JP3621294B2 - Oxide superconducting compression molded conductor and manufacturing method thereof - Google Patents

Description

【００２７】
比較例
実施例の積層板（Ａ）の代わりに、幅４ｍｍ、厚さ２０μｍのＡｇ基板の両面にＢｉ系（２２１２）相を構成する元素を所定の比率で含むペーストを５０μｍの厚さに塗布して積層板（Ｃ）を形成し、一方、実施例と同様の方法により積層板（Ｂ）を形成した。
【００２８】
次いで、積層板（Ｃ）と積層板（Ｂ）の２本をＡｇ基板とペースト層とが交互に位置するように配置した他は、実施例と同様の方法により酸化物超電導線材を製造した。
【００２９】
このようにして製造した図２に示す構造の酸化物超電導線材の有効条長、臨界電流密度（Ｊｃ：４．２Ｋ、０Ｔ）および引張り強度を表１に示した。
【００３０】
【発明の効果】
以上の説明で明らかなように、本発明の酸化物超電導線材およびその製造方法によれば、熱処理時に金属フォイルの突合わせ部側にバリア材を配置したことにより、部分溶融温度域の加熱時に突合わせ部からの溶融酸化物の溶出を防止することができるため、酸化物超電導体の組成変動を防止することができ、これにより所定の均一な特性を有する長尺の線材を得ることができる。さらに、バリア材として銀合金を用いることにより、線材の機械的強度をより向上させることができ、熱処理後のハンドリングも容易になるため、超電導特性を劣化させることなく長尺の線材を取扱いが可能となる。
【００３１】
以上により、本発明の酸化物超電導線材およびその製造方法によれば、その臨界電流密度が極めて高い長尺線材が得られ、その工業的価値は非常に高いものである。
【図面の簡単な説明】
【図１】本発明の酸化物超電導線材の一実施例を示す横断面図である。
【図２】従来の酸化物超電導線材の一比較例を示す横断面図である。
【符号の説明】
１、１０………酸化物超電導線材
２………超電導層
３………基板
４、１３………積層体
５………金属フォイル
５ａ、１４ａ……突合せ部
１１……Ｂｉ系（２２１２）相
１２……Ａｇ基板
１４……Ａｇ−Ｍｇ合金フォイル
１５……バリア材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oxide superconducting wire and a method for manufacturing the same, and more specifically, mainly a power storage, a generator, a motor, and a current limiter. The present invention relates to an oxide superconducting wire used for applied equipment using an oxide superconducting wire such as a transformer and a superconducting cable, and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, various wires have been developed as high-capacity oxide superconducting wires. Among such large-capacity wires, oxide superconducting wires in which the outer periphery of a laminate in which a substrate is arranged between a plurality of oxide superconducting layers are surrounded by a metal plate are practical because of their high critical current density (Jc). It is attracting attention as a wire rod.
[0003]
As shown in FIG. 2 , the wire 1 has a plurality of Bi-based (2212) phases (Bi: Sr: Ca: Cu = 2: 2: 1: 2 element ratio of Bi—Sr—Ca—Cu—). The outer periphery of a laminate 4 in which a substrate 3 made of silver or a silver alloy is disposed between superconducting layers 2 made of an O-based oxide superconductor) is surrounded by a metal plate (metal foil) 5.
[0004]
Such a wire 1 has a plurality of wires in which the same paste is applied to one side of the substrate 3 on the surface of the substrate 3 coated with a paste containing an element constituting the Bi-based (2212) phase in a predetermined ratio. Are laminated so that the substrate 3 is disposed between a plurality of paste layers, and the outer periphery thereof is surrounded by a metal foil 5 made of silver or a silver alloy, and then subjected to heat treatment for generating a superconductor. . By this heat treatment, the metal foil 5, the superconducting layer 2, and the substrate 3 are integrated.
[0005]
In this case, since the butting portion 5a of the metal foil 5 is opened, CO2, H2O, CO2 and other gases generated in the heat treatment process are easily released to the outside, and the expansion of the wire due to the generation of the gas is prevented. Can do.
[0006]
However, in the above oxide superconducting wire, the butt portion 5a of the metal foil 5 is opened as described above, and in the heat treatment step, a partial melting-slow cooling process (after heating to a partial melting temperature range) In this case, when the heat treatment is performed in a batch-type heat treatment furnace, the molten oxide is eluted from the butt portion 5a of the metal foil 5 and the composition varies. As a result, it was difficult to obtain a long wire having predetermined uniform characteristics.
[0007]
Further, there is a problem that the use as a wire becomes impossible due to the generation of solidified oxide eluted out of the metal foil 5 and the fusion of adjacent wires during heat treatment.
[0008]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and in an oxide superconducting wire in which the outer periphery of a laminate in which a substrate is arranged between a plurality of oxide superconducting layers is surrounded by a metal plate, and a method for manufacturing the same, It is an object of the present invention to obtain a long wire rod which prevents elution of molten oxide from the butt portion 5a of the metal foil 5 during heat treatment, has no composition variation, and has predetermined uniform characteristics.
[0009]
Still another object of the present invention is to provide an oxide superconducting wire having improved mechanical strength and a method for producing the same.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an oxide superconducting wire according to claim 1 of the present invention is an oxide superconducting wire in which the outer periphery of a laminate in which a substrate is disposed between a plurality of oxide superconducting layers is surrounded by a metal plate. In this case, a barrier material made of a silver alloy in which one or more elements selected from Mg, Sb, Mn, and Al are added to Ag is disposed on one side surface of the laminate, and the outer periphery is made of metal. While being surrounded by a plate, the abutting portion of the metal plate is positioned on the barrier material side.
[0011]
Moreover, the manufacturing method of the oxide superconducting wire which concerns on Claim 5 of this invention is on the barrier material which consists of a silver alloy which added any 1 or more types of elements selected from Mg, Sb, Mn, and Al to Ag. A laminate (A) coated with a paste containing elements constituting a bismuth-based oxide superconductor at a predetermined ratio, and an element constituting the oxide superconductor on a substrate made of silver or a silver alloy at a predetermined ratio After preparing a laminate (B) coated with paste, and arranging a plurality of laminates (B) on the upper side of the paste layer of the laminate (A) so that the substrate and the paste layer are alternately positioned, The outside is surrounded by a metal plate so that the butt portion is located on the barrier material side, and then heated to a partial melting temperature range of the bismuth-based oxide superconductor and then gradually cooled.
[0012]
In the above invention, as the metal plate, it is preferable to use a silver alloy obtained by adding one or more elements selected from Mg, Sb, Mn, and Al to Ag.
[0013]
The silver alloy used as the barrier material and metal plate in the above invention preferably has an additive element amount in the range of 0.1 to 1.0 at%. The reason is that if the amount of additive element is less than 0.1 at%, it functions as a barrier material, but at the same time the strength cannot be improved, and if the amount of additive element exceeds 1.0 at%, This is because the oxide superconductor is contaminated by the diffusion, and as a result, the superconducting characteristics are deteriorated.
[0014]
Silver or a silver alloy can be used as the substrate, and a Bi-based (2212) phase is preferably selected as the oxide superconducting layer or the oxide superconductor. In this Bi-based (2212) phase, crystals are easily oriented in the partial melting-slow cooling process, and the superconducting properties can be improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention are described below.
[0016]
FIG. 1 shows an oxide superconducting wire 10 according to the present invention. The oxide superconducting wire 10 is a laminate in which an Ag substrate 12 is disposed between oxide superconducting layers 11 composed of a plurality of Bi (2212) phases. A barrier material 15 made of an Ag—Mg alloy plate is disposed on one side of the steel sheet 13 so that the outer periphery thereof is surrounded by the foil 14, and the butted portion 14 a of the foil 14 is positioned on the barrier material 15 side. It is a thing.
[0017]
Such an oxide superconducting wire 10 is manufactured by the following method.
[0018]
That is, a laminated plate (A) in which a paste containing an element constituting a Bi-based (2212) phase in a predetermined ratio is applied to one side of a barrier material 15 made of an Ag—Mg alloy plate, and a Bi-based (2212) on an Ag substrate. ) A laminate (B) coated with a paste containing elements constituting the phase in a predetermined ratio is prepared, and a plurality of laminates (B) are placed on the upper side of the paste layer of the laminate (A) with the substrate and the paste layer. Are arranged so as to be alternately positioned, and the outside is surrounded by the Ag-Mg alloy foil 14 so that the butt portion 14a is positioned on the barrier material 15 side, and then the bismuth oxide superconductor portion. After heating to the melting temperature range, the oxide superconducting wire 10 is manufactured by slow cooling.
[0019]
【Example】
Examples of the present invention and comparative examples will be described below.
[0020]
Example A paste containing an element constituting a Bi-based (2212) phase in a predetermined ratio on one side of a barrier material made of an Ag-0.22 at% Mg alloy having a width of 4 mm and a thickness of 15 μm is applied to a thickness of 50 μm. On the other hand, a laminate (A) is formed, and a paste containing an element constituting a Bi-based (2212) phase in a predetermined ratio is applied to an Ag substrate having a width of 4 mm and a thickness of 20 μm to a thickness of 50 μm. (B) was formed.
[0021]
In this superconducting paste, powders of Bi2O3, SrCO3, CaCO3 and CuO are blended at an element number ratio of Bi: Sr: Ca: Cu = 2: 2: 1: 2 and mixed with an organic binder.
[0022]
Next, after arranging the three laminates (B) on the upper side of the paste layer of the laminate (A) so that the barrier material and the Ag substrate and the paste layer are alternately arranged, the outside is 10 mm wide and thick. It was surrounded by a foil made of an Ag-0.22 at% Mg alloy having a thickness of 20 μm. At this time, the foil was surrounded so that the butted portion of the foil was positioned on the barrier material side.
[0023]
Next, after preliminary firing at 860 ° C. for 30 hours, cold rolling was performed.
[0024]
Then, after heating to the partial melting temperature range of 890 ° C., the oxide superconducting wire having a length of 200 m was manufactured by gradually cooling at a cooling rate of 1 ° C./hr.
[0025]
Table 1 shows the effective length (length that can be used as a wire), critical current density (Jc: 4.2K, 0T), and tensile strength of the oxide superconducting wire having the structure shown in FIG.
[0026]
[Table 1]

[0027]
Instead of the laminate (A) of the comparative example, a paste containing an element constituting a Bi-based (2212) phase in a predetermined ratio is applied to both sides of an Ag substrate having a width of 4 mm and a thickness of 20 μm to a thickness of 50 μm. Then, a laminated plate (C) was formed, while a laminated plate (B) was formed by the same method as in the example.
[0028]
Next, an oxide superconducting wire was manufactured by the same method as in the example except that the two laminates (C) and (B) were arranged so that the Ag substrate and the paste layer were alternately positioned.
[0029]
The effective length, critical current density (Jc: 4.2K, 0T) and tensile strength of the oxide superconducting wire having the structure shown in FIG.
[0030]
【The invention's effect】
As is apparent from the above description, according to the oxide superconducting wire and the manufacturing method thereof of the present invention, the barrier material is disposed on the butt portion side of the metal foil at the time of heat treatment, so that the bump at the time of heating in the partial melting temperature range is achieved. Since elution of the molten oxide from the mating portion can be prevented, composition fluctuation of the oxide superconductor can be prevented, and thereby a long wire having predetermined uniform characteristics can be obtained. In addition, by using a silver alloy as a barrier material, the mechanical strength of the wire can be further improved, and handling after heat treatment becomes easy, allowing handling of long wires without degrading superconducting properties. It becomes.
[0031]
As described above, according to the oxide superconducting wire of the present invention and the method for producing the same, a long wire having an extremely high critical current density can be obtained, and its industrial value is very high.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an oxide superconducting wire according to the present invention.
FIG. 2 is a cross-sectional view showing a comparative example of a conventional oxide superconducting wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,10 ......... Oxide superconducting wire 2 ......... Superconducting layer 3 ......... Substrate 4,13 ......... Laminated body 5 ......... Metal foil 5a, 14a ... Butting part 11 ... Bi system (2212) Phase 12 ... Ag substrate 14 ... Ag-Mg alloy foil 15 ... Barrier material

Claims (7)

In an oxide superconducting wire in which the outer periphery of a laminate in which a substrate is disposed between a plurality of oxide superconducting layers is surrounded by a metal plate , Ag is selected from Mg, Sb, Mn, and Al on one side of the laminate. A barrier material made of a silver alloy to which any one or more elements are added is arranged, the outer periphery thereof is surrounded by a metal plate, and the butted portion of the metal plate is positioned on the barrier material side An oxide superconducting wire characterized by comprising. The oxide superconducting wire according to claim 1 , wherein the metal plate is made of a silver alloy in which at least one element selected from Mg, Sb, Mn, and Al is added to Ag. The oxide superconducting wire according to claim 1 or 2, wherein the substrate is made of silver. The oxide superconducting wire according to any one of claims 1 to 3, wherein the oxide superconducting layer is made of a Bi-based (2212) phase. A paste containing a predetermined ratio of elements constituting a bismuth-based oxide superconductor on a barrier material made of a silver alloy in which at least one element selected from Mg, Sb, Mn, and Al is added to Ag is applied. The laminated plate (A), and the laminated plate (B) obtained by applying a paste containing an element constituting the oxide superconductor in a predetermined ratio on a substrate made of silver or a silver alloy. After arranging a plurality of the laminates (B) on the upper side of the paste layer so that the substrate and the paste layer are alternately positioned, the outer side is metal so that the butt portion is positioned on the barrier material side. A method for producing an oxide superconducting wire, characterized in that it is surrounded by a plate, then heated to a partial melting temperature range of the bismuth-based oxide superconductor and then gradually cooled. The method for producing an oxide superconducting wire according to claim 5 , wherein the metal plate is made of a silver alloy in which at least one element selected from Mg, Sb, Mn, and Al is added to Ag. The method for producing an oxide superconducting wire according to claim 5, wherein the bismuth-based oxide superconductor is composed of a Bi-based (2212) phase.

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