JPS5978409A - Method of producing nb3sn compound 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 superconducting wire. Ultra' + TF wires are essential materials for equipment that requires high magnetic fields, such as nuclear fusion/accelerators and condensed material irradiation devices. There is a long-awaited wire material that can be used in a magnetic field and is reliable. Therefore, recently, one representative compound wire material, Nb5SnK, has been developed.
The upper critical magnetic field is increased by adding the 5th SnK '1liX and raising the gold.

[There has been no attempt to reform the critical current in the eclipse world. That is, taking Ga as an example as the third element added to the Nb3Sn compound, first create a complete ternary alloy of + Cu, Sn, and GK [-1 This is combined with a total Nb core wire to draw fc<i 0M How to perform compound-forming heat treatment at final dimensions. Figure 1 is a cross-sectional view of this method before wire drawing, and in Figure 0 (
11 Nb core wire, (2) Cu-3yl-Ga alloy. Another method is to create a binary alloy of Cu and Sn, combine it with a Nb core wire, and then draw the wire. There is also a method of performing GaF plating on the surface at the final size and then subjecting it to compound generation heat treatment. Figure 2 shows the wire drawing of this latter method.
In Figure 9, which is a cross-sectional view of t, (11 Nb core wires. (31 Cu-Sn alloy, (41 is Ga. In addition, the work hardening is slow and intermediate annealing treatment, which lasts for several dozen times, is not necessary.In addition, the critical current density is also low.Furthermore, these three The original alloy has poor caloric properties and many Ir and Ir forests, making it difficult to manufacture.In addition, the latter limits the amount of Sn that can be alloyed with Cu, and, like the former, has poor workability. Moreover, it has drawbacks such as the inability to uniformly plate the surface of the Ga f wire in the longitudinal direction, and the difficulty of performing heat treatment to generate a compound with Ga attached to the surface. This was done in consideration of the above points. Nb has excellent mass production and reliability, and also mimics the magnetic field characteristics.
The overall purpose of the present invention is to provide a manufacturing method capable of obtaining a 3Sn-based compound wire. ! 1ilIJ, in which the entire surface of the superconducting wire is formed by reducing the cross-section of the Nb-based metal strip and the Cu-based metal material placed around the Sn-based metal material and heat-treating them as one body. Base metal material. This is a method for producing a Nb3Sn-based compound superconducting wire ladle, characterized in that the metal shrine contains Sn and at least one of Ga, Inepb, and At in an amount of 0.5 to 50 wt%. Hereinafter, the case of performing Ga f polishing will be explained in detail based on an example. As shown in the cross-sectional view of Figure 3, the parent phase was Cu (5), and a large number of Nb core wires (11) were buried in the C parent phase. A tube was prepared.In this example, the dimensions of the tube were an outer diameter of 25glue, an inner diameter of 9m, and a diameter of approximately 0.4nm for the Nb core wire fil.
There were 1,200 pieces. Next, S n − with a diameter of 8.8W
Prepare all 5wt% Ga alloy rods, insert them into the hollow part (6) of the composite multi-core tube shown in Fig. Cu tube for f3t L, @4
A composite rod, the cross section of which is shown in the figure, was created. The wire was drawn to a diameter of 0.5 through C cold drawing.The wire drawing process was stable without the need for intermediate annealing, and there was no wire breakage.Next, these 19 openings were drawn at 750°C for 50mm.
All Nb3Sn compounds were generated by heat treatment. The critical current density (Je) of the thus obtained wire in an applied magnetic field was measured at liquid helium temperature (4.2 K). The results are shown in curve A in FIG. Also, for comparison, S
Wire rods with the same structure made by fully inserting pure SFI rods without using n-Ga alloy, and conventional Cu-10vtt%
The same superconducting properties were also measured for a wire prepared using the sn-3 wt % Ga ternary alloy matrix. Curve B ic ii in Figure 5 1 curve cic
The latter result is shown. As can be seen from the figure, in a relatively low magnetic field of 9 T or less, the one without the addition of Gaf has a better Jc, but at 10 T or more, the method of the present invention showed the best Jc. Cu-8n-Ga Kaikin? The wire used as the matrix had lower Je than the wire according to the present invention in all magnetic fields. Also, when comparing the Jcf of each wire at 12T excluding the stabilized Cui, the Ga'i-added thinner is 3
50ν* The wire rod made from Cu-8n-Ga ternary alloy as a matrix has a 300A/vx2, while the wire rod according to the present invention has a very high 450A//+!+112. , Ga is alloyed with Sn, so it can be adjusted freely without impairing workability, and it is also characterized by the fact that it can easily be attached with the stabilization necessary for superconducting wires. As described above, the wire rod according to the present invention has excellent manufacturing reliability and high magnetic field characteristics, so it is optimal as a wire rod for high magnetic field magnets of 10 to 12 T or more. As for the amount of In, it contributes to the improvement of high magnetic field characteristics when it exceeds 0.5 wt%, but when it exceeds 50 wt%, wire drawability is inhibited, so it is not desirable to add more than this.Next, In Another example in which f is added will be described.In place of Sn-5wt%Ga in the above example, 9
K Sn -10 wt% Inf was used. In this case also 5n
The wire drawing process was performed extremely well because the -1n base metal had good loe properties. Furthermore, according to the measurement results of the critical current density in an applied magnetic field, the Jc for the part excluding the stabilized Cu at 12T was a very high value of 460 A/my2. By adding In, the high magnetic field characteristics were significantly improved by one level. In the case of In nitration and the case of Ga cooling and colleagues,
Adding 0.5 wt% or more to Sn contributes to the same high field characteristics as above, but 5Qvrt
% or more, the Jet td will actually decrease.
This will happen. Above, we have described the case where Ga and In were added, but in addition to this, we also created alloys with Sn alloyed with AL and Pb1F4iJ in the same way as in the examples described above, but in all cases the surface magnetic field characteristics were improved at 9T or higher. It was seen. In addition, in this invention, *Sn KB alloyed Ga
. Combining two or more of In, At, and Pb to form a multi-component alloy;
Adding elements such as and T moat, and adding elements such as Sn + Ga T I n + AZI and pb to the Cu fund
It is also a feature of this '16 light that at least one of them is alloyed in an enclosure that is not subject to the restrictions of force U egg.
It's not something. As explained above, according to the present invention, a superconducting wire is produced by integrally processing the Nb-based maple layer and the Cu-based layer around the Sn-based layer to reduce the cross-section and heat-treating. In the method, the Sn fund M
'iA all sns Ga * I n + P b and At
By using gold maple material containing 0.5 to 50 wt% of at least one of the materials, the critical current characteristics VC in the Karasu magnetic field
Because we can stably and reliably manufacture familiar wire rods,
It has become possible to obtain a superconducting magnet for high magnetic fields of 10 to 12 T or more.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional reduction processing fi performed by the conventional method.
Fig. 3 is a cross-sectional view of a composite multicore tube according to an embodiment of the present invention, and Fig. 4 is a cross-sectional view of an iJ wire rod according to an embodiment of the present invention. FIG. Figure 5 shows the relationship between the applied magnetic field and the critical tortoise flow at 11''t4.2KK. Curve 1 is the characteristic of the Gak dipper of the embodiment of this invention. Curve B is the characteristic of the Gak dipper of the comparative example. Curve C in the above characteristic diagram 9 for the wire rod that does not correspond to the conventional Cu-8
It is the said characteristic diagram of the edge material which used n-GaQ gold as a parent phase. In the figure, fil is the Nb core wire, and (2) is the parent phase Cu −
Sn-Q, f gold, (31 is the parent phase Cu-Sn alloy,
(41n Gm plating. (51 is the parent phase Cu, (61 is the hollow part, (7; is 5n
-Ga alloy. (81 is a T & tube, (9) is a Cu tube. In the figures, the same reference numerals indicate the same or equivalent parts. Agent Shin Kuzuno -

Claims (1)

[Claims] A superconducting dipper is manufactured by integrally processing the Nb-based metal layer and the Cu-based metal layer around the Sn 77% metal material and subjecting them to cross-sectional reduction processing and heat treatment.
The Sn-based metal material is at least two of Sn K Ga, Innpb, and At'50.5 to 50wt
1. A method for producing an Nb3Sn-based compound superconductor, characterized in that it has a metal phase of 10%.