JP5837751B2 - Tape-like oxide superconducting wire manufacturing method and heat treatment apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing a tape-shaped oxide superconducting wire and a heat treatment apparatus, and more particularly to a technique for forming a superconducting layer on an oriented metal substrate on which an intermediate layer is formed using a MOD (Metal-organic Deposition) method. .

Conventionally, as a method for producing a YBa ₂ Cu ₃ O _7-X (YBCO) -based tape-shaped oxide superconducting wire, an organic metal salt coating pyrolysis (MOD: Metal- It is known to form a superconducting layer using an organic deposition method (see Patent Documents 1, 2, and 3).

  In this MOD method, first, a tape-like base material on which an oxide intermediate layer is formed is octyl such as trifluoroacetate (TFA salt) containing each metal element constituting a superconductor in a predetermined molar ratio. It is immersed in a superconducting raw material solution which is a mixed solution of metal organic acid salts such as acid salts and naphthenates. Next, the base material is pulled up from the superconducting raw material solution (so-called dip coating method) to apply the mixed solution on the surface of the base material on the substrate. Next, an oxide superconducting layer is formed by performing preliminary firing and main firing.

  Since the MOD method can continuously form an oxide superconducting layer on a long substrate even in a non-vacuum state, the process is more effective than a gas phase method such as a PLD (Pulse Laser Deposition) method or a CVD (Chemical Vapor Deposition) method. It is attracting attention because it is simple and can be reduced in cost.

  Patent Documents 1 and 2 disclose a batch-type heat treatment apparatus that heat-treats a substrate having a superconducting raw material solution attached to the surface thereof. Compared with the reel-to-reel heat treatment apparatus as shown in Patent Document 3, the batch-type heat treatment apparatus has an advantage that a stable superconducting layer can be formed because the atmosphere in the furnace is easily controlled. In addition, the batch-type heat treatment apparatus has an advantage that the firing can be completed in a short time with a small-sized apparatus, compared with the reel-to-reel type heat treatment apparatus. Incidentally, the heat treatment equipment of the reel-to-reel method performs firing by installing a wire feeding mechanism and a winding mechanism at both ends of a tunnel-shaped furnace core tube, and moving the wire at a constant speed in the furnace. is there.

  A schematic configuration of the batch type heat treatment apparatus disclosed in Patent Documents 1 and 2 will be briefly described with reference to FIG. As shown in FIG. 1, the heat treatment apparatus 1 winds a base material 2 having a superconducting raw material attached on a surface thereof around a drum-shaped rotating body 3. The cylindrical rotating body 3 around which the base material 2 is wound is rotationally driven by a rotation driving mechanism in a furnace core tube 4 in which openings at both ends are closed by flanges 4b in a cylindrical main body 4a. A large number of through holes (not shown) are formed in the rotating body 3. The base material 2 is heated by the heater 5 provided in the surface direction of the base material 2 in the state wound around the rotating body 3. In addition, an atmospheric gas 6 made of an inert gas, oxygen gas, water vapor, and the like is ejected from the surface direction of the base material 2 toward the base material, and this atmospheric gas 6 reacts after reacting with the superconducting raw material of the base material 2. As a later gas (exhaust gas), the gas is discharged (indicated by an arrow 6a) through a through hole formed in the rotating body 3 and an exhaust pipe 7 provided as a shaft portion of the rotating body 3.

Japanese Patent No. 4468901 JP 2009-48817 A Japanese Patent No. 44011992

  A superconducting precursor obtained by pre-calcining a base material coated with a mixed solution containing trifluoroacetate using the heat treatment apparatus disclosed in Patent Documents 1 and 2, and a precursor containing fluorine (F) In the method (TFA-MOD method) for forming a YBCO film by subjecting this to a film on the intermediate layer and then subjecting it to firing, as the atmospheric gas (reactive gas) supplied to the precursor film during the firing Use water vapor.

The YBCO production reaction formula at this time is
1 / 2Y ₂ Cu ₂ O ₅ + 2BaF ₂ + 2CuO + 2H ₂ O → YBCO + 4HF
It becomes.

  Thus, during the main firing, since the precursor film is heat-treated using water vapor as an atmospheric gas, HF is generated, and hydrogen fluoride (HF) gas is generated as a post-reaction gas after this reaction. .

In the TFA-MOD method, the fluorine removal rate when decomposing the fluorine compound (BaF ₂ ) is the reaction rate-limiting factor for YBCO formation. Therefore, there is a problem that the superconducting characteristics of the fired YBCO film are deteriorated due to the influence of hydrogen fluoride (HF) gas (exhaust gas) generated after the reaction.

  In particular, in order to obtain a long tape-shaped wire having a critical current density (Jc) of 2.0 or more and a critical current value (Ic) of 300 A or more, the superconducting layer is formed to a thickness of 1.5 μm or more. It is necessary to form a film. When the film thickness is set to the above, complete removal of hydrogen fluoride (HF) gas becomes more difficult, and the above characteristics cannot be obtained.

  For this reason, in order to improve the superconducting characteristics of the YBCO film, it is important how to remove fluorine contained in the precursor in the main firing.

  However, in the heat treatment apparatus 1 shown in FIG. 1, an excessive space R is formed between the drum-shaped rotating body 3 and the flange 4 b in the furnace core tube 4 in the furnace core tube 4.

  For this reason, in the furnace core tube 4, the hydrogen fluoride (HF) gas was not discharged | emitted via the exhaust pipe 7 (arrow 6b in the figure), and the problem that it stayed in the excess space R occurred.

  As a result, it is impossible to create a discharge flow in a certain direction for the hydrogen fluoride (HF) gas 6b generated from the precursor, and it is impossible to completely remove the hydrogen fluoride (HF) gas 6b. If fluorine cannot be completely removed, there is a problem that uniform superconducting properties cannot be obtained in the length direction.

  The present invention has been made in view of the above points, and is a tape-shaped oxide superconducting wire having excellent superconducting characteristics that is uniform in the length direction and improves the exhaust efficiency of the gas after reaction inside the furnace core tube. It aims at providing the manufacturing method and heat processing apparatus of the tape-shaped oxide superconducting wire which can manufacture this.

  A method for producing a tape-shaped oxide superconducting wire that is one aspect of the present invention includes a furnace core tube in which both ends of a cylindrical main body portion provided with a heat treatment space are closed with flange portions, A cylindrical wire around which a tape-like wire having a superconducting precursor film formed is wound on a surface on which a large number of through-holes are formed and which is rotatably arranged with respect to the furnace core axis of the furnace core tube. A heat treatment apparatus comprising: a rotating body; a gas supply pipe for supplying atmospheric gas to the tape-shaped wire; and a gas discharge pipe for discharging atmospheric gas from the inside of the rotating body to the outside of the furnace core pipe. In the manufacturing method of an oxide superconducting wire that supplies the atmospheric gas from a position spaced upward with respect to the film surface of the film body of the tape-shaped wire wound around the rotating body, the flange portion and An end of the rotating body in the rotation axis direction; While partition between a partition plate and adapted to supply the atmospheric gas on the membrane surface of the membrane of the tape-shaped wire material wound around said rotating body.

  A tape-shaped oxide superconducting wire heat treatment apparatus according to an aspect of the present invention includes a furnace core tube in which both ends of a cylindrical main body portion provided with a heat treatment space are closed with flange portions, and the heat treatment space, Cylindrical rotation in which a tape-like wire rod in which a superconducting precursor film is formed is wound around the surface of a furnace core tube, which is rotatably arranged with respect to the core axis of the furnace core tube. A gas supply pipe for supplying an atmospheric gas to the film surface, and a post-reaction, disposed at a position spaced upward from the film surface of the film body of the tape-shaped wire wound around the rotating body A gas discharge pipe for discharging the gas from the inside of the rotating body, and a partition plate for partitioning between the flange portion and an end portion of the rotating body in the rotation axis direction is disposed in the furnace core tube. Take the configuration that is.

  ADVANTAGE OF THE INVENTION According to this invention, the exhaust efficiency of the gas after reaction can be improved and the tape-shaped oxide superconducting wire which has the superconducting characteristic which was uniform in the length direction and was excellent can be manufactured.

Schematic cross-sectional view showing the main components of a conventional batch heat treatment apparatus BRIEF DESCRIPTION OF THE DRAWINGS Schematic sectional drawing which shows the principal part structure of the heat processing apparatus of the tape-shaped oxide superconducting wire which concerns on one embodiment of this invention 2 is a cross-sectional view taken along the line AA in FIG. Schematic showing the rotating body of the heat treatment equipment Schematic showing the manufacturing method of YBCO superconducting wire by MOD method

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Outline of production of tape-shaped oxide superconducting wire by MOD method>
FIG. 5 shows an outline of a method for producing a tape-shaped oxide superconducting wire (YBCO superconducting wire) having a superconducting layer (YBCO superconducting layer) by the MOD method.

First, a composite in which a Gd ₂ Zr ₂ O ₇ intermediate layer was formed as a template by a IBAD method on a tape-shaped Ni alloy substrate (base material), and further a CeO ₂ intermediate layer was formed thereon by a sputtering method On the substrate, Y: TFA salt (trifluoroacetate salt), Ba-TFA salt and Cu-naphthenate salt in an organic solvent were applied in the coating step (a) with Y: Ba: Cu = 1: 1.5: 3. A mixed solution (superconducting raw material solution) 8 dissolved at a ratio is applied by a dip coating method. After the mixed solution 8 is applied, it is temporarily fired in the temporary firing step (b). This coating step (a) and pre-baking step (b) are repeated a predetermined number of times to form a film body as a superconducting precursor on the intermediate layer in the tape-shaped wire 20. Thereafter, in the main firing step (c), a heat treatment for crystallizing the superconducting precursor film in the tape-shaped wire 20, that is, a heat treatment for generating a YBCO superconductor is performed. Next, in step (d), an Ag stabilizing layer is applied on the generated YBCO superconductor by sputtering, and then in step (e), post-heat treatment is performed to manufacture a YBCO superconducting wire.

  The heat treatment apparatus according to the embodiment of the present invention is used for the crystallization heat treatment in the step (c), and heat-treats the precursor of the superconductor formed in the tape-shaped wire to generate a YBCO superconductor. . Note that the heat treatment apparatus may also be applied to the formation of the intermediate layer.

  The Ni alloy substrate may have a biaxial orientation or may be a substrate in which an intermediate layer having a biaxial orientation is formed on a metal substrate having no orientation. Further, the intermediate layer is formed of one layer or a plurality of layers. As an application method, it is possible to use an inkjet method, a spray method, etc. in addition to the dip coating method described above, but basically, this example is applicable as long as it is a process capable of continuously applying a mixed solution onto a composite substrate. Not constrained by. The film thickness to be applied at one time is 0.01 μm to 2.0 μm, preferably 0.1 μm to 1.0 μm.

  The superconducting raw material solution used here is a mixed solution in which a metal organic acid salt or an organic metal compound containing Y, Ba, and Cu in a predetermined molar ratio is dissolved in an organic solvent. The number of moles is such that a raw material solution having a Ba molar ratio within the range of a <2 when Y: Ba: Cu = 1: a: 3 is used. In this case, in order to obtain high Jc and Ic values, the Ba molar ratio in the raw material solution is preferably in the range of 1.0 ≦ a ≦ 1.8, and more preferably the Ba molar ratio in the raw material solution. Is in the range of 1.3 ≦ a ≦ 1.7. Thereby, the segregation of Ba can be suppressed, and as a result, the precipitation of Ba-based impurities at the grain boundaries is suppressed. Therefore, generation of cracks is suppressed and electrical connectivity between crystal grains is improved. By forming a superconducting film by the MOD method, a tape-like oxide having a high-speed uniform thick film and excellent superconducting characteristics. Superconductors can be easily manufactured. In addition, examples of the metal organic acid salt include octyl acid salt, naphthenic acid salt, neodecanoic acid salt, and trifluoroacetic acid salt of each element. Among these, one or more of these salts are uniformly used in an organic solvent. Any material that can be dissolved and applied onto the composite substrate can be used.

<Configuration of heat treatment equipment>
The heat treatment apparatus 100 shown in FIGS. 2 and 3 performs baking of a mixed solution (superconducting raw material solution 8 shown in FIG. 5A) applied as a film body of a superconducting precursor in the tape-shaped wire 20 in a batch type. It is. The heat treatment apparatus 100 includes a furnace core tube 110 having a cylindrical heat treatment space 111, a cylindrical rotating body 120, a gas supply pipe 130, a gas discharge pipe 140, and a partition plate (reflecting plate) 170.

  The furnace core tube 110 is formed in a hollow cylindrical shape. The furnace core tube 110 has a cylindrical furnace core main body (cylindrical main body) 114 and furnace core flanges 116 and 118 that respectively close openings at both ends of the furnace core main body 114. The furnace core flange portions 116 and 118 constitute both end faces of the furnace core tube 110.

  A heat treatment space 111 of the furnace core tube 110 is defined by a furnace core main body 114 and furnace core flanges 116 and 118. The heat treatment space 111 is configured by the furnace core body 114 and the furnace core flanges 116 and 118 so that a reduced-pressure atmosphere or vacuum in the furnace can be maintained.

  The furnace core tube 110 is provided with a heater 150 around it and heats the interior of the heat treatment space 111 by the heater 150.

  Inside the furnace core tube 110, a rotating body 120 is rotatably disposed around a furnace core axis C that is an axis of the furnace core tube 110. In the furnace core tube 110, at least one of the furnace core flange portions 116 and 118 is attached to the furnace core main body 114 so as to be detachable or openable / closable. Thereby, the rotating body 120 can be removed from the heat treatment space 111.

  The rotator 120 is disposed in the furnace core tube 110 at a substantially central position separated from both of the furnace core flange portions 116 and 118, that is, in a substantially central space of the heat treatment space 111 (referred to as the central space 111 a). .

  The rotating body 120 has a cylindrical body 121 around which a tape-like wire 20 on which a precursor is formed is wound on a surface 121a. The tape-shaped wire 20 is coated with a mixed solution (corresponding to the superconducting raw material solution 8 shown in FIG. 5A) and temporarily baked as described with reference to FIG. On top of this, a precursor of the YBCO superconducting product is formed.

The tape-shaped wire 20 is spirally wound around the surface 121a of the cylindrical body 121 (the surface of the rotating body 120) with the film surface of the precursor made of the mixed solution exposed.

  As shown in FIG. 4, a large number of through holes 124 are formed in the cylindrical body 121 of the rotating body 120. The diameter of the through hole 124 is preferably equal to the tape width of the tape-shaped wire 20. Moreover, the hole area ratio is 20 to 95%, and a hole area ratio in the range of 89 to 91% is particularly preferable. The rotating body 120 rotates at a constant speed during the heat treatment by a rotating mechanism (not shown). The rotating body 120 is made of a material that is resistant to high temperatures and hardly oxidizes, such as ceramics such as quartz glass and alumina, or metals such as Hastelloy and Inconel.

  The rotating body 120 is fixed to a gas discharge pipe 140 that is inserted into the cylindrical body 121 concentrically with the furnace core axis C that is the axis of the furnace core pipe 110. The gas discharge pipe 140 functions as a rotating shaft of the rotating body 120.

  Both ends of the cylindrical body 121 are closed by lid bodies 122 and 123 through which the gas discharge pipe 140 is inserted. The lid bodies 122 and 123 together with the cylindrical body 121 form an internal space sealed at a portion other than the gas discharge pipe 140 that is led out. A communication portion (not shown) that connects the internal space of the rotating body 120 and the inside of the gas exhaust pipe 140 is formed at a portion of the cylindrical gas exhaust pipe 140 located in the internal space.

  As shown in FIGS. 2 and 3, a plurality of gas supply pipes 130 are arranged in the central space 111 a in the heat treatment space 111 of the furnace core tube 110 so as to be separated from the surface 121 a of the cylindrical body 121. The plurality of gas supply pipes 130 are arranged in parallel to the furnace core axis C and are arranged symmetrically in a cross section perpendicular to the furnace core axis C. Here, four gas supply pipes 130 are disposed in the furnace core tube 110 symmetrically with respect to the furnace core axis C and parallel to each other. That is, in the furnace core tube 110, the plurality of gas supply tubes 130 are arranged at a pitch of 90 ° in the circumferential direction around the furnace core axis C.

  Each gas supply pipe 130 includes a large number of gas ejection holes 132 through which the atmospheric gas 6 is ejected to the rotating body 120.

  The gas ejection holes 132 in the gas supply pipe 130 are uniformly formed in the main body portion of the gas supply pipe 130 at regular intervals along the longitudinal direction. Each gas ejection hole 132 is a circular hole and ejects the atmospheric gas 6 uniformly. In order to uniformly eject the atmospheric gas and to further remove the fluorine gas, the flow rate when supplying the atmospheric gas, specifically, the flow rate at which the film surface of the film body wound around the rotating body contacts However, it is preferable that they are 200 m / s or more and 500 m / s or less. If it is less than 200 m / s, not only the atmosphere gas cannot be uniformly supplied to the superconducting precursor, but also the exhaust gas (HF gas) staying on the surface of the film body cannot be removed. Therefore, desired superconducting characteristics cannot be obtained. On the other hand, if it exceeds 500 m / s, the atmospheric gas can be uniformly ejected, but the crystallization reaction proceeds rapidly, so that it is difficult to control the epitaxial growth rate. Therefore, desired superconducting characteristics cannot be obtained.

  As shown in FIGS. 2 and 3, each gas supply pipe 130 has a gas ejection hole 132 formed on the surface 121 a of the cylindrical body 121 so as to supply the atmospheric gas 6 from the vertical direction to the surface 121 a of the cylindrical body 121. It arrange | positions so that it may be located in the position spaced apart upwards.

  The gas supply pipe 130 is provided in the furnace core pipe 110 such that the separation distance between the gas ejection hole 132 and the surface 121a of the rotating body 120 is 10 mm to 150 mm. A preferable range of the separation distance is 50 mm to 100 mm. Within the above range, the atmospheric gas can be uniformly ejected to the superconducting precursor, so that the fluorine gas can be further removed. If it is less than the above range, the atmospheric gas ejected to only a part of the film surface of the film body of the tape-shaped wire 20 wound around the rotating body 120 is not in contact, so that it is uniform in the longitudinal direction of the superconducting wire. Superconducting properties cannot be obtained. When the above range is exceeded, not only the gas flow rate increases and the production cost improves, but also the crystallization reaction proceeds rapidly, making it difficult to control the epitaxial growth rate. Therefore, desired superconducting characteristics cannot be obtained.

  Therefore, in order to obtain a long tape-shaped wire superconducting layer having a thick film of 1.5 μm or more, it is necessary to eject atmospheric gas to the superconducting precursor at an appropriate gas flow rate at a separation distance in the above range. In this way, it is possible to obtain a superconducting wire having the characteristics that the film thickness critical current density (Jc) is 2.0 or more and the critical current value (Ic) is 300 A or more.

  The gas supply pipe 130 vertically supplies the atmospheric gas 6 from a position spaced upward from the film surface of the precursor in the tape-shaped wire 20 wound around the surface 121 a of the cylindrical body 121. The diameter of the gas ejection hole 132 needs to be designed so that the gas pressure and the gas flow rate are uniform.

  The atmosphere gas 6 is supplied from an atmosphere gas supply device (not shown) disposed outside the furnace core tube 110 via a connection tube (not shown) connected to the gas supply pipe 130. Incidentally, in the gas supply device, the atmospheric gas 6 made of an inert gas, oxygen gas, water vapor or the like is generated, and the atmospheric gas 6 is ejected from the gas supply pipe 130. This atmospheric gas 6 is a gas (exhaust gas) after reaction with a superconducting precursor film containing fluorine (F) obtained by pre-baking a base material coated with a mixed solution containing trifluoroacetate and the like. It becomes HF gas.

  Here, the axial length of the gas supply pipe 130 is substantially the same as the axial length of the rotating body 120 here, but is preferably longer than the length of the rotating body 120. That is, if the length between the gas ejection holes 132 located at both ends of the gas supply pipe 130 is longer than the length of the rotating body 120, the total length of the tape-shaped wire 20 wound around the cylindrical rotating body 120 is increased. It is possible to carry out a uniform reaction more effectively. The gas supply pipe 130 is made of a material that can withstand high temperatures and hardly oxidizes, such as ceramics such as quartz glass and alumina, or metals such as Hastelloy and Inconel.

  The gas discharge pipes 140 are inserted through the centers of the furnace core flange portions 116 and 118 at both ends extending outward from the lid bodies 122 and 123. Thereby, the gas exhaust pipe 140 is rotatably supported by the furnace core flange portions 116 and 118 at both end portions 141 and 142. Further, both ends of the gas discharge pipe 140 are disposed outside the furnace core pipe 110. Thereby, the inside of the rotator 120 is in communication with the outside of the furnace core tube 110 via the gas discharge tube 140.

  The gas discharge pipe 140 is continuous with the internal space of the cylindrical body 121 and is formed as a part of the rotating shaft of the cylindrical body 121. Here, it is inserted into the inside of the cylindrical body 121, and is formed on the rotating shaft (corresponding to the furnace core axis C) of the cylindrical body 121 as the shaft portion of the cylindrical body 121, that is, the rotating shaft of the rotating body 120. In the gas exhaust pipe 140, a plurality of through holes (not shown) are formed on the outer periphery of the central portion disposed inside the cylindrical body 121. The inside of the cylindrical body 121, that is, the inside of the rotating body 120 and the inside of the gas discharge pipe 140 are in communication with each other through these through holes. Here, the gas exhaust pipe 140 closes between the opening on the one end portion 141 side and the central portion arranged inside the cylindrical body 121, and only the opening on the other end side 142 is continuous with the inside of the cylindrical body 121. Thus, the HF gas is discharged from the opening on the other end 142 side. Note that the gas discharge pipe 140 may be configured to discharge HF gas from the openings on both ends 141 and 142 side by causing the one end 141 to be continuous with the portion inside the cylindrical body 121. Moreover, the gas exhaust pipe 140 may be provided as a separate body from the rotating shaft.

  Here, the gas discharge pipe 140 discharges the gas after reaction (here, HF gas) through a portion that is inserted through the lid 123 from the other end 142 side and led out of the furnace core pipe 110. Yes. As described above, the gas exhaust pipe 140 exhausts the gas inside the cylindrical body 121 (the atmosphere gas 6 and the gas after the reaction) to the outside of the furnace core pipe 110. Here, the gas discharge pipe 140 is formed with a cylindrical body 121. The gas exhaust pipe 140 is made of a material that can withstand high temperatures and hardly oxidizes, such as ceramics such as quartz glass and alumina, or metals such as Hastelloy and Inconel.

  Thus, in the heat treatment space 111 of the furnace core tube 110, the gas supply pipe 130 and the rotating body 120 that discharges HF gas to the outside of the furnace core pipe 110 via the gas discharge pipe 140 are arranged in the central space 111a. ing. A partition plate 170 is disposed in the heat treatment space 111 in the furnace core tube 110 so as to partition the central space 111a.

  The partition plate 170 partitions the space between the core flange portions 116 and 118 and the end portions (cover bodies 122 and 123) in the rotation axis direction of the rotating body 120 on a plane orthogonal to the furnace core axis C. Here, the partition plate 170 is disposed in a space between the rotating body 120 and each of the furnace core flange portions 116 and 118 of the furnace core tube 110, that is, a so-called surplus space 111b (corresponding to a conventional surplus space R). Has been. Specifically, the partition plate 170 partitions the central space 111a in which the rotating body 120 is disposed and the surplus space 111b.

  Here, a plurality of partition plates 170 are arranged in a space (excess space 111b) between the core flange portion 116 and one end portion (lid body 122) in the axial direction of the rotating body 120. A plurality of partition plates 170 are arranged in a space (excess space 111b) between the furnace core flange portion 118 and the other end portion (lid body 123) in the axial direction of the rotating body 120.

  The partition plates 170-1 disposed to face both end portions of the rotating body 120 in the axial direction (the positions of the outer surfaces of the lid bodies 122 and 123) are respectively end portions of the rotating body 120 (the outer surfaces of the lid bodies 122 and 123). It is desirable to arrange it at a position as close as possible.

  Here, the position of the partition plate 170-1 is positioned closer to the rotating body 120 than both ends of the heater 150 longer than the rotating body 120, and faces the end of the gas supply pipe 130 in close proximity.

  The partition plate 170 reflects the post-reaction gas generated in the central space 111a in which the gas supply pipe 130 and the rotator 120 are disposed in the heat treatment space 111, that is, the HF gas 6c, and the HF gas 6c becomes the surplus space 111b. To prevent inflow. That is, the partition plate 170 is configured such that the HF gas generated in the central space 111a is between the end of the rotating body 120 (the position of the outer surface of the lids 122 and 123) and the core flanges 116 and 118 in the furnace core tube 110. To flow into the space. In addition, the partition plate 170 can prevent the atmospheric gas 6 that is a gas before the reaction from flowing into the surplus space 111b, and can react with the superconducting layer more effectively in the central space 111a. Moreover, it is preferable that a plurality of partition plates 170 are arranged in the surplus space 111b. By arranging a plurality of sheets, it is possible to further prevent the HF gas 6c from flowing into the surplus space 111b, so that desired superconducting characteristics can be obtained.

  The partition plate 170 is inserted with the rotation shaft of the rotating body 120, that is, the gas discharge pipe 140.

  Here, these partition plates 170 are fixed to the gas exhaust pipe 140.

  Specifically, in the present embodiment, the plurality of partition plates 170 are redundant spaces between the core flange portions 116 and 118 of the furnace core tube 110 and the rotating body 120 in the furnace core tube 110. Each is fixed to a portion of the gas discharge pipe 140 located at 111b. Thereby, the partition plate 170 is rotatable together with the rotating body 120 in the furnace core tube 110. Further, when removing the rotating body 120 from the furnace core tube 110, it can be removed together with the gas exhaust pipe 140 and the rotating body 120. Thereby, winding of the tape-shaped wire 20 around the rotating body 120 or removal of the tape-shaped wire 20 from the rotating body 120 can be easily performed. Similarly to the gas supply pipe 130 and the gas exhaust pipe 140, the partition plate 170 is made of a material that can withstand high temperatures and hardly oxidizes, such as quartz glass, ceramics such as alumina, or metals such as Hastelloy and Inconel. The The partition plates 170 are fixed to the gas exhaust pipe 140. However, the configuration is not limited thereto, and the partition plate 170 may be fixed to the surplus space 111b in the furnace core pipe 110. Further, the partition plate 170 is provided between the furnace core flange portion 116 and the end portion (cover body 122) in the rotation axis direction of the rotating body 120, and the end portion in the rotation axis direction of the furnace core flange portion 118 and the rotation body 120. Any configuration may be used as long as it partitions at least one of the (lid 123).

  In the heat treatment apparatus 100 described above, the cylindrical rotating body 120 around which the tape-shaped wire 20 is wound is rotated at a constant speed. In addition, the atmosphere gas supplied from a gas supply device (not shown) is heat-treated in the heat treatment space 111 held in the heating atmosphere by the heater 150 through the numerous gas ejection holes 132 of the gas supply pipe 130. It sprays evenly with respect to the film surface of the wire 20. The sprayed atmospheric gas 6 reacts with the film surface to become HF gas, and enters the inside of the cylindrical body 121 through the numerous through holes 124 of the cylindrical body 121 in the rotating body 120.

  At this time, since a plurality of partition plates 170 are arranged in the furnace core tube 110, the furnace core flange part 116 of the furnace core tube 110 from the end portions (cover bodies 122, 123) of the rotating body 120 (cylindrical body 121). , 118 does not flow into the exhaust gas (specifically, HF gas). As a result, the exhaust gas does not stay in the surplus space 111b and enters the cylindrical body 121 as indicated by the arrow 6c in FIG. Thereafter, the exhaust gas inside the cylindrical body 121 is discharged out of the furnace via the gas discharge pipe 140 connected on the other end side of the cylindrical body 121.

  Thus, when supplying the atmospheric gas 6 from a position spaced upward from the film surface of the film body of the tape-shaped wire 20 wound around the rotating body 120 in the furnace core tube 110, the partition plate 170 In the partitioned central space 111a, the gas is supplied from the gas ejection holes 132 (see FIGS. 2 to 4) of the gas supply pipe 130 disposed over the entire length of the rotating body 120. Thereby, the atmospheric gas 6 can be suitably supplied to the whole tape-shaped wire 20 wound around the surface 121a of the cylindrical body 121 in the rotating body 120. As a result, it is possible to improve the exhaust efficiency of HF gas, which is a gas after reaction, and to produce a tape-shaped oxide superconducting wire that is uniform in the length direction and has excellent superconducting characteristics.

In the heat treatment apparatus 100, the gas supply pipes 130 are formed with a length of 2 m and an inner diameter of 20 mmφ, and the gas injection holes 132 are formed in the gas supply pipes 130 at a pitch of 30 mm in the longitudinal direction of the gas supply pipes 130. (Nozzle diameter) was formed at 1.0 mmφ. At this time, the pressure in the furnace core tube 110, that is, the pressure in the heat treatment space 111 was set to 50 to 200 torr, and the gas flow rate was set to 250 to 1000 L / min (converted value at normal temperature and normal pressure). The flow rate of the atmospheric gas ejected from the gas ejection holes 132 in the heat treatment apparatus 100 and supplied to the surface 121a of the rotating body 120 is 300 m / s, and the gas ejection holes 132 and the rotation disposed in the heat treatment apparatus 100 are used. The separation distance from the surface 121a of the body 120 was 80 mm. The film body of the tape-shaped wire 20 wound around the rotating body 120 is formed by forming a Gd ₂ Zr ₂ O ₇ intermediate layer as a template on the tape-shaped Ni alloy substrate (base material) by the IBAD method. Further, a Y-TFA salt (trifluoroacetate salt), a Ba-TFA salt and a Cu-naphthenate salt are added in an organic solvent in a coating process on a composite substrate having a CeO ₂ intermediate layer formed thereon by sputtering. A film body obtained by applying a mixed solution (superconducting raw material solution) dissolved in a ratio of Y: Ba: Cu = 1: 1.5: 3 by dip coating and then pre-baking in a pre-baking step. The film body was heat-treated by a main baking step at a furnace temperature of 750 ° C. to obtain a 1.5 μm superconducting layer. A configuration in which three partition plates are provided on both ends of the rotating body 120 is referred to as Example 1, and a configuration in which no partition plate is provided is referred to as Comparative Example 1.

  The characteristics of the superconducting wire made by the heat treatment apparatus of Example 1 were Jc2.2 and Ic330A, and the characteristics of the superconducting wire made by Comparative Example 1 were Jc1.5 and Ic225A.

  The superconducting wire produced in Example 1 was superior in superconducting characteristics as compared with the superconducting wire produced in Comparative Example 1.

  As described above, the method for producing a tape-shaped oxide superconducting wire using the heat treatment apparatus of the example is more HF gas (hydrogen fluoride gas) than the method for producing a tape-shaped oxide superconducting wire using the heat treatment apparatus of the comparative example. The tape-shaped oxide superconducting wire having excellent superconducting characteristics that is uniform in the length direction can be manufactured.

  Furthermore, since firing is performed in a batch mode, the atmosphere in the furnace can be controlled more easily than in the case of firing in a reel-to-reel mode, so a stable superconducting layer can be formed, and the oxide can be formed in a short time. Superconducting wire can be manufactured.

  The furnace core tube 110 includes a cylindrical furnace core body 114 and furnace core flanges 116 and 118 that close the openings at both ends of the furnace core body 114, respectively. However, the present invention is not limited to this. Any configuration may be used as long as the internal rotating body 120 can be freely attached and detached and the winding and detaching operations of the tape-shaped wire 20 can be easily performed. In the hollow cylindrical furnace core tube 110, the furnace core body 114 may be divided into semicircular shapes.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  The tape-shaped oxide superconducting wire manufacturing method and heat treatment apparatus according to the present invention improve the gas exhaust efficiency after the reaction, and form a tape-shaped oxide superconducting wire having excellent superconducting characteristics that is uniform in the length direction. It is widely applicable when doing.

6, 6a, 6c, atmosphere gas 100 heat treatment apparatus 110 furnace core tube 111 heat treatment space 111b surplus space 114 furnace core main body (tubular main body)
116, 118 Furnace core flange (flange)
120 Rotating Body 121 Cylindrical Body 121a Surface 122, 123 Lid (End of Rotating Body)
130 Gas supply pipe 132 Gas ejection hole 140 Gas exhaust pipe 170 Partition plate 20 Tape-like wire rod

Claims (9)

A furnace core tube in which both ends of a cylindrical main body portion provided with a heat treatment space are closed with flange portions;
Inside the heat treatment space, a tape-shaped wire rod is disposed that is rotatable with respect to the furnace core axis of the furnace core tube, and a film body of a superconducting precursor is formed on a surface on which a large number of through holes are formed. A cylindrical rotating body to be wound;
A gas supply pipe for supplying atmospheric gas to the tape-shaped wire;
A gas discharge pipe for discharging atmospheric gas from the inside of the rotating body to the outside of the furnace core pipe;
A method of manufacturing an oxide superconducting wire that supplies the atmospheric gas from a position spaced upward with respect to the film surface of the film body of the tape-shaped wire wound around the rotating body using a heat treatment apparatus comprising: In
The atmosphere gas is supplied to the film surface of the film body of the tape-shaped wire wound around the rotating body while partitioning between the flange portion and the end of the rotating body in the rotation axis direction with a partition plate. ,
Tape-like oxide superconducting wire manufacturing method.   The method for producing a tape-shaped oxide superconducting wire according to claim 1, wherein a plurality of the partition plates are arranged. The superconducting precursor film body forms an intermediate layer on the substrate, and after applying a mixed solution prepared by dissolving a metal organic acid salt or organic metal compound containing a metal element in an organic solvent on the intermediate layer, pre-baking A film body formed by
The manufacturing method of the tape-shaped oxide superconducting wire of Claim 1 or 2. The metal organic acid salt containing a metal element in the mixed solution consists of one or more selected from octylate, naphthenate, neodecanoate or trifluoride acetate.
A method for producing a tape-shaped oxide superconducting wire according to claim 3. The oxide superconducting wire, an intermediate layer formed on the base plate, said intermediate layer REBa _y Cu ₃ O _z superconducting layer formed on a stabilizing layer formed on the superconducting layer, 2. The method of manufacturing a tape-shaped oxide superconducting wire according to claim 1, wherein the RE is made of one or more elements selected from Y, Nd, Sm, Eu, Gd, and Ho. A furnace core tube in which both ends of a cylindrical main body portion provided with a heat treatment space are closed with flange portions;
Inside the heat treatment space, a tape-like wire rod having a superconducting precursor film formed on a surface on which a large number of through-holes are arranged and is rotatable with respect to the core axis of the furnace core tube is wound. A cylindrical rotating body to be rotated;
A gas supply pipe that is arranged at a position spaced upward from the film surface of the film body of the tape-shaped wire wound around the rotating body, and supplies an atmospheric gas to the film surface;
A gas discharge pipe for discharging the gas after the reaction from the inside of the rotating body;
With
In the furnace core tube, a partition plate that partitions between the flange portion and an end portion of the rotating body in the rotation axis direction is disposed.
Heat treatment equipment for tape-shaped oxide superconducting wire.   The heat processing apparatus for a tape-shaped oxide superconducting wire according to claim 6, wherein a plurality of the partition plates are arranged. Wherein the specification Setsuban, together with the shaft portion is inserted in the rotating body, and is fixed to the shaft portion,
A heat treatment apparatus for a tape-shaped oxide superconducting wire according to claim 6 or 7. The specification Setsuban is the end of the rotating shaft direction of the rotating body, are arranged close to face without contact,
The heat processing apparatus of the tape-shaped oxide superconducting wire according to claim 6.

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