A method of forming a superconducting conductor

Abstract

The embodiment of the application provides a forming method of a superconducting conductor, which comprises the following steps: installing a high-temperature superconducting wire in a mounting groove of a conductor framework and filling a gap between the mounting groove and the high-temperature superconducting wire with a first low-melting-point welding wire to obtain a first mounting body; wherein the high-temperature superconducting wire has an arbitrary torsion angle during the installation process; performing first cold rolling on the first mounting body to make the first low-melting-point welding wire adhere to the mounting groove and the high-temperature superconducting wire, and obtaining a cold-rolled mounting body; installing the cold-rolled mounting body into a metal sleeve with a hollow cylindrical structure, sealing the metal sleeve after vacuumizing the metal sleeve, and obtaining a sealed mounting body; performing second cold rolling on the sealed mounting body, performing hot rolling on the second cold-rolled sealed mounting body, and obtaining the superconducting conductor after cooling. The embodiment of the application realizes low porosity and does not damage the superconductivity of the high-temperature superconducting conductor by filling the low-melting-point welding wire, vacuumizing the metal sleeve, and performing external cold rolling and hot rolling on the sleeve, and effectively improves the mechanical strength of the high-temperature superconducting conductor.

Description

Technical Field

[0001] This invention relates to a method for forming a superconducting conductor. Background Technology

[0002] Currently, low-temperature superconducting high-magnetic-field magnets are widely used in medical, scientific research, and industrial production. However, with increasing demands for magnetic field strength, low-temperature superconductivity is difficult to apply to large magnets exceeding 15 tons due to its low critical magnetic field. Second-generation high-temperature superconducting materials possess extremely high critical magnetic fields and critical current densities, offering a better option for constructing high-magnetic-field magnets. Higher magnetic fields and current densities mean greater electromagnetic forces. However, second-generation high-temperature superconducting tapes have multi-layered composite structures, particularly the superconducting layer, which is a ceramic thin film material grown on a Hastelloy or stainless steel substrate with relatively low bonding strength. This makes the superconducting layer prone to fragmentation and loss of superconductivity under strong electromagnetic forces. Furthermore, the superconducting layer is a temperature-sensitive material; it is generally believed that prolonged exposure to temperatures above 250°C will cause it to lose its superconductivity. Therefore, when applying second-generation high-temperature superconducting tapes to high-magnetic-field magnets, it is necessary to fabricate the high-temperature superconducting tape into a conductor with high mechanical strength and high current carrying capacity, and to reserve cooling channels within the conductor to maintain it in a consistently low-temperature environment.

[0003] Because low-temperature superconducting wires have small diameters (generally less than 1 mm), good flexibility, high mechanical strength, and no anisotropy in mechanical properties, CICC conductors have high porosity after molding (generally higher than 20%). Therefore, the traditional low-temperature superconducting CICC conductor molding process can use a tube-to-tube followed by extrusion molding. High-temperature superconducting tapes have a multi-layered composite structure. Although they have higher tensile and compressive strengths than low-temperature superconducting wires, they can lose superconductivity under relatively small shear, torsional, and tearing stresses. Therefore, the preparation of high-temperature superconducting conductors is difficult to achieve using ordinary cold plastic molding; and high temperatures will cause the superconducting layer to lose its superconductivity, making high-temperature rolling molding also difficult. Patent CN 110767376 B uses a process of first coating with solder and then vacuum brazing, which is difficult to eliminate the non-negligible gaps left after vacuum melting and welding. In particular, if the gaps appear on the surface of the high-temperature superconducting tape, the tape will be unable to withstand the electromagnetic stress under high magnetic fields and high current densities, causing the superconducting layer at the gaps to peel off or collapse and lose its superconductivity. Vacuum pressure impregnation of solder with a high-temperature superconducting conductor after it has been threaded through a tube is another feasible forming method. However, this method requires leaving more solder filling channels, resulting in an excessively high solder filling ratio. Furthermore, gas release and uneven pressure during the vacuum pressure impregnation process can also cause uncontrollable porosity. Summary of the Invention

[0004] This invention provides a method for forming a superconducting conductor to improve the mechanical strength of a high-temperature superconducting conductor and ensure its superconductivity.

[0005] The embodiments of the present invention are achieved through the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a method for forming a superconducting conductor, comprising:

[0007] A high-temperature superconducting wire is installed in the mounting groove of the conductor skeleton, and the gap between the mounting groove and the high-temperature superconducting wire is filled with a first low-melting-point welding wire to obtain a first mounting body; wherein, the high-temperature superconducting wire has an arbitrary torsion angle during the installation process;

[0008] The first mounting body is subjected to a first cold rolling process to ensure that the first low-melting-point welding wire is in contact with both the mounting groove and the high-temperature superconducting wire, thereby obtaining a cold-rolled mounting body.

[0009] The cold-rolled mounting body is inserted into a hollow cylindrical metal sleeve, and the metal sleeve is vacuumed and sealed to obtain a sealed mounting body.

[0010] After the sealing mounting body undergoes a second cold rolling, it is then hot rolled and cooled to obtain the superconducting conductor.

[0011] Furthermore, the mounting groove is a U-shaped groove, and the depth of the mounting groove is the same as the diameter of the high-temperature superconducting wire; the conductor skeleton is a cylindrical structure, and the cross-sectional area S of the first low-melting-point welding wire is calculated by formula (1):

[0012]

[0013] Where R is the conductor skeleton radius and r is the high-temperature superconducting wire radius.

[0014] Furthermore, the conductor skeleton is provided with a cooling channel, the central axis of the cooling channel coincides with the central axis of the conductor skeleton; around the cooling channel, at least a pair of mounting grooves are symmetrically distributed on the conductor skeleton with the central axis of the conductor skeleton as the axis of symmetry, and the mounting grooves are used to install the high temperature superconducting wire and the first low melting point welding wire.

[0015] Furthermore, the first low-melting-point welding wire is a welding wire with a melting point below 250°C, and its material is an alloy containing tin, lead and / or bismuth.

[0016] Furthermore, the diameter of the metal sleeve is 1.05R-1.1R.

[0017] Furthermore, after a second cold rolling of the sealing mounting body, the second cold-rolled sealing mounting body is then hot-rolled, and after cooling, the superconducting conductor is obtained; comprising:

[0018] The sealing mount is subjected to a second cold rolling process to reduce its outer radius to 1.02R+H, where H is the wall thickness of the metal sleeve.

[0019] The second cold-rolled sealing mount is heated to no higher than 250°C and hot-rolled to make the outer radius of the second cold-rolled sealing mount 1.0R+H-1.01R+H. After cooling, the superconducting conductor is obtained.

[0020] Furthermore, the conductor skeleton is made of copper, aluminum, or copper alloy; the metal sleeve is made of stainless steel, copper alloy, or aluminum alloy.

[0021] Furthermore, the high-temperature superconducting wire is a circular wire formed by encapsulating multiple high-temperature superconducting tapes in a metal tube, capable of withstanding transverse compressive stress of over 50 MPa.

[0022] Furthermore, the high-temperature superconducting wire includes:

[0023] Stacked strips, including multiple high-temperature superconducting thin strips stacked together; and

[0024] A copper cladding is used to encapsulate the stacked strips, and the gap between the copper cladding and the stacked strips is filled with a second low-melting-point solder wire.

[0025] Furthermore, the second low-melting-point welding wire is a welding wire with a melting point below 250°C.

[0026] Compared with the prior art, the embodiments of the present invention have the following advantages and beneficial effects:

[0027] The present invention discloses a method for forming a superconducting conductor. By filling with low-melting-point welding wire, vacuuming inside a metal sleeve, and cold rolling and hot rolling outside the sleeve, the porosity inside the high-temperature superconducting conductor can be effectively controlled. This achieves extremely low porosity without damaging the superconductivity of the high-temperature superconducting conductor, effectively improving the mechanical strength of the high-temperature superconducting conductor, especially its ability to resist its own electromagnetic stress. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram illustrating the steps of a superconducting conductor forming process.

[0030] Figure 2 This is a schematic diagram of the process for forming a superconducting conductor.

[0031] Figure 3 This is a schematic diagram of the structure of a high-temperature superconducting wire.

[0032] Figure 4 This is a schematic diagram of the structure of a superconducting conductor.

[0033] Figure 5 This is a schematic diagram of another type of superconducting conductor.

[0034] Figure 6 for Figure 5 A schematic diagram of the conductor skeleton in the diagram.

[0035] The attached diagram shows the markings and corresponding component names:

[0036] 1-First low melting point welding wire, 2-Conductor skeleton, 3-High temperature superconducting wire, 4-U-shaped groove, 5-Cooling channel, 6-Metal sheath, 7-Copper cladding, 8-Stacked strip, 9-Second low melting point welding wire, 10-Strip direction. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0038] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0039] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0041] Example

[0042] To improve the mechanical strength and ensure the superconductivity of high-temperature superconducting conductors, this invention provides a method for forming superconducting conductors, referring to... Figure 1-6 As shown, it includes:

[0043] S1. A high-temperature superconducting wire 3 is installed in the mounting groove of the conductor skeleton 2 and the gap between the mounting groove and the high-temperature superconducting wire is filled with a first low-melting-point welding wire to obtain a first mounting body; wherein, the high-temperature superconducting wire has an arbitrary torsion angle during the installation process;

[0044] S2. The first mounting body is subjected to a first cold rolling process to make the first low melting point welding wire 1 adhere to both the mounting groove and the high temperature superconducting wire, thereby obtaining a cold-rolled mounting body;

[0045] S3. Insert the cold-rolled mounting body into a hollow cylindrical metal sleeve, evacuate the metal sleeve and seal it to obtain a sealed mounting body;

[0046] Armoring the high-temperature superconducting conductor with a metal sleeve further enhances its mechanical strength, enabling the high-temperature superconducting tape inside the conductor to withstand electromagnetic stress under strong magnetic fields and large currents.

[0047] S4. After the sealing mounting body is subjected to a second cold rolling, the sealing mounting body after the second cold rolling is then subjected to hot rolling, and after cooling, the superconducting conductor is obtained.

[0048] In this embodiment of the invention, low melting point welding wire refers to welding wire with a melting point below 250°C.

[0049] Therefore, the embodiments of the present invention can effectively control the porosity inside the high-temperature superconducting conductor by filling with low-melting-point welding wire, vacuuming inside the metal sleeve, and cold rolling and hot rolling outside the tube. This achieves extremely low porosity without damaging the superconductivity of the high-temperature superconducting conductor, effectively improving the mechanical strength of the high-temperature superconducting conductor, especially its ability to resist its own electromagnetic stress.

[0050] Optionally, the conductor skeleton is provided with a cooling channel 5, the central axis of which coincides with the central axis of the conductor skeleton; at least one pair of mounting slots are symmetrically distributed on the conductor skeleton around the cooling channel with the central axis of the conductor skeleton as the axis of symmetry, and the mounting slots are used to install the high-temperature superconducting wire and the first low-melting-point welding wire. The conductor skeleton 2 has a cooling channel 5 at its center, through which liquid nitrogen, cold helium or liquid helium can be introduced to cool the superconducting conductor.

[0051] Furthermore, the mounting groove is a U-shaped groove 4, and the depth of the mounting groove is the same as the diameter of the high-temperature superconducting wire; the conductor skeleton is a cylindrical structure, and the cross-sectional area S of the first low-melting-point welding wire is calculated by formula (1):

[0052]

[0053] Where R is the conductor skeleton radius and r is the high-temperature superconducting wire radius.

[0054] Furthermore, the first low-melting-point welding wire is a welding wire with a melting point below 250°C, and its material is an alloy containing tin, lead and / or bismuth.

[0055] Furthermore, the diameter of the metal sleeve is 1.05R-1.1R.

[0056] Furthermore, after a second cold rolling of the sealing mounting body, the second cold-rolled sealing mounting body is then hot-rolled, and after cooling, the superconducting conductor is obtained; comprising:

[0057] The sealing mount is subjected to a second cold rolling process to reduce its outer radius to 1.02R+H, where H is the wall thickness of the metal sleeve 6.

[0058] The second cold-rolled sealing mount is heated to no higher than 250°C and hot-rolled to make the outer radius of the second cold-rolled sealing mount 1.0R+H-1.01R+H. After cooling, the superconducting conductor is obtained.

[0059] Exemplary superconducting conductors have at least the following two structures.

[0060] In some embodiments, the structure of the mounting slot is referenced Figure 4 As shown, the mounting groove is a U-shaped groove; the opening of the U-shaped groove faces the inner wall of the metal sleeve, and all the U-shaped grooves are arranged parallel to the central axis of the conductor skeleton along the surface of the conductor skeleton.

[0061] refer to Figure 2As shown, the conductor skeleton is a cylindrical structure; the central axis of the conductor skeleton coincides with the central axis of the cooling channel. Multiple U-shaped grooves parallel to the cooling channel are excavated on the outer surface of the conductor skeleton around the cooling channel along an axis parallel to the central axis of the conductor skeleton. The opening of the mounting groove faces the inner wall of the metal sleeve. Optionally, there are 6 U-shaped grooves, and each U-shaped groove is evenly distributed in the circumference of the conductor skeleton.

[0062] In other embodiments, the structure of the mounting slot is referenced. Figure 5 and 6 As shown, the mounting groove is a U-shaped spiral mounting groove; the opening of the U-shaped spiral mounting groove faces the inner wall of the metal sleeve, and all the U-shaped spiral mounting grooves are spirally arranged on the surface of the conductor skeleton with the central axis of the conductor skeleton as the center line. Optionally, there are 6 U-shaped spiral mounting grooves, and each U-shaped spiral mounting groove is evenly distributed in the circumference of the conductor skeleton.

[0063] refer to Figure 6 As shown, the conductor skeleton is a cylindrical structure; the central axis of the conductor skeleton coincides with the central axis of the cooling channel. With the central axis of the conductor skeleton as the center line, multiple U-shaped spiral mounting grooves are spirally arranged on the outer surface of the conductor skeleton around the cooling channel, and the openings of the mounting grooves face the inner wall of the metal sleeve.

[0064] Optionally, the U-shaped spiral mounting groove has a cutoff of 20R-50R, a semi-circular bottom with a diameter of 1.0r-1.02r, and a groove depth of 2.0r-2.04r, where R is the conductor skeleton radius and r is the high-temperature superconducting wire radius.

[0065] Furthermore, the conductor skeleton is made of copper, aluminum, or copper alloy; the metal sleeve is made of stainless steel, copper alloy, or aluminum alloy.

[0066] Furthermore, the high-temperature superconducting wire is a circular wire formed by encapsulating multiple high-temperature superconducting tapes in a metal tube, capable of withstanding transverse compressive stress of over 50 MPa.

[0067] Furthermore, the high-temperature superconducting wire includes:

[0068] Stacked strip 8, comprising multiple high-temperature superconducting thin strips stacked together; and

[0069] The copper cladding 7 is used to encapsulate the stacked strip, and the gap between the copper cladding and the stacked strip is filled with a second low-melting-point solder wire 9.

[0070] Furthermore, the second low-melting-point welding wire 9 is a welding wire with a melting point below 250°C.

[0071] Furthermore, the surface direction 10 of the stacked strip is parallel to the direction of the external magnetic field. Furthermore, the high-temperature superconducting wire has a cylindrical structure.

[0072] The direction of the strip surface refers to the direction parallel to the surface of the high-temperature superconducting thin strip.

[0073] The copper cladding 7 and the second low-melting-point welding wire 9 effectively protect the internal high-temperature superconducting conductor when the high-temperature superconducting wire 3 is stranded into the conductor skeleton, ensuring uniform stress distribution and preventing loss of superconductivity due to stress concentration. The copper cladding 7 and the second low-melting-point welding wire 9 possess excellent thermal and electrical conductivity at low temperatures, ensuring good thermal stability of the high-temperature superconducting wire 3. After the hot rolling step, the melting of the second low-melting-point welding wire allows for a tighter connection between the stacked strip and the copper cladding, enhancing the overall mechanical strength of the high-temperature superconducting wire structure.

[0074] The high-temperature superconducting wire 3 has a cylindrical structure. Therefore, when the high-temperature superconducting wire 3 is stranded in the U-shaped groove of the skeleton, the direction of the strip surface of the high-temperature superconducting wire 3 can be arbitrarily controlled. In particular, according to the magnetic field distribution of the superconducting conductor, the arrangement of its strip surface direction 10 can be designed and realized so that the strip surface direction 10 is as parallel as possible to the magnetic field. This allows full use of the high current carrying capacity of the high-temperature superconducting tape in a parallel field (the critical current of the high-temperature superconducting tape in a parallel field at low temperature is 3-8 times that in a vertical field).

[0075] Specifically, the methods for forming superconducting conductors include:

[0076] 1. Material preparation

[0077] The conductor skeleton is formed by hot extrusion, and has cooling holes inside to allow liquid nitrogen, cold helium, or liquid helium to cool the conductor; the outer side of the skeleton has axisymmetrically distributed U-shaped grooves. Figure 2 (Only one is shown in the picture for illustration), its depth is the diameter of the high-temperature superconducting wire, used to embed the high-temperature superconducting wire and solder; the skeleton material is copper, aluminum or copper alloy with high strength.

[0078] High-temperature superconducting wire is a circular wire formed by encapsulating multiple high-temperature superconducting tapes in a metal tube. It can withstand transverse compressive stress of more than 50MPa without damaging the superconductivity of the internal high-temperature superconducting tapes.

[0079] The welding wire is a low-temperature welding wire with a melting point below 200℃. Its material is an alloy containing tin, lead, bismuth, and other materials, and its cross-sectional area is... Where R is the skeleton radius and r is the radius of the high-temperature superconducting wire;

[0080] The metal sleeve is a high-strength alloy with an inner radius of 1.05R to 1.1R, and the material is stainless steel, copper alloy, aluminum alloy, etc.

[0081] 2. High-temperature superconducting wire and welding wire winding

[0082] The high-temperature superconducting wire is wound into the U-shaped groove of the conductor skeleton, so that the high-temperature superconducting wire and the arc segment of the U-shaped groove are closely fitted. The U-shaped groove structure allows the high-temperature superconducting circle to be twisted at any angle during the winding process, which is beneficial to utilizing the high current carrying capacity of the high-temperature superconducting tape under parallel field.

[0083] Two welding wires are tightly wound around both sides of the high-temperature superconducting wire, which facilitates the uniform filling of the entire conductor by the solder in subsequent processes. The solder can fully absorb stress and strain during the rolling process, protecting the high-temperature superconducting tape from damage. The solder fills the gaps between the metal sleeve, the high-temperature superconducting wire and the skeleton, which can effectively enhance the strength of the high-temperature superconducting conductor.

[0084] 3. Cold-rolled solder

[0085] The high-temperature superconducting conductor that has been wound in the previous step is rolled using a round tube cold rolling mill. Since the strength of the welding wire is much lower than that of the high-temperature superconducting wire, the welding wire can be cold rolled appropriately to allow the solder to better adhere to the skeleton and the high-temperature superconducting wire, and to reduce the inner diameter of the sleeve that needs to be threaded through the tube later, thereby reducing the final rolling deformation.

[0086] 4. Tube sealing

[0087] The high-temperature superconducting conductor, cold-rolled in the previous step, is inserted into a metal sleeve. A vacuum is then evacuated from both ends of the sleeve to a vacuum level less than 10 Pa before sealing both ends. This internal vacuum prevents oxidation reactions in the high-temperature superconducting conductor, its framework, and the sleeve, thus avoiding interference with the bonding between components and reducing the thermal stability of the high-temperature superconducting conductor. The internal vacuum eliminates the need for a large vacuum chamber, allowing the high-temperature superconducting conductor to be rolled using a general-purpose round tube rolling mill, reducing production difficulty and cost.

[0088] 5. Hot rolling forming

[0089] The sealed high-temperature superconducting conductor is initially cold-rolled to an outer radius of 1.02R+H using a round tube cold rolling mill, where H is the wall thickness of the metal sleeve. The high-temperature superconducting conductor is then heated to no higher than 250℃ and further hot-rolled to an outer radius of 1.0R+H-1.01R+H, followed by natural cooling. The initial cold rolling reduces the gap between the metal sleeve, the skeleton, and the high-temperature superconducting wire, preventing excessive compressive stress that could damage its superconductivity and reducing deformation during subsequent hot rolling. Heating allows the solder to fully melt and wet the gaps between the metal sleeve, the high-temperature superconducting wire, and the skeleton, and then welds them together after cooling, effectively enhancing the mechanical strength of the high-temperature superconducting conductor. The rapid hot rolling at a relatively low temperature avoids damage to the superconductivity of the high-temperature superconducting wire due to excessive temperature or stress, while simultaneously controlling the internal porosity of the high-temperature superconducting conductor to a very small proportion, enhancing the high-temperature superconducting strand's resistance to internal stress.

[0090] Thus, the embodiments of the present invention realize the application of cold rolling and hot rolling to the rolling forming of high-strength high-temperature superconducting conductors, avoiding the disadvantage of general rolling that easily causes damage to the superconductivity of the high-temperature superconducting tape inside the conductor, while having the advantages of high forming efficiency, low cost and high strength.

[0091] Among them, the cold rolling of welding wire reduces the required diameter of the metal sleeve and the amount of subsequent rolling deformation, thereby reducing the over-hardening of the metal sleeve caused by cold plastic forming (the high temperature superconducting tape limits the heat treatment temperature and cannot anneal the formed metal sleeve).

[0092] The vacuuming inside the metal sleeve eliminates the need for a huge vacuum chamber that would otherwise require placing all the metal tubes in a vacuum environment simultaneously. This not only prevents oxidation of the high-temperature superconducting wire, frame, and metal sleeve during heating in a vacuum environment, but also effectively reduces equipment costs.

[0093] Among them, the combination of vacuuming the metal sleeve, filling with low-temperature solder and heating and rolling outside the tube can effectively control the porosity inside the high-temperature superconducting conductor, achieving extremely low porosity without damaging the superconductivity of the high-temperature superconducting tape, effectively improving the mechanical strength of the high-temperature superconducting conductor, especially the ability of the internal high-temperature superconducting wire to resist its own electromagnetic stress.

[0094] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for forming a superconducting conductor, characterized in that, include: A high-temperature superconducting wire is installed in the mounting groove of the conductor skeleton, and the gap between the mounting groove and the high-temperature superconducting wire is filled with a first low-melting-point welding wire to obtain a first mounting body; wherein, the high-temperature superconducting wire has an arbitrary torsion angle during the installation process; The first mounting body is subjected to a first cold rolling process to ensure that the first low-melting-point welding wire is in contact with both the mounting groove and the high-temperature superconducting wire, thereby obtaining a cold-rolled mounting body. A cold-rolled mounting body is inserted into a hollow cylindrical metal sleeve, and the metal sleeve is vacuumed and sealed to obtain a sealed mounting body. After the sealing mounting body undergoes a second cold rolling, the sealed mounting body after the second cold rolling is then hot rolled, and after cooling, the superconducting conductor is obtained. The first low-melting-point welding wire is a welding wire with a melting point below 250°C; The hot rolling of the second cold-rolled sealing mounting body includes heating the second cold-rolled sealing mounting body to a temperature not exceeding 250°C and then hot rolling it.

2. The method for forming a superconducting conductor as described in claim 1, characterized in that, The mounting groove is a U-shaped groove, and the depth of the mounting groove is the same as the diameter of the high-temperature superconducting wire; the conductor skeleton is a cylindrical structure, and the cross-sectional area S of the first low-melting-point welding wire is calculated by formula (1): （1） Where R is the conductor skeleton radius and r is the high-temperature superconducting wire radius.

3. The method for forming a superconducting conductor as described in claim 1, characterized in that, The conductor skeleton is provided with a cooling channel, the central axis of which coincides with the central axis of the conductor skeleton; around the cooling channel, at least a pair of mounting slots are symmetrically distributed on the conductor skeleton with the central axis of the conductor skeleton as the axis of symmetry, and the mounting slots are used to install high temperature superconducting wire and first low melting point welding wire.

4. The method for forming a superconducting conductor as described in claim 2, characterized in that, The first low-melting-point welding wire is made of an alloy containing tin, lead and / or bismuth.

5. The method for forming a superconducting conductor as described in claim 2, characterized in that, The diameter of the metal sleeve is 1.05R-1.1R.

6. The method for forming a superconducting conductor as described in claim 2, characterized in that, After a second cold rolling of the sealing mount, the sealed mount after the second cold rolling is hot rolled, and after cooling, the superconducting conductor is obtained; comprising: The sealing mount is subjected to a second cold rolling process to reduce its outer radius to 1.02R+H, where H is the wall thickness of the metal sleeve. The second cold-rolled sealing mount is heated to no higher than 250°C and hot-rolled to reduce the outer radius of the second cold-rolled sealing mount to 1.0R+H to 1.01R+H. After cooling, the superconducting conductor is obtained.

7. The method for forming a superconducting conductor as described in claim 1, characterized in that, The conductor skeleton is made of copper, aluminum, or copper alloy; the metal sleeve is made of stainless steel, copper alloy, or aluminum alloy.

8. The method for forming a superconducting conductor as described in claim 1, characterized in that, High-temperature superconducting wires are circular wires formed by encapsulating multiple high-temperature superconducting tapes in a metal tube, capable of withstanding transverse compressive stresses of over 50 MPa.

9. The method for forming a superconducting conductor as described in claim 8, characterized in that, The high-temperature superconducting wire includes: Stacked strips, including multiple high-temperature superconducting thin strips stacked together; and A copper cladding is used to encapsulate the stacked strips, and a second low-melting-point solder wire is filled in the gap between the copper cladding and the stacked strips. The second low-melting-point welding wire is a welding wire with a melting point below 250°C.

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