Precursor for manufacturing superconducting wire and superconducting wire using same

Abstract

The present invention relates to a precursor of a superconducting wire and a superconducting wire using same, in which the precursor can further improve superconducting performance such as high critical current density and the like. The precursor comprises: a first Cu tube; and a plurality of sub-elements stacked and disposed in the first Cu tube, wherein the sub-elements are formed by mixed stacking of, in a second Cu tube, a Nb wire consisting of Nb or a Nb alloy and a Sn wire consisting of Sn or an Sn alloy.

Description

Precursor for manufacturing superconducting wire and superconducting wire using the same

[0001] The present invention relates to a precursor of a superconducting wire and a superconducting wire using the same, and more specifically, to a precursor of a superconducting wire and a superconducting wire using the same, which can improve superconducting properties and thermo-magnetic stability through structural improvement.

[0002]

[0003] Since the discovery of the superconductivity phenomenon, research on the superconductivity of alloys and compounds has been continuously conducted with the discovery of the second type of superconductor, and as a result, great progress has been made in the technological development of superconducting wires using Nb3Sn, NbTi, etc.

[0004] Nonetheless, the current superconducting wire market is experiencing an increasing demand for superconducting wires with improved critical current characteristics, such as the demand for high-field magnets.

[0005] However, in the case of conventional high-performance superconducting wires, despite continuous technological improvements, there are still problems in obtaining sufficient mechanical and superconducting properties.

[0006] Related technology includes Korean Patent Registration No. 10-01847880 (announced on May 24, 2018).

[0007]

[0008] The present invention was invented to solve the above-mentioned problems, and the purpose of the present invention is to provide a precursor of a superconducting wire and a superconducting wire using the precursor, which can further improve superconducting performance and stability by having a high critical current density through structural improvement and allowing current to flow stably even in a low magnetic field region.

[0009]

[0010] As a means to solve the above-mentioned problem, the precursor of the superconducting wire of the present invention is,

[0011] 1st Cu tube and

[0012] It is composed of a plurality of sub-elements that are stacked and arranged within the first Cu tube,

[0013] The above sub-elements are:

[0014] Inside the second Cu tube,

[0015] Nb wire and Nb wire including Nb or Nb alloy

[0016] It is characterized by being composed of mixed and laminated Sn wires including Sn or Sn alloy.

[0017] In addition, the Nb wire is characterized in that it is arranged in a honeycomb structure around the Sn wire.

[0018] In addition, the above Nb wire,

[0019] The third Cu tube,

[0020] It is characterized in that it is made of a plurality of Nb filaments made of Nb or a Nb alloy within the third Cu tube.

[0021] In addition, a thermal stabilization barrier layer is provided between the second Cu tube inside the sub-element and the mixed laminate of the Nb wire and the Sn wire.

[0022] The area of ​​the above thermal stabilization barrier layer is 5 to 25% of the total area of ​​the sub-element.

[0023] The area of ​​the above second Cu tube is characterized by being 15 to 40% of the total area of ​​the sub-element.

[0024] In addition, it further comprises a Cu core part installed at the center of a plurality of sub-element stacks inside the first Cu tube,

[0025] The above Cu core portion is characterized by being composed of 5 to 25% of the total precursor area.

[0026] In addition, the present invention is characterized by being a superconducting wire using a precursor of the above-mentioned superconducting wire.

[0027]

[0028] Through the problem-solving means described above, the precursor of the superconducting wire of the present invention and the superconducting wire using the precursor have various advantages, such as improving the wire structure, ensuring uniform diffusion of Sn, and thermal stability, thereby improving the mechanical properties or superconducting properties of the wire.

[0029]

[0030] FIG. 1 is a cross-sectional view showing an example of a superconducting wire precursor according to the present invention.

[0031] Fig. 2 is a cross-sectional view showing another example of a superconducting wire precursor according to the present invention.

[0032] FIG. 3 is a cross-sectional view showing another example of a superconducting wire precursor according to the present invention.

[0033] Figure 4 is a photograph showing a cross-sectional view of a superconducting wire using a superconducting wire precursor according to the present invention.

[0034] [Explanation of symbols]

[0035] 10: First Cu tube

[0036] 20: Sub-element

[0037] 21: Nb wire 22: Sn wire

[0038] 24: Third Cu tube 25: Sn rod

[0039] 26: Nb filament 26': 4th Cu tube

[0040] 27: Diffusion barrier layer

[0041] 28: Thermal stabilization barrier layer

[0042] 30: Second Cu tube

[0043] 40: Cu core

[0044]

[0045] Preferred embodiments of a precursor of a superconducting wire according to the present invention and a superconducting wire using the precursor are described in detail with reference to the attached drawings.

[0046]

[0047] FIG. 1 is a cross-sectional view showing an example of a superconducting wire precursor according to the present invention, FIG. 2 is a cross-sectional view showing another example of a superconducting wire precursor according to the present invention, FIG. 3 is a cross-sectional view showing another example of a superconducting wire precursor according to the present invention, and FIG. 4 is a photograph showing a cross-sectional appearance of a superconducting wire using a superconducting wire precursor according to the present invention.

[0048]

[0049] As illustrated in FIG. 1, the precursor of the superconducting wire according to the present invention is composed of a first Cu tube (10) installed on the outside and a plurality of sub-elements (20) stacked and arranged inside the first Cu tube (10), and the sub-elements (20) are formed by mixing and stacking a Nb wire (21) including Nb or a Nb alloy and a Sn wire (22) including Sn or a Sn alloy inside a second Cu tube (30).

[0050]

[0051] The precursor thus formed is heat treated so that Sn existing in the Sn wire (22) diffuses into the Nb wire (21) and reacts with Nb to produce Nb3Sn, a superconductor.

[0052]

[0053] And, between the first Cu tube (10) and the plurality of sub-elements (20) stacked and arranged within the first Cu tube (10), a diffusion prevention layer (27) made of Nb, Ta, etc. to block further diffusion of Sn to the outside may be provided.

[0054]

[0055] The above Nb wire (21) is arranged in a honeycomb structure around the Sn wire (22) so that Sn is uniformly diffused in all directions.

[0056]

[0057] Specifically, in the present invention, the Sn wire (22) is formed of a third Cu tube (24) and a Sn rod (25) made of Sn or a Sn alloy inside the third Cu tube (24), and the Nb wire (21) is formed of a third Cu tube (24) and a plurality of Nb filaments (26) made of Nb or a Nb alloy inside the third Cu tube (24).

[0058]

[0059] Each Nb filament (26) is positioned within the fourth Cu tube (26').

[0060]

[0061] By configuring a plurality of Nb filaments (26) inside the sub-element (20) in this way, more uniform diffusion of Sn is possible, and there are advantages such as shortening the heat treatment time by reducing the diffusion distance.

[0062]

[0063] As an application example, as shown in FIG. 2, in the present invention, the second Cu tube (30) inside the sub-element (20) is made of oxygen-free copper (OFC), and a thermal stabilization barrier layer (28) is installed between the second Cu tube (30) and the mixed laminate of the Nb wire (21) and the Sn wire (22).

[0064]

[0065] Here, the thermal stabilization barrier layer (28) is made of Nb, Ta, NbTi, etc. to prevent Sn from diffusing inside to the outside, and as a result, the thermal stability is strengthened by positioning the oxygen-free copper (OFC) connecting the outer periphery (border) of the plurality of sub-elements (20) after heat treatment, thereby increasing the critical current value (I c ) and the superconducting properties such as the increase in the magnetic hysteresis loss (Qh) are improved.

[0066]

[0067] The area of ​​the above thermal stabilization barrier layer (28) is set to 5 to 25% of the total area of ​​the sub-element (20), and the area of ​​the second Cu tube (30) is set to 15 to 40% of the total area of ​​the sub-element (20). This is because if it is less than 15%, it is difficult to expect a sufficient heat diffusion effect, and if it exceeds 40%, the superconductor area is reduced, which is detrimental to the superconducting characteristics.

[0068]

[0069] In addition, as shown in FIG. 3, the present invention may include a Cu core portion (40) installed at the center of a plurality of sub-elements (20) stacked inside the first Cu tube (10).

[0070]

[0071] Through this, it is possible to minimize the occurrence of excessive stress in the center of the wire during the drawing process and the resulting wire breakage.

[0072]

[0073] It is preferable that the above Cu core portion (40) be comprised of 5 to 25% of the total precursor area.

[0074]

[0075] Fig. 4 shows a cross-section of a superconducting wire manufactured through processing such as heat treatment of a precursor of a superconducting wire according to the embodiment shown in Fig. 3.

[0076]

[0077] Through the above-described configuration, the precursor of the superconducting wire according to the present invention and the superconducting wire using the precursor have various advantages, such as improving the wire structure, uniformly diffusion of Sn, and improving the mechanical properties or superconducting properties of the wire by securing thermal stability.

[0078]

[0079] The present invention relates to a superconducting wire and has industrial applicability.

Claims

1. 1st Cu tube and It is composed of a plurality of sub-elements that are arranged and stacked within the first Cu tube, The above sub-elements are: Inside the second Cu tube, Nb wire and Nb wire comprising Nb or Nb alloy It is characterized by being composed of a mixed lamination of Sn wires including Sn or Sn alloy. Precursor of superconducting wire 2. In claim 1, The above Nb wire is characterized in that it is arranged in a honeycomb structure around the Sn wire. Precursor of superconducting wire 3. In claim 2, The above Nb wire is, The third Cu tube, It is characterized by comprising a plurality of Nb filaments made of Nb or Nb alloy within the third Cu tube. Precursor of superconducting wire 4. Using a precursor of a superconducting wire as claimed in any one of claims 1 to 4. Superconducting wire

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