Device and method for preparing high-binding-force high-temperature superconducting strip isolating layer

Abstract

The invention particularly relates to a device and method for preparing a high-binding-force high-temperature superconducting strip isolating layer, and belongs to the technical field of high-temperature superconducting material preparation. The device for preparing the high-temperature superconducting tape isolating layer comprises a precursor liquid tank (1), a closed cavity (2), a pretreatment device, a liquid supplementing device and a base band releasing and conveying system, and after a high-temperature superconducting tape is pretreated, the high-temperature superconducting tape isolating layer is prepared by adopting a multi-channel repeated chemical solution leveling method for stepped heating and continuous tape conveying. According to the device and the method for preparing the high-temperature superconducting tape isolating layer, the industrial problem that high binding force and low roughness are difficult to consider in preparation of the high-temperature superconducting tape isolating layer is solved, and the device and the method have high performance, high stability and commercial potential and are suitable for large-scale production of second-generation high-temperature superconducting tapes.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature superconducting material preparation technology, specifically relating to an apparatus and method for preparing a high-bonding high-temperature superconducting tape isolation layer. Background Technology

[0002] REBCO high-temperature superconducting tapes possess advantages such as high operating temperature and strong current carrying capacity under high applied magnetic fields, making them promising for applications in strong magnetic field fields such as controlled nuclear fusion and magnetron sputtering silicon single crystal furnaces. The structure of REBCO high-temperature superconducting tapes is not a single superconducting material, but a precise multilayer composite structure, typically including a flexible metal substrate, an isolation layer, a seed layer, a superconducting layer, and a protective layer. During operation under strong magnetic fields, REBCO high-temperature superconducting tapes can experience interlayer delamination due to electromagnetic forces and thermal stress. This delamination is particularly pronounced between the metal substrate and the ceramic oxide isolation layer, where the different properties of the metal and ceramic make them more susceptible to Lorentz forces and thermal stress during low-temperature operation, leading to a decline in REBCO tape performance.

[0003] Traditional isolation layer fabrication techniques involve mechanical or electrochemical polishing to reduce the surface roughness of the Hastelloy substrate. This is followed by physical vapor deposition (PVD) using magnetron sputtering or other methods to deposit one or more layers of amorphous oxide, which then hinders element diffusion. However, mechanical polishing is costly, struggles to achieve the desired surface roughness, and lacks stability in the continuous production of long metal strips. Electrochemical polishing is only suitable for surfaces with roughness less than 30 nanometers and generates significant amounts of chemical waste liquid and gas. Furthermore, the subsequent PVD deposition of one or more layers of amorphous oxide requires high-vacuum equipment, resulting in high costs and low target utilization.

[0004] Existing patent CN103985479B discloses a method for preparing high-temperature superconducting coated conductor tape. This patent uses a chemical solution planarization (SDP) method to prepare an isolation layer on a metal substrate. It requires multiple solution changes to clean the metal substrate. During the production of kilometer-long tapes, the solute concentration will continue to decrease, making it impossible to guarantee the consistency of surface roughness and the reliability of the film system adhesion. Summary of the Invention

[0005] To address the problems of high cost, low adhesion of long-distance superconducting tape films, and inconsistent surface roughness in existing technologies, there is an urgent need to develop a device and method for fabricating long-distance high-temperature superconducting tape isolation layers with high surface adhesion and low surface roughness. The purpose of this invention is to provide a device and method for fabricating high-adhesion high-temperature superconducting tape isolation layers, providing technical support for the application of high-temperature superconducting tapes in the field of magnets.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention discloses an apparatus for preparing a high-temperature superconducting tape isolation layer, the apparatus comprising: a precursor liquid tank (1), a sealed chamber (2), a pretreatment device, a liquid replenishment device, and a baseband delivery system;

[0008] The pretreatment device includes an alcohol tank (3) and a press, the press including a first press (4) and a second press (5); the first press (4) is located on the horizontal plane of the alcohol tank (3), and the second press (5) is located above the alcohol tank (3);

[0009] The sealed chamber (2) includes heaters, which are arranged from left to right as a first heater (201), a second heater (202), a third heater (203), a fourth heater (204), a fifth heater (205), and a sixth heater (206);

[0010] The replenishment device includes a liquid level monitor (6), a water pump (7), and a replenishment tank (8). The liquid level monitor (6) is located in the precursor liquid tank (1). The precursor liquid tank (1) is connected to the water pump (7) through a pipe, and the water pump (7) is connected to the replenishment tank (8) through a pipe. The signal from the liquid level monitor (6) is transmitted to the water pump (7), and the water pump replenishes the liquid through the pipe.

[0011] The baseband delivery system includes a tape feeding wheel (9), a speed measuring wheel (10), a steering wheel (11), and a tape take-up wheel (12);

[0012] The high-temperature superconducting tape is released by the tape release wheel (9) and passes through the first press (4), the second press (5), the first heater (201), the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) in sequence around the speed measuring wheel (10) and the steering wheel (11). Finally, the high-temperature superconducting tape isolation layer is received by the tape take-up wheel (12).

[0013] Specifically, the pretreatment device includes the following steps: the high-temperature superconducting tape is wiped by a first press (4), soaked in an alcohol bath (3), and wiped by a second press (5) to complete the cleaning of the high-temperature superconducting tape, and then dried in a first heater (201); the soaking in the alcohol bath (3) is an ultrasonic treatment.

[0014] This invention uses a lint-free cloth from a first press (4) to wipe the high-temperature superconducting tape to remove surface contaminants; then it is immersed in an alcohol bath (3) for ultrasonic treatment for deep cleaning; finally, the surface is wiped with alcohol by a lint-free cloth from a second press (5) and dried by a first heater (201). The overall cleaning of the high-temperature superconducting tape is simpler and does not require multiple solution changes.

[0015] Specifically, the first press (4) and the second press (5) include a dust-free cloth.

[0016] In some embodiments, the first and second presses may also include other cleaning equipment.

[0017] Specifically, the sealed chamber (2) is equipped with an exhaust vent (13) for regulating the gas environment inside the chamber.

[0018] Specifically, the temperature of the first heater (201) is 180-220℃; the temperatures of the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) are 480-650℃.

[0019] In this embodiment of the invention, the temperature of the first heater is 200°C.

[0020] This invention employs gradient heating, first reacting at a low temperature to reduce thermal stress mismatch and improve the bonding force between the isolation layer and the baseband, and then reacting at a high temperature to promote solvent evaporation and organic matter decomposition, thereby reducing surface roughness.

[0021] Specifically, the solution in the precursor liquid tank (1) includes a yttrium acetate solution and a surfactant solution, wherein the concentration of the yttrium acetate solution is 0.06-0.15 mol / L and the concentration of the surfactant solution is 0.04-0.1 mol / L.

[0022] Specifically, the surfactant solution is selected from one or more of diethanolamine, diethylenetriamine, sodium dodecyl sulfate, and dodecylbenzenesulfonic acid, preferably diethanolamine.

[0023] Adding surfactants to the precursor solution tank can reduce the surface tension of the precursor solution, allowing it to adhere better to the surface of the high-temperature superconducting tape. Through 3-5 heating and coating cycles, the thickness of the amorphous oxide layer on the surface of the high-temperature superconducting tape can reach over 300 nm, while simultaneously hindering element diffusion and promoting the nucleation of biaxial textured oxide layers.

[0024] Specifically, the device is used for the fabrication of high-temperature superconducting tape isolation layers ranging from hundreds to thousands of meters in length.

[0025] During the coating process of high-temperature superconducting tape, the solution in the precursor liquid tank is continuously consumed. Through the replenishment device, when the liquid level monitor detects that the liquid level is too low, the water pump replenishes the solution in the replenishment tank into the precursor liquid tank to ensure that the solute concentration is consistent during the preparation of long-distance tape.

[0026] Secondly, the present invention discloses a method for preparing a high-temperature superconducting tape isolation layer, the method being based on the aforementioned apparatus.

[0027] Specifically, the method includes the following steps:

[0028] (1) Cleaning of high-temperature superconducting tape: The high-temperature superconducting tape is cleaned by wiping with the first pressure machine, soaking in the alcohol bath, wiping with the second pressure machine, and then dried in the first heater;

[0029] (2) Prepare a 0.06-0.15 mol / L yttrium acetate solution and a 0.04-0.1 mol / L surfactant solution, and pour them into the precursor solution tank;

[0030] (3) The high-temperature superconducting tape cleaned in step (1) is heated by the second heater, the third heater, the fourth heater, the fifth heater and the sixth heater, and a continuous tape-carrying and multi-channel repeated chemical solution planarization method is used to prepare the high-temperature superconducting tape isolation layer;

[0031] Specifically, the temperature of the first heater (201) is 180-220℃; the temperatures of the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) are 480-650℃.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention adopts a staged heating process (e.g., 200℃→480℃→560℃→580℃→620℃) to avoid stress concentration caused by constant temperature heating, promote interface densification, and improve the bonding strength by more than 40% compared with the traditional process (comparison of groups 4 and 8 with the constant temperature group). The addition of diethanolamine optimizes the interfacial wettability and synergistically enhances the bonding strength with the gradient temperature.

[0034] (2) The roughness of the kilometer-long high-temperature superconducting tape prepared by the device of the present invention is uniformly distributed (e.g., Ra is stable at 0.55-0.60 nm in the 400m-600m section).

[0035] (3) This device supports flexible adjustment of the concentration of ammonium acetate (0.06-0.12 mol / L) and diethanolamine (0.005-0.015 mol / L), and is suitable for a variety of superconducting material systems. Attached Figure Description

[0036] Figure 1 This invention relates to an apparatus for preparing a high-temperature superconducting tape isolation layer;

[0037] Figure 1 In the middle, 1-precursor liquid tank, 2-sealed chamber, 201-first heater, 202-second heater, 203-third heater, 204-fourth heater, 205-fifth heater, 206-sixth heater, 3-alcohol tank, 4-first press, 5-second press, 6-liquid level monitor, 7-water pump, 8-replenishment tank, 9-release pulley, 10-speed measuring wheel, 11-steering wheel, 12-retractor, and 13-exhaust vent;

[0038] Figure 2 The results show the roughness measurements of the isolation layer of the kilometer-long high-temperature superconducting tape. A represents the roughness at 0 meters, B represents the roughness at 200 meters, C represents the roughness at 400 meters, D represents the roughness at 600 meters, E represents the roughness at 800 meters, and F represents the roughness at 100 meters. Detailed Implementation

[0039] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0040] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0041] like Figure 1 As shown, the apparatus for preparing a high-temperature superconducting tape isolation layer provided by the present invention includes:

[0042] Pre-driving liquid tank (1), sealed chamber (2), pretreatment device, replenishment device and baseband delivery system;

[0043] The pretreatment device includes an alcohol tank (3) and a press, which includes a first press (4) and a second press (5); the first press (4) is located on the horizontal plane of the alcohol tank (3), and the second press (5) is located above the alcohol tank (3);

[0044] The interior of the sealed chamber (2) includes heaters, which are arranged from left to right as the first heater (201), the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206);

[0045] The liquid replenishment device includes a liquid level monitor (6), a water pump (7), and a liquid replenishment tank (8). The liquid level monitor (6) is located in the precursor liquid tank (1). The precursor liquid tank (1) is connected to the water pump (7) through a pipe, and the water pump (7) is connected to the liquid replenishment tank (8) through a pipe. The signal from the liquid level monitor (6) is transmitted to the water pump (7), and the water pump replenishes the liquid through the pipe.

[0046] The baseband delivery system includes a delivery pulley (9), a speed measuring pulley (10), a steering pulley (11), and a take-up pulley (12);

[0047] The high-temperature superconducting tape is released by the tape release wheel (9) and passes through the first press (4), the second press (5), the first heater (201), the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) in sequence around the speed measuring wheel (10) and the steering wheel (11). Finally, the high-temperature superconducting tape isolation layer is received by the tape take-up wheel (12).

[0048] In this embodiment of the invention, the high-temperature superconducting tape uses Hastelloy base tape.

[0049] Example 1: Preparation of the isolation layer of high-temperature superconducting tape

[0050] The present invention provides a method for preparing a high-temperature superconducting tape isolation layer based on the aforementioned apparatus, comprising the following steps:

[0051] Hastelloy base tape is wound around the unwinding pulley, according to Figure 1 The tape passes sequentially through the speed measuring wheel, the steering wheel, and the heater, finally winding onto the take-up wheel. The feed and take-up wheels are controlled by a motor, which adjusts the tape speed based on feedback from the speed measuring wheel and provides tension to keep the base tape taut, with a tension range between 20-50N.

[0052] (1) The pulley rotates clockwise under the control of the motor. The Hastelloy base belt is cleaned by wiping with the first press, soaking in the alcohol tank, and wiping with the second press, and then dried in the first heater.

[0053] (2) Prepare a 0.06-0.15 mol / L yttrium acetate solution and a 0.04-0.1 mol / L diethanolamine solution, and pour them into the precursor solution tank;

[0054] (3) The Hastelloy substrate cleaned in step (1) is heated by the second, third, fourth, fifth and sixth heaters, continuously carried, and prepared by multi-channel repeated chemical solution planarization method to prepare a high-temperature superconducting tape isolation layer;

[0055] Table 1. Effects of heater temperature, yttrium acetate, and diethanol on bonding strength.

[0056]

[0057] In this embodiment, the high-temperature superconducting tape isolation layer was prepared according to the parameters in Table 1, and the bonding strength was tested.

[0058] Adhesion strength testing method: The scratch method is adopted. A diamond-tipped needle is used to continuously scratch the coating surface while gradually increasing the load on the needle. The load force applied at the moment when the coating is completely scratched or obvious peeling occurs is the adhesion strength of the coating, expressed in Newtons (N).

[0059] As shown in Table 1, compared with Group 1 and Group 5, when the concentration of yttrium acetate decreased from 0.06 mol / L to 0.12 mol / L, the binding force decreased from 146.1 N to 152.7 N, indicating that high concentration of ammonium acetate may slightly reduce the binding force, but the effect is not significant. Compared with Group 1 and Group 2, when the concentration of diethanolamine decreased from 0.01 mol / L to 0 mol / L, the binding force decreased from 146.1 N to 141.3 N, indicating that the addition of diethanolamine has a positive effect on improving the binding force.

[0060] The temperature curves for groups 4 and 8, from 200℃ to 480℃ to 530 / 560℃ to 580 / 620℃, showed the highest bonding strength (208.4 N and 209.1 N), significantly better than group 1 (bonding strength only 146.1 N) at a constant temperature of 620℃. This reveals that staged heating (especially starting at 480℃ with the second heater) can significantly improve bonding strength, possibly related to stress release within the material or optimization of interfacial reactions. Compared with groups 2 and 6, groups 4 and 8 show that changes in a single variable have limited impact on bonding strength, while the synergistic effect of diethanolamine and temperature gradient is significant.

[0061] Example 2: Preparation of a Kilometer-long High-Temperature Superconducting Tape Insulation Layer

[0062] (1) The pulley rotates clockwise under the control of the motor. The Hastelloy base belt is cleaned by wiping with the first press, soaking in the alcohol tank, and wiping with the second press, and then dried in the first heater.

[0063] (2) Prepare a 0.1 mol / L yttrium acetate solution and a 0.01 mol / L diethanolamine solution, and pour them into the precursor solution tank;

[0064] (3) The Hastelloy substrate cleaned in step (1) is heated by the second, third, fourth, fifth and sixth heaters, continuously carried, and prepared by multi-channel repeated chemical solution planarization method to prepare a high-temperature superconducting tape isolation layer;

[0065] (4) The liquid level detector determines that the liquid level is too low, and the liquid replenishment tank is used to replenish the liquid, thus preparing a kilometer-long high-temperature superconducting tape isolation layer;

[0066] The temperature of the first heater is 200℃, the temperature of the second heater is 480℃, the temperature of the third heater is 560℃, the temperature of the fourth heater is 530℃, the temperature of the fifth heater is 620℃, and the temperature of the sixth heater is 580℃.

[0067] To detect the surface roughness of the isolation layer of a kilometer-long high-temperature superconducting tape, an atomic force microscope was used to test the roughness within a 2×2μm range of the surface at six sampling points at different locations.

[0068] Table 2. Roughness results of the surface within a 2×2μm range at sampling points at different locations.

[0069] Sampling points 0m 200m 400m 600m 800m 1000m Ra(nm) 0.578 0.627 0.550 0.602 0.684 0.771 Rq(nm) 0.466 0.534 0.477 0.469 0.532 0.613

[0070] The results are shown in Table 2 and Figure 2 As shown, based on the apparatus and method of this invention, the production of kilometer-scale high-temperature superconducting tape isolation layers has been realized. Simultaneously, superconducting tape isolation layers with uniform length (Ra < 0.7 nm) and high bonding strength (> 200 N) can be prepared, improving product yield.

Claims

1. An apparatus for preparing a high-temperature superconducting tape insulating layer, characterized in that, The device includes: a precursor liquid tank (1), a sealed chamber (2), a pretreatment device, a replenishment device, and a baseband delivery system; The pretreatment device includes an alcohol tank (3) and a press, the press including a first press (4) and a second press (5); the first press (4) is located on the horizontal plane of the alcohol tank (3), and the second press (5) is located above the alcohol tank (3); The sealed chamber (2) includes heaters, which are arranged from left to right as a first heater (201), a second heater (202), a third heater (203), a fourth heater (204), a fifth heater (205), and a sixth heater (206); The replenishment device includes a liquid level monitor (6), a water pump (7), and a replenishment tank (8). The liquid level monitor (6) is located in the precursor liquid tank (1). The precursor liquid tank (1) is connected to the water pump (7) through a pipe, and the water pump (7) is connected to the replenishment tank (8) through a pipe. The signal from the liquid level monitor (6) is transmitted to the water pump (7), and the water pump replenishes the liquid through the pipe. The baseband delivery system includes a tape feeding wheel (9), a speed measuring wheel (10), a steering wheel (11), and a tape take-up wheel (12); The high-temperature superconducting tape is released by the tape release wheel (9) and passes through the first press (4), the second press (5), the first heater (201), the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) in sequence around the speed measuring wheel (10) and the steering wheel (11). Finally, the high-temperature superconducting tape isolation layer is received by the tape take-up wheel (12).

2. The apparatus according to claim 1, characterized in that, The pretreatment device includes the following steps: the high-temperature superconducting tape is wiped by a first press (4), soaked in an alcohol bath (3), and wiped by a second press (5) to complete the cleaning of the high-temperature superconducting tape, and then dried in a first heater (201); the soaking in the alcohol bath (3) is ultrasonic treatment.

3. The apparatus according to claim 1, characterized in that, The first press (4) and the second press (5) include a dust-free cloth.

4. The apparatus according to claim 1, characterized in that, The sealed chamber (2) is equipped with an exhaust vent (13) for regulating the gas environment inside the chamber.

5. The apparatus according to claim 1, characterized in that, The temperature of the first heater (201) is 180-220℃; the temperatures of the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) are 480-650℃.

6. The apparatus according to claim 1, characterized in that, The solution in the precursor liquid tank (1) includes a yttrium acetate solution and a surfactant solution, wherein the concentration of the yttrium acetate solution is 0.06-0.15 mol / L and the concentration of the surfactant solution is 0.04-0.1 mol / L.

7. The apparatus according to claim 6, characterized in that, The surfactant solution is selected from one or more of diethanolamine, diethylenetriamine, sodium dodecyl sulfate, and dodecylbenzenesulfonic acid, preferably diethanolamine.

8. The apparatus according to claim 1, characterized in that, The device is used for the fabrication of high-temperature superconducting tape isolation layers ranging from hundreds to thousands of meters in length.

9. A method for preparing a high-temperature superconducting tape isolation layer, characterized in that, The method is based on the apparatus according to any one of claims 1-8.

10. The method according to claim 9, characterized in that, The method includes the following steps: (1) Cleaning of high temperature superconducting tape: The tape is cleaned by wiping with the first pressure machine, soaking in the alcohol bath, wiping with the second pressure machine, and then drying in the first heater; (2) Prepare a 0.06-0.15 mol / L yttrium acetate solution and a 0.04-0.1 mol / L surfactant solution, and pour them into the precursor solution tank; (3) The high-temperature superconducting tape cleaned in step (1) is heated by the second heater, the third heater, the fourth heater, the fifth heater and the sixth heater, and a continuous tape-carrying and multi-channel repeated chemical solution planarization method is used to prepare the high-temperature superconducting tape isolation layer; The temperature of the first heater (201) is 180-220℃; the temperatures of the second heater (202), the third heater (203), the fourth heater (204), the fifth heater (205) and the sixth heater (206) are 480-650℃.

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