JPS6127016A - Method of producing copper-coated niobium-titanium compositewire - 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] The present invention relates to a method for manufacturing a copper-coated niobium-titanium composite wire.

[Problems with the Prior Art] Conventionally, in the production of single-core copper-coated niobium-titanium composite wires used in the production of copper-coated niobium-titanium multicore superconducting wires, the composite wires have been manufactured according to the process diagram shown in FIG. This is followed by assembly of a copper-coated niobium-titanium billet for hot extrusion.

As shown in between, the Cu pipe 1 has a smaller diameter N b
- Insert the Ti rod 2 and process it to reduce the area, for example, process it into a hexagonal shape to produce the area-reduced Cu coated Nb-Ti composite wire 3, and then collect a large number of them in the copper pipe 4 to form a billet. assembly, then heating and hot extrusion.

By the way, a billet for hot extrusion is assembled with a composite wire of single-core Cu coating N b -T, and the billet for hot extrusion is 500 to [i50
'When heating C, T at the interface between Cu and N b -T t
i2Cu.

Alloys and intermetallic compounds such as (TiNb)2cu are produced.

These are harder than Nb-Ti, and during wire drawing, these hard alloys and intermetallic compounds bite into the Nb-T1 filament, easily causing the filament to break.

[Object and structure of the invention] As described above, the present invention aims to prevent disconnection of Nb-Ti filaments during hot extrusion and wire drawing after billet assembly. C for inter-extrusion
In manufacturing the u-coated N b -T + composite wire, after surface reduction processing to its final size, the composite wire is repeatedly bent twice or more with a bending diameter of 300 times or less than the wire diameter, thereby achieving CLI The purpose is to reduce the adhesion of the interface between the coating and the Nb-Ti filament, thereby suppressing the formation of the alloy and intermetallic compounds that occur during subsequent heating of the billet.

The present invention will be explained in detail below with reference to the process diagram of FIG.

As shown in the figure, a Nb-Ti rod 2 is inserted into a Cu pipe 1 and subjected to surface reduction processing to produce, for example, a hexagonal composite wire 3, and the composite wire has a hexagonal cross section in its final dimensions. Average wire diameter, or 30 of the wire diameter when not in a hexagonal shape
Bending is performed two or more times with a bending diameter of 0 times or less, and finally straightening is performed.

In this case, the bending process may be performed during the area reduction process.

After that, a large number of single-core copper coated N were subjected to the above-mentioned straightening process.
b - T L composite wires 3 are assembled into a copper pipe 4 to assemble a billet. However, it is inappropriate to make the bending diameter extremely small.

[Test Example] The inner surface of a Cu pipe with an outer diameter of 20 mmφ and an inner diameter of 18 mmφ was degreased, and a N b -T i rod with an outer diameter of IG mmφ was degreased.
Polish and insert into Cu pipe, 20 to 3+IIIφ
% reduction was used to reduce the area by wire drawing. This 3
After bending the open φ composite wire twice by changing the bending radius to various sizes, it was straightened and heat treated at a hot extrusion temperature of 650° C. for 3 hours.

Regarding these composite wires with different bending radii, copper and N b
When the formation of an alloy layer and an intermetallic compound layer at the -T + interface was investigated, no formation of an alloy layer or an intermetallic compound layer was observed when the bending diameter was 300 times or less than the self diameter.

[Effects] As explained above, in the present invention, by the bending process, Cu
The adhesion of the interface between N b -T i and
It is possible to prevent the i-filament north from breaking.

[Brief explanation of drawings]

FIG. 1 is a manufacturing process diagram of a copper-coated niobium-titanium composite wire of the present invention. FIG. 2 is a manufacturing process diagram of a conventional copper-coated niobium-titanium composite wire. ■...Copper pipe, 2...Niobium-titanium rod, 3...
・Copper coated niobium-titanium composite wire, 4...Copper pipe. Fountain 1 figure (koF=2=2222=) Saichujin pot Mff3

Claims (1)

[Claims] (1) In the production of copper-coated niobium-titanium composite wire for hot extrusion, after reducing the area to the final size, the composite wire is repeatedly bent twice or more at a bending diameter of 300 times or less than the wire diameter. 1. A method for producing a copper-clad niobium-titanium composite wire.