Non-contact electrolytic polishing system and electrolytic polishing method for superconducting base band

Abstract

The invention provides a non-contact type electrolytic polishing system and an electrolytic polishing method for a superconducting baseband, and relates to the technical field of surface treatment of the superconducting baseband, the non-contact type electrolytic polishing system comprises a feeding device, a receiving device and a non-contact type electrolytic polishing device, the non-contact type electrolytic polishing device is arranged between the feeding device and the receiving device, and the non-contact type electrolytic polishing device is arranged between the feeding device and the receiving device. The feeding device unrolls a strip, the strip penetrates through the non-contact electrolytic polishing device to be subjected to electrolytic polishing, and the strip subjected to electrolytic polishing is wound by the receiving device. An anode and a cathode are isolated to form an anode area and a cathode area, under the action of an electric field and electrolyte, the cathode area achieves electrolytic polishing, the anode area achieves slight electroplating, a base band enters from a base band inlet and exits from a base band outlet, dynamic continuous non-contact electrolytic polishing is achieved, and the continuous partition bypass current non-contact electrolytic polishing efficiency is high; and the influence of the fringe effect is greatly avoided, and the thickness uniformity is good.

Description

Technical Field

[0001] The present invention relates to the technical field of surface treatment of superconducting substrates, and in particular to a non-contact electrolytic polishing system and an electrolytic polishing method for superconducting substrates. Background Art

[0002] The second generation of high temperature superconducting tapes is a superconducting film grown epitaxially on a thin metal substrate using coating technology. Considering the industrial application needs of superconducting tapes and the requirements of the preparation environment, the substrate must have excellent crystal structure, surface chemical stability, thermal expansion coefficient matching, high temperature resistance and oxidation resistance. After repeated experiments and research, scientists found a nickel alloy substrate with (102) orientation. Combining various factors, people have developed Hastelloy (C276) tape as a metal substrate.

[0003] Due to the limitations of the Hastelloy alloy base strip rolling process itself, the surface is rough and there are contaminants, which cannot meet the process requirements of the second-generation high-temperature superconducting tape. The importance of electrolytic polishing to the second-generation high-temperature superconducting tape includes: improving the surface quality of the base strip, removing surface contaminants, and improving the overall roughness of the superconducting tape; this method can reduce the roughness of the strip surface to below 0.6nm, improving the crystallization quality and uniformity of the superconducting layer; and enhancing the mechanical properties. The electropolished base strip has better mechanical properties, can better support the superconducting layer, and provide stable mechanical support, thereby enhancing the overall mechanical properties of the strip.

[0004] The recent mass production of second-generation high-temperature superconducting tapes has promoted more and more applications in superconducting systems. Correspondingly, the demand for superconducting tapes of different thicknesses is also increasing. The conventional required thickness is 50um. With the demand for thin superconductors in the compact nuclear fusion and high-field magnet industries, the electrolytic polishing of 30um to 40um thin base tapes is particularly critical, which requires both controlling the surface roughness and solving other uncontrollable factors, such as deformation and curling caused by tension.

[0005] Traditional contact electrolytic polishing is prone to sparking, scratching, dirt and other defects. The development of a non-contact electrolytic polishing method can effectively avoid the above problems, and is more conducive to improving the quality of superconducting tapes and promoting the industrialization process of superconducting tapes. Summary of the invention

[0006] In view of the defects in the prior art, an object of the present invention is to provide a non-contact electrolytic polishing system and an electrolytic polishing method for a superconducting substrate.

[0007] According to the present invention, a non-contact electrolytic polishing system for a superconducting base tape is provided, comprising a feeding device, a receiving device, and a non-contact electrolytic polishing device. The non-contact electrolytic polishing device is arranged between the feeding device and the receiving device. The feeding device unwinds the strip, and the strip passes through the non-contact electrolytic polishing device for electrolytic polishing. The strip after electrolytic polishing is wound up by the receiving device.

[0008] Preferably, the electrolytic polishing device comprises an electrolyte circulation tank, parallel cathodes and parallel anodes; The parallel anodes form an anode region in the electrolyte circulation tank, the parallel cathodes form a cathode region in the electrolyte circulation tank, the cathode region and the anode region are alternately arranged in the electrolyte circulation tank, and the strip passes through the alternating regions of the anode region and the cathode region in sequence.

[0009] Preferably, the parallel anode comprises a first mounting bar and an anode plate, wherein the first mounting bar is mounted above the electrolyte circulation tank along the length direction of the electrolyte circulation tank, and a plurality of anode plates are arranged at intervals along the length direction of the first mounting bar by fasteners; The parallel cathode comprises a second mounting bar and a cathode plate, wherein the second mounting bar is mounted above the electrolyte circulation tank along the length direction of the electrolyte circulation tank, and a plurality of cathode plates are arranged at intervals along the length direction of the second mounting bar by fasteners; The material of the anode plate includes: titanium, platinum, graphite, pure lead, and the material of the cathode plate includes stainless steel, lead, graphite; The area ratio of the cathode plate to the anode plate is 1.5:1 to 3:1.

[0010] Preferably, the surface of the anode plate not facing the strip is packaged with corrosion-resistant insulating polyethylene with an inner liner, and the surface facing the strip is packaged with an open-pore polytetrafluoroethylene plate; A bypass current separator is also provided in the electrolyte circulation tank, and one bypass current separator is provided at each end of the alternating region between the anode region and the cathode region; Any of the bypass current separators is formed with a hole that allows the strip to pass through; The bypass current separator is made of polytetrafluoroethylene.

[0011] Preferably, the electrolytic polishing device uses different current densities to achieve rough polishing and then fine polishing of the strip.

[0012] Preferably, it also includes a first ultrasonic cleaning tank, a first spray cleaning tank, a first pure water spray tank, a second spray cleaning tank, a second ultrasonic cleaning tank, a second pure water spray tank, a third ultrasonic cleaning tank, a third pure water spray tank, a drying box and a dust removal and receiving platform, and the receiving device is arranged in the dust removal and receiving platform; Before electrolytic polishing, the strip is first cleaned in a first ultrasonic cleaning tank, a first spray cleaning tank, and a first pure water spray tank in sequence. After electrolytic polishing, the strip is cleaned in a second spray cleaning tank, a second ultrasonic cleaning tank, a second pure water spray tank, a third ultrasonic cleaning tank, and a third pure water spray tank in sequence, and then enters a drying box for drying, and finally enters a dust removal and collection table for winding.

[0013] Preferably, it also includes a dust removal and material collection platform and a drying box, wherein the dust removal and material collection platform is isolated from the external environment by an isolation cover, and the drying box is connected to the isolation cover through a quartz tube; The drying box includes a drying area and a drying holding area. The strip first passes through the drying area and then the drying holding area, and then enters the isolation cover through a quartz tube and is wound up by a material receiving device. The drying temperature of the drying box is 350°C to 400°C.

[0014] Preferably, a pinhole air knife is provided between any two adjacent working grooves to sweep away residual liquid on the surface of the strip.

[0015] Preferably, the strips are arranged in a plurality of groups at intervals along the height direction, and any group of the strips is reeled and unreeled by a corresponding unwinding device and a rewinding device.

[0016] According to a non-contact electrolytic polishing method for a superconducting base tape provided by the present invention, the electrolytic polishing method comprises the following steps: Step S1, pre-cleaning of the strip; Step S2, strip electrolytic polishing; Step S3, post-cleaning treatment of the strip; Step S4, strip drying process; Step S5: coiling the strip.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention isolates the anode and the cathode to form an anode area and a cathode area. Under the action of the electric field and the electrolyte, the cathode area is electropolished, and the anode area produces hydrogen precipitation. Since a large amount of hydrogen is precipitated near the surface, it is difficult to form metal deposition, or trace amounts of metal ion deposition may occur. The base tape enters at the base tape inlet and exits at the base tape outlet, thereby realizing dynamic continuous non-contact electropolishing. The continuous partitioned bypass current non-contact electropolishing has high efficiency, greatly avoids the influence of edge effects, and has good thickness uniformity.

[0018] 2. Due to the extremely high requirements on the roughness of the base strip after electro-polishing, compared with traditional electro-polishing, there is no friction, it is not easy to spark, or produce scratches on the surface of the strip.

[0019] 3. The present invention optimizes the type of anode material, so that the anode has a long service life and does not need to be replaced frequently, which helps to improve the working efficiency of the system.

[0020] 4. The present invention connects the drying box and the internal space of the isolation cover through a quartz tube. On the one hand, the strip enters the isolation cover from the inside of the quartz tube for winding without contacting the external environment. On the other hand, the temperature in the drying box can be transferred to the isolation cover through the quartz tube, so that the internal space of the isolation cover remains dry, avoiding water vapor from adhering to the surface of the strip during winding, which helps to improve the quality of subsequent strip processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 This is a schematic diagram of the overall structure of the electrolytic polishing device mainly embodied in the present invention; Figure 2 This is a schematic diagram of the overall structure of the electrolyte circulation tank mainly embodied in the present invention; Figure 3 This is a schematic diagram of the connection structure between the drying box and the dust removal and material receiving platform, which is mainly embodied in the present invention; Figure 4 This is a schematic diagram of the wind knife blowing structure mainly embodied in the present invention.

[0022] As shown in the figure: DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0024] It should be noted that the strip material in this application is the base strip.

[0025] Embodiment 1 like Figures 1 to 4 As shown, a non-contact electrolytic polishing system for a superconducting base tape provided according to the present invention includes a feeding device, a collecting device, and a non-contact electrolytic polishing device 160. The non-contact electrolytic polishing device 160 is arranged between the feeding device and the collecting device. The feeding device unwinds the strip 100, and the strip 100 passes through the non-contact electrolytic polishing device 160 for electrolytic polishing. The electropolished strip 100 is reeled up by the collecting device.

[0026] Specifically, the strip 100 relies on the unloading device and the receiving device to provide a certain tension and run the strip. The unloading device is arranged on the unloading table 110, and the receiving device is arranged on the dust removal receiving table 250. Both the loading device and the receiving device include a stepping motor, a magnetic powder coupler, and a tension controller to provide stable tension to the strip 100 and unload the strip. It should be noted that the technical solution of the present application is particularly suitable for electrolytic polishing of Hastelloy base strips, and can also be used for electrolytic polishing of other strips 100.

[0027] The technical solution of the present application provides an electrolytic polishing device 160 capable of achieving contactless electrolytic polishing, and the electrolytic polishing device 160 includes an electrolyte circulation tank 163, a parallel cathode 164, and a parallel anode 165. The parallel anode 165 forms an anode area in the electrolyte circulation tank 163, and the parallel cathode 164 forms a cathode area in the electrolyte circulation tank 163. The cathode area and the anode area are alternately arranged in the electrolyte circulation tank 163, and the strip passes through the alternating areas of the anode area and the cathode area in sequence. Specifically, in a feasible embodiment: at least one group of parallel anodes 165 is respectively arranged on both sides of the electrolyte circulation tank 163, and the parallel anodes 165 on both sides of the electrolyte circulation tank 163 are arranged oppositely to form an anode area, and a gap is formed in the middle of the anode area to allow the strip 100 to pass through. At least one group of parallel cathodes 164 is respectively arranged on both sides of the electrolyte circulation tank 163. The parallel cathodes 164 on both sides of the electrolyte circulation tank 163 are arranged oppositely to form a cathode area, and a gap is formed in the middle of the cathode area to allow the strip 100 to pass through. The cathode area and the anode area are alternately arranged in the electrolyte circulation tank 163. A bypass current separator 162 is also arranged in the electrolyte circulation tank 163. The bypass current separator 162 is respectively arranged at both ends of the alternating area of ​​the anode area and the cathode area. Further, a bypass current separator 162 is arranged between any adjacent cathode area and anode area, and a hole is formed on the bypass current separator 162 to allow the strip 100 to pass through, and the hole is a base belt hole. The strip 100 passes through the alternating regions of the anode region and the cathode region in sequence. The strip 100 is electropolished in the cathode region and electroplated in the anode region. Specifically, hydrogen is precipitated in the anode region. Since a large amount of hydrogen is precipitated near the surface, it is difficult to form metal deposition, or a trace amount of metal ion deposition may occur. The electroplating rate of the strip 100 in the anode region is lower than the electropolishing rate of the strip 100 in the cathode region.

[0028] The technical solution of the present application adopts the structure of electrolyte circulation tank 163 combined with bypass current separator 162, multiple parallel cathodes 164, and multiple parallel anodes 165 to realize non-contact electrolytic polishing and prevent the strip 100 from curling during the processing. In a feasible implementation: the parallel anode 165 includes ten anodes arranged at equal intervals, and the parallel cathode 164 includes ten cathodes arranged at equal intervals. Ten groups of anodes are connected to the same electrode rod to connect the anode of high-frequency DC rectifier 170, and ten groups of cathodes are connected to the same electrode rod to connect the cathode of high-frequency DC rectifier 170. The area ratio of the cathode plate to the anode plate is 1.5:1 to 3:1. Preferably, the area ratio of the cathode plate to the anode plate is 2:1 to 2.5:1. The electrode structure is combined with a bypass current partition 162 to form an anode area and a cathode area in the electrolytic cell. The strip 100 enters the electrolyte circulation tank 163 from the base strip inlet 161 on the side wall of the electrolyte circulation tank 163, and the strip 100 leaves the electrolyte circulation tank 163 from the base strip outlet 166 on the side wall of the electrolyte circulation tank 163. Under the action of the electric field and the electrolyte in the electrolyte circulation tank 163, the cathode area is electropolished and the anode area is slightly electroplated. The strip 100 passes through ten groups of alternating areas of the anode area and the cathode area in turn. During the whole process, the base strip and the device are non-contact, realizing dynamic non-contact electropolishing. The bypass current separator 162 is provided with a base strip conducting hole, and the strip 100 passes through the center of the conducting hole. The aperture is 3-7mm, which is suitable for non-contact electrolytic polishing of 25-60um thick base strips. It can effectively reduce the edge effect in electrolytic polishing, has good thickness uniformity, and can achieve continuous electrolytic polishing of more than 100km of a batch of electrolyte. The roughness of the upper and lower passes is basically consistent and less than 0.6nm.

[0029] More specifically, the parallel anode 165 includes a first mounting bar and an anode plate, the first mounting bar is mounted above the electrolyte circulation tank 163 along the length direction of the electrolyte circulation tank 163, and a plurality of anode plates are arranged at intervals along the length direction of the first mounting bar by fasteners. The parallel cathode 164 includes a second mounting bar and a cathode plate, the second mounting bar is mounted above the electrolyte circulation tank 163 along the length direction of the electrolyte circulation tank 163, and a plurality of cathode plates are arranged at intervals along the length direction of the second mounting bar by fasteners, so as to realize the installation of the parallel anode 165 and the parallel cathode 164 on the electrolyte circulation tank 163.

[0030] The electrolyte in the electrolyte circulation tank 163 can be configured according to actual needs. The technical solution of this application provides an environmentally friendly electrolyte suitable for electrolytic polishing of Hastelloy alloy, with the following ingredients: 15-25% 98% concentrated sulfuric acid; 70-85% ≥85% concentrated phosphoric acid; 1.5-3.5% glycerol; 1-2.5% citric acid. The new electrolyte needs to be stirred for 2-3 hours and activated for more than 0.5 hours. The optimal polishing temperature of the electrolyte is 50-60°C.

[0031] In a preferred embodiment: the material of the anode plate includes: titanium, platinum, graphite or lead, preferably, the material of the anode plate is pure lead, and the material of the cathode plate includes stainless steel, lead or graphite, preferably, the material of the cathode plate is stainless steel. The surface of the anode plate not facing the strip 100 is packaged with corrosion-resistant insulating polyethylene with an inner liner, and the surface facing the strip 100 is packaged with an open-pore polytetrafluoroethylene plate, and the material of the bypass current separator 162 is polytetrafluoroethylene. The service life of the anode plate is increased, and the anode plate does not need to be replaced frequently.

[0032] In another preferred embodiment, at least two groups of electrolytic polishing devices 160 are provided, and the two groups of electrolytic polishing devices 160 use different current densities to achieve rough polishing and then fine polishing of the strip 100. The electrolytic polishing current is 130-170A, and the rough polishing of the electrolytic polishing tank of the present invention is preferably 100-140A, and the fine polishing of the electrolytic polishing tank is preferably 140-170A. The polishing speed is 1.5-3m / min, and the present invention is preferably 2m / min.

[0033] The non-contact electrolytic polishing system for superconducting base tape of the present application further includes a first ultrasonic cleaning tank 130, a first spray cleaning tank 140, a first pure water spray tank 150, a second spray cleaning tank 180, a second ultrasonic cleaning tank 190, a second pure water spray tank 200, a third ultrasonic cleaning tank 210, a third pure water spray tank 230, a drying box 240 and a dust removal and receiving platform 250, and a receiving device is arranged in the dust removal and receiving platform 250. Before electrolytic polishing, the strip 100 is firstly cleaned by the first ultrasonic cleaning tank 130, the first spray cleaning tank 140, and the first pure water spray tank 150 in sequence. After electrolytic polishing, the strip 100 is cleaned by the second spray cleaning tank 180, the second ultrasonic cleaning tank 190, the second pure water spray tank 200, the third ultrasonic cleaning tank 210, and the third pure water spray tank 230 in sequence, and then enters the drying box 240 for drying, and finally enters the dust removal and receiving platform 250 for winding.

[0034] Specifically, pure water from the first ultrasonic cleaning reservoir 270 is pumped into the first ultrasonic cleaning tank 130 through a vertical lifting pump, and the ultrasonic power supply 120 controls the ultrasonic vibration plate to perform decontamination cleaning; pure water from the first spray cleaning reservoir 280 is pumped into the first spray cleaning tank 140 through a vertical lifting pump to remove the ultrasonic cleaning residual liquid on the strip 100. The first pure water spray tank 150 passes 0.3MPa pressure deionized water to remove the residual liquid of the spray cleaning of the strip 100. The electrolyte in the electrolyte reservoir 290 is pumped into the electrolyte circulation tank 163 through a vertical lifting pump to perform baseband activation treatment electrolytic polishing and baseband functional electrolytic polishing. The pure water from the second spray cleaning reservoir 300 is pumped into the second spray cleaning tank 180 through a vertical lifting pump to remove the baseband electrolyte residue. The pure water from the second ultrasonic cleaning reservoir 310 is pumped into the second ultrasonic cleaning tank 190 through a vertical lifting pump, and the ultrasonic power supply 120 controls the ultrasonic vibration plate to remove the baseband electrolyte residue. The second pure water spray tank 200 is passed through 0.3MPa pressure deionized water to remove residual electrolyte in the baseband. The pure water in the third ultrasonic cleaning liquid storage tank 320 is pumped into the third ultrasonic cleaning tank 210 through a vertical lifting pump, and the ultrasonic power supply 120 controls the ultrasonic vibration plate to remove residual impurities in the baseband. The third pure water spray tank 230 is passed through 0.3MPa pressure deionized water for baseband purification. The drying box 240 dries and removes residual moisture and organic matter. The spray water of the third pure water spray tank 230, the second pure water spray tank 200 and the first pure water spray tank 150 all comes from the pure water replenishment tank 330.

[0035] In a preferred embodiment, an air knife is provided between any two adjacent working slots to sweep away residual liquid on the surface of the strip 100. The sweeping angle of the air knife is preferably 45 degrees to sweep away residual liquid on the surface of the base strip and prevent cross-flow of liquid in each channel.

[0036] In a feasible implementation manner: the dust-removing material receiving platform 250 is isolated from the external environment by an isolation cover 252, and the drying box 240 is connected to the isolation cover 252 through a quartz tube 242. The drying box 240 includes a drying area and a drying holding area. The strip 100 first passes through the drying area and then the drying holding area, and then enters the isolation cover 252 through the quartz tube 242 to be wound up by the receiving device. The drying temperature of the drying box 240 is 350°C to 400°C. Specifically, the quartz tube 242 is used for connection, and the base tape passes through the quartz tube 242, which can bring the heat of the drying box 240 into the isolation cover 252 of the dust-removing material receiving platform 250, ensuring the relative dryness of the receiving environment, and the FFU251 device enters the isolation cover 252 and the quartz tube 242 of the dust-removing material receiving platform 250 from top to bottom through the clean air, ensuring the relative cleanliness of the surface of the base tape. The drying temperature is preferably 400°C. It should be noted that the technical solution of the present application connects the drying box 240 and the dust removal receiving table 250 to prevent the dried strip 100 from contacting the external environment. The water vapor in the external environment will adhere to the surface of the strip 100 and cannot be directly observed by the naked eye. If there is too much water vapor attached to the strip 100, the strip 100 is prone to film exposure and low points in the subsequent processing. Therefore, the present application uses the drying box 240 to be set as a drying area and a dry holding area to ensure the drying effect of the strip 100, and combines the dry internal environment of the isolation cover 252 to ensure that the surface of the wound strip 100 will not adhere to too much water vapor, which is helpful for the subsequent processing of the strip 100. It should be noted that in actual production, the technical solution of the present application is to dry the strip, and there is no visible water vapor on the surface of the strip, and then the dried strip is wound in a dustproof room. By comparison, it is found that the film exposure problem of the technical solution of the present application is far less than that of the solution of winding in a dustproof room.

[0037] In a preferred embodiment: multiple groups of strips 100 are arranged at intervals along the height direction, and any group of strips 100 is wound and unwound by the corresponding unwinding device and the receiving device. The dust-removing receiving table 250 includes 2 sets of stepper motors, 2 sets of magnetic powder clutches, 2 sets of tension sensors, 2 sets of tension controllers, and 1 set of transmission devices, which respectively provide stable tension and dust-free receiving for the upper and lower strips 100, and the surface defects of the base belt are identified through the online detection system 260. The pure water replenishing tank is quantitatively replenished to the above storage tank through an adjustable replenishing device.

[0038] According to the present invention, a non-contact electrolytic polishing method for a superconducting base tape is provided, and the electrolytic polishing method comprises the following steps: step S1, pre-cleaning treatment of the strip 100; step S2, electrolytic polishing of the strip 100; step S3, post-cleaning treatment of the strip 100; step S4, drying treatment of the strip 100; step S5, winding of the strip 100. Specifically, an environmentally friendly electrolyte suitable for electrolytic polishing of Hastelloy is prepared, and the composition is: 15-25% 98% concentrated sulfuric acid; 70-85% ≥85% concentrated phosphoric acid; 1.5-3.5% glycerol; 1-2.5% citric acid. The new electrolyte needs to be stirred for 2-3h and activated for more than 0.5h. The optimal polishing implementation temperature of the electrolyte is 50-60℃. Electrolytic polishing, current 130-170A, voltage 13.0-16.0V. Polishing speed 1.5-3m / min, preferably 2m / min in the present invention.

[0039] Embodiment 2 Based on Example 1, a non-contact electrolytic polishing system for a superconducting substrate is provided according to the present invention, taking the electrolytic polishing of a 30um thick Hastelloy substrate as an example: The main differences are electrolyte ratio, aperture opening of bypass current separator 162, tension setting, current, and polishing speed.

[0040] Electrolyte formula: 98% concentrated sulfuric acid 15-18%; ≥85% concentrated phosphoric acid 70-80%; glycerol 1.5-3.5%; citric acid 1-2.5%. The new electrolyte needs to be stirred for 2-3 hours and activated for more than 0.5 hours. The best polishing temperature of the electrolyte is 55℃.

[0041] Two base tapes with a thickness of 30um, a width of 10mm and a length of 1500m are used. The electrolytic polishing process is adopted: the speed is 2.0m / min, the current of the first electrolytic polishing device 160 is 100-130A, and the current of the second electrolytic polishing device 160 is 140-160A. The unwinding tension is set to 20N, and the receiving tension is set to 18N.

[0042] The bypass current separator 162 is provided with upper and lower base belt holes, and the base belt passes through the center of the holes, and the aperture opening is 4-6mm.

[0043] The specific implementation method is to prepare 2 base tapes with a thickness of 30um, a width of 10mm, and a length of 1500m, and divide them into upper and lower lanes and discharge them counterclockwise from the discharge table 110 at the same time, and enter the first ultrasonic cleaning tank 130 for decontamination and cleaning, enter the first spray cleaning tank 140 to remove the residual liquid in the first ultrasonic cleaning tank 130, enter the first pure water spray tank 150 to spray the residual liquid in the first spray cleaning tank 140, enter the first electrolytic polishing device 160 for activation treatment and electrolytic polishing, enter the second electrolytic polishing device 160 for functional electrolytic polishing, enter the second spray cleaning tank 180 to remove electrolyte residues, enter the second ultrasonic cleaning tank 190 to remove electrolyte residues, enter the second pure water spray tank 200 to remove electrolyte residues, enter the third ultrasonic cleaning tank 210 to remove impurity residues, enter the third pure water spray tank 230 for cleaning, enter the drying box 240 to dry residual moisture and organic matter, and enter the dust removal and receiving table 250 to receive the material. After electrolytic polishing of the upper and lower substrates, AFM@1um was tested, and the head and tail Rq were both less than 0.5nm. The thickness of the upper and lower substrates after electrolytic polishing was 25±1um.

[0044] Embodiment 3 Based on Example 1, a non-contact electrolytic polishing system for a superconducting substrate is provided according to the present invention, taking the electrolytic polishing of a 50um thick Hastelloy substrate as an example: the method is the same as that of Example 2, and the main differences are the electrolyte ratio, the aperture opening of the bypass current partition 162, the tension setting, the current, and the polishing speed.

[0045] Electrolyte formula: 98% concentrated sulfuric acid 20-25%; ≥85% concentrated phosphoric acid 70-85%; glycerol 1.5-3.5%; citric acid 1-2.5%. The new electrolyte needs to be stirred for 2-3 hours and activated for more than 0.5 hours. The best electrolyte polishing temperature is 55°C. Two base belts with a thickness of 50um, a width of 12mm, and a length of 1500m are used. The electrolytic polishing process is adopted: the speed is 2.0m / min, the current of the first electrolytic polishing device 160 is 140A, and the current of the second electrolytic polishing device 160 is 150A. The unwinding tension is set to 25N, and the receiving tension is set to 23N. The bypass current separator 162 is provided with upper and lower base belt holes, and the base belt passes through the center of the belt hole, and the aperture opening is 5-7mm.

[0046] The specific implementation method is to prepare 2 base tapes with a thickness of 50um, a width of 12mm, and a length of 1500m, and divide them into upper and lower lanes and discharge them counterclockwise from the discharge table 110 at the same time, and enter the first ultrasonic cleaning tank 130 for decontamination and cleaning, enter the first spray cleaning tank 140 to remove the residual liquid in the first ultrasonic cleaning tank 130, enter the first pure water spray tank 150 to spray the residual liquid in the first spray cleaning tank 140, enter the first electrolytic polishing device 160 for activation treatment and electrolytic polishing, enter the second electrolytic polishing device 160 for functional electrolytic polishing, enter the second spray cleaning tank 180 to remove electrolyte residues, enter the second ultrasonic cleaning tank 190 to remove electrolyte residues, enter the second pure water spray tank 200 to remove electrolyte residues, enter the third ultrasonic cleaning tank 210 to remove impurity residues, enter the third pure water spray tank 230 for cleaning, enter the drying box 240 to dry residual moisture and organic matter, and enter the dust removal and receiving table 250 to receive the material. After electrolytic polishing of the upper and lower substrates, AFM@1um was tested, and the head and tail Rq were both less than 0.5nm. The thickness of the upper and lower substrates after electrolytic polishing was 44±1um.

[0047] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A non-contact electrolytic polishing system for superconducting substrate, characterized in that: It includes a discharging device, a receiving device, and a non-contact electrolytic polishing device. The non-contact electrolytic polishing device is arranged between the discharging device and the receiving device. The discharging device unwinds the strip. The strip passes through the non-contact electrolytic polishing device for electrolytic polishing. The electrolytically polished strip is reeled by the receiving device. The electrolytic polishing device comprises an electrolyte circulation tank, parallel cathodes and parallel anodes; The parallel anodes form an anode region in the electrolyte circulation tank, the parallel cathodes form a cathode region in the electrolyte circulation tank, the cathode region and the anode region are alternately arranged in the electrolyte circulation tank, and the strip passes through the alternating regions of the anode region and the cathode region in sequence.

2. The non-contact electrolytic polishing system for superconducting substrate according to claim 1, characterized in that: The parallel anode comprises a first mounting bar and an anode plate, wherein the first mounting bar is mounted above the electrolyte circulation tank along the length direction of the electrolyte circulation tank, and a plurality of anode plates are arranged at intervals along the length direction of the first mounting bar by fasteners; The parallel cathode comprises a second mounting bar and a cathode plate, wherein the second mounting bar is mounted above the electrolyte circulation tank along the length direction of the electrolyte circulation tank, and a plurality of cathode plates are arranged at intervals along the length direction of the second mounting bar by fasteners; The material of the anode plate includes: titanium, platinum, graphite or lead, and the material of the cathode plate includes stainless steel, lead or graphite; The area ratio of the cathode plate to the anode plate is 1.5:1 to 3:

1.

3. The non-contact electrolytic polishing system for superconducting tape according to claim 2, characterized in that: The surface of the anode plate not facing the strip is packaged with corrosion-resistant insulating polyethylene with an inner liner, and the surface facing the strip is packaged with an open-pore polytetrafluoroethylene plate; A bypass current separator is also provided in the electrolyte circulation tank, and one bypass current separator is provided at each end of the alternating region between the anode region and the cathode region; Any of the bypass current separators is formed with a hole that allows the strip to pass through; The bypass current separator is made of polytetrafluoroethylene.

4. The non-contact electrolytic polishing system for superconducting substrate according to claim 1, characterized in that: The electrolytic polishing device uses different current densities to achieve rough polishing and then fine polishing of the strip.

5. The non-contact electrolytic polishing system for superconducting substrate according to claim 1, characterized in that: It also includes a first ultrasonic cleaning tank, a first spray cleaning tank, a first pure water spray tank, a second spray cleaning tank, a second ultrasonic cleaning tank, a second pure water spray tank, a third ultrasonic cleaning tank, a third pure water spray tank, a drying box and a dust removal and receiving platform, wherein the receiving device is arranged in the dust removal and receiving platform; Before electrolytic polishing, the strip is first cleaned in a first ultrasonic cleaning tank, a first spray cleaning tank, and a first pure water spray tank in sequence. After electrolytic polishing, the strip is cleaned in a second spray cleaning tank, a second ultrasonic cleaning tank, a second pure water spray tank, a third ultrasonic cleaning tank, and a third pure water spray tank in sequence, and then enters a drying box for drying, and finally enters a dust removal and collection table for winding.

6. The non-contact electrolytic polishing system for superconducting substrate according to claim 1, characterized in that: It also includes a dust removal and material collection platform and a drying box, wherein the dust removal and material collection platform is isolated from the external environment by an isolation cover, and the drying box is connected to the isolation cover through a quartz tube; The drying box includes a drying area and a drying holding area. The strip first passes through the drying area and then the drying holding area, and then enters the isolation cover through a quartz tube and is wound up by a material receiving device. The drying temperature of the drying box is 350°C to 400°C.

7. The non-contact electrolytic polishing system for superconducting tape according to claim 1, characterized in that: An air knife is arranged between any two adjacent working grooves to sweep away the residual liquid on the surface of the strip.

8. The non-contact electrolytic polishing system for superconducting substrate according to claim 1, characterized in that: The strips are arranged in a plurality of groups at intervals along the height direction, and any group of the strips is reeled and unreeled by a corresponding unwinding device and a rewinding device.

9. A non-contact electrolytic polishing method for a superconducting substrate, characterized in that: The non-contact electrolytic polishing system for a superconducting substrate according to any one of claims 1 to 8 is used, and the electrolytic polishing method comprises the following steps: Step S1, pre-cleaning of the strip; Step S2, strip electrolytic polishing; Step S3, strip post-cleaning treatment; Step S4, strip drying process; Step S5: coiling the strip.

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