JPS59201319A - Method of producing multicore superconductive wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to IP of superconducting wire! ! The present invention relates to a manufacturing method, particularly a method for manufacturing a multi-core superconducting wire that enables stable IC extrusion during hydrostatic extrusion.

[Technical weight of the invention] Conventionally, a method using C1 hydrostatic extrusion T is known as a method for efficiently manufacturing a superconducting wire having a multicore structure.

In this method, for example, the CL shown in FIG.
A composite wire 3 in which an alloy superconducting wire 2 such as Nb-Ti or Nb-7r is pushed into a stabilizing material 1, or a composite wire 3 in the same figure (b'
) Nb5 is added to the CI stabilizing material 1' by heat treatment.
C
A large number of composite wires 3' arranged through 11 layers 6 are housed in a C1l tube 6 made of a stabilizing material, as shown in FIG. Then, vacuum the inside of the
112, and after joining both ends with the tip member 7 forming the nose and the rear end '+A8, welded the CLI tube 6, the tip member 7, and the rear end member 8 to [electronic] with 1 beam welding. A superconducting wire having a multicore structure is manufactured by manufacturing one piece 1-0 and then hydrostatically extruding this billet.

For the abrasive quality of the tip members 7 of the billets 1 to 9, an alloy such as CLI-Or 1Cu-Be is selected so that the extrusion pressure of the tip abrasion is lower than the extrusion pressure of the billet body. There is.

[Back technique 1 (problems with IJ) However, in the above J and eel methods, the fin
The average hardness (Co) of the billet 90, that is, the average value of the hardness of each material in the cross section perpendicular to the axial direction of the billet 90, distributed over its area It (in the part where the cross-sectional area of the billet is the same, C is the extrusion pressure ) is approximated in Fig. 2 (b
), there is a large change between the tip member 7 and the part where the composite wire 3 is housed, so when the part where the composite wire is housed reaches the vicinity of the die during hydrostatic extrusion of the billet, Then, the extrusion pressure increased dramatically, and there was a risk that the composite wire 3 would break through the wall of the C1l tube 6 and the tip part j47 would break out due to the shock.

Such a phenomenon tends to cause a culm in which the copper ratio (ratio of C11 stabilizing material to superconducting material) of the composite wire becomes small, and it is therefore difficult to hydrostatically extrude a multicore superconducting wire with a small copper ratio.

[Object of the invention] The present invention has been made to solve the above-mentioned conventional drawbacks, and by improving the structure of the extrusion billets 1 to 1, it is possible to hydrostatically extrude a superconducting wire with a multicore structure in a stable state. The purpose is to provide a method.

[Summary of the Invention] The method for manufacturing a multi-core superconducting wire of the present invention comprises incorporating a superconducting material or a metal that forms a Cl electric material immediately upon heat treatment into a plurality of metal matrices. A composite wire is housed in a metal tube, both ends of which are sealed using front and rear end members, and an extrusion billet formed by -C is extruded with a hydrostatic bar (Ja'-3-C1 front pipe). The first protrusion is characterized by having a protrusion having a cross-sectional area smaller than the hollow cross-sectional area of the tube toward the rear end side of the extruded billet.

In the present invention, since the tip member has a protrusion toward the rear end of the billet, this protrusion penetrates into the composite wire bundle and gradually changes the average hardness from the tip member to the part where the offshore wire is accommodated. This prevents a sudden increase in extrusion pressure.

This protrusion is made smaller than the hollow cross-sectional area of the metal tube (J, but over two or more stages toward the rear end of the extrusion billet 1-), and is made smaller than C1 by sequentially decreasing the cross-sectional area. Stable extrusion becomes possible.

The cross-sectional area of the protruding part is determined by the difference between the average hardness tα of the cross section including the protruding part and the average hardness of the part where the composite wire is housed. It is preferable to set it to have an intermediate value, and when protruding over two or more stages, the average hardness of the cross section including each protrusion has an intermediate value of the average hardness of the cross sections at positions before and after it. Preferably, the cross-sectional area of each protrusion is determined as follows.

In the present invention, the metal matrix and metal tube of the composite wire are pure Cu (OF
HC) and Cu alloys, such as CIJ-N+gold alloys, are used for special purposes.

Furthermore, the composite wire itself can have a multicore structure, for example, a plurality of NbT in a Cu or Cu alloy matrix.
By arranging the C11-coated 3n wire in the i-wire or Nb tube, it is possible to easily increase the number of cores.

The billet used in the present invention is, for example, a compound wire (single wire or multi wire) having a regular hexagonal cross section.
The protruding part of the tip member is pushed into one end of the composite wire, and the composite wire protruding from the other side is cut, and then this is housed in a tube made of stabilizing material, and the back width is 1. C1 tube and tip,
The rear end member can be heat welded to the parts 1 to 11 to produce C4. Since the billet is held in a vacuum system during this welding, the inside of the billet can be evacuated at the same time, and the composite wire drawing q can be perfectly bonded during extrusion.

[Embodiments of the invention] 1': lI=Explanation 1 of one embodiment of the present invention.

Fig. 3(a) shows the longitudinal direction of the extruded billet used in the present invention.
This figure shows an i-plane view, and the same parts as in FIG. 2 are designated by the same reference numerals.

Cu stabilization shrine J: Nb-
11 A large number of composite wires 3 embedded with superconducting cable wires are accommodated, and both ends of A are connected to the tip member 7' and the rear end member 8T. End member 8
is Flet-rl beam welded and C extruded billet 9'
is formed and C is formed. The tip member 7' is a protrusion 7/ having a circular cross section or a regular hexagonal surface with a diameter smaller than the inner diameter of the C11 tube.
This protrusion penetrates into the composite wire bundle.

As shown in FIG. 7(b), the average hardness of the composite wire 7'a is intermediate between the average hardness of the cylindrical portion Δ of the tip member 7' and the tube portion B in which the composite wire is accommodated. Therefore, it is possible to prevent a sudden increase in extrusion pressure when extruding this extrusion dot.

Copper ratio 0.5 in a Cu tube with a specific exception diameter of 80 wmφ and an inner diameter of 70 mmφ
931 Nb-Ti composite wires were accommodated, and the tip member was made of a Cu Cr alloy with a hardness of Hv=150. The structure of the billet in this case corresponded to FIG. 2, and the average hardness of the part where the composite wire was accommodated was Hv-180.

On the other hand, a part of the tip member of this billet was made to protrude with a cross-sectional area of 571 mφ to create a billet with the structure shown in Fig. 3, and these extruded billets were hydrostatically extruded using a die of 40 mφ. , in the former billet,
Maximum pressure of the tip member from the cuff 500 kg / cd to the housed part of the composite wire 9 500 kg / cd
The extrusion pressure suddenly increased to C, and when the composite wire broke through the 011 tube, the tip member was scattered, and extrusion 1
It became impossible.

On the other hand, (in the case of a billet made by a foreigner), the extrusion pressure is 9Fi
00 kg/r, d71'' billet was extruded uniformly over the entire length.

[Effect of the invention 1] As explained above, according to the present invention, it is possible to prevent the extrusion pressure of the hydrostatic extrusion process from being severe, so that a superconducting wire with a multicore structure can be manufactured in a stable state. I can do it.

[Brief explanation of the drawing]

The first figures (a) and (b) are cross-sectional views of a composite wire to explain the conventional extrusion billet manufacturing process, and the same figure (C) is a cross-sectional view showing the composite wire accommodated in a C1l pipe. Figure, Figure 2 (
Figure 3 (a) is a vertical cross-sectional view of a conventional extruded billet, Figure 3 (b) is an explanatory diagram of the average hardness at each position, and Figure 3 (a) is a longitudinal cross-sectional view of a conventional extruded billet.
) is a cross-sectional view of one embodiment of the extrusion billet 1 used in the present invention, and FIG. 3(b) is an explanatory view showing the average hardness at each position. 8- 3.3'...Composite wire 6...Cu tube 7.7'...Tip member 7'a...Protrusion part 8... ...... Rear end member 9.9'...Billette's instant patent attorney Sa Suyama - (1 idiot) 1st section ((1) (b) ('C) 2nd Figure 3 Figure 6 ((:r) f” 76 7...-ichiki-b 1 11 1 3 +'l1 1 11 1 '+l' 1 eye 1-bian 1 饗rh+ '-
−←IE Co., Ltd.

Claims (5)

[Claims] (1) A plurality of composite wires of superconducting material or C- embedded in a metal 7 matrix ('A heat treatment to form a superconducting material) are housed in a metal tube, In a method of isostatically extruding an extruded billet formed by sealing both ends thereof using first and rear end members, the method described in the previous ii[l! A method for manufacturing a multi-core superconducting wire in which the tip member has a protruding portion having a cross-sectional area smaller than the hollow cross-sectional area of the front pipe toward the rear end side of the extruded billet. (2) In the multi-core superconducting wire according to claim 1, the metals 71 to 6 are made of C11 or C++ alloy! '! J construction method. (3) A method for manufacturing a multicore superconducting wire according to claim 1, wherein a plurality of metals forming the superconducting material by superconducting S+4 or heat treatment are embedded in the metal 7 trix. (4) The method for manufacturing a multicore superconducting wire according to claim 1, wherein the metal tube is made of C11 or C11 alloy. (5) The method for manufacturing a multi-core superconducting wire according to claim 1, wherein the protrusion has a cross-sectional area that decreases in steps toward the rear end of the extruded billet.