JPS5832308A - Method of producing compound series composite 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 The present invention relates to a method for manufacturing a compound (Nbs8n)-based composite superconducting wire.

As is well known, Nb and Sn-based superconducting materials, which are intermetallic compounds, have better superconducting properties and manufacturing value than other compound-based superconducting materials, and are expected to be used as superconducting wires for superconducting magnets to be used in the future for nuclear fusion Ise. ing. However, since Nb1Sn-based superconducting materials are intermetallic compounds, they are mechanically fragile, and unlike alloy-based superconducting materials, it is difficult to make them into composite wires using heavy processing methods.

The manufacturing method for Nb1Sn-based superconducting material is generally called the Bronze method.
This is a method in which an alloy is used as a matrix and a tooth bar is embedded, and the wire is repeatedly subjected to diameter reduction processing and heat treatment to obtain a desired size, and then diffusion heat treatment is performed to obtain a Nb or Sn-based superconducting wire. Due to the limitations of heat and cold workability in this method, the amount of Sn is 141.
! Since the amount of Nb, 8m produced is small, the critical current is low. In addition, during the rounding and diameter reduction process in which the matrix is Cu-8~l4''tloSn, the cross-section reduction rate (processing rate) is 20~301G, and heat treatment (annealing) is required to recover workability. 10 times of heat treatment is required to reach the size of .This makes it disadvantageous to manufacture NbBSn-based composite superconducting wires at low cost and in large quantities.

On the other hand, as a manufacturing method of Nb18n wire rod which is an improvement of the above-mentioned bronze method, a tooth bar and an 8n or 5n-Cu alloy rod are
There is a method of manufacturing Nb5Sn: $ superconducting wire by placing it in a bundle in the u''q trix (matrix), drawing it to the desired dimensions without intermediate softening annealing treatment, and then applying heat treatment by a woodcutter. However, with Jin's method, Id
Since an, which supplies the Nb and Sn reactions, diffuses from several points to several tens of points in the cross section of the multi-core wire, the generation of Nb and an, which is far away from Sn, is insufficient and the critical current of the composite wire. becomes lower. Due to the difference in material strength between Cu and Nb in the matrix, there are cases where the shape of the running lines becomes non-uniform in the length direction, and there are disadvantages such as disadvantages from the formation of Nb and 8n. This invention was made to solve the above-mentioned drawbacks of the conventional ones, and was made to solve the problem of scratching sticks and Sn? Nb,
It is an object of the present invention to provide a method for manufacturing a Sn-based composite superconducting wire.

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

In Figure 1, the matrix prepared in advance by a draw bench pull plate or extrusion process is Cu-3-51.
05nOCu=Sn alloy 2 is selected, and a large number of cold core wires are drilled into the wire bundle to create a round tube with an outer diameter of 34 cm.

Next, in the hollow part 3 of the tooth center groove, as shown in FIG.
■ Insert the an rod 4 into the outside of the tube with an outer diameter of 50 and an inner diameter of 4.
After covering the ninth Cu tube with a stabilization of 0 mm and the diffusion barrier metal tube 5 made of T1 with an outer diameter of 3911 m and an inner diameter of 35 mm, this composite material was subjected to drawing processing using a do-venture wire drawing machine. do. In addition to Ta, the diffusion barrier metal tube 5 is made of V,
, Nb, , Ti, Zr, etc. are effective.

After drawing the composite material to the desired dimensions, it is heated in a vacuum at 650 to 850°C in an inert atmosphere.
When heated for 00 hours, the Sn rod 4 diffuses into the Cu-Sn alloy 2 to form a bronze with a high 8nfi, and further reacts with the excitation to form a sufficiently thick NbaSn layer on its surface continuously in the length direction. to be generated. At this time, migration of the diffusion barrier metal tubes 5 and 8n to the outside is prevented, thereby keeping the good conductor metal 6 sufficiently pure and serving as a stabilizing metal. In the process of heating the composite metal, at temperatures below 600°C, the 8n rod contained in the center first melts and diffuses into the Cu-Sn alloy 2, and at temperatures above 650°C, the reaction between TiNb and am causes the formation of NbaSn. will be carried out.

Fig. 3 shows a cross-sectional view of the composite superconducting wire manufactured as described above, and Fig. 4 is a partially enlarged view of Fig. 3, in which Cu-Sn alloy 2 with a uniform composition is It shows the state of Nb3Si 7 formed in close contact with Nb rod 1. All of the composite materials according to the manufacturing method of this invention are highly ductile materials,
Since the matrix is a Cu-8m alloy, it has an appropriate tensile strength, and the wire drawing process is equivalent to or easier than that of alloy-based composite superconducting wire. Furthermore, since the tooth rod L is surrounded by Cu-Sn alloy 2, there is no supplementary supply of Sn (Sn diffusion distance) for the distant continuous line, and furthermore, Cu-8n alloy 2 is Cu-Sn alloy 2. There is less difference in strength between cold wire and cold wire, which allows the tooth edges to be drawn evenly. Moreover, during wire drawing, the parent phase is a Cu-Sn alloy, and C
The strength of the matrix is high, and even when the wire is thinned, it will not break at all, and it is long! i! can be obtained.

FIG. 5 shows the relationship between tensile strength and processing rate of Cuk and Cu-1,0,3,5'9$sn alloy. According to this, it is clear that the Cu-Ann alloy has a higher tensile strength than Cu, and it can be processed even with a machining rate of 99, so heat treatment is not required during the processing process. It is understood that it is not necessary. Fig. 6 The one in Fig. 2 has an outer diameter of 0.
．． 1 heated at 750°C for 100 hours after thinning to 5-
This is the value of the critical current density of a composite wire with two cores in relation to the applied magnetic field. According to this, it can be seen that the material of the present invention shows a sufficiently higher value than the conventional Nb and sn 4I, and is superior in terms of quality.

In addition, as other embodiments of the present invention, the number of Nb1l[1] or the Sn rods 4 may be arranged on the outer periphery or the middle part of the tooth bar 1, the overall shape may be square or tape-like, or the partition wall may be Various configurations are possible in which the inside of the metal tube 5 and the good conductor metal 6 are divided into fan shapes, rectangles, hexagons, hexagons, etc. and bundled and arranged, but all of them deviate from the scope of the present invention and are therefore not covered herein.

As explained above, it is easy to manufacture a uniform ultrafine multifilamentary wire using the method for manufacturing a chemical composite superconducting wire of the present invention.
The supply of 8n, which is a reactive component, can be adjusted, and a superconducting wire with a stable and high critical current can be manufactured.The strength of the entire wire is improved by using Cu-an alloy as a matrix, and wire breakage during the wire drawing process is prevented. It has the advantage of being able to obtain a long wire without any problems, and being able to be applied to threaded wires and braided wires.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an intermediate material according to the present invention, and FIG. 2 is a cross-sectional view of an intermediate material whose production has progressed further from that of FIG. 1.
Figure 3 is a cross-sectional view of the completed final wire, Figure 4 is a partially enlarged view of Figure 3, Figure 5 is a characteristic diagram of tensile strength/processing rate of aCu and Cu-Sn alloys, Figure 6 is a characteristic diagram of critical current density/magnetic field 111M. l...Nb rod, 2...Cu-an alloy, 3...hollow part, 4...Sn rod, 5...diffusion barrier metal tube, 6...
... Good conductor metal, 7... Product of Nb1Sn. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Makoto Kuzuno - 5th factor j) a work rate (%) □

Claims (2)

[Claims] (1) A Sn-based or an-Cu alloy metal layer, or a Ga-based metal layer can be easily deformed by processing, such as a dead line Ga-Cu-based metal layer or a cold-type metal wire. 2) A step of obtaining a composite wire having a structure in which a metal layer and a parent phase are juxtaposed, and heat treating this composite wire to form Nb@gn
Alternatively, in a method for manufacturing a compound-based composite superconducting wire comprising a step of generating a FiV, Ga superconducting compound, the easily deformable metal layer is a Cu-0,1-4W-8n alloy or a Cu-0,1- A method for manufacturing a metal compound composite superconducting wire, characterized in that it is a 10''% Ga alloy. (2) Sn-based or a8n-Cu alloy-based metal layer or expanded G
& or the Cu concentration of the Qa-Cu alloy metal layer is 0 to 2G
The method for producing a compound-based composite superconducting wire according to claim 1, wherein