JP2009170221A - Method of manufacturing superconducting tape and manufacturing device of superconducting tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a superconducting tape, and a manufacturing device of the superconducting tape, capable of reducing an allowable bending diameter, by improving a tensile strain resistant characteristic and a tensile stress resistant characteristic. <P>SOLUTION: This manufacturing method of the superconducting tape 1a comprises the following process. First of all, a tape-like body part 7 having a superconductor is prepared. Reinforcing parts 9a and 9b are prepared. At least one main surface and the reinforcing parts 9a and 9b of the body part 7 are joined in a state of applying tension of yield stress or less of the reinforcing parts 9a and 9b to the reinforcing parts 9a and 9b in the extending direction of the reinforcing parts 9a and 9b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a superconducting tape manufacturing method and a superconducting tape manufacturing apparatus, for example, a superconducting tape manufacturing method and a superconducting tape manufacturing apparatus provided with a reinforcing portion.

  Conventionally, for example, a tape-shaped ceramic superconducting wire composed of a multi-core wire in which an oxide superconductor having a Bi2223 phase or the like is covered with a sheath portion such as silver can be used at a liquid nitrogen temperature, and has a relatively high critical current density. Therefore, the application to superconducting coils and cables is expected.

  For example, when a superconducting coil or cable is manufactured, a large tension or bending is applied to the superconducting wire. Also, a large tension is applied to the superconducting wire during operation of the superconducting coil, cable, etc., or during cooling for operation. For this reason, the superconducting wire is required to improve the maximum tension that can maintain the performance of the superconductor.

  In the superconducting wire, the sheath portion plays a role of securing an allowable tension and a good electrical contact between the external terminal and the superconductor. However, since the superconductor is fired in a high-temperature and oxygen-containing atmosphere after the superconductor is coated with the sheath portion, the materials that can be used for the sheath portion are limited to noble metals and their alloys, and the tension obtained by reinforcement by the sheath portion There was a limit to improvement.

  Therefore, techniques for preventing the superconducting characteristics from deteriorating due to mechanical bending of the superconducting wire are disclosed in, for example, US Pat. No. 5,801,124 (Patent Document 1) and US Pat. No. 6,649. No. 280 (Patent Document 2) and Japanese Patent Laid-Open No. 4-43510 (Patent Document 3). Patent Document 1 discloses a superconducting tape in which a thin plate made of stainless steel, copper, a copper alloy and a copper superalloy is attached to one or both main surfaces of a superconducting wire, and the superconducting wire and the thin plate are joined with a bonding agent containing a metal. The structure of is disclosed.

  Patent Document 2 discloses a superconducting tape in which a thin plate of stainless steel is attached to one or both main surfaces of a superconducting wire, and the superconducting wire and stainless steel are joined by solder made of Su (tin) -Pb (lead). The structure of is disclosed.

Patent Document 3 discloses a structure of a superconducting tape in which a reinforcing metal material made of nickel, a nickel alloy, and stainless steel is attached to one side of a superconducting wire.
US Pat. No. 5,801,124 US Pat. No. 6,649,280 JP-A-4-43510

  However, the superconducting tapes of Patent Documents 1 to 3 have a problem that the tensile strain resistance and tensile stress resistance are not sufficient. The first reason is that, when bending is applied to the superconducting wire, the ceramic superconducting wire is strong against compressive strain and compressive stress, and weak against tensile strain and tensile stress. For this reason, when bending is applied to the superconducting tape in which thin plates are attached to both main surfaces of the superconducting wire, there is a problem that the tensile strain and tensile stress resistance characteristics of the superconducting tape are weak.

  The second reason is that in a superconducting tape in which a metal plate is attached to one main surface of the superconducting wire, tensile strain and tensile stress are applied to the ceramic superconducting wire when the thickness of the thin plate or metal reinforcing material is small. In order to prevent this, even if the thin plate or the metal reinforcing material is bent so as to be on the outer peripheral side, the neutral line where the amount of strain becomes zero hardly shifts to the outer peripheral side. For this reason, when bending is applied to the superconducting tape, there is a problem that the tensile strain resistance and tensile stress resistance of the superconducting tape are not sufficient.

  If the tensile strain resistance of the superconducting tape is low, the diameter (allowable bending diameter) when the superconducting tape is bent to such an extent that the superconducting characteristics of the superconductor are maintained increases. For this reason, there exists a problem that size reduction of the superconducting apparatus using this superconducting tape cannot be achieved.

  Accordingly, an object of the present invention is to provide a superconducting tape manufacturing method and a superconducting tape manufacturing apparatus capable of improving the tensile strain resistance and tensile stress resistance and reducing the allowable bending diameter.

  The manufacturing method of the superconducting tape of the present invention includes the following steps. First, a tape-shaped main body having a superconductor is prepared. And a reinforcement part is prepared. And the tension part below the yield stress of a reinforcement part is applied to the reinforcement part along the extension direction of a reinforcement part, and at least one main surface of a main-body part and a reinforcement part are joined.

  According to the method of manufacturing a superconducting tape of the present invention, the main body portion and the reinforcing portion in a contracted state of the reinforcing portion by joining the main body portion while applying tension to the reinforcing portion along the extending direction of the reinforcing portion. Therefore, compressive stress and compressive strain applied to the superconductor of the main body can be increased. For this reason, the superconducting tape to which the reinforcing portion is bonded becomes strong against tensile stress and tensile strain.

  When the superconducting tape is bent, the superconductor of the main body located in the region near the center of bending with the neutral axis as a boundary is subjected to compressive strain, and the superconductor located in the region far from the center is subjected to tensile strain. Since the superconductor of the main body portion has a smaller allowable strain on the tension side than the allowable strain on the compression side, the allowable bending diameter of the superconducting tape is determined by the allowable tensile strain of the main body portion. The superconducting tape manufactured by the method of manufacturing a superconducting tape according to the present invention is in a state in which a compressive strain has been applied to the superconductor of the main body portion in advance and has a strong property against bending. The bending diameter can be reduced.

  Preferably, in the method of manufacturing a superconducting tape, the step of joining the main body portion and the reinforcing portion includes a step of applying tension to the main body portion along the extending direction of the main body portion, and a tension larger than the tension applied to the main body portion. Adding to the reinforcing portion along the extending direction of the reinforcing portion.

  Accordingly, even when tension is applied to the main body, the reinforcing portion can be further contracted and joined to the main body, so that a larger compressive strain is applied to the main body in advance. For this reason, when the superconducting tape is bent, the tensile strain resistance and tensile stress resistance of the superconducting tape can be improved. As a result, even if this superconducting tape is bent, it is possible to suppress the deterioration of the superconducting characteristics of the main body. Therefore, the allowable bending diameter can be reduced.

  Preferably, in the method of manufacturing a superconducting tape, the reinforcing portion is formed only on one main surface side of the main body portion.

  When bending so that one main surface of the main body is on the outside, the neutral line where the strain is zero in the superconducting tape shifts to this one main surface side, so the maximum tensile strain applied to the superconductor of the main body is reduced. Can be reduced. For this reason, the tensile strain resistance can be further improved. As a result, the manufactured superconducting tape can be bent so as to have a smaller diameter while suppressing a decrease in the critical current value, so that the allowable bending diameter can be further reduced.

  Further, since the volume ratio of the reinforcing portion in the superconducting tape can be reduced, the critical current density per total cross-sectional area of the superconducting tape can be improved.

  The superconducting tape manufacturing apparatus of the present invention includes a first feeding part, a second feeding part, a receiving part, a first tension applying part, a second tension applying part, and a joining part. Yes. The first feeding part sends the reinforcing part. The second feeding portion feeds a tape-like main body portion having a superconductor. The receiving part receives the reinforcing part sent from the first feeding part and the main body part sent from the second feeding part. The first tension applying unit is provided between the first feeding unit and the receiving unit, and applies a tension equal to or lower than the yield stress of the reinforcing unit in the extending direction of the reinforcing unit. The joining portion is provided between the first tension applying portion and the second feeding portion and the receiving portion, and joins at least one main surface of the main body portion and the reinforcing portion to form a superconducting tape.

  According to the superconducting tape manufacturing apparatus of the present invention, the first tension applying portion is joined to the main body portion at the joining portion while applying tension to the reinforcing portion along the extending direction of the reinforcing portion. A superconducting tape capable of increasing the compressive stress and compressive strain applied to the superconductor can be manufactured. For this reason, the superconducting tape manufactured by the superconducting tape manufacturing apparatus of the present invention is strong against tensile stress and tensile strain.

  Also, when bending is applied to the superconducting tape manufactured by the superconducting tape manufacturing apparatus of the present invention, it becomes strong against the tensile strain applied to the superconductor contained in the main body, so the allowable bending diameter should be reduced. Can do.

  Preferably, in the superconducting tape manufacturing apparatus, a second tension applying unit that is provided between the second feeding unit and the receiving unit and applies a tension equal to or less than the yield stress of the main body in the extending direction of the main body. In addition, the first tension applying unit applies a tension larger than the tension applied to the main body by the second tension applying unit along the extending direction of the reinforcing unit.

  Thereby, even when tension is applied to the main body by the second tension applying section, the reinforcing section can be further contracted by the first tension applying section and can be joined to the main body. A state in which a larger compressive strain is applied in advance. For this reason, when bending is applied to the superconducting tape manufactured by this manufacturing apparatus, the tensile strain resistance and tensile stress resistance of the superconducting tape can be improved. As a result, even if this superconducting tape is bent, it is possible to suppress a decrease in superconducting characteristics of the superconductor of the main body. Therefore, the allowable bending diameter can be reduced.

  According to the superconducting tape manufacturing method and superconducting tape manufacturing apparatus of the present invention, the tensile strain resistance and tensile stress resistance can be improved and the allowable bending diameter can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a partial cross-sectional perspective view schematically showing the configuration of the superconducting tape according to Embodiment 1 of the present invention. As shown in FIG. 1, the superconducting tape 1 a in the present embodiment includes a main body portion 7, reinforcing portions 9 a and 9 b, and a solder layer 11. The reinforcing portions 9a and 9b are respectively disposed on the upper surface 7a side and the lower surface 7b side of the main body portion 7, and are disposed along the longitudinal direction (extending direction) of the main body portion 7. The main body portion 7 and each of the reinforcing portions 9a and 9b are joined by a solder layer 11.

  The main body portion 7 has a tape shape which is a shape extending in a uniaxial direction, and includes a plurality of superconductors 3 extending in the longitudinal direction and a sheath portion 5 covering the entire circumference of the plurality of superconductors 3. Yes. The sheath portion 5 is in contact with the superconductor 3. Each of the plurality of superconductors 3 is preferably, for example, a bismuth-based superconductor having a composition of Bi (bismuth) -Pb-Sr (strontium) -Ca (calcium) -Cu (copper) -O (oxygen). , (Bismuth and lead): strontium: calcium: copper is most suitable a material containing a Bi2223 phase represented by an approximate atomic ratio of 2: 2: 2: 3. The material of the sheath portion 5 is made of, for example, silver (Ag) or a silver alloy.

  A compressive stress and compressive strain larger than those of the reinforcing portions 9a and 9b are applied to the main body portion 7.

  The reinforcing portions 9a and 9b play the role of improving the mechanical strength of the superconducting tape 1a and maintaining a high allowable tensile stress. From the viewpoint of improving the mechanical strength of the superconducting tape 1a, the reinforcing portions 9a and 9b preferably have higher mechanical strength than the main body portion 7.

  Each of the reinforcing portions 9a and 9b is in a tape shape, and is higher than the thermal expansion coefficient of the main body portion 7 (that is, the thermal expansion coefficient of the superconductor 3 and the sheath portion 5) at room temperature or higher and below the melting point of the solder layer 11. It is preferable to have a large coefficient of thermal expansion. Stainless steel, copper alloy, nickel alloy, or the like is used as the material of the reinforcing portions 9a, 9b, and stainless steel, copper alloy, or the like is preferably used from the viewpoint of a high coefficient of thermal expansion. In addition, room temperature is 0 degreeC or more and 40 degrees C or less, for example.

  The reinforcing portion 9 a has a softening temperature higher than the melting point of the solder layer 11, and preferably has a softening temperature higher than the softening temperature of the solder layer 11. The softening temperature of the reinforcing portion 9a is preferably higher by 20 ° C. than the melting point of the solder layer 11. Here, the softening temperature (softening point) is a temperature at which a substance starts to be deformed and softened by heating.

  The solder layer 11 is for joining the main body part 7 and the reinforcing parts 9a and 9b by being heated and cooled. The material of the solder layer 11 preferably has a melting point of 200 ° C. or higher. As the solder layer 11 having a melting point of 200 ° C. or more, for example, Sn, Pb, Sn—Ag, Sn—Sb (antimony), Sn—Ag—Au (gold), Sn—Cu—Ni (nickel), Sn—Ag— Ni, Sn—Ag—Cu—Bi, Sn—Ag—In (indium) —Bi, etc. are used, and Sn, Sn—Ag containing no Pb from the viewpoint of reducing the influence on the working environment and the use environment, Sn-Sb, Sn-Ag-Au, Sn-Cu-Ni, Sn-Ag-Ni, Sn-Ag-Cu-Bi, and Sn-Ag-In-Bi are preferably used.

  In the above description, the case where the main body 7 has a structure (multi-core wire) having a plurality of superconductors 3 has been described, but the main body 7 has a structure having only one superconductor ( Single-core wire).

  Here, as an example of specific dimensions of the superconducting tape 1a, the thickness (length in the vertical direction in the drawing) of the reinforcing portion 9a is 0.02 mm, and the width (length in the horizontal direction in the drawing) is 4. .3 mm. The main body 7 has a thickness of 0.22 mm and a width of 4.2 mm.

  FIG. 2 is a schematic diagram showing an apparatus for producing the superconducting tape in Embodiment 1 of the present invention. Then, with reference to FIG. 2, the apparatus 100a for manufacturing the superconducting tape 1a in this Embodiment is demonstrated.

  As shown in FIG. 2, the apparatus 100a includes a first feeding unit 101, support units 102 and 103, and a first tension applying unit in the order of manufacturing the superconducting tape 1a (from the left side to the right side in FIG. 2). 104, support portion 105, second feed portion 106, support portions 107 to 109, third feed portion 110, support portions 111 and 112, third tension applying portion 113, and support portion 114. In addition, a flux tank 115, a joining part 116, a collecting part 117, a cleaning tank 118, a winding part 119, and a receiving part 120 are provided.

  The first feeding part 101 is a reel for feeding the reinforcing part 9a to the receiving part 120, for example, winding and holding the reinforcing part 9a.

  When the reinforcing part 9a sent from the first feeding part 101 passes through the supporting parts 102, 103, 105, the first tension applying part 104 attached to the supporting part 103 is below the yield stress of the reinforcing part 9a. Tension is applied in the extending direction of the reinforcing portion 9a. The first tension applying unit 104 preferably applies a strain equal to or less than the yield strain of the reinforcing portion 9a in the extending direction of the reinforcing portion 9a. The support units 102 and 105 are, for example, fixed pulleys, the support unit 103 is, for example, a moving pulley, and the first tension applying unit 104 is a weight hung on the support unit 103.

  Here, the 1st sending part 101 and the 1st tension application part 104 may be one member which has both the function to send reinforcement part 9a and the function to add tension to reinforcement part 9a, for example.

  The second feeding portion 106 is a reel for feeding the tape-like main body portion 7 having a superconductor to the receiving portion 120, for example, for winding and holding the main body portion 7. The main body portion 7 sent from the second feeding portion 106 passes through the support portions 107 to 109 and is sent from the reinforcing portion 9a sent from the first feeding portion 101 and the second feeding portion 106 by the support portion 109. The main body 7 is stacked. The support portions 107 and 109 are, for example, fixed pulleys, and the support portion 108 is, for example, a moving pulley.

  As shown in FIG. 3, the support portion 108 has a second tension for applying a tension that is equal to or less than the yield stress of the main body portion 7 and less than the tension applied to the main body portion 7 in the extending direction of the main body portion 7. The application unit 108a may be disposed. FIG. 3 is a schematic diagram showing another apparatus for manufacturing the superconducting tape according to Embodiment 1 of the present invention.

  Here, the second feeding unit 106 and the second tension applying unit 108a may be, for example, one member having both a function of feeding the main body 7 and a function of applying tension to the main body 7.

  The third sending part 110 sends the reinforcing part 9b to the receiving part 120. The third feed part 110 is a reel for winding and holding the reinforcing part 9b, for example. When the reinforcing part 9b sent from the third feeding part 110 passes through the supporting parts 111, 112, 114, the third tension applying part 113 attached to the supporting part 112 has a yield stress equal to or lower than the yield stress of the reinforcing part 9b. Tension is applied in the extending direction of the reinforcing portion 9b. The third tension applying unit 113 preferably applies a strain equal to or less than the yield strain of the reinforcing portion 9b in the extending direction of the reinforcing portion 9b. The reinforcing portion 9b sent from the third feeding portion 110 passes through the supporting portions 111, 112, and 114, and the supporting portion 114 and the reinforcing portion 9a sent from the first feeding portion 101 and the second feeding portion. The main body part 7 sent from the part 106 and the reinforcing part 9b sent from the third feeding part 110 are stacked in this order.

  Here, the third feeding unit 110 and the third tension applying unit 113 may be, for example, one member having both a function of feeding the reinforcing part 9b and a function of applying tension to the reinforcing part 9b.

  The laminated state is sent to the flux tank 115. In the flux tank 115, flux for removing the oxide film on the joint surfaces of the reinforcing portions 9a and 9b is accommodated inside.

  It is sent to the joint part 116 in a state where the oxide film on the joint surface of the reinforcing parts 9a and 9b is removed by the flux tank 115. A material to be the solder layer 11 is accommodated in the joint 116. The joining portion 116 joins the upper surface 7a and the lower surface 7b of the main body portion 7 and the reinforcing portions 9a and 9b through the solder layer 11.

  In a state where the main body portion 7 and the reinforcing portions 9a and 9b are joined by the solder layer 11, they are integrated by the collecting portion 117. The collective portion 117 is attached to the outlet of the joint portion 116, and is, for example, a collective die. Thereby, the superconducting tape 1a is obtained.

  The superconducting tape 1 a integrated by the collecting portion 117 is sent to the cleaning tank 118. The cleaning tank 118 contains a cleaning liquid such as warm water in order to clean the superconducting tape 1a.

  The superconducting tape 1 a sent from the cleaning tank 118 is received by the receiving unit 120 using the winding unit 119.

  Then, with reference to FIGS. 1-3, the manufacturing method of the superconducting tape in this Embodiment is demonstrated.

  First, a tape-like main body 7 having a superconductor 3 is prepared. Specifically, raw material powder of oxide or carbonate is mixed so that Bi, Pb, Sr, Ca and Cu have a predetermined composition ratio. By repeating the heat treatment and pulverization of this mixed powder, a precursor powder composed of a Bi2223 phase, a Bi2212 phase, and a non-superconducting phase is produced. Next, the precursor powder is filled into a metal tube. Thereafter, wire drawing is performed on the metal powder filled with the precursor powder. In this case, the wire drawing process and the intermediate softening process are repeated to obtain a clad wire covered with a metal tube using the precursor filament as a core material. Next, a plurality of clad wires are bundled and fitted again into the metal tube. Thereby, for example, a multi-core wire having 55 cores is produced. Next, the multifilamentary wire is drawn. As a result, a wire having a form in which the precursor powder of the oxide superconductor containing the Bi2223 phase is covered with the sheath portion 5 is produced. Thereafter, a plurality of rolling processes and heat treatments are repeated for the multifilamentary wire. This heat treatment is performed in an oxygen atmosphere, and the oxygen partial pressure in the atmosphere is, for example, 0.01 MPa or less. As a result, the precursor powder changes and becomes a superconductor 3. Moreover, a wire becomes tape-like by rolling. Through the above steps, a tape-shaped main body portion 7 having the superconductor 3 and the sheath portion 5 covering the entire circumference of the superconductor 3 is formed. Such a main body portion 7 is arranged in the second feeding portion 106.

  Next, the reinforcement parts 9a and 9b are prepared. The reinforcing portions 9a and 9b preferably have a thermal expansion coefficient larger than the thermal expansion coefficient of the main body portion 7 at a temperature between room temperature and the melting point of the solder layer 11. The reinforcing portions 9 a and 9 b preferably have a softening temperature higher than the softening temperature of the solder layer 11. The softening temperature of the reinforcing portions 9a and 9b is higher than the temperature at which the solder layer 11 is heated when the main body portion 7 and the reinforcing portions 9a and 9b are joined using the solder layer 11 described later, and the melting point of the solder layer 11 It is preferably 20 ° C. or higher. Specifically, for example, the reinforcing portions 9a and 9b made of the above-described material are prepared and arranged on the first and third feeding portions 101 and 110.

  Next, in a state where tension (tensile tension) equal to or lower than the yield stress of the reinforcing portions 9a and 9b is applied to the reinforcing portions 9a and 9b along the extending direction of the reinforcing portions 9a and 9b, The lower surface 7b and the reinforcing portions 9a and 9b are joined. The main body 7 and the reinforcing portions 9a and 9b are joined in a state where a tensile strain below the yield strain of the reinforcing portions 9a and 9b is applied to the reinforcing portions 9a and 9b along the extending direction of the reinforcing portions 9a and 9b. It is preferable to join. In addition, the plastic deformation of a reinforcement part can be prevented by applying a tensile stress to the reinforcement part below the yield stress of a reinforcement part.

  Specifically, for example, the following steps are performed. First, the surface of the reinforcing portions 9a and 9b is activated by removing the oxide film on the joint surfaces of the reinforcing portions 9a and 9b through the flux tank 115. It is preferable that the flux is a material that improves the bonding properties of the reinforcing portions 9a and 9b to the main body portion 7. Moreover, it is preferable to use a non-strongly acidic flux for the purpose of not adversely affecting the sheath portion 5 and the manufacturing equipment. Examples of such a flux include an organic acid flux and a resin flux.

  Thereafter, the main body portion 7 and the reinforcing portions 9a and 9b are passed through the joint portion 116 in which the material of the solder layer 11 is melted. Thereafter, the material is made into the solder layer 11 by setting the atmosphere below the melting point of the solder layer 11 and cooling and hardening the material of the solder layer 11. As a result, the main body portion 7 and the reinforcing portions 9a and 9b are integrated via the solder layer 11. In the present embodiment, the aggregate portion 117 provided at the outlet portion of the joint portion 116 is set to be less than the melting point of the material of the solder layer 11, and the main body portion 7, the reinforcing portions 9 a and 9 b, and the solder layer 11 that have passed through the joint portion 116. In order to integrate them, the main body part 7 and the reinforcing parts 9a and 9b are joined through the assembly part 117 and the solder layer 11.

  At the time of joining, in the apparatus 100a shown in FIG. 2, tension is applied to the reinforcing portions 9a and 9b by the first and third tension applying portions 104 and 113, respectively. For this reason, in the joining part 116, the main-body part 7 and the reinforcement parts 9a and 9b are joined in the state in which the tensile stress was applied to the reinforcement parts 9a and 9b.

  Moreover, the tension | tensile_strength added to the extension direction of the reinforcement parts 9a and 9b can be easily controlled by changing the weight of the 1st and 3rd tension application parts 104 and 113. FIG.

  Further, as shown in FIG. 3, when the apparatus 100 b including the second tension applying unit 108 a such as a weight hung on the support unit 108 is used, the main body unit 7 extends along the extending direction of the main body unit 7. And a step of applying a tension larger than the tension applied to the main body portion 7 to the reinforcing portions 9a and 9b along the extending direction of the reinforcing portions 9a and 9b. In this case, the main body portion 7 and the reinforcing portions 9a and 9b are bonded to each other at the bonding portion 116 in a state where a tensile stress larger than that of the main body portion 7 is applied to the reinforcing portions 9a and 9b.

  Further, when the melting point of the solder layer 11 is 200 ° C. or higher and the thermal expansion coefficient of the reinforcing parts 9 a and 9 b is larger than the thermal expansion coefficient of the main body part 7, the reinforcing parts 9 a and 9 b that pass through the inside of the joint part 116. In the joint portion 116, the reinforcing portions 9 a and 9 b expand more than the main body portion 7. When cooled, the reinforcing portions 9a and 9b contract more than the main body portion 7, so that further tensile strain is generated on the reinforcing portions 9a and 9b side, and further compressive strain is generated on the main body portion 7 side.

  The method for forming the solder layer 11 is not particularly limited to the above-described plating method, and is formed by, for example, a vapor deposition method.

  When the apparatuses 100a and 100b shown in FIGS. 2 and 3 are used, the surface of the main body 7 and the reinforcing portions 9a and 9b are plated with the solder layer 11 on the surface other than the joint portion, so that the corrosion resistance is improved and the solder is used at the terminal. Connection becomes easy.

  By performing the above steps, the superconducting tape 1a in the present embodiment shown in FIG. 1 can be manufactured.

  In the method of manufacturing the superconducting tape 1a described above, the main body portion 7 and the reinforcing portions 9a and 9b are joined via the solder layer 11, but the present invention does not use the solder layer 11 and the main body portion 7 and A method of joining the reinforcing portions 9a and 9b is also included.

  As described above, in the method of manufacturing the superconducting tape 1a in the present embodiment, the tension below the yield stress of the reinforcing portions 9a and 9b is applied to the reinforcing portions 9a and 9b along the extending direction of the reinforcing portions 9a and 9b. In the added state, the upper surface 7a and the lower surface 7b of the main body 7 and the reinforcing portions 9a and 9b are joined.

  In addition, the superconducting tape 1a manufacturing apparatus 100a, 100b according to the present embodiment applies first and third tensions for applying tension below the yield stress of the reinforcing portions 9a, 9b in the extending direction of the reinforcing portions 9a, 9b. The tension applying portions 104 and 113, and the joining portion 116 for joining the upper surface 7a and the lower surface 7b of the main body 7 and the reinforcing portions 9a and 9b to form the superconducting tape 1a are provided.

  According to the manufacturing method and the manufacturing apparatuses 100a and 100b of the superconducting tape 1a in the present embodiment, the first and third tension applying units 104 and 13 use the reinforcing portion 9a along the extending direction of the reinforcing portions 9a and 9b. , 9b can be joined to the main body portion 7 while applying tension, thereby increasing the compressive stress and compressive strain applied to the superconductor 3 of the main body portion 7. For this reason, the superconducting tape 1a to which the reinforcing portion 7 is bonded becomes strong against tensile stress and tensile strain. As a result, even if this superconducting tape 1a is bent so as to reduce its diameter, it is possible to suppress a decrease in superconducting characteristics of the superconductor 3 of the main body 7.

  When the superconducting tape 1a is bent, the superconductor 3 of the main body portion 7 located in a region near the center of bending with the neutral axis as a boundary is subjected to compressive strain, and the superconductor 3 located in a region far from the center is subjected to tensile strain. Receive. Since the superconductor 3 of the main body 7 has a smaller allowable strain on the tension side than that on the compression side, the allowable bending diameter of the superconducting tape 1a is determined by the allowable tensile strain of the main body 7. In the superconducting tape 1a manufactured according to the present embodiment, the superconducting tape 1a is in a state in which a compressive strain is applied in advance to the superconductor of the main body 7 and has a strong characteristic against bending. The diameter can be reduced.

  In addition, by arranging the reinforcing portions 9a and 9b on the upper surface 7a side and the lower surface 7b side of the main body portion 7, the tensile stress resistance of the superconducting tape 1a can be improved.

  In the method of manufacturing superconducting tape 1a in the present embodiment, preferably, in the step of bonding main body 7 and reinforcing portions 9a and 9b, main body 7 and the reinforcing portion are used using solder layer 11 having a melting point of 200 ° C. or higher. In the step of joining the reinforcing portions 9a and 9b to the reinforcing portions 9a and 9b, the reinforcing portions 9a and 9b having a thermal expansion coefficient larger than the thermal expansion coefficient of the main body portion 7 at room temperature or more and below the melting point of the solder layer 11 are prepared. In the step of preparing and joining the main body portion 7 and the reinforcing portions 9a and 9b, the solder layer 11 is heated to a temperature equal to or higher than the melting point of the solder layer 11.

  Thereby, since the thermal expansion coefficient of the reinforcement parts 9a and 9b is larger than the thermal expansion coefficient of the main-body part 7, a solder layer is heated by heating the solder layer 11 (the material of the solder layer 11 in this Embodiment) more than melting | fusing point. When 11 is melted and then the solder layer 11 is cured, the reinforcing portions 9 a and 9 b are joined to the main body portion 7 in a contracted state with respect to the main body portion 7 by cooling. When the melting point of the solder layer 11 is 200 ° C. or higher, the reinforcing portions 9a and 9b are joined to the main body portion 7 in a sufficiently contracted state. For this reason, the compressive stress and the compressive strain applied to the superconductor 3 of the main body 7 can be further increased. For this reason, the tensile strain resistance and the tensile stress resistance can be further improved. Therefore, the allowable bending diameter of the superconducting tape 1a can be reduced.

(Embodiment 2)
FIG. 4 is a partial cross-sectional perspective view schematically showing the configuration of the superconducting tape in Embodiment 2 of the present invention. As shown in FIG. 4, the superconducting tape 1b in the present embodiment basically has the same configuration as the superconducting tape 1a in the first embodiment, but the reinforcing portion 9a is one of the main body portions 7. It differs only in the point formed only on the main surface side. In this Embodiment, as shown in FIG. 4, the reinforcement part 9a is arrange | positioned only at the upper surface 7a side of the main-body part.

  FIG. 5 is a schematic diagram showing a superconducting tape manufacturing apparatus according to Embodiment 2 of the present invention. As shown in FIG. 5, the apparatus 100c for manufacturing the superconducting tape 1b in the present embodiment basically has the same configuration as that of the first embodiment, but the third feeding section, the third Only in that the tension applying unit 113 and the supporting units 111, 112, and 114 are not provided.

  The manufacturing method of superconducting tape 1b in the present embodiment basically has the same configuration as the manufacturing method of superconducting tape 1a in Embodiment 1, but the step of joining main body portion 7 and reinforcing portion 9a. Then, it differs only in the point which forms the reinforcement part 9a only in the one main surface (in this Embodiment, upper surface 7a) side of the main-body part 7. FIG.

  Since other superconducting tape 1b and its manufacturing method are the same as those of superconducting tape 1a and its manufacturing method in Embodiment 1, the same members are denoted by the same reference numerals, and the description thereof is repeated. Absent.

  FIG. 6 (A) is a schematic diagram showing a state where bending is applied to superconducting tape 1b according to Embodiment 2 of the present invention, and FIG. 6 (B) is an enlarged view of region VIB in FIG. 6 (A). Then, with reference to FIG. 6 (A) and (B), the effect of the superconducting tape 1b in this Embodiment is demonstrated.

  As shown in FIG. 6A, when the superconducting tape 1b in the present embodiment is bent so that the reinforcing portion 9a is on the outer peripheral side, as shown in FIG. And tensile stress are applied, and compressive strain and compressive stress are applied to the inner peripheral side. Thus, since the reinforcement part 9a is located in the outer peripheral side, the neutral line B from which the amount of distortion becomes zero is a position shifted from the main body part 7 to the reinforcement part 9a. In other words, since the neutral line B is positioned in the vicinity of the solder layer 11, compressive strain and compressive stress are applied to the main body portion 7, and the tensile strain and tensile stress applied to the main body portion 7 can be reduced.

  In addition, in order to suppress the fall of a critical current density, when reducing the thickness of the reinforcement part 9a, the neutral line B may be located in the main-body part 7 side. However, since the reinforcing portion 9a is formed only on the upper surface 7a, the neutral line B can be positioned on the reinforcing portion 9a side as compared with the case where the reinforcing portions 9a are arranged on both surfaces. For this reason, the tensile strain and tensile stress applied to the main body 7 can be reduced.

  Moreover, compared with the case where reinforcement part 9a, 9b is arrange | positioned on both sides of the main-body part 7 of Embodiment 1, the volume ratio which reinforcement part 9a, 9b accounts in the superconducting tape 1b can be reduced. For this reason, the superconducting tape 1b in the present embodiment can improve the critical current density.

  Thus, since the tensile strain of the superconducting tape 1b can be reduced, as shown in FIG. 6A, the allowable bending diameter R (from the bending center A when the bending is performed while maintaining the superconducting characteristics of the superconducting tape 1b. 2 times the distance to the superconducting tape 1b) can be reduced.

  The present embodiment includes a step of joining at least one main surface of the main body portion and the reinforcing portion in a state where a tension equal to or lower than the yield stress of the reinforcing portion is applied to the reinforcing portion along the extending direction of the reinforcing portion. We investigated the effects of this. Specifically, each of the superconducting tapes of Examples 1 to 3 and Comparative Examples 1 to 4 was manufactured, and allowable tensile strain, allowable tensile stress, and allowable bending diameter of the superconductive tape were measured.

Example 1
In Example 1, the superconducting tape shown in FIG. 1 was manufactured using the superconducting tape manufacturing apparatus 100a shown in FIG. 2 in accordance with the superconducting tape manufacturing method in the first embodiment.

  Specifically, first, a tape-shaped main body portion 7 in which the Bi2223 superconductor 3 was covered with a sheath portion 5 made of silver was prepared. The main body 7 had a thickness of 0.22 mm and a width of 4.2 mm.

  Next, two reinforcing portions 9a and 9b made of SUS304 were prepared. The thickness of the reinforcement parts 9a and 9b was 0.02 mm, and the width was 4.3 mm.

  Next, the upper surface 7a and the lower surface 7b of the main body 7 are reinforced with a tension equal to or less than the yield stress of the reinforcing portions 9a and 9b applied to the reinforcing portions 9a and 9b along the extending direction of the reinforcing portions 9a and 9b. The parts 9a and 9b were joined to each other. More specifically, by applying a load of 30N to the first tension applying unit 104 and the third tension applying unit 113, a tension of 30N was applied to the reinforcing portions 9a and 9b, respectively. In a state where the material of the solder layer 11 made of Sn-0.7% Cu having a melting point of 227 ° C. is melted by heating to 300 ° C., the main body portion 7 and the reinforcement portions 9a and 9b to which a tension of 30 N is applied The body part 7 and the reinforcing parts 9a and 9b were joined by the solder layer 11 by dipping and then curing the material. The superconducting tape of Example 1 was manufactured through the above steps.

(Example 2)
The second embodiment basically has the same configuration as the superconducting tape manufacturing method in the first embodiment, but differs only in that the reinforcing portion 9a is formed only on the upper surface 7a side of the main body portion 7.

  Specifically, in Example 2, the superconducting tape shown in FIG. 4 was manufactured using the superconducting tape manufacturing apparatus 100 c shown in FIG. 5 in accordance with the superconducting tape manufacturing method in Embodiment 2.

  More specifically, first, the same superconducting tape as in Example 1 was prepared. Next, one reinforcing part 9a made of the same material as in Example 1 was prepared.

  Next, in the same manner as in the first embodiment, the upper surface 7a and the reinforcing portion 9a of the main body 7 are applied in a state where a tension equal to or lower than the yield stress of the reinforcing portion 9a is applied to the reinforcing portion 9a along the extending direction of the reinforcing portion 9a. And were joined respectively. In Example 2, as in Example 1, a tension of 30 N was applied only to the reinforcing portion 9a. The superconducting tape of Example 2 was manufactured through the above steps.

(Example 3)
Example 3 basically had the same configuration as the superconducting tape manufacturing method in Example 1, but differs only in that the solder layer is Sn-37% Pb having a melting point of 183 ° C. In detail, the main body part 7 and the two reinforcement parts 9a and 9b similar to Example 1 were prepared. Next, a tension of 30 N is applied to the reinforcing portions 9a and 9b, the solder layer 11 is heated to 190 ° C. and melted, and the main body portion 7 and the reinforcing portions 9a and 9b are immersed in the material of the solder layer 11, The main body part 7 and the reinforcing parts 9a and 9b were joined. Thereby, the superconducting tape of Example 3 was manufactured.

(Comparative Example 1)
In Comparative Example 1, a reinforcing part was not formed, and the same main body part as in Examples 1 to 3 was prepared. This main body part was used as the superconducting tape of Comparative Example 1.

(Comparative Example 2)
Comparative Example 2 was basically manufactured in the same manner as the superconducting tape manufacturing method of Example 1, but when the main body 7 and the reinforcing portions 9a and 9b were joined, tension was applied to the reinforcing portions 9a and 9b. It differs only in the points that were not.

(Comparative Example 3)
Comparative Example 3 was basically manufactured in the same manner as the method of manufacturing the superconducting tape of Example 2, except that no tension was applied to the reinforcing part 9a when the main body part 7 and the reinforcing part 9a were joined. Only different.

(Comparative Example 4)
Comparative Example 4 was basically manufactured in the same manner as the superconducting tape manufacturing method of Example 3, but when the main body 7 and the reinforcing portions 9a and 9b were joined, tension was applied to the reinforcing portions 9a and 9b. It differs only in the points that were not.

(Measuring method)
For the superconducting tapes of Examples 1 to 3 and Comparative Examples 1 to 4, the allowable tensile strain, the allowable tensile stress, and the allowable bending diameter were measured.

  Specifically, the allowable tensile strain can maintain 95% of the initial critical current value of each superconducting tape by applying tensile strain to the superconducting tapes of Examples 1 to 3 and Comparative Examples 1 to 4 at room temperature. Maximum distortion.

  The allowable tensile stress is the maximum at which 95% of the initial critical current value of each superconducting tape can be maintained by applying tensile stress in the longitudinal direction to the superconducting tapes of Examples 1 to 3 and Comparative Examples 1 to 4 at room temperature. Stress.

  The allowable bending diameter is the minimum diameter that can be maintained at 95% of the initial critical current value of each superconducting tape by bending the superconducting tapes of Examples 1 to 3 and Comparative Examples 1 to 4 at room temperature (FIG. 6). The diameter R) in (A). These results are shown in Table 1 below.

(Measurement result)
As shown in Table 1, Examples 1 to 3 were able to improve all of the allowable tensile stress, the allowable tensile strain, and the allowable bending diameter as compared with Comparative Example 1 that did not include the reinforcing portion.

  Comparing Example 1 and Comparative Example 2, which includes two reinforcing portions and uses a solder layer having a melting point of 200 ° C. or higher for joining, the superconducting tape of Example 1 joined by applying tension to the reinforcing portions. Was able to improve the allowable tensile stress, the allowable tensile strain and the allowable bending diameter as compared with the superconducting tape of Comparative Example 2 which was joined without applying tension to the reinforcing portion.

  Comparing Example 2 and Comparative Example 3, which includes a single reinforcing portion and uses a solder layer having a melting point of 200 ° C. or higher for joining, the superconducting tape of Example 2 joined by applying tension to the reinforcing portion. Was able to improve the allowable tensile stress, the allowable tensile strain and the allowable bending diameter as compared with the superconducting tape of Comparative Example 3 which was joined without applying tension to the reinforcing portion.

  Comparing Example 3 and Comparative Example 4, which includes two reinforcing portions and uses a solder layer having a melting point of less than 200 ° C. for joining, the superconducting tape of Example 3 joined by applying tension to the reinforcing portions. Was able to improve the allowable tensile stress, the allowable tensile strain and the allowable bending diameter as compared with the superconducting tape of Comparative Example 4 which was joined without applying tension to the reinforcing portion.

  In particular, when Example 1 and Example 3 in which tension was applied at the time of joining were compared, Example 1 with a melting point of the solder layer of 200 ° C. or higher was higher in allowable tensile strain and than Example 3 with a melting point of less than 200 ° C. The allowable bending diameter could be improved. From this result, since the heat applied to the reinforcing part and the main body part during joining in Example 1 is higher than the heat applied to the reinforcing part and the main body part during joining in Example 3, the reinforcing part is the main body part. In the process of cooling the body part with the reinforcing part to room temperature, the superconductor of the body part is pre-compressed and compressed. It was found that the tensile strain resistance of the tape can be improved.

  Further, when Examples 1 and 3 having two reinforcing portions are compared with Example 2 having one reinforcing portion, the volume ratio of the reinforcing portion in the superconducting tape increases, so that the allowable tensile stress And the allowable tensile strain could be improved.

  In Example 2 in which the reinforcing portion was formed only on one main surface, the allowable bending diameter could be greatly improved despite the small volume ratio of the reinforcing portion in the superconducting tape.

  As described above, according to the present embodiment, at least one main surface of the main body portion and the reinforcing portion are applied in a state where a tension equal to or lower than the yield stress of the reinforcing portion is applied to the reinforcing portion along the extending direction of the reinforcing portion. It was confirmed that by providing the joining step, the tensile strain resistance and tensile stress resistance can be improved and the allowable bending diameter can be reduced.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  The superconducting tape manufactured by the superconducting tape manufacturing method and superconducting tape manufacturing apparatus of the present invention is particularly suitable as a technique related to a superconducting tape containing a bismuth-based superconducting material.

It is a fragmentary sectional perspective view which shows roughly the structure of the superconducting tape in Embodiment 1 of this invention. It is a schematic diagram which shows the apparatus for manufacturing the superconducting tape in Embodiment 1 of this invention. It is a schematic diagram which shows another apparatus for manufacturing the superconducting tape in Embodiment 1 of this invention. It is a fragmentary sectional perspective view which shows roughly the structure of the superconducting tape in Embodiment 2 of this invention. It is a schematic diagram which shows the manufacturing apparatus of the superconducting tape in Embodiment 2 of this invention. (A) is a schematic diagram which shows the state which added the bending to the superconducting tape 1b in Embodiment 2 of this invention, (B) is an enlarged view of the area | region VIB in (A).

Explanation of symbols

  1a, 1b Superconducting tape, 3 superconductor, 5 sheath portion, 7 body portion, 7a upper surface, 7b lower surface, 9a, 9b reinforcing portion, 11 solder layer, 100a, 100b, 100c device, 101 first feeding portion, 102, 103, 105, 107 to 109, 111, 112, 114 Support section, 104 First tension applying section, 106 Second feeding section, 108a Second tension applying section, 110 Third feeding section, 113 Third Tension applying part, 115 flux tank, 116 joint part, 117 collecting part, 118 cleaning tank, 119 winding part, 120 receiving part.

Claims (5)

Preparing a tape-like body having a superconductor;
Preparing a reinforcing part;
A step of joining at least one main surface of the main body portion and the reinforcing portion in a state where a tension equal to or lower than the yield stress of the reinforcing portion is applied to the reinforcing portion along the extending direction of the reinforcing portion. A method for producing a superconducting tape. The step of joining the main body portion and the reinforcing portion includes:
Applying tension to the main body along the extending direction of the main body;
The method for manufacturing a superconducting tape according to claim 1, further comprising: applying a tension larger than a tension applied to the main body portion to the reinforcing portion along an extending direction of the reinforcing portion.   The method of manufacturing a superconducting tape according to claim 1, wherein the reinforcing portion is formed only on one main surface side of the main body portion. A first feed section for feeding the reinforcement section;
A second feeding section for feeding a tape-shaped main body having a superconductor;
A receiving portion for receiving the reinforcing portion sent from the first feeding portion and the main body portion sent from the second feeding portion;
A first tension applying unit that is provided between the first feeding unit and the receiving unit and applies a tension equal to or less than a yield stress of the reinforcing unit in the extending direction of the reinforcing unit;
To provide a superconducting tape provided between the first tension applying section, the second feeding section, and the receiving section, and joining at least one main surface of the main body section and the reinforcing section. And a superconducting tape manufacturing apparatus. A second tension applying unit that is provided between the second feeding unit and the receiving unit and applies a tension equal to or lower than the yield stress of the main body in the extending direction of the main body;
The first tension applying unit applies a tension larger than a tension applied to the main body by the second tension applying unit to the reinforcing unit along an extending direction of the reinforcing unit. Superconducting tape manufacturing equipment.

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