within a range of a rolling rate of 50% to 80%.   6. The method for producing a tape-shaped substrate for a superconducting wire according to claim 5, further comprising a step of polishing the surface of the tape-shaped substrate before the step of forming the tape-shaped substrate by the rolling. .   The method for producing a tape-like substrate for a superconducting wire according to claim 5, further comprising a step of precisely polishing the surface of the metal plating layer after the step of performing the mirror finish rolling.   A superconducting wire formed by forming a superconducting layer directly or via an intermediate layer on the surface of the tape-like base material for a superconducting wire according to claim 1.

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