JPS5945021A - Billet for extrusion - Google Patents

Abstract

PURPOSE:To arrange properly the ends of wire rods in longitudinal direction by extrusion in an extruding billet in which many wire rods are arranged parallel in a copper pipe by forming the front ends of the wire rods to a concave surface and rear ends to a convex surface. CONSTITUTION:A wire rod 4 made of Nb, Ti alloy etc. is coated with oxygen- free copper, and many such wire rods are lined up longitudinally and inserted into an oxygen-free copper pipe. A conical front end member 6 and a discoid rear end member 7 are provided on both ends and welded to the pipe 5 to form a billet for extrusion. By making the face of the front end member 6 facing the bundle of wire rods a convex surface, the end face of the bundle of wire rods is formed to a concave face, and by making the face of the rear end member 7 facing the bundle of wire rods a concave surface, the end face of the bundle of wire rods is formed to a convex face. A billet formed thus is extruded to make a composite wire. By this way, the end face of extruded wire rods 4 can be arranged properly in longitudinal direction and material yield of the composite wire can be improved.

Description

[Detailed description of the invention] This invention relates to a billet for extrusion L7.

An extrusion billet containing Nb-Ti alloy superconductor #ll31Y will be described as an example. Recently, superconducting wires have become stable.
] 1. (In order to do this, a large number of very thin filaments, such as Nb-Ti alloy filaments with a diameter of 10 to 40 μm, are embedded in a normal conductive metal with low electrical resistance, such as oxygen-free copper, and then twisted into such a composite wire.) It is manufactured and used in the form of a so-called ultra-fine multi-core twisted superconducting wire. Figure 1 shows such Nl) @ Ti
FIG. 1 is a cross-sectional view showing an example of an alloy ultra-fine multi-core twisted superconducting wire. In the figure, (1) is a normal conductive metal such as Nl), Ti alloy filament), and (2j is oxygen-free copper), and these are the composite wire N1.+ Ti alloy ultrafine multicore superconducting wire (3 ) to form.

The Nl) -Ti alloy ultrafine multicore superconducting wire has a uniform cross section as shown in FIG. 1 over its entire length.

In order to manufacture such a composite wire, the following method is generally adopted. A large number of copper-coated Hb e Ti alloy single-core wires are aligned and inserted into a large diameter copper pipe under medium pressure, and a wire bundle is obtained by inserting a wire bundle on both end surfaces as a tip member and a rear end member, often copper plates. by welding.

Make a billet for extrusion. Then, the billet is extruded into a composite wire, which is further processed to reduce its cross section by swaging, wire drawing, rolling, etc., and is finished into a predetermined shape. FIG. 2 is a longitudinal sectional view showing an example of a billet for extrusion processing.

In the figure, (4) is a single-core Nb-Ti rod coated with oxygen-free copper wire, (5) is an oxygen-free copper pipe, (6) is a conical tip member that forms the tip of the billet, and (7) is an oxygen-free copper pipe. is a disc-shaped rear end member forming the rear end of the billet.

Here, the front and rear ends refer to the front and rear ends 2 of the billet with respect to the extrusion direction. In order to produce such an extrusion billet, first the Nb e
'l''i alloy wire rods are manufactured, a large number of the wire rods are aligned and inserted into the copper pipe (5), and then a 9-conical tip member (6) and a disc-shaped rear end member (7) are inserted. Weld to the pipe.2 Usually electron beam welding is used to maintain a vacuum inside the pipe.

The shape of the tip of the conical tip member (6) depends on the type of extrusion method,
Constituent material of billet, number of wire rods in billet.

It is determined by considering the extrusion ratio, etc. The type of extrusion method is the range of forward extrusion that can extrude composite materials, and regarding the shape of the die, a flat die 17 is used where the billet does not have a taper in the area from the container diameter to the die hole diameter.
', Cheaper die type with conical turning part tb) or l whose extrusion method is fundamentally different from these.
Hf hydraulic extrusion method.

When extruding the above billet l-'2, a phenomenon was observed in which Nb-T1 alloy 1 was advanced in the extruded composite wire at medium heat in the rod. FIG. 3 is a sectional view taken at t1 of a joining line manufactured by extrusion using a conventional extruder using a tapered die.

Advance [d generally increases as it approaches the center of the compound line. There is an uneven part of the Nb-Par-I alloy wire at the tip of the composite wire or near the rear QIM.

This portion cannot be used as a superconducting wire after the 11qllFi processing.9 Although the torque varies depending on the extrusion method, this problem exists in all extrusion methods.

Therefore, in FIG. 2, J: 5 inches, r: billet for extrusion.

There is a great deal of material loss due to the advancement of the central part of the material.

For example, in an experiment using an extruder using a tapered die, it is 15-20%, and in the case of a flat die, it is 20-3%.
This results in a loss of 0%. In particular, N is a superconducting material.
b * If Ti alloy or Nb3Sn superdirect wire is not manufactured, the loss of Nb alloy and Nt will be significant, since Nb alloy and Nt are expensive. Furthermore, it is impossible to connect the superconducting wires manually without deteriorating the forward current characteristics after the superconducting wires are finished to the desired diameter.
Since there is a limit to the number of seedlings per ton, if the September yield is low, it may be impossible to produce long super-heavy conductor wires. Currently, the wires are being processed with these inconveniences in place, which is a major drawback in the production of ultra-fine multi-D superelectric wires.

This invention provides both members in which the opposing surfaces of the front end member and the rear end member are respectively formed into a convex shape and a concave shape so that the front end surface of the bundle is concave and the rear end surface is convex. The purpose of this is to align the ends of the extruded wire in the longitudinal direction by using an extrusion billet l arranged with .

FIG. 4 is a longitudinal sectional view of an extrusion billet showing one embodiment of the present invention. (6) is the revised tip member.

(7) is an improved rear end section. To fabricate this bit, copper clad Nb, Ti
The gauze material bundle (4) is cut to a certain length, and then the gauze material bundle (4) is aligned and inserted into the copper pipe.At this time, the gauze material bundle (4) is formed at the tip of the billet. The leading end surface is a concave surface, and conversely, the rear end surface formed by the wire bundle (4) at the rear end of the billet is a convex surface. In order to do this, the opposing IMi of the tip end cap (6) that comes into contact with the tip surface of the wire bundle (4) is made into a convex shape.

The opposing surface of the rear end member (7) that contacts the rear end surface of the old wire bundle (4) is formed into a concave shape. As a result, the positions of the leading and trailing ends of a large number of Nb-Tj wires in the extruded t7-processed wire could be gathered closer together in the longitudinal direction of the composite wire3. When the final pillar was extruded into 10 wires by direct extrusion using a die with a conical hole, the tip of the hJb-Tii material had a maximum deviation of 20 mm in the extruded composite wire, compared to the conventional 150 mm. compared to.

It is clear that this has been greatly improved.

In the above example, the case of a cylindrical extrusion L14 billet was described, but when extruding a hollow pipe-shaped extrusion billet and manufacturing a composite pipe, the same filament and the deviation of the 1ltJ material can be used. A) Therefore,
It is effective to place the advanced filler material some distance back in the billet.

Furthermore, in the above embodiments, the case of an extrusion billet of Nl)-Ti alloy-copper was described, but the billet is not limited to such a billet.
Ta alloy, N1)3Sn, Vy, Ga, Nb
3Al, V3Si, )Jt130a, V2H
f.

It can also be applied to all cases of extrusion billets for manufacturing superconducting wires manufactured by so-called composite processing methods such as v2 (Hf-2r). Especially 1(1)5S
When manufacturing n-compound superconducting wire, Nt) or H
b Gold alloy Sn or Sn alloy'+2. cu
In addition, when processing the cross section of the CU gold alloy as an integral part when placed around it, or when processing a composite material mainly composed of Nb metal, Cu-Sn alloy, or aU, etc., N1)
3. Make Sn superconducting wire. Even in the so-called bronze process, the extrusion billet of the present invention is efficient and indispensable.

In addition, in the above embodiment, the case where a large number of composite wires of the same type #c are inserted into the pipe in order to manufacture a push 111 billet has been described. However, even if the type of wire is convergent, or even if it is simply an inserted wire or not a composite material, this invention is effective in all cases where the extruded wire is used to form a stranded wire. 7. Regarding the shape of the wire rod inserted into the pipe, it was not specifically described in the examples, but generally the outer shape is hexagonal. Regarding this invention, even if the shape of the line changes, the same effect can be obtained; the shape of the line does not matter. After inserting the wire into the pipe.

l'Jj in the pipe! , knotted filler wire inserted in between,
Or it has nothing to do with the shape.

The method of inserting a large number of wires into a pipe is different from the method of inserting a large number of wires into a pipe. Even when manufacturing a composite wire by extrusion processing, similar effects can be obtained by utilizing the concave and convex surfaces described above.

Moreover, it is effective regardless of the material of the extruded billet pipe and whether or not the pipe is a composite material, and is also effective when manufacturing a composite wire that is not a superconducting material.

In the second embodiment, the opposing surfaces where the end surfaces of the wire bundle of the tip end member and the rear end member come into contact were made convex at the tip member and concave at the rear end member, but instead of being made smooth, they were given nine steps. The purpose can also be achieved by making the surface convex or concave overall.

It is important that the tip and rear ends of the ends of the elements constituting the composite wire are located in a convex shape.

Further, in the above embodiment, the case was described in which the tip member and the rear end member were welded to the metal pipe.

Separately, it is possible to manufacture a cylindrical container with a concave bottom on a pipe, fill it with material, and then weld a convex end member to it. This will not affect the effects of the invention. .

As described above, the present invention includes both members in which the wire bundle facing surfaces of the leading end member and the trailing end member are respectively formed in a convex shape and a concave shape so that the leading end surface of the wire bundle is concave and the rear end surface is convex. By using a billet for extrusion with a device, the ends of the extruded composite wire can be aligned closely in the longitudinal direction, and the material yield of the extruded composite wire can be improved. For example, especially in the production of superconducting wires, +Nb/Ti alloys, Nb-N
Since the loss of expensive materials such as B-alloy can be reduced, the economical effects of this invention are extremely significant. It is also possible to make longer wire ropes.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of Nb*'I'j ultra-fine multi-core twisted superconducting wire, Fig. 2 is a longitudinal sectional view showing an example of a conventional extrusion billet, and Fig. 3 is a conventional extrusion billet. FIG. 4 is a longitudinal sectional view of a billet for extrusion which is an embodiment of the present invention. In the figure, (4) is a wire rod, (5) is a copper pipe, (6) is a tip part, and (7) is a rear end member. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Makoto Kuzuno - Figure 1 Figure 2 1 Step 1 Figure 3 I

Claims (1)

[Scope of Claims] fil In an extrusion machine in which a large number of wire rods are arranged along each other [7] and a front end member and a rear end member are arranged on both sides of the wire profit bundle, the tip member is The above Fi!
The wire bundle facing surface of the tip part is formed in a convex shape so that the end surface of the wire bundle is concave, and the end surface of the wire bundle facing the rear end member is formed in a convex shape. A billet for extrusion in which the surface of the end member facing the wire bundle is formed into a concave shape. , (2+ l1ilil yield) is a multi-core composite superconducting wire, the extrusion billet according to claim @f11.