JP2869858B2 - Manufacturing method of oxide superconducting wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an oxide superconducting wire by a plasma spraying method.

[0002]

2. Description of the Related Art In 1986, an oxide superconductor having a superconducting transition temperature (Tc) exceeding 30 K (La, Sr) ₂ CuO _4.
Has been discovered and research and development in this area has been actively conducted since then. As a result, various oxide superconductors have now become known. Especially Y system, Bi system, T
Since the transition temperature Tc is higher than the liquid nitrogen temperature,
If these are used, there is a possibility that a superconducting system using liquid nitrogen cooling can be configured.

Since liquid nitrogen has a large specific heat and is inexpensive as compared with liquid helium which has been conventionally used as a refrigerant in a superconducting system, if it can be used, the system can be simplified, downsized, and reduced in maintenance cost. And so on. For that purpose, research on the practical application of Y, Bi and Tl systems has been conducted in various fields.

Since the superconductor has a DC electric resistance of 0 in a superconducting state, the energy loss caused by the electric resistance can be extremely reduced when used as a power transmission body. Also, if a coil is made using a superconducting wire, it may be a very strong electromagnet. Research is also being carried out on making oxide superconductors into wires for such applications.

[0005] There are various methods for producing a long wire rod of an oxide superconductor. One of them is a method using a plasma spraying method. The plasma spraying method is a type of film forming method in which a powdery raw material is charged into a high-temperature, high-speed plasma frame and the molten raw material is sprayed onto a base material to form a film. In this method, the film forming speed is 100 cm ²
Since it is as large as about 100 μm / min, it is considered suitable for mass production. The following is known as a method for manufacturing an oxide superconducting wire using this method. That is, a tape-shaped substrate is prepared, and an oxide superconductor or its raw material is sprayed thereon. This is a manufacturing method in which the resulting tape-shaped oxide film is subjected to rolling, heat treatment, or the like, as necessary, to obtain an oxide superconducting wire.

[0006]

However, in the above-mentioned manufacturing method, there is a limit to the length of the manufactured oxide superconducting wire. When performing thermal spraying, it is possible to form a film over a wide range by moving a plasma torch that blows out the raw material powder in a direction including a component perpendicular to the blowing direction. Conventionally, it has been difficult to continuously produce such a wire rod.

An object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing an oxide superconducting wire suitable for manufacturing a long wire.

Another object of the present invention is to provide an oxide superconducting coil, an oxide superconducting cable or an oxide superconducting current lead manufactured by the above-mentioned manufacturing method.

[0009]

In order to achieve the above object, the present invention is a method for continuously producing a long oxide superconducting wire using a plasma spraying method. A part of a long tape serving as a base of the wire is wound around the grooved cylindrical drum along the groove, and the tape is pulled from one end while the cylindrical drum is fixed in a non-rotating manner. Feeding from the end side, while moving this tape so as to slide in the groove, the material to be the oxide superconductor is wound from the plasma torch onto the tape wound around the cylindrical drum at a fixed position in the tape traveling direction. It is characterized by spraying.

When the distance from the beginning to the end of the spiral groove is larger than the diameter of the plasma frame generated from the plasma torch, the plasma torch is preferably reciprocated in the axial direction of the cylindrical drum. Further, it is preferable to provide a plate having holes corresponding to the pitch of the spiral groove between the plasma torch and the cylindrical drum. Further, it is preferable that a series of rollers is rotatably provided at the bottom of the spiral groove.

The oxide superconductor sprayed in a tape shape by the above method has any of the following chemical formulas (1) to (5). The main components of the tape material are Ag, Au, Cu,
SrTiO ₃ , MgO, Al ₂ O ₃ and yttrium-stabilized zirconia.

[0012]

Embedded image

Another object of the present invention is achieved by an oxide superconducting coil, an oxide superconducting cable, or an oxide superconducting current lead manufactured by the above-described method.

[0014]

In the method for producing an oxide superconducting wire of the present invention, the spiral groove is provided on the outer peripheral surface of the cylindrical drum in order to prevent tapes from overlapping on the drum. Providing a series of rollers at the bottom of the spiral groove reduces the frictional force at the contact surface between the tape and the drum when the tape slides in the groove, and allows the tape to move easily in its longitudinal direction. That's why.

[0015] Further, providing a perforated plate having holes corresponding to the pitch of the spiral groove between the plasma torch and the cylindrical drum is because the molten powder injected from the plasma torch adheres only to the tape, This is to prevent the other parts, for example, the outer peripheral surface of the drum between the grooves from adhering to the rollers and the like.

Further, by using a perforated plate, it is possible to prevent excessive spraying on the substrate and to make the thickness of the oxide film uniform.

According to such a method, each part after the first spiral of the tape wound around the cylindrical drum is sprayed by the plasma torch as many times as the number of turns of the tape. It is possible to continuously manufacture a long oxide superconducting wire on which a thermal sprayed film is formed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. FIG. 1 is a structural view showing an embodiment of an apparatus embodying a method for manufacturing an oxide superconducting wire according to the present invention, and FIGS. 2 and 3 are peripheral portions of a drum provided with a guide groove around which a tape substrate for a wire is wound. FIG. 4 is a cross-sectional view of the vicinity of a plasma frame for spraying an oxide serving as a superconducting material and a tape substrate for a wire.

The apparatus for manufacturing an oxide superconducting wire of this embodiment is as follows.
Generally, a cylindrical drum 10 for spirally winding a tape-shaped substrate 40, and a plasma frame 22 for spraying an oxide serving as a superconducting wire on the wound tape-shaped substrate 40
A tape feed reel 60 that feeds the tape-shaped substrate 40 to the cylindrical drum 10, and a winding reel 50 that pulls out the sprayed tape-shaped substrate 40 from the cylindrical drum 10 and winds it. Have been.

The cylindrical drum 10 has an outer diameter of 30 cm and is fixed without rotation. The cylindrical drum 10 has a drum outer peripheral surface 11.
A silver tape-shaped substrate 40 having a width of 5 mm and a thickness of 0.2 mm is spirally wound 10 turns. At this time, the tape-shaped substrate 40 is wound along the inner surface of the groove 12 having a width of 6 mm spirally formed on the outer peripheral surface 11 of the drum. The length of the portion of the tape-shaped substrate 40 that is in contact with the drum outer peripheral surface 11 is about 9.4 m. As shown in FIG. 2, a roller 14 is provided at the bottom of a groove 12 provided on the outer peripheral surface 11 of the drum.
When the tape-shaped substrate 40 moves in the longitudinal direction of the groove 12, the tape-shaped substrate 40 rotates in contact with the tape-shaped substrate 40. Instead of the rollers 14, a rotating ball 15 may be attached as shown in FIG. The start end of the tape-shaped substrate 40 is wound around a tape take-up reel 50, while the end end is wound around a tape feed reel 60.

The plasma torch 20 is provided on the outer peripheral surface 11 of the drum.
The torch axis is oriented in a direction orthogonal to the central axis of the cylindrical drum 10 near the center axis of the cylindrical drum 10. As a result, the center axis 24 of the plasma frame 22 ejected from the plasma torch 20 is perpendicular to the drum outer peripheral surface 11. Further, between the cylindrical drum 10 and the plasma torch 20, the drum outer peripheral surface 1 is provided.
A perforated plate 30 having holes 31 formed in a row in the axial direction of the cylindrical drum 10 is installed at the same pitch as the grooves 12 provided in 1. The hole 31 has a width approximately equal to the groove width.

Next, a process of spraying an oxide serving as a superconductor onto the tape-shaped substrate 40 wound around the cylindrical drum 10 will be described. By rotating the tape take-up reel 50 and the tape feed reel 60, the tape-shaped substrate 40 is rotated.
Is moved in its longitudinal direction. At this time, the cylindrical drum 1
Since 0 is fixed in a non-rotating manner, the tape-shaped substrate 40 moves so as to come into contact with the rollers 14 in the spirally formed grooves 12 on the drum outer peripheral surface 11 so as to slide. Then, the oxide superconductor or its raw material is blown out from the plasma torch 20 reciprocating in the direction of the arrow in FIG. 1, that is, in the axial direction of the cylindrical drum 10, and adheres onto the tape-shaped substrate 40 to form the oxide film 41. I do. At this time, a part of the plasma frame 22 hits the perforated plate 30 before reaching the drum outer peripheral surface 11, and the other part of the plasma frame 23
Passes through the hole 31 and hits the tape-shaped substrate 40. Assuming that the tape feeding speed is 1 m / min, a certain point of the tape-shaped substrate 40 is wound around the drum outer peripheral surface 11 and sprayed, and the thickness of 50 μm is increased for 9.4 minutes until the tape substrate 40 is separated from the drum outer peripheral surface 11 again. Oxide layer 41 is formed. Thereafter, if necessary, rolling, heat treatment, and the like are also applied to obtain an oxide superconducting wire. Further, a coil, a cable, a current lead and the like are manufactured by using the wire thus obtained.

In this embodiment, the tape-shaped substrate 40 is continuously moved in the longitudinal direction, and plasma spraying is performed on the way. This makes it possible to continuously manufacture a long oxide superconducting wire. The tape-shaped substrate 40
Is spirally wound around the outer peripheral surface 11 of the drum.
Oxide superconductor blown from 0 or its raw material is
Sprayed onto multiple rows of substrates at once. As a result, the adhesion efficiency of the oxide superconductor blown out from the plasma torch 20 or the raw material thereof onto the tape-shaped substrate 40 is increased as compared with the case where the plasma frame hits only one row of substrates at a time.

The groove 12 provided on the outer peripheral surface 11 of the drum can prevent the tape-shaped substrate 40 from overlapping on the cylindrical drum 10, and by making the width of the groove 12 wider than the width of the tape-shaped substrate 40. The contact between the side wall 13 of the groove 12 and the tape-shaped substrate 40 is reduced, and the tape-shaped substrate 40 can be easily moved in the longitudinal direction.

The rollers 14 (or balls 15) provided in the grooves 12 of the drum outer peripheral surface 11 reduce the frictional force at the contact surface between the tape-shaped substrate 40 and the cylindrical drum 10, and the tape-shaped substrate 40 It can be easily moved in the longitudinal direction.

The plasma torch 20 and the cylindrical drum 1
By providing the perforated plate 30 during the period 0, the powder in a molten state sprayed from the plasma torch 20 adheres to the tape-shaped substrate 40 through the holes 31 and is not attached to other portions, for example, the grooves 12 and It can be made hard to adhere to the portion of the drum outer peripheral surface 11 between the rollers 12 and the rollers 14 and the like. As a result, there is an effect of preventing the tape-shaped substrate 40 from being difficult to move in the longitudinal direction. Furthermore, by using a perforated plate, there is an effect that excessive thermal spraying is prevented and the thickness of the oxide film is made uniform.

FIG. 4 is a cross-sectional view of the drum outer peripheral surface 11 located immediately below the plasma frame 22. The groove 12 as shown in FIGS. 2 and 3 is not provided in the drum outer peripheral surface 11 in this portion. This is because the molten powder is more likely to adhere to the side wall 13 in the groove 12 immediately below the plasma frame 22 than at other positions. If the groove 12 is also provided at this position, the molten powder may adhere to the side wall 13 and the tape-shaped substrate 40 may not be easily moved. Therefore, it is desirable not to provide the groove 12 at a position directly below the plasma frame 22.

In the present embodiment, the tape-shaped substrate 40 is made of silver.
u, Cu, SrTiO ₃ , MgO, Al ₂ O ₃ or YS
Any one can be selected from Z (yttrium-stabilized zirconia). Also, the outer diameter of the cylindrical drum 10,
The width and thickness of the tape-shaped substrate 40 and the number of windings on the cylindrical drum 10 can also be arbitrarily selected as long as the performance of the wire rod and the manufacturing operation are not hindered. The width of the groove 12 may be larger than the width of the tape-like substrate 40.
Since the tape-shaped substrate 40 may meander in the inside, the characteristics of the superconducting wire to be manufactured may be reduced. Therefore, it is better not to make the superconducting wire extremely wide. In addition, since the rollers 14 are provided so that the tape-shaped substrate 40 can be easily moved in the longitudinal direction, it is most desirable that the body length of the rollers 14 matches the width direction of the tape-shaped substrate 40.

As for the perforated plate 30 provided between the plasma torch 20 and the cylindrical drum 40, the material of the plate 30 is heat-resistant, oxidation-resistant, and mechanical which does not damage even when hit by the high-temperature and high-speed plasma frame 22. Strength is required. Heat-resistant stainless steel and copper are suitable. Also,
Regarding the outer dimensions of the perforated plate 30, the thickness of the perforated plate 30 is required to be so large that the perforated plate 30 is not deformed so as not to be operable even when hit by the plasma frame 22.
Of the plasma frame 22 in the traveling direction) must have a length such that the plasma frame 22 does not exceed the outer edge. Further, regarding the shape and size of the hole 31, it is minimum that the powder in a molten state injected from the plasma torch 20 adheres only to the tape-shaped substrate 40 wound around the drum outer peripheral surface 11. Required. In order to satisfy this condition, the length of the hole 31 in the direction corresponding to the width direction of the tape-shaped substrate 40 (the width of the hole) needs to be shorter than the width of the tape-shaped substrate 40. However, since the width of the hole corresponds to the width of the oxide layer 41 to be formed, it is not preferable that the width is extremely narrower than the width of the tape-shaped substrate 40. On the other hand, hole 31
The length (length of the hole) in the direction corresponding to the longitudinal direction of the tape-shaped substrate 40 is not particularly limited. However, from the viewpoint of using the sprayed oxide superconductor or its raw material without waste, it is desirable that the length of the hole 31 is longer than the plasma diameter at the cut surface of the plasma frame 22 by the perforated plate 30. Regarding the installation position of the perforated plate 30,
It is sufficient if it is between the plasma torch 20 and the cylindrical drum 10, but most preferably, it is installed at a position as close to the cylindrical drum 10 as possible without contacting the oxide film 41 adhered on the tape-shaped substrate 40. It is desirable. This makes it difficult for the plasma frame 23 that has passed through the hole 31 to hit a portion other than the tape-shaped substrate 40. (At this time, the projected figure of the shape of the hole 31 in a plane perpendicular to the direction of travel of the plasma frame 22 fits within the width of the tape-shaped substrate 40 on the outer peripheral surface of the drum.) It can be selected from the substances shown in chemical formulas (1) to (5).

[0030]

As described in detail above, according to the present invention,
A method of manufacturing an oxide superconducting wire, winding a part of a long tape around a spiral groove formed on an outer peripheral surface of a cylindrical drum,
With the cylindrical drum fixed non-rotating, this tape is slidably moved in the groove, and a material to be an oxide superconductor is sprayed onto the tape from a plasma torch at a fixed position in the tape traveling direction. The method makes it possible to continuously manufacture a long oxide superconducting wire having a sprayed film having an appropriate thickness.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus for manufacturing an oxide superconducting wire.

FIG. 2 is a partial cross-sectional view of a drum outer peripheral surface provided with a guide groove around which a wire tape substrate is wound.

FIG. 3 is a partial cross-sectional view of an outer peripheral surface of a drum provided with another guide groove around which a wire tape substrate is wound.

FIG. 4 is a cross-sectional view around a plasma frame for spraying an oxide and a tape substrate for a wire rod.

[Explanation of symbols]

 Reference Signs List 10 cylindrical drum 11 outer peripheral surface of cylindrical drum 12 groove 13 groove side wall 14 roller 15 ball 20 plasma torch 21 tip of plasma torch 22 plasma frame 23 plasma frame having passed through hole 24 center axis of plasma frame 30 aperture plate 31 hole 40 tape Substrate 41 Oxide layer 50 Tape take-up reel 60 Tape feed reel

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01B 12/06 ZAA H01B 12/06 ZAA (72) Inventor Kazuhisa Higashiyama 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Hitachi, Ltd. (56) References JP-A-63-269420 (JP, A) JP-A-56-38425 (JP, A) JP-A-1-61619 (JP, A) JP-A-2-291611 (JP) JP-A-6-318411 (JP, A) JP-A-64-82407 (JP, A) JP-A-4-17217 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB Name) H01B 13/00 565 C01G 1/00 C01G 3/00 ZAA C01G 15/00 ZAA C01G 29/00 ZAA H01B 12/06 ZAA

Claims (11)

(57) [Claims] 1. A method for continuously producing a long oxide superconducting wire using a plasma spraying method, comprising: a cylindrical drum provided with a spiral groove on an outer peripheral surface; A part of a long tape serving as a base portion is wound, the cylindrical drum is fixed in a non-rotating manner, and the tape is pulled from one end and fed from the other end so that the tape slides in the groove. While moving, a material to be an oxide superconductor is sprayed from a plasma torch on a tape wound around the cylindrical drum at a fixed position in the tape advancing direction, and the cylindrical drum is a portion where the plasma torch faces. A method for producing an oxide superconducting wire having a smooth surface without the spiral groove. 2. The method according to claim 1, wherein the plasma torch is reciprocated in an axial direction of the cylindrical drum. 3. A perforated plate having a hole of substantially the same width at the same pitch as the spiral groove between the plasma torch and the cylindrical drum is opposed to a position where the hole passes through the tape.
The method for producing an oxide superconducting wire according to claim 1, wherein: 4. A spiral roller according to claim 1, wherein a series of rollers are rotatably provided at the bottom of said spiral groove.
3. The method for producing an oxide superconducting wire according to item 1. 5. The method for producing an oxide superconducting wire according to claim 1, wherein the oxide superconductor is represented by the following formula. Embedded image 6. The method for producing an oxide superconducting wire according to claim 1, wherein the oxide superconductor is represented by the following formula. Embedded image 7. The method for producing an oxide superconducting wire according to claim 1, wherein the oxide superconductor is represented by the following formula. Embedded image 8. The method for producing an oxide superconducting wire according to claim 1, wherein the oxide superconductor is represented by the following formula. Embedded image 9. The method for producing an oxide superconducting wire according to claim 1, wherein the oxide superconductor is represented by the following formula. Embedded image 10. The main component of the tape material is Ag,
_{3. The method according} to claim 1, wherein the material is Au, Cu, SrTiO ₃ , MgO, Al ₂ O ₃ or yttrium-stabilized zirconia.
5. The method for producing an oxide superconducting wire according to any one of items 3 and 4. 11. An oxide superconducting coil, an oxide superconducting cable or an oxide superconducting current lead manufactured by the method for producing an oxide superconducting wire according to any one of claims 1, 2, 3 and 4.