A method for continuous forming of superconducting core wires based on in-situ curing via ion crosslinking

Abstract

This invention relates to the field of high-temperature superconducting material preparation and additive manufacturing technology, specifically to a method for continuous forming of superconducting core wires based on in-situ curing via ion crosslinking. The specific technical solution involves: mixing yttrium, barium, and copper sources, followed by ball milling to obtain YBCO precursor powder, which is then added to a sodium alginate aqueous solution, along with a plasticizer, and stirred to obtain a composite slurry; using a multi-channel extrusion device to separately deliver the metal slurry and the composite slurry, simultaneously extruding to form core-shell structured wet fibers; immediately after extrusion, the core-shell structured wet fibers are introduced into a crosslinking solution to undergo an ion crosslinking reaction, achieving in-situ curing of the composite slurry; the pre-cured core-shell structured fibers are continuously stretched and collected to form continuous core-shell structured core wires, which are then heat-treated to obtain composite core wires with superconducting properties. This invention constructs a preparation method integrating printing, in-situ curing, and continuous collection, providing a new technical path for the long-scale preparation of multi-material composite superconducting core wires.

Description

Technical Field

[0001] This invention relates to the field of high-temperature superconducting material preparation and additive manufacturing technology, specifically to a method for continuous forming of superconducting core wires based on ion crosslinking and in-situ curing. Background Technology

[0002] High-temperature superconducting materials, capable of zero-resistance transport and perfect diamagnetism at liquid nitrogen temperatures, hold significant application value in fields such as strong magnetic field equipment, power transmission, and medical imaging. Among them, YBa₂Cu₃O₃… 7-x YBCO, as a typical second-generation high-temperature superconducting material, has become one of the core systems for current research and application of high-temperature superconducting conductors due to its high critical current density and excellent magnetic field performance. However, how to achieve continuous fabrication of YBCO materials under long-scale conditions, while taking into account the flexibility of structural design and the ability to combine with multiple materials, remains an important problem restricting its further engineering application.

[0003] Currently, the fabrication technologies for high-temperature superconducting wires and tapes are mainly divided into powder-in-tube (PIT) technology, represented by Bi-based superconducting materials, and coated conductor (CC) technology, represented by YBCO. The powder-in-tube method involves processing Bi₂Sr₂Ca₂Cu₃O₄... 10 Superconducting powders such as BSCCO are filled into metal tubes, and then subjected to multiple machining and heat treatment processes to form a composite conductor. This method has been successfully applied in engineering for first-generation high-temperature superconducting wires. For the YBCO system, a similar powder-packed tube technique was initially attempted. However, because YBCO is a typical strongly anisotropic layered copper oxide superconductor, its superconducting current transport is highly dependent on grain orientation consistency. The high-angle grain boundaries commonly present in the sintered powder state significantly reduce the critical current density. Furthermore, YBCO suffers from a narrow phase stability window, easy decomposition, and difficulty in recrystallization during high-temperature processing, making it difficult to obtain continuous superconducting channels with high texture orientation using the traditional PIT process. Therefore, this approach was gradually abandoned at the end of the last century.

[0004] Against this backdrop, coated conductor technology has become the mainstream approach for YBCO tape fabrication. This method achieves high critical current density conductors by constructing multiple buffer layers on a metal substrate and epitaxially growing well-oriented YBCO thin films. However, this method is highly dependent on vacuum deposition processes and complex multilayer structure designs, requiring sophisticated equipment and process control, resulting in relatively high fabrication costs. Furthermore, the conductor morphology is typically strip-shaped, limiting structural freedom and restricting its application in three-dimensional configurations, multi-material composites, and flexible structures. Moreover, the performance of YBCO coated conductors depends on strict epitaxial growth conditions, essentially a substrate-template-driven texture control mechanism. The close coupling between the material system and the process window limits its application in unconventional structures and novel fabrication processes.

[0005] With the development of additive manufacturing technology, direct-write 3D printing has been gradually introduced into the field of superconducting material preparation. This method constructs structures by extruding slurries containing superconducting powders, thus improving the flexibility of structural design to some extent. However, existing direct-write printing methods for superconducting material construction typically rely on subsequent drying or heat treatment processes for structural solidification, lacking real-time stabilization methods during the forming process. This makes wet structures prone to deformation or instability during printing. Furthermore, in multi-material co-forming processes, the consistency and stability of interface structures still need improvement due to differences in the rheological properties and curing behavior of different components. Moreover, related research is mostly focused on bulk or finite-length structures, lacking mature technical pathways for the stable preparation of continuous long-scale fibers or wires. In addition, the printing, curing, and collection processes in existing technologies are often independent, making it difficult to form a continuous, integrated preparation process.

[0006] On the other hand, hydrogel systems formed by the ionic crosslinking reaction between sodium alginate and divalent metal ions have been used in the preparation of continuous fibers in fields such as biomaterials and flexible electronics. These systems achieve structural solidification through rapid crosslinking, offering certain advantages in shaping. However, this type of method is mainly applied to polymer or low-solids systems. For composite slurry systems containing a high proportion of inorganic powders (such as superconducting ceramic powders), the rheological behavior, ion diffusion, and crosslinking kinetics are more complex. How to ensure shaping stability while simultaneously maintaining structural uniformity and functional performance still requires further research.

[0007] Building upon this foundation, the inventors' preliminary research revealed for the first time that in the silver-containing (Ag) YBCO system, Ag can enter YBa2Cu3O through solid solution substitution. 7-xThe Cu(1) sites in the crystal structure induce a directional relaxation effect in the local lattice structure, thereby regulating the grain orientation evolution and microstructure formation process, exhibiting a certain structure-inducing or template-like effect. This mechanism differs from the texture-inducing mechanism in traditional coated conductors that relies on the epitaxial substrate, providing a new approach for microstructure control of superconducting materials under non-epitaxygian conditions. However, existing research mainly focuses on sintered or bulk material systems, and this type of structure control mechanism has not yet been combined with continuous forming processes. Especially under the conditions of multi-material collaborative construction and dynamic forming, its role in the stability of core-shell structures and microstructure evolution still lacks systematic research.

[0008] In summary, existing technologies still have certain limitations in the structured and continuous fabrication of YBCO high-temperature superconducting materials. In particular, under the condition of multi-material collaborative construction, there is a lack of effective technical means to achieve structural stability control during the forming process and to balance continuous fabrication capability with structural design freedom. At the same time, the synergistic relationship between the intrinsic structure regulation mechanism of the material and the continuous forming process also needs to be further explored.

[0009] Therefore, it is necessary to propose a new preparation method to achieve stable construction and efficient fabrication of core-shell structured superconducting wires during continuous forming. Based on this, this invention provides a continuous forming method for core-shell structured superconducting wires based on in-situ solidification via ion crosslinking. By introducing an in-situ ion crosslinking mechanism and combining it with a continuous traction collection process, a new technical path is provided for the continuous fabrication of multi-material composite superconducting wires. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a method for continuous forming of superconducting core wires based on in-situ curing via ion crosslinking, applicable to the forming and continuous preparation of precursor fibers for ceramic superconducting materials such as YBCO.

[0011] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for continuous forming of superconducting core wires based on in-situ curing via ion crosslinking. Yttrium, barium, and copper sources are mixed and ball-milled to obtain YBCO precursor powder, which is then added to a sodium alginate aqueous solution. A plasticizer is added, and the mixture is stirred to obtain a composite slurry. A multi-channel extrusion device is used to separately deliver the metal slurry and the composite slurry, simultaneously extruding to form core-shell structured wet fibers. Immediately after extrusion, the core-shell structured wet fibers are introduced into a crosslinking solution containing divalent metal ions to undergo an ion crosslinking reaction, achieving in-situ curing of the composite slurry. The pre-cured core-shell structured fibers are continuously stretched and collected to form continuous core-shell structured core wires, which are then heat-treated to obtain composite core wires with superconducting properties.

[0012] Preferably, the sodium alginate has a mass fraction of 4-5 wt%, the YBCO precursor powder has a solid content of 50-60 wt%, the plasticizer is glycerol, and the amount of glycerol added accounts for 10-20 wt% of the mass of the sodium alginate aqueous solution.

[0013] Preferably, the composite slurry is a non-Newtonian fluid, and the yield stress of the composite slurry is 50-70 Pa, and the consistency coefficient is 1200-2000 Pa·s. n The liquidity index is 0.1-0.4.

[0014] Preferably, the metal paste is an electronic silver paste, which is a non-Newtonian fluid with a yield stress of 20-50 Pa and a consistency coefficient of 20-100 Pa·s. n The liquidity index is 0.5-1.5.

[0015] Preferably, the outer layer of composite slurry is fed using a constant flow conveying method, with the flow rate controlled at 0.05-0.25 mL / min; the inner layer of metal slurry is conveyed using a pneumatic drive method, with the driving air pressure controlled at 0.1-0.3 MPa.

[0016] Preferably, the divalent metal ion is Ca. 2+ Ba 2+ 、Sr 2+ Cu 2+ At least one of them, with a concentration of 0.5-3 wt%.

[0017] Preferably, the pre-cured core-shell structured fibers are collected by rollers, which are driven by a motor to rotate at a speed of 10-15 rpm, and the linear velocity of the wet core-shell structured fibers is 1-2 mm / s.

[0018] Preferably, the ratio of the traction speed of the core-shell structure wet fiber to the extrusion speed of the core-shell structure wet fiber at the roller rotation speed is controlled between 0.9 and 1.1.

[0019] Preferably, the core-shell structure filament is dried at 80-125 °C for 24-36 h; then, the dried core-shell structure filament is heated to 400-500 °C in air or oxygen atmosphere and held at that temperature for 10-15 h; then, it is sintered at 850-950 °C for 15-20 h at a heating rate of 2-5 °C / min.

[0020] Preferably, after sintering, the core-shell structure core wire is subjected to oxygen replenishment treatment. The oxygen replenishment treatment is carried out in an oxygen atmosphere at a temperature of 400-500 ℃ for a holding time of 20-30 h.

[0021] The present invention has the following beneficial effects: The present invention proposes a method for continuous forming and collection of core-shell superconducting core wires based on in-situ curing of ion crosslinking. By combining the forming process with a rapid ion crosslinking mechanism, the shell material is gelled and cured in situ during fiber extrusion, thereby providing effective support for the wet structure during continuous forming. This enables the core-shell structure to remain stable under dynamic forming conditions, forming a continuous and complete fiber structure. This provides a new way to maintain the structure of multi-material composite systems during continuous preparation.

[0022] Meanwhile, this invention constructs an integrated process flow that combines printing, curing and traction collection, enabling effective connection between each process step in space and time. This is beneficial to improving the continuity and stability of the preparation process, and enables continuous output of long-scale fibers without the need for complex subsequent support or intermittent processing, demonstrating good potential for process integration.

[0023] In terms of structural design, this invention achieves the synchronous construction of core-shell structures through multi-channel collaborative transport, providing a feasible path for the composite of metals and superconducting ceramic materials, which is conducive to the collaborative construction of multiple material interfaces in a single forming process. At the same time, based on the inventors' previous research on the structural regulation role of silver in the YBCO system, this composite structure has the potential to further regulate the microstructure during subsequent heat treatment, providing a new approach for the microstructure optimization of superconducting materials under non-epitaxy conditions.

[0024] Furthermore, the ion crosslinking system used in this invention has the characteristics of mild reaction conditions and strong adaptability, and can be combined with high solid content superconducting powder slurry system, ensuring the stability of the forming while taking into account the scalability of the material system. The method is not only applicable to YBCO system, but can also be extended to other high temperature superconducting or functional composite material systems. It has potential application value in long-scale conductors, structured functional devices and complex morphology construction, and has potential application value and engineering promotion prospects in the fields of national defense equipment, strong magnetic field large scientific facilities, high-end medical imaging and advanced power systems.

[0025] In summary, this invention has comprehensive advantages in terms of continuous forming capability, structural stability, process integration, and multi-material synergistic construction, providing a new technical approach for the structured and continuous fabrication of high-temperature superconducting core wires. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the process flow of the present invention; Figure 2 This is a schematic diagram of a multi-channel extrusion nozzle structure; Figure 3 This is a schematic diagram of an ion crosslinking and continuous collection device; Figure 4 The diagram shows the rheological properties test results of the composite slurry; where: (a) is the relationship between storage modulus (G′) and loss modulus (G″) and shear stress; (b) is the curve of apparent viscosity as a function of shear rate; (c) is the curve of shear stress as a function of shear rate; and (d) is the fitting curve of the Herschel-Bulkley model for the rheological behavior of the slurry. Figure 5 The diagram shows the morphology of a continuous core-shell superconducting wire; (a) is a macroscopic morphology of a superconducting wire approximately 3.3 m long after winding; (b) is a scanning electron microscope (SEM) image of the cross-section of the superconducting wire's core-shell structure. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise specified, the technical means used in the implementation examples are conventional means well known to those skilled in the art.

[0029] like Figure 1 As shown, this invention provides a method for continuous forming of core-shell structured superconducting core wires based on ion crosslinking and in-situ solidification, comprising the following steps: Step 1: Preparation of YBCO precursor powder Yttrium source, barium source, and copper source are mixed in a stoichiometric molar ratio, preferably Y:Ba:Cu=1:2:3; the yttrium source is Y₂O₃, the barium source is BaCO₃, and the copper source is CuO. The above mixed powder is added to anhydrous ethanol as a dispersion medium and uniformly mixed by ball milling, preferably for 12-15 h. After ball milling, the slurry is dried to obtain a uniformly mixed YBCO precursor powder.

[0030] In a further embodiment, the dried powder can be sieved or lightly ground to reduce particle agglomeration and obtain precursor powder with uniform particle size distribution; wherein, the sieving is preferably carried out using a 200-400 mesh sieve, thereby improving the uniformity and forming stability of the subsequent slurry preparation.

[0031] Step 2: Preparation of composite slurry and metal slurry The YBCO precursor powder obtained in step one is added to an aqueous solution of sodium alginate, along with a certain proportion of a plasticizer, preferably glycerol. The powder is then uniformly dispersed by a combination of mechanical stirring and ultrasonic dispersion, followed by vacuum degassing to obtain a homogeneous and stable composite slurry. Preferably, the mechanical stirring speed is 500–800 r / min and the stirring time is 30–60 min, while the ultrasonic dispersion power is 100–300 W and the ultrasonic dispersion time is 10–20 min.

[0032] The preferred content of sodium alginate is 4-5 wt%, the preferred content of YBCO precursor powder is 50-60 wt%, and the preferred amount of glycerol added is 10-20 wt% of the sodium alginate aqueous solution, in order to adjust the viscosity and flexibility of the slurry, thereby improving its extrusion molding performance and subsequent structural stability.

[0033] Preferably, the composite slurry exhibits typical non-Newtonian fluid behavior, such as... Figure 4 As shown in (a), a fluid with a storage modulus greater than its loss modulus is a non-Newtonian fluid; it exhibits shear-thinning behavior. Figure 4 As shown in (b), the apparent viscosity decreases with increasing shear rate, and its rheological behavior conforms to the Herschel-Bulkley model, with its shear stress... τ With shear rate The following relationship exists between them: ,in For yield stress, K This is the consistency coefficient. n The flow index; the yield stress of the composite slurry. Preferably, the Pa value is 50-70, and the consistency coefficient is... K Preferably 1200-2000 Pa·s n Flow Index n The preferred value is 0.1-0.4, which allows the slurry to maintain its shape stability under low shear conditions and exhibit obvious shear thinning characteristics during extrusion. Figure 4 (c) and Figure 4 As shown in (d), the rheological parameters are obtained by model fitting. (d) is a magnified view of (c) for x=0-0.4, which facilitates fitting.

[0034] Simultaneously, as the core layer material, a conductive metal paste is selected, preferably an electronic silver paste. This electronic silver paste is preferably a commercially available conductive silver paste used in thick-film circuits or printed electronics, and should possess good conductivity and rheological properties suitable for extrusion. Preferably, the electronic silver paste also exhibits non-Newtonian fluid behavior conforming to the Herschel-Bulkley model, with a yield stress of... The preferred Pa value is 20-50 Pa, and the consistency coefficient is... KPreferably 20-100 Pa·s n Flow Index n The preferred value is 0.5-1.5 to ensure stable transport in the inner channel and coordinated extrusion with the outer slurry.

[0035] Furthermore, by adjusting the rheological properties of the composite slurry and the electronic silver paste, the two slurries can exhibit compatible flow behavior during extrusion, which is beneficial for forming core-shell composite fibers with continuous interfaces and stable structures.

[0036] Step 3: Simultaneous extrusion molding of wet fibers with core-shell structure like Figure 2 As shown, a multi-channel extrusion nozzle is used to simultaneously extrude an inner layer metal slurry and an outer layer composite slurry. The inner layer metal slurry and the outer layer composite slurry are transported through independent channels and converge at the nozzle exit to form a core-shell structured wet fiber. The metal slurry constitutes the core layer of the fiber, and the composite slurry constitutes the shell layer. During the extrusion process, the transport states of the inner and outer slurries are coordinated and controlled to form a continuous and stable coaxial flow structure at the nozzle exit, thereby achieving continuous construction of the core-shell interface.

[0037] Preferably, the outer composite slurry can be supplied using a constant flow delivery method, with its flow rate preferably controlled within the range of 0.05-0.25 mL / min; the inner metal slurry can be delivered using a pneumatic drive method, with its driving air pressure preferably controlled within the range of 0.1-0.3 MPa. By matching and controlling the above delivery parameters, it is beneficial to achieve coordinated flow rates and stable interface coating of the inner and outer slurries at the nozzle outlet.

[0038] Furthermore, the core-shell structured wet fiber maintains a continuous output state during the extrusion process, providing a stable structural basis for subsequent ion crosslinking, in-situ curing, and continuous traction collection.

[0039] Step 4: Ion crosslinking and in-situ curing The core-shell structured wet fibers obtained in step three are immediately introduced into a crosslinking solution containing divalent metal ions (Ca) for in-situ curing after extrusion. 2+ Ba 2+ 、Sr 2+ Cu 2+ At least one of the above, wherein the crosslinking solution is a salt solution of the aforementioned metal ions; preferably Ca 2+ The crosslinking solution is preferably an aqueous solution of CaCl2, and its concentration is preferably 0.5-3 wt%. During the crosslinking process, the sodium alginate molecular chains in the outer composite slurry react with the CaCl2 in the solution. 2+Coordination occurs, forming an ionic cross-linked network structure, which rapidly transforms the shell material from a fluid state to a gel state with certain mechanical strength, thereby achieving in-situ fixation and morphological preservation of the core-shell structure.

[0040] Preferably, the crosslinking process is carried out in a continuous fiber movement state. By controlling the residence state of the fiber in the crosslinking region (taking CaCl2 as an example, the CaCl2 aqueous solution is in a crucible, the moistened fiber is introduced into the leftmost part of the crucible and then controlled to exit from the rightmost part, and finally collected on the collection device. The crucible length, collection speed, etc. will affect the curing state. If the time is too short, the curing will not be complete and the fiber will break when drawn; if the time is too long, the curing will be too hard and it will be impossible to use rollers to curl and collect it), the shell material can be gradually cured while maintaining structural continuity, thereby avoiding structural defects caused by uneven curing.

[0041] Furthermore, through the in-situ ionic cross-linking process, the core-shell coating structure formed in step three is stably maintained during subsequent traction and collection processes, providing structural support for continuous forming.

[0042] Step 5: Continuous Traction and Collection A continuous traction and collection device is installed downstream of the ion crosslinking region described in step four, such as... Figure 3 As shown, the device includes a roller and a drive motor. The motor drives the roller to rotate, thereby achieving continuous traction and collection of the pre-cured core-shell structure fibers. During the traction process, the traction speed of the fibers is controlled by adjusting the roller speed, so that the fibers are kept in a continuous output state under controlled tension.

[0043] Preferably, the rotational speed of the roller is controlled within the range of 10-15 rpm, corresponding to a fiber linear speed preferably of 1-2 mm / s, and is consistent with or close to the extrusion speed in step three, so as to avoid the fiber from tensile breakage or stacking and bending during the traction process.

[0044] Preferably, the ratio of the traction speed to the extrusion speed is controlled within the range of 0.9-1.1 to achieve dynamic matching between the extrusion and collection processes, thereby improving the continuity and structural stability of the core-shell structure fiber.

[0045] Preferably, the traction speed is coordinated with the curing state of the fiber in the cross-linking region, so that the fiber has a certain mechanical strength before being effectively tractioned, thereby avoiding structural deformation or interface damage caused by insufficient curing.

[0046] Furthermore, by adjusting the traction tension, the core-shell structure fibers maintain structural integrity and interface stability during continuous collection.

[0047] Preferably, the collection method is winding collection or directional arrangement collection to achieve stable preparation of continuous long-scale core-shell structure filaments.

[0048] Step Six: Post-processing The core-shell structured filaments collected in step five are then subjected to further heat treatment to obtain a composite filament structure with superconducting properties. First, the filaments are dried to remove moisture from the system. Preferably, the drying temperature is 80-125 °C, and the drying time is 24-36 h. Subsequently, the dried core-shell structured filaments undergo organic matter removal treatment (degreasing treatment). Preferably, the temperature is raised to 400-500 °C in an air or oxygen atmosphere and held for 10-15 h to remove organic components such as sodium alginate and plasticizers.

[0049] Furthermore, the degreased core-shell structure wire is subjected to high-temperature sintering to form a YBCO superconducting phase structure. Preferably, the sintering temperature is 850-950 ℃ and the holding time is 15-20 h. During the sintering process, the heating rate is preferably controlled at 2-5 ℃ / min to reduce the generation of structural cracks or interface defects.

[0050] Preferably, after sintering, the core-shell structure wire is subjected to oxygen supplementation treatment to improve the superconducting performance of the material. The oxygen supplementation treatment is carried out in an oxygen atmosphere, preferably at a temperature of 400-500 ℃ and a holding time of 20-30 h.

[0051] Furthermore, by controlling the temperature and atmosphere conditions during sintering and oxygen supplementation, the core-shell structure can maintain overall continuity while achieving the formation and performance optimization of the YBCO phase.

[0052] Testing showed that the core-shell structured superconducting wires prepared by the method of this invention exhibit good continuity and structural integrity, and can achieve stable fabrication of meter-scale lengths; for example... Figure 5 As shown in (a), its macroscopic morphology is uniform, its winding performance is good, and no obvious breakage or collapse is observed. Scanning electron microscopy (SEM) reveals that… Figure 5 (b) The prepared core wire has a clear core-shell structure interface, and the shell is dense and evenly distributed.

[0053] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for continuous forming of superconducting core wires based on ion crosslinking and in-situ curing, characterized in that: Yttrium source, barium source and copper source are mixed and ball-milled to obtain YBCO precursor powder, which is then added to sodium alginate aqueous solution, followed by plasticizer, and stirred to obtain composite slurry; metal slurry and composite slurry are transported separately by a multi-channel extrusion device and extruded simultaneously to form core-shell structure wet fibers. The core-shell structure wet fibers are immediately introduced into a crosslinking solution containing divalent metal ions after extrusion to undergo ionic crosslinking reaction, thereby realizing in-situ curing of composite slurry; The pre-cured core-shell structured fibers are continuously stretched and collected to form a continuous core-shell structured filament, and after heat treatment, a composite filament with superconducting properties is obtained.

2. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1, characterized in that: The sodium alginate has a mass fraction of 4-5 wt%, the YBCO precursor powder has a solid content of 50-60 wt%, the plasticizer is glycerol, and the amount of glycerol added accounts for 10-20 wt% of the mass of the sodium alginate aqueous solution.

3. A method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1 or 2, characterized in that: The composite slurry is a non-Newtonian fluid with a yield stress of 50-70 Pa and a consistency coefficient of 1200-2000 Pa·s. n The liquidity index is 0.1-0.

4.

4. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 3, characterized in that: The metal paste is an electronic silver paste, which is a non-Newtonian fluid with a yield stress of 20-50 Pa and a consistency coefficient of 20-100 Pa·s. n The liquidity index is 0.5-1.

5.

5. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1, characterized in that: The outer layer of composite slurry is fed using a constant flow method, with the flow rate controlled at 0.05-0.25 mL / min; the inner layer of metal slurry is fed using a pneumatic drive method, with the driving air pressure controlled at 0.1-0.3 MPa.

6. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1, characterized in that: The divalent metal ion is Ca. 2+ Ba 2+ 、Sr 2+ Cu 2+ At least one of them, with a concentration of 0.5-3 wt%.

7. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1, characterized in that: The pre-cured core-shell structured fibers are collected by rollers driven by a motor, with the rotation speed controlled at 10-15 rpm. The linear velocity of the wet core-shell structured fibers is 1-2 mm / s.

8. A method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 1 or 7, characterized in that: The ratio of the traction speed to the extrusion speed of the core-shell structure wet fiber at the roller speed is controlled between 0.9 and 1.

1.

9. The method for continuous forming of superconducting core wire based on in-situ curing via ion crosslinking according to claim 1, characterized in that: The core-shell structure filament is dried at 80-125 °C for 24-36 h; then, the dried core-shell structure filament is heated to 400-500 °C in air or oxygen atmosphere and held at that temperature for 10-15 h; then, it is sintered at 850-950 °C for 15-20 h at a heating rate of 2-5 °C / min.

10. The method for continuous forming of superconducting core wire based on ion crosslinking and in-situ curing according to claim 9, characterized in that: After sintering, the core-shell structure core wire is subjected to oxygen replenishment treatment. The oxygen replenishment treatment is carried out in an oxygen atmosphere at a temperature of 400-500 ℃ for 20-30 h.

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