SN-TI ALLOY POWDER FOR SUPERCONDUCTING WIRE, METHOD FOR PREPARING SAME, AND METHOD FOR MANUFACTURING SUPERCONDUCTING WIRE USING THE SAME

Abstract

Provided are a Sn—Ti alloy powder for a superconducting wire, the Sn—Ti alloy powder making it possible to improve superconducting characteristics by minimizing the size of Sn—Ti particles dispersed in a Sn-based alloy, a method for preparing the same, and a method for manufacturing a superconducting wire using the same, wherein a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 μm or less, and a content of Ti in the entire alloy is 0.5 wt % to 3 wt %, and the method of preparing the Sn—Ti alloy powder for a superconducting wire includes: a Sn—Ti alloy melting step of melting a Sn—Ti alloy or a Sn—Ti alloy processed material; and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

Claims

1. A method of preparing a Sn—Ti alloy powder for a superconducting wire, wherein a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 μm or less, and a content of Ti in the entire alloy is 0.5 wt % to 3 wt %, the method comprising: a Sn—Ti alloy melting step of melting the Sn—Ti alloy or a Sn—Ti alloy processed material; and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

2. A method of manufacturing a superconducting wire by using the Sn—Ti alloy powder for a superconducting wire, of claim 1, the method comprising: a sub-element or spacer formation step of manufacturing a sub-element or spacer by performing press processing or powder extrusion on the Sn—Ti alloy powder or inserting the Sn—Ti alloy into a Cu tube and performing drawing thereon; an sub-element assembly step of installing the manufactured sub-element in the Cu tube; and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

3. A method of preparing a Sn—Ti alloy powder for a superconducting wire, wherein a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 u m or less, and a content of Ti in the entire alloy is 0.5 wt % to 3 wt %, the method comprising: a Sn—Ti alloy melting step of adding, on the basis of Sn and Ti, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In, and melting the same; and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

4. The method of claim 3, wherein in the entire alloy, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In are 0.1 wt % to 2 wt %.

5. A method of manufacturing a superconducting wire by using the Sn—Ti alloy powder for a superconducting wire, of claim 3, the method comprising: a sub-element or spacer formation step of manufacturing a sub-element or spacer by performing press processing or powder extrusion on the Sn—Ti alloy powder or inserting the Sn—Ti alloy into a Cu tube and performing drawing thereon; a sub-element assembly step of installing the manufactured sub-element in the Cu tube; and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

6. A method of preparing a Sn—Ti alloy powder for a superconducting wire, wherein a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 u m or less, and a content of Ti in the entire alloy is 0.5 wt % to 3 wt %, the method comprising: a Sn—Ti alloy melting step of melting the Sn—Ti alloy; a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere; a sub-element or spacer formation step of manufacturing a sub-element or spacer by adding one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In, in addition to the Sn—Ti alloy powder, performing press processing or powder extrusion on the above Sn—Ti alloy powder and the added materials or inserting on the above Sn—Ti alloy powder and the added materials into a Cu tube and performing drawing processing thereon; an sub-element assembly step of installing the manufactured sub-element in the Cu tube; and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

7. The method of claim 6, wherein in the entire alloy, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In are 0.1 wt % to 2 wt %.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0035] FIG. 1 is a block diagram illustrating a method of preparing a Sn—Ti alloy powder for a superconducting wire according to the present disclosure, and a method of manufacturing a superconducting wire by using the same.

[0036] FIGS. 2A-2B are photographic images comparing tissues of a cross-section of a Sn—Ti intermetallic compound prepared according to the method of preparing a Sn—Ti alloy powder for a superconducting wire according to the present disclosure and a cross-section of an intermetallic compound in a Sn alloy according to the related art.

MODE OF DISCLOSURE

[0037] A preferred embodiment of a method of manufacturing a superconducting wire, according to the present disclosure, will be described in detail with reference to the attached drawings.

[0038] FIG. 1 is a block diagram illustrating a method of manufacturing a superconducting wire according to the present disclosure, and FIGS. 2A-2B are photographic images comparing tissues of a cross-section of a Sn—Ti intermetallic compound prepared according to a method of preparing a Sn—Ti alloy powder for a superconducting wire, according to the present disclosure, and a cross-section of an intermetallic compound in a Sn alloy according to the related art.

[0039] In general, Nb.sub.3Sn superconducting wires are manufactured by densely arranging, in an anti-diffusion tube, a plurality of modules, in which sub-elements and spacers are formed by forming a hole in a forged Cu billet through gun drilling, inserting a Nb rod into the hole, and then inserting Nb filaments in a Cu base around the Nb rod, and the sub-elements and spacers are cut and cleaned, and forming a restacking billet and performing steps such as drawing, wire drawing, heat treatment, or the like thereon. The superconducting wire according to the present disclosure is characterized in the process of formation of sub-elements and spacers during the above manufacturing process.

[0040] In the present disclosure, in manufacturing a sub-element or spacer, a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 μm or less, and the melted Sn—Ti alloy is directly used in as the sub-element or spacer.

[0041] Here, a content of Ti in the entire Sn—Ti alloy is 0.5 wt % to 3 wt %.

[0042] A method of preparing the Sn—Ti alloy powder as above includes, as illustrated in FIG. 1, a Sn—Ti alloy melting step of melting a Sn—Ti alloy or a Sn—Ti alloy processed material, and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

[0043] In detail, in the Sn—Ti alloy powder formation step, a method of inserting Sn and Ti into a furnace, performing vacuum pumping to lower the inside of a spray chamber to 2.5×10.sup.−5 Torr or less, and then, forming an inert gas atmosphere to substitute the inside of the spray chamber with an inert gas such as Ar gas, to 1 bar, and spraying the inert gas at 100 bar by heating a Sn—Ti alloy in the furnace to 1100° C. to 1300° C. and melting the same, and opening an orifice of the furnace to spray a molten product of the Sn—Ti alloy, may be applied, but the step is not limited to the above-described conditions.

[0044] The method of manufacturing a superconducting wire by using the Sn—Ti alloy powder prepared as described above may include a sub-element or spacer formation step of manufacturing a sub-element or spacer by performing press processing or powder extrusion on the Sn—Ti alloy powder or inserting the Sn—Ti alloy powder into a Cu tube and performing drawing thereon, an sub-element assembly step of installing the manufactured sub-element in a Cu tube, and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

[0045] According to this, hardening of the interface due to residual stress on the surface due to forced grinding of Sn alloy castings according to the related art, through mechanical grinding, and deterioration of the superconducting properties caused by the hardening, and the difficulty in terms of processing such as the increase of heat treatment time in the manufacturing process may be addressed, and furthermore, excellent bonding between powders during processing may be achieved, and above all, the particle shape of the Sn—Ti intermetallic compound formed in a final superconducting wire may be optimized, and the size thereof may be minimized to a state, which is difficult to achieve according to the methods of the related art.

[0046] In addition, the processability and productivity may be increased by simplifying the complex powder manufacturing process consisting of rolling, drawing, crushing, grinding, and the like.

[0047] In fact, when comparing photograph (A) of the Sn—Ti intermetallic compound prepared according to the present disclosure with photograph (B) of the Sn—Ti intermetallic compound in the Sn alloy according to the related art, the particles of the Sn—Ti intermetallic compound particles formed according to the present disclosure are much closer to a spherical shape than the particles formed by the related art, and the particle size thereof is also significantly smaller.

[0048] Hereinafter, application examples of the method of preparing Sn—Ti alloy powder according to the present disclosure are described.

[0049] Application Example 1 of the method of preparing a Sn—Ti alloy powder, according to the present disclosure, includes a Sn—Ti alloy melting step of adding, on the basis of Sn and Ti, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, In, and melting the same, and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

[0050] Here, in the entire alloy, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In are 0.1 wt % to 2 wt %.

[0051] In detail, in the Sn—Ti alloy powder formation step, a method of inserting, into a furnace, in addition to Sn and Ti, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In, at a 0.1 wt % to 2 wt % with respect to the entire alloy, performing vacuum pumping to lower the inside of a spray chamber to 2.5×10.sup.−5 Torr or less, and then, forming an inert gas atmosphere to substitute the inside of the spray chamber with an inert gas such as Ar gas, to 1 bar, and spraying the inert gas at 100 bar by heating a Sn—Ti alloy in the furnace to 1100° C. to 1300° C. and melting the same, and opening an orifice of the furnace to spray a molten product of the Sn—Ti alloy, may be applied, but the step is not limited to the above-described conditions.

[0052] The method of manufacturing a superconducting wire by using the Sn—Ti alloy powder prepared using the Sn—Ti alloy powder preparing method according to Application Example 1 may include a sub-element or spacer formation step of manufacturing a sub-element or spacer by performing press processing or powder extrusion on the Sn—Ti alloy powder or inserting the Sn—Ti alloy powder into a Cu tube and performing drawing thereon, an sub-element assembly step of installing the manufactured sub-element in a Cu tube, and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

[0053] Application Example 2 of the method of preparing a Sn—Ti alloy powder, according to the present disclosure, includes a Sn—Ti alloy melting step of melting a Sn—Ti alloy and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy in an inert gas atmosphere through a nozzle.

[0054] In detail, in the Sn—Ti alloy powder formation step, a method of inserting Sn and Ti into a furnace, performing vacuum pumping to lower the inside of a spray chamber to 2.5×10.sup.−5 Torr or less, and then, forming an inert gas atmosphere to substitute the inside of the spray chamber with an inert gas such as Ar gas, to 1 bar, and spraying the inert gas at 100 bar by heating a Sn—Ti alloy in the furnace to 1100° C. to 1300° C. and melting the same, and opening an orifice of the furnace to spray a molten product of the Sn—Ti alloy, may be applied, but the step is not limited to the above-described conditions.

[0055] The method of manufacturing a superconducting wire by using the Sn—Ti alloy powder prepared using the Sn—Ti alloy powder preparing method according to Application Example 2 may include a sub-element or spacer formation step of manufacturing a sub-element or spacer by adding one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In, in addition to the Sn—Ti alloy powder, performing press processing or powder extrusion on the above Sn—Ti alloy powder and the added materials or inserting on the above Sn—Ti alloy powder and the added materials into a Cu tube and performing drawing processing thereon, an sub-element assembly step of installing the manufactured sub-element in a Cu tube, and a superconducting wire manufacturing step of completing a superconducting wire by performing wire fabricating process such as drawing.

[0056] Here, in the entire alloy, one or more materials selected from Nb, Ta, Cu, Zr, Hf, V, Zn, and In are 0.1 wt % to 2 wt %.

[0057] According to this, hardening of the interface due to residual stress on the surface due to forced grinding of Sn alloy castings according to the related art, through mechanical grinding, and deterioration of the superconducting properties caused by the hardening, and the difficulty in terms of processing such as the increase of heat treatment time in the manufacturing process may be addressed, and furthermore, excellent bonding between powders during processing may be achieved, and above all, the particle shape of the Sn—Ti intermetallic compound formed in a final superconducting wire may be optimized, and the size thereof may be minimized to a state, which is difficult to achieve according to the methods of the related art. In addition, by adding Nb, Ta, Cu, Zr, Hf, V, Zn, In, the mechanical properties may be improved to thereby improve the processibility during processing to a superconducting wire.

[0058] In addition, the processability and productivity may be increased by simplifying the complex powder manufacturing process consisting of rolling, drawing, crushing, grinding, and the like.

[0059] According to the configuration as described above, the superconducting properties and mechanical properties may be improved and processibility and productivity may be increased by minimizing the size of the Sn—Ti intermetallic compound particles dispersed in a Sn-based alloy of the present disclosure, to an average particle size of 3 μm or less, and adding Nb, Ta, Cu, Zr, Hf, V, Zn, In, or the like to the alloy.

INDUSTRIAL APPLICABILITY

[0060] The Sn—Ti alloy powder for a superconducting wire, the method of preparing the same, and the method of manufacturing a superconducting wire by using the same, according to the present disclosure, are applicable the manufacture of superconducting wire and various industrial fields where superconducting wires are used.