JPH0536718U - Superconducting composite beret for hydrostatic extrusion - Google Patents

Abstract

(57) [Summary] [Objective] To form a composite billet capable of stable extrusion processing. [Structure] The composite billet 10 includes a large number of superconducting wires 12
A metal tube 11 made of a Cu alloy, which is filled with Cu, and a tip member 13 and a rear end member 14 which are electron beam welded to both ends of the metal tube 11. The tip end side of the superconducting wire 12 is formed on the rear end side of the tip member 13. The metal tube 11 is fitted in the recessed portion 13a formed therein and prevents breakage of the metal tube 11 when the main body of the composite billet reaches the die during hydrostatic extrusion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a superconducting composite billet for hydrostatic extrusion used for manufacturing superconducting wires.

[0002]

[Prior Art]

 Conventionally, as a method for efficiently manufacturing a superconducting wire having a multi-core structure, a method using hydrostatic extrusion has been known.

In this method, as shown in FIG. 2, a large number of superconducting wires or a wire 2 which forms a superconducting wire by heat treatment are housed in a metal tube 1, and the front end side and the rear end side thereof are accommodated. After the lid is covered with the front end member 3 and the rear end member 4 forming the nose, the metal tube 1 and the front and rear end members 3 and 4 are electron beam welded to each other while vacuum degassing the inside thereof for extrusion. A composite billet 5 is used.

When performing hydrostatic extrusion using the composite billet 5 having the above-described structure, the average hardness (value of hardness obtained by dividing the hardness of each material in the cross section perpendicular to the axial direction by the area ratio) The average value) greatly changes between the tip member 3 and the main body of the composite billet, and when the portion containing the superconducting wire reaches the vicinity of the extrusion die, the extrusion pressure rapidly increases and the superconducting wire 2 Sometimes pierces the metal tube 1 and the tip member 3 separates, making extrusion impossible and causing a danger.

Such a phenomenon is more likely to occur, for example, as the matrix ratio of the superconducting wire (matrix / superconducting material ratio) becomes smaller, that is, the strength difference between the metal tube and the superconducting wire becomes larger, and thus the matrix ratio becomes smaller. In the case of hydrostatic extrusion of superconducting wires, there is a problem that the processing yield decreases because the extrusion ratio is set to a small value that is empirically determined by the average hardness of the composite billet.

[0006]

[Problems to be solved by the device]

 In order to prevent the destruction of the composite billet during the above extrusion, the present applicant jointly seals both ends of a metal tube accommodating a plurality of superconducting wires with a tip member and a rear end member, and I applied for a superconducting composite billet for hydrostatic extrusion in which the part was tightly fitted in the metal pipe and a reinforcing pipe was fitted over the outer periphery of the rear end surface of the fitting part (Jpn. Pat. Appln. KOKAI No. 2-8564).

According to this extrusion billet, it is possible to prevent the billet from being broken during hydrostatic extrusion. However, a large number of superconducting wires of different lengths are prepared and housed in a metal pipe together with a reinforcing pipe. However, there is a problem that the work is complicated because it needs to be combined with the rear end member.

The present invention has been made to solve the above-mentioned conventional problems, and it is possible to improve the yield of extrusion and to easily extrude a superconducting wire having a multi-core structure, which is easy to manufacture. It is an object of the present invention to provide a superconducting composite billet for hydrostatic extrusion.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the superconducting composite billet for hydrostatic extrusion of the present invention joins and seals both ends of a metal tube accommodating multiple superconducting wires with a tip member and a back end member, and A concave portion is formed on the rear end side, and the tip portion of the superconducting wire is fitted into the concave portion.

As the metal tube in the present invention, pure Cu (OFHC) that functions as a stabilizing material or a Cu alloy such as a Cu—Ni alloy for a special purpose is used.

The superconducting wire accommodated in the metal tube may be a superconducting wire having a structure in which a plurality of Nb or Nb—Ti alloy element wires are arranged in a Cu or Cu alloy matrix, or a Cu or Cu alloy matrix. By using a metal that forms a superconducting material by heat treatment therein, for example, a composite wire in which a plurality of Nb tubes accommodating Cu-coated Sn wires are arranged, it is possible to easily achieve multicore.

Further, as the front and rear end members, in addition to Cu, a Cu alloy, for example, one having an adjusted alloy composition such as Cu—Cr, Cu—Ni, and Cu—Be is selected.

[0013]

[Action]

 In the composite billet with the above configuration, since the tip of the superconducting wire is fitted in the concave part formed on the rear end side of the tip member, the average hardness from the tip member to the main part of the composite billet increases rapidly. Can be mitigated, and the metal tube can be prevented from breaking during hydrostatic extrusion.

[0014]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a composite billet 10. In a metal tube 11 made of a Cu alloy, a large number of superconducting wires 12 each having a hexagonal cross section are brought into contact with their side surfaces to form spacers. , And both ends thereof are covered with a front end member 13 and a rear end member 14. A concave portion 13a is formed on the rear end side of the tip member 13, and the front end side of the superconducting wire 12 is fitted into the concave portion, and the metal tube 11 and the front and rear end members 13 and 14 are welded by an electron beam. Has been done. Since the entire composite billet 10 is placed in a vacuum system during this welding, the inside of the composite billet is simultaneously degassed, facilitating the joining of the superconducting wires during extrusion.

In FIG. 1, the line X-Y connecting the outer edges A of the tips of the multiple superconducting wires 12 fitted in the recess 13 a and the outer edge B of the joint between the tip member 13 and the metal tube 11 is the above-mentioned. It is preferable to form the composite billet 10 so that the angle α formed with respect to the axis is larger than the die half angle. By forming the structure of the composite billet 10 in this way, it becomes possible to perform hydrostatic extrusion even under the conditions where the average hardness of the billet main body portion is 150 or more and the extrusion ratio is 2 or more, which was conventionally impossible to perform hydrostatic extrusion. The yield also improves from about 60% to 80%. However, in this case, it is necessary that the average hardness of the billet body is 180 or less and the extrusion ratio is 4 or less.

When the angle α is smaller than the die half angle, that is, when the length L is large, the joint portion between the tip member 13 and the metal tube 11 is reached after the tip outer edge A of the superconducting wire 12 reaches the die during hydrostatic extrusion. Since the outer edge B reaches the die, the metal tube 11 easily breaks at this point.

Concrete Example A Cu-10 wt% Ni alloy tube having an outer diameter of φ49.0 mm and an inner diameter of φ41.0 mm is provided with a Cu-10 wt% Ni alloy-coated Nb-Ti alloy wire (Cu-Ni alloy / Nb- After filling 301 pieces of Ti alloy having an area ratio of 0.5) with their side surfaces in contact with each other, and sealing both ends with a front end member and a rear end member formed of a Cu-Cr alloy having a hardness Hv of 130, respectively. Then, these were electron beam welded to form a composite billet.

In this case, the average hardness of the composite billet body is Hv = 160, and the depth of the concave portion formed on the rear end side of the tip member is L = 2.6 mm, L in correspondence with FIG. ′ = 8 mm.

The composite billet thus formed was subjected to hydrostatic extrusion using a die having a die diameter of 33 mm and a die angle of 50 degrees. As a result, stable extrusion was achieved over the entire composite billet at an extrusion pressure of 7000 kg / cm ^2. It was possible.

Comparative Example A composite billet was formed in the same manner as in the specific example except that the tip member in the above specific example had the shape shown in FIG. 2 and a superconducting wire of the same length was used. out processed results, increased from the maximum extrusion pressure = 6300kg / cm ² of the tip member to the extrusion pressure = 7000 kg / cm ² when reaching the Filling has been that the body portion of the superconducting wire, simultaneously superconducting wire is Cu -It was impossible to extrude through the Ni alloy tube.

[0022]

[Effect of the device]

 As described above, according to the present invention, it is possible to prevent breakage of the composite billet during hydrostatic extrusion of a multi-conductor superconducting wire and to perform stable extrusion, which improves the yield of extrusion. In addition, it has the advantage that it is easy to manufacture.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a superconducting composite billet for hydrostatic extrusion according to the present invention.

FIG. 2 is a longitudinal sectional view of a conventional superconducting composite billet for hydrostatic extrusion.

[Explanation of symbols]

 10 ... Composite billet 11 Metal tube 12 Superconducting wire 13 Tip member 13a Recessed part 14 Rear member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuo Aoki Inventor No. 1-1 Sakae Oda, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture, Showa Electric Wire & Cable Co., Ltd. (72) Tomoyuki Kumano 2 Sakae Oda, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture 1st-1st Showa Electric Cable Co., Ltd. (72) Inventor Ichiro Noguchi 2-1-1 1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa

Claims (3)

[Scope of utility model registration request] 1. In an extrusion billet in which both ends of a metal tube containing a large number of superconducting wires are joined and sealed by a tip member and a trailing end member, a concave portion is formed on the rear end side of the tip member, and the concave portion is formed in the concave portion. A superconducting composite billet for hydrostatic extrusion, wherein the tip of the superconducting wire is fitted. 2. A line connecting a tip outer edge of a plurality of superconducting wires fitted in a concave portion and a joint outer edge of a tip member and a metal tube in a plane including an axis of an extruded billet with respect to the axis. The superconducting composite billet for hydrostatic extrusion according to claim 1, wherein the formed angle is larger than the die half angle. 3. The superconducting composite billet for hydrostatic extrusion according to claim 1, wherein the superconducting wire is formed by embedding a superconducting material or a metal forming the superconducting material by heat treatment in a metal matrix.