A superconducting wire and a method for preparing the same

Abstract

The present invention discloses a superconducting wire and a preparation method thereof, belonging to the technical field of superconducting wires. In the present invention, a ceramic insulating material is sprayed on the surface of an Nb3Sn superconducting baseline through a plasma spraying process to obtain a superconducting wire including an insulating layer. The insulating layer prepared in the present invention is uniform and dense, and is tightly combined with the Nb3Sn superconducting wire, effectively solving the insulation problem of the Nb3Sn superconducting wire after phase-forming heat treatment. The preparation method provided by the present invention has the advantages of high working efficiency, simple repair process, strong repeatability, etc., and can be widely applied to superconducting wires that require high-temperature phase-forming heat treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of superconducting wires, and relates to a superconducting wire and a preparation method thereof. Background Art

[0002] Nb3Sn superconducting wires have important application values in many fields such as energy transmission, magnetic resonance imaging, and particle accelerators. However, high-performance Nb3Sn superconducting wires must undergo high-temperature heat treatment to complete the phase formation reaction. At the same time, to ensure their stable operation and avoid safety hazards such as leakage and performance degradation problems, the superconducting wires also need to have good insulation performance.

[0003] Traditional insulation means are difficult to meet the strict requirements of superconducting wires for insulation performance in high-temperature environments. For example, some organic insulation materials will decompose or age under high-temperature conditions, thereby losing their insulation effectiveness; while some inorganic insulation materials, such as glass fiber insulation materials, are difficult to form a tightly bonded insulation layer with superconducting wires in actual applications. In addition, the mechanical properties of glass fiber materials are easily affected by environmental conditions. Especially in high-temperature and high-humidity environments, their mechanical properties will significantly decrease, resulting in weakened insulation performance. The weaving process of glass fiber materials is time-consuming and inefficient, and it is easy to wear during the weaving process, forming weaving weak points, which affect the insulation effect. Once the insulation performance fails to meet the standards, the repair process is quite complex, affecting the reliability and stability of superconducting wires in high-temperature environments.

[0004] Therefore, a new method is developed to ensure that the surface insulation layer of Nb3Sn superconducting wires can still remain intact and have excellent insulation performance after phase formation heat treatment. Summary of the Invention

[0005] The present invention aims to solve the problems and defects existing in the above-mentioned prior art. The present invention provides a preparation method for a high-temperature insulation layer of Nb3Sn superconducting wires to solve the problems that the existing Nb3Sn superconducting wires use glass fiber insulation, with low working efficiency, difficult repair, and the mechanical properties will decline and the insulation performance will weaken after high-temperature phase formation heat treatment.

[0006] In a first aspect, the present invention provides a preparation method for a superconducting wire, including: preparing an insulation layer on the surface of a superconducting baseline. The method of the present invention includes: spraying an insulation material on the surface of the superconducting baseline by a plasma spraying process to obtain a superconducting wire containing an insulation layer.

[0007] Further, the superconducting baseline of the present invention is Nb3Sn; the preparation method of the Nb3Sn is any one of the internal tin method and the bronze method.

[0008] Further, the insulating material of the present invention is any one of alumina and 8YSZ, or a mixture of any one of silicon nitride and aluminum nitride and any one of polyimide, polyether ether ketone, and aramid fiber;

[0009] The particle size of the mixture is 5 - 100 μm.

[0010] Further, before preparing the insulating layer on the superconducting baseline of the present invention, the surface of the superconducting baseline needs to be polished and cleaned.

[0011] Further, the plasma gas used in the plasma spraying of the present invention is any one of argon, helium, and nitrogen, or a mixture of two of them, or a mixture of any one of them and hydrogen.

[0012] Further, the flow rate of the plasma gas of the present invention is 10 - 60 L / min;

[0013] The power of the plasma gas is 10 - 120 kW;

[0014] The purity of the plasma gas is 99.99% or above.

[0015] Further, when spraying using the plasma spraying process of the present invention, the distance between the spray gun and the superconducting baseline is 10 - 150 mm;

[0016] The spraying method is 360° rotary spraying, and the rotation speed of the spray gun is 100 - 500 rpm;

[0017] The rotation mode is positive - negative alternating spraying.

[0018] Further, when spraying using the plasma spraying process of the present invention, the incoming line speed of the superconducting baseline is 5 - 30 m / min;

[0019] The powder feeding rate is 5 - 30 g / min.

[0020] Further, after the plasma spraying of the present invention is completed, the superconducting wire is subjected to water cooling or air cooling treatment.

[0021] In the second aspect, the present invention provides a superconducting wire prepared by the above - mentioned preparation method.

[0022] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0023] 1. The present invention adopts plasma spraying technology to cover a uniform and dense ceramic insulating layer on the surface of the Nb3Sn superconducting baseline. This insulating layer can still maintain good insulating performance after the high-temperature phase formation heat treatment of the superconducting wire, effectively isolating the superconducting wire from the external environment, preventing leakage and other situations, and ensuring the normal operation of the superconducting wire after the high-temperature phase formation heat treatment.

[0024] 2. The present invention adopts plasma spraying technology to insulate the Nb3Sn superconducting wire. In terms of work efficiency, plasma spraying insulation can accurately and quickly form a uniform, continuous and thickness-controlled insulating layer on the surface of the superconducting wire through automated equipment, greatly improving the work rate, while the traditional glass fiber insulation is slow and time-consuming.

[0025] 3. The present invention adopts plasma spraying technology to insulate the Nb3Sn superconducting wire. In terms of repair characteristics, when the plasma spraying insulating layer is locally damaged, it can be quickly repaired through a specific plasma spraying process, with simple operation and a high degree of recovery of insulating performance after repair. Once the traditional glass fiber insulation is damaged, the repair process is complex and cumbersome, often requiring large-area removal of the glass fiber insulating layer and re-winding, with high repair costs and long time consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart for preparing an insulating layer on the Nb3Sn superconducting wire by plasma spraying. DETAILED DESCRIPTION OF THE INVENTION

[0027] Next, the technical solutions of the present invention will be described in conjunction with the embodiments. However, the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0028] Example 1

[0029] This example provides a method for realizing high-temperature insulation of Nb3Sn superconducting wire based on plasma spraying.

[0030] S1: Select an Nb3Sn superconducting baseline prepared by the conventional internal tin method, and the wire diameter of the Nb3Sn superconducting baseline is Φ2.0 mm. Use ethanol to clean the surface of the Nb3Sn superconducting baseline, remove the surface oil stain, then polish the surface with a scouring pad to remove the oxide layer, making the surface of the Nb3Sn superconducting baseline have a certain roughness. Ultrasonically clean the superconducting baseline and dry it, so that the surface of the Nb3Sn superconducting baseline is clean and conducive to the adhesion of the insulating layer.

[0031] S2: Mix alumina powder, silicon nitride powder, and polyimide powder evenly at a mass percentage of 70%, 25%, and 5% respectively, and make a powder with a particle size of 20 - 50 μm through mechanical ball milling as the insulating material. The purity of the alumina powder, silicon nitride powder, and polyimide powder is not less than 99.99%.

[0032] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: The plasma gas selects a mixed gas of argon and helium, where the purity of argon and helium reaches over 99.99%, the argon flow rate is 30 L / min, and the helium flow rate is 10 L / min; the power is set at 40 kW. The distance between the spray gun and the superconducting baseline is 70 mm, the rotation speed of the spray gun is 100 rpm, the incoming speed of the superconducting baseline is 30 m / min, and the powder feeding rate is 5 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation method adopts positive - negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real - time through the monitoring equipment and adjust the equipment parameters in a timely manner to ensure the uniformity and stability of spraying.

[0033] S4: Perform post - treatment on the superconducting wire after spraying, and conduct air - cooling treatment to further improve the densification and bonding force of the insulating layer.

[0034] Example 2

[0035] This example provides a method for achieving high - temperature insulation of Nb3Sn superconducting wires based on plasma spraying.

[0036] S1: Select an Nb3Sn superconducting baseline prepared by the conventional bronze method, and the wire diameter of the Nb3Sn superconducting baseline is Φ1.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol, remove the surface oil stain, then polish the surface with a scouring pad to remove the oxide layer, making the surface of the Nb3Sn superconducting baseline have a certain roughness. Ultrasonically clean the superconducting baseline and dry it, so that the surface of the Nb3Sn superconducting baseline is clean and conducive to the adhesion of the insulating layer.

[0037] S2: Mix 8YSZ (yttria - stabilized zirconia with 8% yttria) powder, aluminum nitride powder, and polyether ether ketone powder evenly at a mass percentage of 45%, 45%, and 10% respectively, and make a powder with a particle size of 5 - 15 μm through the sol - gel method as the insulating material. The purity of the 8YSZ powder, aluminum nitride powder, and polyether ether ketone powder is not less than 99.99%.

[0038] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: the plasma gas is a mixed gas of argon and helium, with the argon flow rate being 40 L / min and the helium flow rate being 5 L / min; the power is set at 100 kW. The distance between the spray gun and the superconducting baseline is 20 mm, the rotation speed of the spray gun is 500 rpm, the incoming speed of the superconducting baseline is 5 m / min, and the powder feeding rate is 30 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive - negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters timely to ensure the uniformity and stability of spraying.

[0039] S4: Post - process the superconducting wire after spraying, and perform cooling treatment by air cooling to further improve the density and bonding force of the insulating layer.

[0040] Example 3

[0041] This embodiment provides a method for realizing high - temperature insulation of Nb3Sn superconducting wire based on plasma spraying.

[0042] S1: Select an Nb3Sn superconducting baseline prepared by the conventional bronze method, and the wire diameter of the Nb3Sn superconducting baseline is Φ1.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol. After removing the surface oil stain, polish the surface with a scouring pad to remove the oxide layer, making the surface of the Nb3Sn superconducting baseline have a certain roughness. Ultrasonically clean the superconducting baseline and dry it, so that the surface of the Nb3Sn superconducting baseline is clean and conducive to the adhesion of the insulating layer.

[0043] S2: Mix 8YSZ (yttria - stabilized zirconia with 8% yttria), silicon nitride powder and aramid fiber powder evenly according to the mass percentages of 45%, 45% and 10%, and make a powder with a particle size of 50 - 70 μm through the screening method as the insulating material. The purity of 8YSZ powder, silicon nitride powder and aramid fiber powder is not less than 99.99%.

[0044] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: the plasma gas is a mixed gas of hydrogen and nitrogen, with the hydrogen flow rate being 5 L / min and the nitrogen flow rate being 55 L / min; the power is set at 120 kW. The distance between the spray gun and the superconducting baseline is 150 mm, the rotation speed of the spray gun is 500 rpm, the incoming line speed of the superconducting baseline is 5 m / min, and the powder feeding rate is 30 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive-negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters in a timely manner to ensure the uniformity and stability of spraying.

[0045] S4: Perform post-treatment on the superconducting wire after spraying, and carry out cooling treatment by air cooling to further improve the density and bonding force of the insulating layer.

[0046] Example 4

[0047] This example provides a method for realizing high-temperature insulation of Nb3Sn superconducting wires based on plasma spraying.

[0048] S1: Select a Nb3Sn superconducting baseline prepared by the conventional internal tin method, and the wire diameter of the Nb3Sn superconducting baseline is Φ2.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol. After removing the surface oil stain, polish the surface with a scouring pad to remove the oxide layer, so that the surface of the Nb3Sn superconducting baseline has a certain roughness. Ultrasonically clean the superconducting baseline and dry it to make the surface of the Nb3Sn superconducting baseline clean and conducive to the adhesion of the insulating layer.

[0049] S2: Mix alumina powder, aluminum nitride powder and polyimide powder evenly according to the mass ratio of 7:2:1, and make the powder with a particle size of 70 - 100 μm by the screening method as the insulating material. The purity of the alumina powder, aluminum nitride powder and polyimide powder is not less than 99.99%.

[0050] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operations on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: argon is selected as the plasma gas, with the purity of argon reaching over 99.99%, the argon flow rate is 10 L / min; the power is set at 10 kW. The distance between the spray gun and the superconducting baseline is 10 mm, the rotation speed of the spray gun is 100 rpm, the incoming line speed of the superconducting baseline is 30 m / min, and the powder feeding rate is 5 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive-negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters in a timely manner to ensure the uniformity and stability of spraying.

[0051] S4: Post-treat the superconducting wire after spraying, and perform cooling treatment through air cooling to further improve the density and bonding force of the insulating layer.

[0052] Example 5

[0053] This example provides a method for realizing high-temperature insulation of Nb3Sn superconducting wires based on plasma spraying.

[0054] S1: Select an Nb3Sn superconducting baseline prepared by the conventional internal tin method, with the wire diameter of the Nb3Sn superconducting baseline being Φ2.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol. After removing the surface oil stain, polish the surface with a scouring pad to remove the oxide layer, making the surface of the Nb3Sn superconducting baseline have a certain roughness. Ultrasonically clean the superconducting baseline and dry it to make the surface of the Nb3Sn superconducting baseline clean and conducive to the adhesion of the insulating layer.

[0055] S2: Mix alumina powder, silicon nitride powder, and polyetheretherketone powder evenly according to a mass ratio of 10:9:1, and make a powder with a particle size of 70 - 100 μm through the screening method as the insulating material. The purity of the alumina powder, silicon nitride powder, and polyetheretherketone powder is not less than 99.99%.

[0056] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: helium is selected as the plasma gas, and the purity of helium reaches over 99.99%, the helium flow rate is 30 L / min; the power is set at 50 kW. The distance between the spray gun and the superconducting baseline is 60 mm, the rotation speed of the spray gun is 100 rpm, the incoming line speed of the superconducting baseline is 30 m / min, and the powder feeding rate is 5 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive-negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters timely to ensure the uniformity and stability of spraying.

[0057] S4: Post-treat the superconducting wire after spraying, and perform cooling treatment through water cooling to further improve the density and bonding force of the insulating layer.

[0058] Example 6

[0059] This example provides a method for realizing high-temperature insulation of Nb3Sn superconducting wire based on plasma spraying.

[0060] S1: Select a Nb3Sn superconducting baseline prepared by the conventional bronze method, and the wire diameter of the Nb3Sn superconducting baseline is Φ1.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol, remove the surface oil stain, then polish the surface with a scouring pad to remove the oxide layer, making the surface of the Nb3Sn superconducting baseline have a certain roughness. Ultrasonically clean the superconducting baseline and dry it to make the surface of the Nb3Sn superconducting baseline clean and conducive to the adhesion of the insulating layer.

[0061] S2: Mix aluminum nitride powder, 8YSZ (yttria-stabilized zirconia with 8% yttria) powder and aramid fiber powder evenly according to the mass percentages of 45%, 45% and 10%, and make a powder with a particle size of 50 - 70 μm through the screening method as the insulating material. The purity of the aluminum nitride powder, 8YSZ powder and aramid fiber powder is not less than 99.99%.

[0062] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: nitrogen is selected as the plasma gas, and the nitrogen flow rate is 60 L / min; the power is set at 60 kW. The distance between the spray gun and the superconducting baseline is 80 mm, the rotation speed of the spray gun is 500 rpm, the incoming line speed of the superconducting baseline is 5 m / min, and the powder feeding rate is 30 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive-negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters in a timely manner to ensure the uniformity and stability of spraying.

[0063] S4: Post-treat the superconducting wire after spraying, and perform cooling treatment through water cooling to further improve the density and bonding force of the insulating layer.

[0064] Example 7

[0065] This example provides a method for realizing high-temperature insulation of Nb3Sn superconducting wire based on plasma spraying.

[0066] S1: Select an Nb3Sn superconducting baseline prepared by the conventional bronze method, and the wire diameter of the Nb3Sn superconducting baseline is Φ1.0 mm. Clean the surface of the Nb3Sn superconducting baseline with ethanol. After removing the surface oil stain, polish the surface with a scouring pad to remove the oxide layer, so that the surface of the Nb3Sn superconducting baseline has a certain roughness. Ultrasonically clean the superconducting baseline and dry it to make the surface of the Nb3Sn superconducting baseline clean and conducive to the adhesion of the insulating layer.

[0067] S2: Mix 8YSZ (yttria-stabilized zirconia with 8% yttria), aluminum nitride powder and aramid fiber powder evenly according to the mass percentages of 45%, 45% and 10%, and make a powder with a particle size of 50 - 70 μm through the screening method as the insulating material. The purities of the 8YSZ powder, aluminum nitride powder and aramid fiber powder are not less than 99.99%.

[0068] S3: Start the plasma spraying equipment, feed the prepared insulating powder into the plasma jet through the powder feeding device, and perform spraying operation on the surface of the Nb3Sn superconducting baseline to form an initial insulating layer. The plasma spraying parameters are as follows: The plasma gas is a mixed gas of hydrogen and helium, with the hydrogen flow rate being 5 L / min and the helium flow rate being 50 L / min; the power is set at 100 kW. The distance between the spray gun and the superconducting baseline is 100 mm, the rotation speed of the spray gun is 500 rpm, the incoming line speed of the superconducting baseline is 5 m / min, and the powder feeding rate is 30 g / min. During the spraying process, 360° rotary spraying is adopted, and the rotation mode is positive-negative alternating spraying to ensure that the insulating material can be evenly sprayed on the surface of the superconducting baseline. Observe the spraying situation in real time through the monitoring equipment and adjust the equipment parameters in a timely manner to ensure the uniformity and stability of spraying.

[0069] S4: Post-treat the superconducting wire after spraying, and perform cooling treatment through air cooling to further improve the density and bonding strength of the insulating layer.

[0070] Example 8

[0071] This example provides the performance parameters of the superconducting wire.

[0072] Table 1 Performance Parameters of Nb3Sn Superconducting Wire

[0073]

[0074] As shown in Table 1, in the present invention, an insulating layer is sprayed on the Nb3Sn superconducting baseline through plasma spraying technology. Compared with the traditional glass fiber insulation, the working efficiency is increased from 10 m / h to 300 - 1800 m / h, and the working efficiency is increased by 30 - 180 times; the insulation resistance is also increased from 500 MΩ to 2000 MΩ, an increase of 4 times; the leakage point repair rate is also increased from 5 h / time to 0.5 h / time, and the efficiency is increased by 10 times. It effectively improves the insulation efficiency and insulation resistance of the Nb3Sn superconducting baseline, greatly reduces the leakage point repair time, improves the working efficiency, and reduces the repair cost.

[0075] The thickness of the insulating layer of the present invention is controlled by controlling the plasma gas, gas flow rate, power, spraying distance, gun rotation speed, powder feeding rate, and wire feeding speed. When the gas flow rate increases and the power increases, both will result in an increase in the plasma jet velocity and the powder particle flight velocity, and the insulating layer will be denser. In addition, after spraying the insulating layer on the Nb3Sn superconducting substrate by plasma spraying technology, water cooling or air cooling treatment is carried out to further improve the densification and bonding strength of the insulating layer, prevent defects such as cracks and peeling of the insulating layer caused by excessive temperature, refine the insulating layer structure, and help improve the quality of the insulating layer. Among them, the cooling rate is 200~500 °C / min. If the cooling rate is too low, the excessive temperature will affect the bonding strength between the insulating layer and the substrate, resulting in peeling of the insulating layer; if the cooling rate is too fast, the insulating layer and the substrate will be damaged due to excessive thermal stress.

[0076] In addition, the main purpose of using plasma spraying technology to spray ceramics on alloy wires is to improve the wear resistance, corrosion resistance, and high-temperature resistance of the alloy wires. Among them, "high-temperature resistance" refers to the ability of the alloy material to resist workpiece deformation under special working environments, such as high temperature and high-intensity working conditions, when the temperature rises due to friction. The purpose of spraying the ceramic layer in the present invention is to ensure the insulation effect under low-temperature working conditions after high-temperature phase formation heat treatment, and the main function is still insulation.

[0077] The embodiments described above are some embodiments of the present invention, rather than all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the present invention claimed, but merely represents the selected embodiments of the present invention. All other embodiments obtained by relevant deductions and substitutions made by those of ordinary skill in the art under the premise of not making creative efforts based on the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A method for preparing a superconducting wire, comprising: An insulating layer is prepared on the surface of a superconducting baseline, which is characterized by including: spraying an insulating material on the surface of the superconducting baseline by a plasma spraying process to obtain a superconducting wire containing the insulating layer; The superconducting baseline is Nb3Sn; the preparation method of the Nb3Sn is any one of the internal tin method and the bronze method; The insulating material is a mixture of three materials, wherein, the first material is one of alumina and 8YSZ, the second material is one of silicon nitride and aluminum nitride, and the third material is one of polyimide, polyether ether ketone, and aramid fiber; The particle size of the mixture is 5 - 100 μm.

2. The preparation method according to claim 1, characterized in that, Before preparing the insulating layer on the superconducting baseline, the surface of the superconducting baseline needs to be polished and cleaned.

3. The preparation method according to claim 1, characterized in that, The plasma gas used in the plasma spraying is any one or a mixture of two of argon, helium, nitrogen, and hydrogen; 4. The preparation method according to claim 3, characterized in that, The flow rate of the plasma gas is 10 - 60 L / min; The power of the plasma gas is 10 - 120 kW; The purity of the plasma gas is 99.99% or more.

5. The preparation method according to claim 1, wherein When spraying by using the plasma spraying process, the distance between the spray gun and the superconducting baseline is 10 - 150 mm; The spraying method is 360° rotary spraying, and the rotation speed of the spray gun is 100 - 500 rpm; The rotation mode is positive - negative alternating spraying.

6. The preparation method according to claim 1, wherein When spraying by using the plasma spraying process, the incoming line speed of the superconducting baseline is 5 - 30 m / min; The powder feeding rate is 5 - 30 g / min.

7. The preparation method according to claim 1, characterized in that, After the plasma spraying is completed, the superconducting wire is subjected to water cooling or air cooling treatment.

8. A superconducting wire, characterized in that, Obtained by the preparation method according to any one of claims 1 - 7.

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