Lap joint method of high-temperature superconducting tape and high-temperature superconducting wire

Abstract

The invention discloses a lapping method of a high-temperature superconducting tape and a high-temperature superconducting wire, and belongs to the technical field of superconducting electricians, and the method comprises the steps: plating a first metal layer and a second metal layer on the side surface of the to-be-lapped end part of the obtained high-temperature superconducting tape, and removing a stable layer at the to-be-lapped end part, removing a part of the first metal layer or a part of the first metal layer and a part of the second metal layer at the end part to be lapped in the obtained pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape with a concave lapping structure or a second high-temperature superconducting tape with a convex lapping structure; and embedding and splicing the concave lap joint structure and the convex lap joint structure so as to weld the to-be-lapped end parts of the first high-temperature superconducting tape and the second high-temperature superconducting tape. Therefore, the technical problems that in the prior art, due to the fact that the two sides of the superconducting layer are not limited, the qualified rate of lap joint of the high-temperature superconducting tape is low, and the service life of the high-temperature superconducting tape after lap joint is short can be solved.

Description

Technical Field

[0001] The present invention relates to the field of superconducting electrical technology, and in particular to a method for splicing high-temperature superconducting tapes and a high-temperature superconducting wire. Background Art

[0002] Second-generation superconducting tapes made of REBCO (second-generation high-temperature superconducting rare earth barium copper oxide), also known as coated conductors, offer broader and more promising applications in a wide range of fields, including medicine, military, and energy, due to their greater current-carrying capacity, higher magnetic field performance, and lower material cost compared to bismuth-based tapes. Because REBCO, the superconducting current-carrying core, is inherently hard and brittle, second-generation high-temperature superconducting tapes are typically produced using a multilayer coating process on a nickel-based alloy substrate. The tapes primarily consist of a stabilizing layer, a superconducting layer, a transition layer, and a base layer. The transition and base layers are also referred to as a buffer layer.

[0003] High-temperature superconducting tape is often used to make superconducting cables and coils. However, due to performance limitations during the production process, it's difficult to produce a single tape long enough for these applications. Currently, multiple tapes are typically joined together to form a single tape for winding superconducting cables or coils. Existing methods include splicing and overlapping.

[0004] Currently, superconducting tapes are spliced by welding the superconducting layers together or by welding the stabilizing layers together. Superconducting layer-to-superconducting layer welding is a common method of splicing due to its lower electrical resistance. However, prior art often involves completely stripping the buffer layer above the superconducting layer and then welding the superconducting layers together by aligning them. However, due to the smooth surface of the superconducting layer and the length of the overlapped area, the lack of restraint on either side of the superconducting layer often leads to misalignment between the upper and lower tapes during welding. This significantly increases the joint resistance in the overlapped area, reducing the yield rate of the spliced tapes. Furthermore, the superconducting wire formed by the spliced superconducting tapes can develop tiny cracks or holes on the sides during welding, which can easily infiltrate moisture during actual use, causing damage to the splice and reducing the service life of the superconducting wire. Summary of the Invention

[0005] The present invention provides a method for splicing high-temperature superconducting tapes and a high-temperature superconducting wire, which can solve the technical problems in the prior art of low splicing qualification rate of high-temperature superconducting tapes and short service life of the spliced high-temperature superconducting tapes due to the lack of limit on both sides of the superconducting layer.

[0006] The present invention discloses a method for splicing high-temperature superconducting tapes, which is applicable to stacked high-temperature superconducting tapes. The stacked high-temperature superconducting tapes have a structure comprising, from top to bottom, a stabilizing layer, a superconducting layer, and a buffer layer. The splicing method comprises:

[0007] Obtaining at least two high-temperature superconducting tapes, and sequentially plating a first metal layer and a second metal layer on the side of the end portion to be overlapped of each of the high-temperature superconducting tapes to obtain a plurality of high-temperature superconducting tapes to be overlapped;

[0008] removing the stabilizing layers at the ends of the high-temperature superconducting tapes to be joined, to obtain a plurality of pretreated high-temperature superconducting tapes;

[0009] removing a portion of the first metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape having a concave overlap structure;

[0010] removing a portion of the first metal layer and a portion of the second metal layer from the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a second high-temperature superconducting tape having a raised overlap structure;

[0011] The concave overlapping structure of the first high-temperature superconducting tape and the convex overlapping structure of the second high-temperature superconducting tape are interlocked and spliced to weld the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped.

[0012] The present invention discloses a method for overlapping high-temperature superconducting tapes, which realizes precise positioning and sealing protection of superconducting tape overlap through structured metal layer plating and mechanical interlocking design, thereby improving the qualified rate of high-temperature superconducting tape overlap and the service life of the high-temperature superconducting tape after overlap. First, a double-layer metal layer is plated on the side of the end portion to be overlapped of the high-temperature superconducting tape, on the one hand, providing a material basis for the subsequent formation of a concave-convex structure, and on the other hand, ensuring the superconducting performance of the tape. Among them, the height of the metal layer is level with the height of the tape, ensuring that the metal layer covers the complete side of the end portion to be overlapped. After removing the stabilizing layer, the superconducting layer is exposed, so that the welding surface is in direct contact with the superconducting layer to improve the superconducting performance and reduce the resistance of the end portion to be overlapped. By selectively removing part of the first metal layer or removing the first and second metal layers at the same time, a concave and convex structure is formed, and the concave-convex interlocking is used to achieve physical limitation during overlap, thereby preventing the tape from being dislocated during welding. During the interlocking process, the combination of the concave and convex structures not only enhances joint stability but also covers the side areas with the remaining metal layer, preventing moisture intrusion caused by cracks or holes in the sides. During welding, the combination of the metal layer and the superconducting layer further enhances the mechanical strength and conductive continuity of the joint area, improving the pass rate of the strip joint and the service life of the strip after joining.

[0013] As a preferred example, the first metal layer and the second metal layer are sequentially plated on the side of the end portion to be overlapped of each of the high-temperature superconducting tapes to obtain a plurality of high-temperature superconducting tapes to be overlapped, comprising:

[0014] For any one of the high temperature superconducting tapes;

[0015] The end portion of the high-temperature superconducting tape to be overlapped is placed between the cathode motor and the anode motor, so that two side surfaces of the end portion to be overlapped are connected to the cathode motor and the anode motor respectively;

[0016] The side surface is electroplated by the cathode motor and the anode motor to form a first metal layer on the side surface and a second metal layer on the first metal layer, thereby obtaining a high-temperature superconducting tape to be overlapped corresponding to the high-temperature superconducting tape; wherein the heights of the first metal layer and the second metal layer are the same as the height of the high-temperature superconducting tape.

[0017] In the above scheme, by placing the end to be overlapped between the cathode motor and the anode motor, an electroplating circuit is formed on both sides at the same time, thereby simultaneously plating the metal layer on both sides. This design ensures uniform current distribution during the electroplating process, avoids deviation in the thickness of the coating on one side, and thus improves the bonding strength between the metal layer and the side of the strip. The first metal layer and the second metal layer are plated in steps, so that different metal layers can subsequently form raised and recessed structures to provide a limit basis for the overlap. Limiting the height of the metal layer to the height of the strip avoids interference with the overlapping structure caused by the coating being too high, and also avoids the coating being too low to achieve limit and protect the side of the strip.

[0018] As a preferred example, the step of removing the stabilizing layer at the ends of the high-temperature superconducting tapes to be spliced to obtain a plurality of pretreated high-temperature superconducting tapes includes:

[0019] For any one of the high-temperature superconducting tapes to be spliced;

[0020] The stabilizing layer at the end portion to be overlapped in the high-temperature superconducting tape to be overlapped is removed until the upper surface of the superconducting layer appears at the end portion to be overlapped, thereby obtaining a pretreated high-temperature superconducting tape corresponding to the high-temperature superconducting tape to be overlapped.

[0021] The above scheme first limits the treatment target to any single high-temperature superconducting tape, ensuring consistent pretreatment of each tape and avoiding structural deviations caused by batch processing. By precisely controlling the termination condition for stabilizing layer removal to expose the superconducting layer's top surface, the surface overlap of the superconducting layers reduces the resistance of the overlap area, improving the yield rate of the tape overlap. Furthermore, the complete exposure of the superconducting layer's top surface provides a precise positioning reference for the subsequent construction of the stepped metal layer structure, ensuring a continuous, closed metal protective layer on the sides of the overlap area, thereby limiting the overlap and providing lateral protection.

[0022] As a preferred example, removing a portion of the first metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape having a recessed overlap structure includes:

[0023] For any one of the pretreated high-temperature superconducting tapes;

[0024] The first metal layer at the end of the pretreated high-temperature superconducting tape to be overlapped is removed until the height of the first metal layer is level with the height of the upper surface of the superconducting layer, thereby obtaining a first high-temperature superconducting tape with a recessed overlap structure.

[0025] The above scheme creates a recessed structure to improve joint accuracy by defining a specific processing method for pre-treated high-temperature superconducting tape. First, operations are performed on the pre-treated high-temperature superconducting tape to ensure that the stabilizing layer has been removed and the superconducting layer surface is exposed, providing a reference plane for subsequent metal layer processing. By precisely removing the first metal layer to the same height as the top surface of the superconducting layer, a recessed structure is formed by the height of the outer second metal layer and the height of the inner first metal layer and superconducting layer. The depth of this recess complements the raised structure of the subsequent second tape, preventing lateral displacement during mating due to the physical restraint of the metal layer sidewalls. The requirement that the height of the first metal layer be flush with the top surface of the superconducting layer preserves the second metal layer as the welding contact surface while also forming a recessed boundary by partially retaining the first metal layer, providing precise insertion space for the raised structure. This layered removal of different metal layers achieves mechanical interlocking by leveraging the structural differences of the metal layers while ensuring direct contact and conduction between the superconducting layers.

[0026] As a preferred example, removing part of the first metal layer and part of the second metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a second high-temperature superconducting tape having a raised overlap structure includes:

[0027] For any one of the pretreated high-temperature superconducting tapes;

[0028] removing the first metal layer and the second metal layer at the end to be overlapped in the pretreated high-temperature superconducting tape until the heights of the first metal layer and the second metal layer are level with the height of the upper surface of the superconducting layer, thereby obtaining a treated high-temperature superconducting tape;

[0029] The first metal layer and the second metal layer at the ends to be overlapped in the processed high-temperature superconducting tape are removed according to the height of the stabilizing layer to obtain a second high-temperature superconducting tape with a raised overlap structure.

[0030] In the above scheme, a raised overlapping component with a specific structure is formed by precisely removing the metal layer in stages. First, by adjusting the height of the first metal layer and the second metal layer to be lower than the upper surface of the superconducting layer and making the height difference between the first metal layer and the second metal layer and the upper surface of the superconducting layer equal to the height of the stabilizing layer, the raised structure finally formed forms a complementary interlocking relationship with the recessed structure in the first high-temperature superconducting tape where the first metal layer and the upper surface of the superconducting layer are level. This step-by-step control method not only ensures the dimensional accuracy of the raised structure, but also forms a lateral limit by retaining part of the metal layer to prevent the strip from being misaligned during welding. At the same time, the retained metal layer can cover the side of the overlapping surface, reducing the exposure of cracks or holes, thereby improving the sealing of the joint, ultimately reducing the joint resistance and extending the service life.

[0031] As a preferred example, the recessed overlap structure of the first high-temperature superconducting tape and the convex overlap structure of the second high-temperature superconducting tape are embedded and spliced together, including:

[0032] Applying solder and flux on the upper surface of the superconducting layer, and bringing the upper surface of the superconducting layer at the end to be overlapped in the first high-temperature superconducting tape into contact with the upper surface of the superconducting layer at the end to be overlapped in the second high-temperature superconducting tape;

[0033] The second metal layer at the end to be overlapped in the first high-temperature superconducting tape is overlapped and contacted with the second metal layer at the end to be overlapped in the second high-temperature superconducting tape, so that the ends to be overlapped are overlapped in pairs to form an overlapping area.

[0034] In the above scheme, by coating solder and flux on the upper surface of the superconducting layer and forcing the upper surfaces of the two superconducting layers to overlap and contact, direct alignment welding between the superconducting layers is ensured, avoiding the increase in resistance caused by the misalignment of the superconducting layers. Secondly, by overlapping and contacting the second metal layer of the first high-temperature superconducting tape with the second metal layer of the second high-temperature superconducting tape, the rigidity of the metal layer is used to form a lateral limiting structure, further constraining the lateral displacement of the overlapping area and preventing the strips from sliding and dislocating during welding. At the same time, the overlapping contact of the second metal layer covers the side gaps of the overlapping area, forming a continuous and closed metal protective layer, which effectively blocks the intrusion of external moisture from side cracks or holes, thereby improving the long-term stability of the overlapping structure.

[0035] As a preferred example, the welding of the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped includes:

[0036] Using a clamp to continuously pressurize the overlapped area;

[0037] The overlapped area to which the continuous pressurization is applied is heated according to the preset welding temperature and welding time.

[0038] In the above scheme, stable welding of the overlap area is achieved by combining continuous pressure applied by the clamp with temperature control. Using the clamp to continuously pressurize the overlap area can keep the contact surfaces between the superconducting layers and the contact surfaces between the second metal layers in close contact during the welding process, avoiding relative displacement caused by external force disturbance or thermal expansion. By heating the pressurized overlap area by presetting the welding temperature and welding time, it can be ensured that the solder fully melts and penetrates under controlled thermal conditions, while avoiding thermal damage to the superconducting layer or buffer layer caused by excessive temperature.

[0039] As a preferred example, the welding of the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped further includes:

[0040] Solder and flux are coated on the exposed end faces in the overlap area, and are welded and solidified to form a filling structure for covering the end faces; wherein the side surface of the filling structure overlaps and contacts the end faces; and the lower surface of the filling structure overlaps and contacts the upper surface of the buffer layer.

[0041] In the above scheme, solder and flux are applied to the exposed end faces in the overlapped area and then solidified by soldering to form a filling structure covering the end faces. This structure protects the exposed end faces at the overlapped area by fully contacting the side surfaces with the end faces and contacting the lower surface with the buffer layer. The application of solder and flux ensures that the liquid solder fully infiltrates the end face gaps, while the filling structure formed by solidification by soldering effectively closes the side gaps that are prone to remain in traditional overlap processes by virtue of its morphological design of overlapping contact between the side surfaces and the end faces. Furthermore, the contact between the lower surface of the filling structure and the upper surface of the buffer layer ensures the bonding strength between the filling layer and the base material while preventing the filling material from penetrating downward and affecting the performance of the superconducting layer.

[0042] As a preferred example, the length of the overlapping area is 2 cm to 10 cm.

[0043] In the above scheme, by limiting the length of the overlap area to 2cm to 10cm, the effective contact area between the superconducting layers is guaranteed, and the insufficient mechanical strength caused by the overlap length being too short is avoided. This length range can ensure that the concave-convex structure formed by the metal layers on both sides of the superconducting layer during welding has sufficient interlocking constraint force to prevent the strip from being laterally displaced and dislocated during the welding process. At the same time, this length range not only meets the low resistance requirements required for superconducting current transmission, but also avoids material waste and increased process complexity caused by excessive overlap. Specifically, the lower limit setting of 2cm can ensure that the overlap area has the necessary tensile strength, while the upper limit setting of 10cm effectively controls the range of the welding heat-affected zone to prevent damage to the superconducting layer due to thermal stress concentration.

[0044] On the other hand, the present invention further discloses a high-temperature superconducting wire, comprising a plurality of high-temperature superconducting tapes spliced according to a high-temperature superconducting tape splicing method.

[0045] The high-temperature superconducting wire disclosed in the present invention ensures protection of the side surfaces of the overlapping region between two high-temperature superconducting tapes and performance protection of the superconducting layer in the high-temperature superconducting tapes through the plating of the metal layer in the overlapping method of high-temperature superconducting tapes, thereby increasing the service life of the high-temperature superconducting wire, reducing the resistance of the overlapping region, and improving the overlap qualification rate of the high-temperature superconducting wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1 This is a schematic flow chart of a method for splicing high-temperature superconducting tapes disclosed in an embodiment of the present invention;

[0048] Figure 2 1 is a schematic structural diagram of a high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0049] Figure 3 Schematic diagram of electroplating treatment of a high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0050] Figure 4 This is a side view structural diagram of a pretreated high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0051] Figure 5 is a schematic side view of the structure of a first high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0052] Figure 6 is a schematic top view of the structure of a first high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0053] Figure 7 is a schematic side view of the structure of a second high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0054] Figure 8 is a schematic top view of the structure of a second high-temperature superconducting tape disclosed in an embodiment of the present invention;

[0055] Figure 9 is a cross-sectional view of a first high-temperature superconducting tape and a second high-temperature superconducting tape according to an embodiment of the present invention;

[0056] Figure 10 This is a schematic diagram of a filling structure disclosed in an embodiment of the present invention;

[0057] Among them, 1. protective layer; 2. superconducting layer; 3. transition layer; 4. base layer; 5. first metal layer; 6. second metal layer; 7. space; 8. filling structure. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0060] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0061] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0062] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0063] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0064] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0065] See also Figure 1 To address the existing issues of low splicing pass rates and reduced service life of high-temperature superconducting tapes, one embodiment of the present invention provides a splicing method for high-temperature superconducting tapes, applicable to stacked high-temperature superconducting tapes. The stacked high-temperature superconducting tapes comprise, from top to bottom, a stabilizing layer, a superconducting layer, and a buffer layer. Specifically, the splicing method includes:

[0066] Step 101: Obtain at least two high-temperature superconducting tapes, and sequentially plate a first metal layer and a second metal layer on the side of the end portion to be overlapped of each high-temperature superconducting tape to obtain a plurality of high-temperature superconducting tapes to be overlapped.

[0067] Step 102: removing the stabilizing layers at the ends of the high-temperature superconducting tapes to be spliced, to obtain a plurality of pre-treated high-temperature superconducting tapes.

[0068] Step 103: removing a portion of the first metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape with a recessed overlap structure.

[0069] Step 104: removing a portion of the first metal layer and a portion of the second metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a second high-temperature superconducting tape having a raised overlap structure.

[0070] Step 105: Engage and splice the concave overlapping structure of the first high-temperature superconducting tape and the convex overlapping structure of the second high-temperature superconducting tape to weld the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped.

[0071] In one embodiment of this invention, a plurality of high-temperature superconducting tapes are first obtained to prepare a high-temperature superconducting wire, i.e., a high-temperature superconducting tape having a sufficiently long length, by overlapping. The side view structure of each high-temperature superconducting tape is as follows: Figure 2 As shown. Figure 2 It can be seen that the high-temperature superconducting tape comprises, from top to bottom, a protective layer 1, a superconducting layer 2, a transition layer 3, and a base layer 4. The protective layer 1 serves to provide a good template for the epitaxial growth of the superconducting layer 2, thereby ensuring the superconducting performance of the superconducting layer 2. Therefore, the protective layer 1 can also be referred to as a stabilization layer. The base layer 4 is generally made of a metal base, and its function is to provide excellent mechanical properties for the high-temperature superconducting tape. The transition layer 3 prevents the mutual diffusion of elements between the superconducting layer 2 and the metal base. Therefore, the base layer 4 and the transition layer 3 can be collectively referred to as a buffer layer. The superconducting layer 2 is made of a coated conductor with excellent superconducting performance. It has a consistent biaxial texture and exhibits zero resistance below the critical temperature. It can carry large currents without generating Joule heat, thereby improving energy transmission efficiency. Among them, biaxial texture means that the grains have almost uniform arrangement in both directions of a / b axis and c axis (c axis is perpendicular to a / b plane); the thickness of the superconducting layer 2 is usually 1-3 microns; it should be noted that the stabilization layer usually includes a double-layer metal protective layer 1, such as a silver protective layer and a copper protective layer. Among them, the silver protective layer is used to prevent the superconducting tape from being oxidized during manufacturing and use (the material cannot be replaced), and its thickness is generally 1 to 2 microns. The copper protective layer has good electrical conductivity, which can ensure the smooth transmission of current in the tape and reduce resistance loss. It helps heat conduction and helps disperse the heat generated by the superconducting tape during operation (the material cannot be replaced). The thickness of the copper protective layer is generally 1-10 microns, but the protective layer setting of the tape is a prior art and is not an invention in this field. This application does not elaborate on this technology.

[0072] After obtaining at least two Figure 2When the high-temperature superconducting tapes are overlapped, in order to reduce the resistance generated by the overlap, this embodiment uses a method of arranging the superconducting layer 2 surface-to-superconducting layer 2 surface to overlap the high-temperature superconducting tapes. The overlap refers to placing one end of one high-temperature superconducting tape on top of one end of another high-temperature superconducting tape.

[0073] Specifically, in order to prevent the strip from moving laterally during the overlap, thereby increasing the resistance generated by the overlap, step 101 is to plate the side of the strip with a metal layer through the following steps, so that the metal layer provides a limit for the overlap of the strip. Specifically, the steps are:

[0074] Step 1011: For any one of the high-temperature superconducting tapes, place the end portion of the high-temperature superconducting tape to be overlapped between the cathode motor and the anode motor, so that two side surfaces of the end portion to be overlapped are connected to the cathode motor and the anode motor respectively;

[0075] Step 1012: Electroplating the side surface by the cathode motor and the anode motor to form a first metal layer on the side surface and a second metal layer on the first metal layer, thereby obtaining a high-temperature superconducting tape to be overlapped corresponding to the high-temperature superconducting tape; wherein the heights of the first metal layer and the second metal layer are the same as the height of the high-temperature superconducting tape.

[0076] In this embodiment, the ends of at least two high-temperature superconducting tapes to be overlapped are placed in an electroplating device for electroplating to form a double metal layer on the side of the ends to be overlapped. Specifically, Figure 3 As shown, the end portion of the high-temperature superconducting tape to be overlapped is placed between two electrodes of the electroplating device, namely the cathode motor and the anode motor, so that one side of the end portion to be overlapped is connected to the cathode electrode, and the other side of the end portion to be overlapped is connected to the anode electrode, thereby forming a double metal layer on each side of the end portion to be overlapped of the high-temperature superconducting tape, and then obtaining a high-temperature superconducting tape to be overlapped generated after each high-temperature superconducting tape is electroplated.

[0077] It should be noted that each metal layer needs to be made of a metal material that does not affect the superconducting performance of the superconducting layer 2. As an example, the metal layer can be made of metal materials such as silver and copper.

[0078] In this embodiment, by placing the end to be overlapped between the cathode motor and the anode motor, an electroplating loop is formed on both sides at the same time, thereby simultaneously plating the metal layer on both sides. This design ensures uniform current distribution during the electroplating process, avoids deviation in the thickness of the coating on one side, and thus improves the bonding strength between the metal layer and the side of the strip. The first metal layer 5 and the second metal layer 6 are plated in steps, so that different metal layers can subsequently form a raised structure and a recessed structure, providing a limit basis for the overlap. The height of the metal layer is limited to the same height as the strip, which not only avoids interference with the overlapping structure caused by the coating being too high, but also avoids the coating being too low to achieve limit and protect the side of the strip.

[0079] In one embodiment of this embodiment, after obtaining a plurality of electroplated high-temperature superconducting tapes to be overlapped, in order to prevent displacement of the different high-temperature superconducting tapes during overlap and ensure the accuracy of the overlap alignment of the high-temperature superconducting tapes, step 102 first pre-treats the high-temperature superconducting tapes to be overlapped through the following steps, so as to align the concave structures and convex structures based on the pre-treated tapes, thereby ensuring the accuracy of the overlap. Step 102 specifically includes:

[0080] For any one of the high-temperature superconducting tapes to be spliced, the stabilizing layer at the end to be spliced in the high-temperature superconducting tape to be spliced is removed until the upper surface of the superconducting layer 2 appears at the end to be spliced, thereby obtaining a pretreated high-temperature superconducting tape corresponding to the high-temperature superconducting tape to be spliced.

[0081] Specifically, in this embodiment, the high-temperature superconducting tape to be overlapped after electroplating includes a stabilizing layer, a superconducting layer 2, a buffer layer, and a double metal layer located on both sides of the high-temperature superconducting tape to be overlapped. Then, the overlapped ends of the two high-temperature superconducting tapes to be overlapped are processed. Specifically, the high-temperature superconducting tape obtained after the overlapped ends are processed is as follows: Figure 4 As shown. Figure 4 It can be seen that in order to ensure face-to-face contact of the superconducting layers 2, the stabilizing layer at the end to be overlapped is first removed. The removal method can be physical grinding, photolithography, etc. until the upper surface of the superconducting layer 2 is exposed, thereby obtaining a pretreated high-temperature superconducting tape. At this time, the height of the double metal layer in the pretreated high-temperature superconducting tape is higher than the upper surface of the superconducting layer 2.

[0082] In this embodiment, the above steps first limit the treatment target to any single high-temperature superconducting tape, ensuring consistent pretreatment of each tape and avoiding structural deviations caused by batch processing. By precisely controlling the termination condition for stabilizing layer removal to expose the upper surface of superconducting layer 2, the surface overlap of superconducting layer 2 reduces the resistance of the overlap area, thereby improving the yield rate of the tape overlap. Furthermore, the complete exposure of the upper surface of superconducting layer 2 provides a precise positioning reference for the subsequent construction of the stepped metal layer structure, ensuring the formation of a continuous, closed metal protective layer on the sides of the overlap area, thereby achieving positional limitation and lateral protection of the overlap.

[0083] In one implementation of this embodiment, after each of the high-temperature superconducting tapes to be overlapped is processed to obtain a pretreated high-temperature superconducting tape, in order to ensure that the two pretreated high-temperature superconducting tapes do not shift laterally during overlap and to protect the sides of the ends to be overlapped, so as to extend the service life of the tape, step 103 and step 104 can respectively form aligned overlapping concave structures and convex structures on different pretreated high-temperature superconducting tapes through the following steps, so as to complete the overlap limitation and side protection through the concave structures and convex structures.

[0084] Wherein, step 103 includes: for any one of the pretreated high-temperature superconducting tapes; removing the first metal layer 5 at the end portion to be overlapped of the pretreated high-temperature superconducting tape until the height of the first metal layer 5 is level with the height of the upper surface of the superconducting layer 2, thereby obtaining a first high-temperature superconducting tape with a recessed overlap structure.

[0085] Step 104 includes: for any one of the pretreated high-temperature superconducting tapes; removing the first metal layer 5 and the second metal layer 6 at the end to be overlapped in the pretreated high-temperature superconducting tape until the height of the first metal layer 5 and the second metal layer 6 is level with the height of the upper surface of the superconducting layer 2, thereby obtaining a treated high-temperature superconducting tape; and removing the first metal layer 5 and the second metal layer 6 at the end to be overlapped in the treated high-temperature superconducting tape according to the height of the stabilization layer, thereby obtaining a second high-temperature superconducting tape having a raised overlap structure.

[0086] Specifically, in this embodiment, for any of the pretreated high-temperature superconducting tapes, a portion of the first metal layer 5 located inside the double metal layer is removed along the height of the upper surface of the superconducting layer 2, so that the height of the first metal layer 5 is flush with the height of the upper surface of the superconducting layer 2. At this time, the first high-temperature superconducting tape formed after removing a portion of the first metal layer 5 is as follows: Figure 5 and Figure 6 As shown. Figure 5 and Figure 6As can be seen in the figure, the height of the second metal layer 6 outside the double metal layer is higher than the first metal layer 5, and the height difference between the second metal layer 6 and the first metal layer 5 is equal to the height of the stabilization layer. The second metal layer 6, the first metal layer 5 with a portion of the first metal layer 5 removed, and the superconducting layer 2 with the upper surface exposed form a recessed structure at the end of the pre-treated high-temperature superconducting tape to be overlapped.

[0087] In order to perfectly overlap with the concave structure, this embodiment prepares a convex structure in another pre-treated high-temperature superconducting tape. Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 As can be seen from the figure, part of the first metal layer 5 and part of the second metal layer 6 are removed along the height of the upper surface of the superconducting layer 2, so that the height of the first metal layer 5 and the second metal layer 6 is flush with the height of the upper surface of the superconducting layer 2. Then, part of the first metal layer 5 and the second metal layer 6 are removed again, so that the height of the first metal layer 5 and the second metal layer 6 is lower than the upper surface of the superconducting layer 2, and the height difference with the upper surface of the superconducting layer 2 is equal to the height of the stabilizing layer. Figure 7 and Figure 8 It can be seen that by removing the second metal layer 6 and the first metal layer 5, the superconducting layer 2 is raised to form a raised structure at the end portion to be overlapped of the pretreated high-temperature superconducting tape, thereby obtaining a second high-temperature superconducting tape.

[0088] In this embodiment, step 103 is first performed based on the pre-processing of the high-temperature superconducting tape to ensure that the stabilizing layer has been removed and the surface of the superconducting layer 2 is exposed, providing a reference plane for subsequent metal layer processing. By precisely removing the first metal layer 5 to a height level with the top surface of the superconducting layer 2, a recessed structure is formed by the height of the outer second metal layer 6 and the height of the inner first metal layer 5 and the superconducting layer 2. The depth of this recess complements the raised structure of the subsequent second tape, and the physical restraint of the metal layer sidewalls prevents lateral displacement during insertion. The requirement that "the height of the first metal layer 5 is level with the top surface of the superconducting layer 2" not only preserves the second metal layer 6 as a welding contact surface, but also forms a recessed boundary by partially retaining the first metal layer 5, providing a precise embedding space 7 for the raised structure. This hierarchical removal method of different metal layers achieves mechanical interlocking by utilizing the structural differences of the metal layers while ensuring direct contact and conduction of the superconducting layer 2.

[0089] Step 104 forms a raised overlapping component with a specific structure by precisely removing the metal layer in stages. First, by adjusting the height of the first metal layer 5 and the second metal layer 6 to be lower than the upper surface of the superconducting layer 2 and making the height difference between the first metal layer 5 and the second metal layer 6 and the upper surface of the superconducting layer 2 equal to the height of the stabilizing layer, the raised structure finally formed forms a complementary interlocking relationship with the recessed structure in the first high-temperature superconducting tape where the first metal layer 5 is level with the upper surface of the superconducting layer 2. This step-by-step control method not only ensures the dimensional accuracy of the raised structure, but also forms a lateral limit by retaining part of the metal layer to prevent the strip from being misaligned during welding. At the same time, the retained metal layer can cover the side of the overlapping surface, reducing the exposure of cracks or holes, thereby improving the sealing of the joint, and ultimately reducing the joint resistance and extending the service life.

[0090] In one embodiment of this invention, after obtaining the first high-temperature superconducting tape and the second high-temperature superconducting tape, step 105 performs the following steps to overlap the first high-temperature superconducting tape and the second high-temperature superconducting tape. Specifically, step 105 includes:

[0091] Step 1051: coating solder and flux on the upper surface of the superconducting layer 2, and bringing the upper surface of the superconducting layer 2 at the end to be overlapped in the first high-temperature superconducting tape into contact with the upper surface of the superconducting layer 2 at the end to be overlapped in the second high-temperature superconducting tape;

[0092] Step 1052: overlap and contact the second metal layer 6 at the end to be overlapped in the first high-temperature superconducting tape with the second metal layer 6 at the end to be overlapped in the second high-temperature superconducting tape, so that the ends to be overlapped are overlapped in pairs to form an overlapping area.

[0093] Specifically, in this embodiment, solder and flux are applied to the upper surfaces of the exposed superconducting layer 2 of the concave overlap structure of the first high-temperature superconducting tape and the convex overlap structure of the second high-temperature superconducting tape, so that the upper surface of the superconducting layer 2 of the first high-temperature superconducting tape overlaps and contacts with the upper surface of the superconducting layer 2 of the second high-temperature superconducting tape, and the second metal layer 6 of the first high-temperature superconducting tape overlaps and contacts with the second metal layer 6 of the second high-temperature superconducting tape. Figure 9 As shown. Figure 9It can be seen that since the first metal layers 5 on both sides of the concave overlap structure are as high as the superconducting layer 2 and cannot contact the first metal layer 5 of the convex overlap structure, a space 7 is formed between the upper and lower first metal layers 5. Excess solder and flux will flow out from between the two superconducting layers 2 and enter the space 7 and the gap between the two superconducting tapes. After the solder solidifies, it not only connects the two superconducting tapes to each other, but also achieves reliable sealing of the overlap area to avoid damage caused by the entry of external moisture.

[0094] It should be noted that the length of the overlapping area formed after the recessed overlapping structure and the convex overlapping structure are aligned and overlapped is between 2 cm and 10 cm.

[0095] After the overlapping area is formed, a clamp is used to continuously pressurize the overlapping area, and the continuously pressurized overlapping area is heated according to a preset welding temperature and welding time.

[0096] It should be noted that in order to ensure that the superconducting properties of the strip are not damaged during welding, the welding temperature cannot be higher than 350° C. The materials of the solder and flux are not limited, and ordinary brazing materials such as Sn60Pb40 with a melting point of 183° C. can be used.

[0097] In this embodiment, the above steps ensure direct alignment welding between the superconducting layers 2 by coating solder and flux on the upper surface of the superconducting layer 2 and forcing the upper surfaces of the two superconducting layers 2 to overlap and contact, thereby avoiding an increase in resistance caused by the misalignment of the superconducting layers 2. Secondly, by overlapping and contacting the second metal layer 6 of the first high-temperature superconducting tape with the second metal layer 6 of the second high-temperature superconducting tape, the rigidity of the metal layer is used to form a lateral limiting structure, further constraining the lateral displacement of the overlapping area and preventing the strips from sliding and dislocating during welding. At the same time, the overlapping contact of the second metal layer 6 covers the side gaps of the overlapping area, forming a continuous and closed metal protective layer, effectively blocking external moisture from invading through side cracks or holes, and improving the long-term stability of the overlapping structure. By combining continuous pressurization of the clamp with temperature control, stable welding of the overlapping area is achieved. Then, a clamp is used to continuously pressurize the overlapping area, so that the contact surfaces between the superconducting layers 2 and the contact surfaces between the second metal layers 6 can remain in close contact during the welding process, avoiding relative displacement caused by external force disturbance or thermal expansion; by heating the pressurized overlapping area through preset welding temperature and welding time, it can be ensured that the solder is fully melted and penetrated under controlled thermal conditions, while avoiding thermal damage to the superconducting layer 2 or the buffer layer caused by excessive temperature.

[0098] In one implementation of this embodiment, after welding the overlapping area, solder and flux can be applied again to the ends of the two high-temperature superconducting tapes in the overlapping area, and welded and solidified to form a filling structure 8 covering the ends; wherein the filling structure 8 can be obtained by grinding the solidified solder.

[0099] In this embodiment, the above step of welding the filling structure at the end is to fill the gap between the two strips and to cover the strips that may be exposed to protect the superconducting properties of the strips.

[0100] In one embodiment of this embodiment, the filling structure 8 can be polished into a triangular structure, that is, a slope structure. Specifically, the filling structure 8 of the slope structure is as follows: Figure 10 As shown. Figure 10 It can be seen that the side surface of the filling structure 8 made into a slope structure covers the end of a strip, i.e. Figure 10 The circled portion is in the middle, and the lower surface of the filling structure 8 is in contact with the stabilizing layer of another strip.

[0101] In this embodiment, the above steps facilitate the bending and winding of the superconducting tape by setting the shape of the filling structure 8. After winding, the inclined surface will not scratch the adjacent superconducting tapes. The triangular joint covers the exposed end of the tape with a smooth transition, good mechanical effect, and is not easy to fall off.

[0102] On the other hand, this embodiment also discloses a high temperature superconducting wire, wherein the high temperature superconducting wire includes several Figures 5 to 7 The first high temperature superconducting tape and several Figures 7 to 8 The second high-temperature superconducting tape is formed by overlapping the concave overlapping structure of the first high-temperature superconducting tape and the convex overlapping structure of the second high-temperature superconducting tape to form a high-temperature superconducting wire.

[0103] It should be noted that the recessed overlap structure and the raised overlap structure can be respectively provided at both ends of a high-temperature superconducting tape, as long as the recessed overlap structure at one end is connected to the raised overlap structure of another high-temperature superconducting tape and the raised overlap structure at the other end is connected to the recessed overlap structure of another high-temperature superconducting tape.

[0104] The present embodiment discloses a method for splicing high-temperature superconducting tapes and a high-temperature superconducting wire, which realizes precise positioning and sealing protection of superconducting tape splices through structured metal layer plating and mechanical interlocking design, thereby improving the qualified rate of high-temperature superconducting tape splices and the service life of the high-temperature superconducting tape after splicing. First, a double-layer metal layer is plated on the side of the end portion to be spliced of the high-temperature superconducting tape, on the one hand, providing a material basis for the subsequent formation of a concave-convex structure, and on the other hand, ensuring the superconducting performance of the tape. Among them, the height of the metal layer is level with the height of the tape, ensuring that the metal layer covers the complete side of the end portion to be spliced. After removing the stabilizing layer, the superconducting layer is exposed, so that the welding surface is in direct contact with the superconducting layer to improve the superconducting performance and reduce the resistance of the end portion to be spliced. By selectively removing part of the first metal layer or removing the first and second metal layers at the same time, a concave and convex structure is formed, and the concave-convex interlocking is used to achieve physical limitation during splicing to prevent the tape from being dislocated during welding. During the interlocking process, the combination of the concave and convex structures not only enhances joint stability but also covers the side areas with the remaining metal layer, preventing moisture intrusion caused by cracks or holes in the sides. During welding, the combination of the metal layer and the superconducting layer further enhances the mechanical strength and conductive continuity of the joint area, improving the pass rate of the strip joint and the service life of the strip after joining.

[0105] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for splicing high-temperature superconducting tapes, suitable for stacked high-temperature superconducting tapes; The structure of the stacked high-temperature superconducting tape is composed of a stabilizing layer, a superconducting layer and a buffer layer from top to bottom; it is characterized in that: The overlapping method comprises: Obtaining at least two high-temperature superconducting tapes, and sequentially plating a first metal layer and a second metal layer on the side of the end portion to be overlapped of each of the high-temperature superconducting tapes to obtain a plurality of high-temperature superconducting tapes to be overlapped; removing the stabilizing layers at the ends of the high-temperature superconducting tapes to be joined, to obtain a plurality of pretreated high-temperature superconducting tapes; removing a portion of the first metal layer at the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape having a concave overlap structure; removing a portion of the first metal layer and a portion of the second metal layer from the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a second high-temperature superconducting tape having a raised overlap structure; The concave overlapping structure of the first high-temperature superconducting tape and the convex overlapping structure of the second high-temperature superconducting tape are interlocked and spliced to weld the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped.

2. The method for splicing high-temperature superconducting tapes according to claim 1, wherein: The method comprises: sequentially plating a first metal layer and a second metal layer on the side surface of the end portion to be overlapped of each high-temperature superconducting tape to obtain a plurality of high-temperature superconducting tapes to be overlapped, comprising: For any one of the high temperature superconducting tapes; The end portion of the high-temperature superconducting tape to be overlapped is placed between the cathode motor and the anode motor, so that two side surfaces of the end portion to be overlapped are connected to the cathode motor and the anode motor respectively; The side surface is electroplated by the cathode motor and the anode motor to form a first metal layer on the side surface and a second metal layer on the first metal layer, thereby obtaining a high-temperature superconducting tape to be overlapped corresponding to the high-temperature superconducting tape; wherein the heights of the first metal layer and the second metal layer are the same as the height of the high-temperature superconducting tape.

3. The method for splicing high-temperature superconducting tapes according to claim 1, wherein: The step of removing the stabilizing layer at the ends of the high-temperature superconducting tapes to be overlapped to obtain a plurality of pretreated high-temperature superconducting tapes comprises: For any one of the high-temperature superconducting tapes to be spliced; The stabilizing layer at the end portion to be overlapped in the high-temperature superconducting tape to be overlapped is removed until the upper surface of the superconducting layer appears at the end portion to be overlapped, thereby obtaining a pretreated high-temperature superconducting tape corresponding to the high-temperature superconducting tape to be overlapped.

4. A method for splicing high-temperature superconducting tapes according to claim 3, characterized in that: The step of removing a portion of the first metal layer from the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a first high-temperature superconducting tape having a recessed overlap structure includes: For any one of the pretreated high-temperature superconducting tapes; The first metal layer at the end of the pretreated high-temperature superconducting tape to be overlapped is removed until the height of the first metal layer is level with the height of the upper surface of the superconducting layer, thereby obtaining a first high-temperature superconducting tape with a recessed overlap structure.

5. The method for splicing high-temperature superconducting tapes according to claim 3, wherein: The step of removing a portion of the first metal layer and a portion of the second metal layer from the end portion to be overlapped in the pretreated high-temperature superconducting tape to obtain a second high-temperature superconducting tape having a raised overlap structure includes: For any one of the pretreated high-temperature superconducting tapes; removing the first metal layer and the second metal layer at the end to be overlapped in the pretreated high-temperature superconducting tape until the heights of the first metal layer and the second metal layer are level with the height of the upper surface of the superconducting layer, thereby obtaining a treated high-temperature superconducting tape; The first metal layer and the second metal layer at the ends to be overlapped in the processed high-temperature superconducting tape are removed according to the height of the stabilizing layer to obtain a second high-temperature superconducting tape with a raised overlap structure.

6. A method for splicing high-temperature superconducting tapes according to any one of claims 4 to 5, characterized in that: The recessed overlapping structure of the first high-temperature superconducting tape and the convex overlapping structure of the second high-temperature superconducting tape are embedded and spliced together, including: Applying solder and flux on the upper surface of the superconducting layer, and bringing the upper surface of the superconducting layer at the end to be overlapped in the first high-temperature superconducting tape into contact with the upper surface of the superconducting layer at the end to be overlapped in the second high-temperature superconducting tape; The second metal layer at the end to be overlapped in the first high-temperature superconducting tape is overlapped and contacted with the second metal layer at the end to be overlapped in the second high-temperature superconducting tape, so that the ends to be overlapped are overlapped in pairs to form an overlapping area.

7. A method for splicing high-temperature superconducting tapes according to claim 6, characterized in that: The welding of the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped comprises: Using a clamp to continuously pressurize the overlapped area; The overlapped area to which the continuous pressurization is applied is heated according to the preset welding temperature and welding time.

8. The method for splicing high-temperature superconducting tapes according to claim 6, wherein: The welding of the ends of the first high-temperature superconducting tape and the second high-temperature superconducting tape to be overlapped further comprises: Solder and flux are coated on the exposed end faces in the overlap area, and are welded and solidified to form a filling structure for covering the end faces; wherein the side surface of the filling structure overlaps and contacts the end faces; and the lower surface of the filling structure overlaps and contacts the upper surface of the buffer layer.

9. The method for splicing high-temperature superconducting tapes according to claim 6, wherein: The length of the overlapping area is 2 cm to 10 cm.

10. A high-temperature superconducting wire, characterized in that: The invention comprises a plurality of high-temperature superconducting tapes spliced according to the method for splicing high-temperature superconducting tapes according to claims 1 to 9.

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