JPS60253113A - Method of producing nb3al 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] [Technical field of invention] The present invention relates to a method for manufacturing Nt)3Aβ superconducting wire.

[Technical background of the invention and its problems] Nb5AJ! compared to Nb3Sn, the critical magnetic field (HO2
IC01, that is, Nb-A
According to research on the diffusion process of the β system, Nb5Aβ
The diffusion rate of NI is extremely slow;
Several hundred years of diffusion time is required to obtain T:+Aj2.

However, when the crystal grain size of Nl) becomes very small, grain boundary diffusion becomes dominant, making it possible to create a superconducting material of Nb5AJ2, and experimentally using a mixed powder of Nb and 8β, A sample has been prepared, but in order to make a practical wire, it is difficult to uniformly fill the Nl) and Δ℃ powder, and it cannot be processed unless Nb particles containing many oxides are eliminated. It has been difficult to obtain long wire rods because it is not possible to wire-draw directly from a molded body of mixed powder, and a swaging process or the like is required.

OBJECT OF THE INVENTION] The present invention has been made to solve these conventional difficulties, and makes it possible to uniformly process long wire rods and to manufacture Nb5A superconducting wires under practical heat treatment conditions. The purpose is to provide a method.

[Summary of the invention] In other words, the method for manufacturing the NbaA°C superconducting wire of the present invention
CL multiple composites containing Δλ lots coated with Cu or CO-based alloy inside b or Nb1 alloy tubes.
It is characterized in that after being placed in the I stabilizing material, a heat treatment is performed to form Nb5Aβ in a vacuum or an inert gas atmosphere.

In order to improve wire drawability and refine the NbaA-J2 layer, the Nb-based alloy tube in the present invention is
It is desirable to use a Nb alloy to which at% Ti or 0.1 to 2 at% 7n is added.

In addition, Cu placed on the outer periphery of 8β[1] is NbaA
Although it facilitates the diffusion heat treatment for LB formation, 0.1 to 5% of Ti is added as above to improve the midline J property.
Alternatively, a Cu alloy to which 0.1 to 2 at % of 7r is added can be used.

In the present invention, the heat treatment strip 1 for producing Nb5AJ2 with a multi-core structure has a wire diameter of 700 to 90%, depending on the structure of the wire.
The time is appropriately selected within the range of 10-odd hours to 100-odd hours at a temperature range of 50°C.

[Embodiment of the Invention j Hereinafter, an embodiment of the present invention will be described (3゜Example to be explained) A Δ℃ rod with an outer diameter of 2.Onφ was housed inside a C1l pipe with an outer diameter of 5.Onφ and an inner diameter of 2.2nφ. Then, on the outer periphery of this Cu tube, Nb (¥8.Onφ, inner diameter 5.2nφ)
A pipe and a Cu pipe with an outer diameter of 14.2 nφ and an inner diameter of 8.2 nφ are coated, and then a cross-section reduction process is performed to reduce the distance between C parallel surfaces to 2.
．． A composite wire (A) having a hexagonal cross section was manufactured.

The 913 tree of this offshore line (A) has an outer diameter of 821-φ and an inner diameter of 7.
After filling it into a 2nφ CLI tube and sealing both ends in a vacuum, it was subjected to hydrostatic extrusion and wire drawing to produce a composite wire <8) with a hexagonal cross section of 11f4.2n parallel plane openings. .

The 61 tree of this compound line (B) has an outer diameter of 50nφ and an inner diameter of 40n.
It was filled into a Cu tube of φ, and the same operation as above was repeated to obtain a wire with an outer diameter of 11 nφ (an outer diameter of 4 mm for a Nb tube).

This wire was heat treated in vacuum with 760'Cr for 3 days to form a Nb5AJ2 layer on the inside of the Nb tube.

The critical current value of this superconducting wire was 12T (50A).

Furthermore, while applying bending strain to this superconducting wire, the critical current (
1 was set at 1lllll, no decrease in the critical current value at a maximum bending strain of 1% was observed.

Implementation VA2 Nb -2at%■1 instead of the Nb tube in Example 1
When a wire rod was manufactured by using an alloy tube and repeating the process of inserting and joining in the same manner as in Example 1, Nb
It was successfully possible to process alloy tubes up to an outer diameter of 2.5nφ without breakage.

[Effects of the Invention] As described below, according to the present invention, a multicore Nb5Aλ superconducting wire can be manufactured without the need for intermediate annealing, and the wire can be easily heat-treated and thinned. It has certain advantages.

Representative Patent Attorney 10 Su Yamasa - (1 idiot) Continued from page 1 ■ Int, C1,' Identification symbol // H01B 12/10 @ Inventor Tomoyuki Kumano Office docket number 7227-5E Oda Sakae, Kawasaki-ku, Kawasaki City 2-1-1 Showa Electric Cable Co., Ltd.

Claims (1)

[Claims] C
A method for producing a Nb5Aβ superconducting wire, which comprises placing it in a stabilizing material and then subjecting it to heat treatment to form Nb5A° C. in a vacuum or an inert gas atmosphere.