High-temperature superconducting composite wire forming method and composite wire

Abstract

The invention discloses a high-temperature superconducting composite wire rod forming method and a composite wire rod. The high-temperature superconducting composite wire rod forming method comprises the following steps of pipe penetrating; performing vacuum sealing; heating and vibrating; inclined mold passing; quenching; and rolling and pulling. The composite wire is manufactured through the forming method of the high-temperature superconducting composite wire. Through vacuum, local heating vibration, inclined hot drawing and quenching technologies, inner brazing filler metal is in a liquid state while the diameter of the pipe sleeve is reduced, the heating time is greatly shortened, too large extrusion stress caused to the high-temperature superconducting tape in the forming process is avoided, and superconductivity decline possibly caused by high temperature and stress strain in the forming process is greatly reduced. The continuous casting effect is formed under gravity and rapid air cooling through the vibration, inclined mold passing and quenching processes, the problem that filler gaps exist in the prior art can be reduced or even eliminated, and the low porosity is beneficial for improving the strength of the cable.

Description

Technical Field

[0001] The present invention relates to the field of high-temperature superconducting composite wires, and in particular to a high-temperature superconducting composite wire forming method and the composite wire. Background Art

[0002] With the development of high-temperature superconducting material technology, the second-generation high-temperature superconducting tape represented by REBCO has fully reached the practical level and can be widely used in electric power, magnetic confinement fusion reactors, scientific research equipment, magnetic resonance imaging, large motors, magnetic levitation and other fields. High-temperature superconducting materials have an operating temperature and critical magnetic field that are much higher than low-temperature superconductors. Under strong magnetic fields, REBCO high-temperature superconducting tapes need to withstand huge electromagnetic stresses, and the huge width-to-thickness ratio of REBCO high-temperature superconducting tapes and the insufficient bonding strength between the superconducting layer and the substrate lead to insufficient mechanical properties. The current carrying capacity of a single tape is limited, and multiple tapes need to be connected in parallel to meet the needs of high-current applications. Therefore, packaging REBCO high-temperature superconducting tapes into cables with high strength and large current carrying capacity is a necessary condition for their widespread application.

[0003] At the same time, the superconducting body of REBCO high-temperature superconducting tape is ceramic, which will be irreversibly damaged and lose its superconductivity when it is strained by about 0.5% and exposed to high temperatures above 200°C for a long time. Existing packaging methods, such as brazing, laser welding, vacuum impregnation, extrusion, etc., cannot prepare REBCO high-temperature superconducting tape into low-porosity, high-strength composite wires without causing obvious superconductivity degradation during the preparation process, which is difficult to meet actual engineering needs. Summary of the invention

[0004] The technical problem to be solved by the present invention is that it is difficult to simultaneously produce a high-temperature superconducting cable with low current decay, low porosity and high strength in the prior art. The purpose is to provide a high-temperature superconducting composite wire forming method and a composite wire to solve the above-mentioned problem.

[0005] The present invention is achieved through the following technical solutions:

[0006] Pipe penetration: the core wire coated with filler is inserted into the pipe sleeve to obtain an assembly;

[0007] Vacuum sealing: Cleaning gas is used to purge the inside of the tube sleeve, and the front end of the tube sleeve is sealed and then vacuumed. After the vacuum reaches the standard, the rear end of the tube sleeve is sealed;

[0008] Heating and vibration: The assembly moves along the forming processing line to the heating box, where it is heated and vibrated. The filler melts into liquid and falls off and accumulates at the front end of the drawing die.

[0009] Tilt over-molding: The assembly is tilted through the drawing die, the outer periphery of the core wire is coated with liquid filler, and the sleeve is reduced in diameter;

[0010] Rapid cooling: The assembly passes through a cooling box and is cooled, the liquid filler solidifies and connects the core wire and the sleeve to obtain a composite wire;

[0011] Coiling: The wire is pulled and reeled by applying a pulling force through a coiler.

[0012] In a possible design, the core wire is coated with a filler, and the forming processing line includes a guide mechanism, a heating box, a drawing die, a cooling box, and a winding machine which are arranged in sequence.

[0013] In one possible design, the step of vacuum sealing includes the following steps:

[0014] Blow cleaning gas into the assembly from one end until the oxygen content of the gas at the other end of the assembly is less than 0.1%;

[0015] Squeeze the front end of the tube sleeve 3-5cm and apply vacuum sealing grease, and evacuate the assembly from the front end of the assembly. When the vacuum degree is lower than 500Pa, squeeze the rear end of the tube sleeve 3-5cm and apply vacuum sealing grease to seal the assembly.

[0016] In a possible design, the guide mechanism is used to install and convey the assembly so that the assembly moves along the forming processing line, and one end of the sleeve is connected to the reel and pulled by the reel so that the core wire and the sleeve have a speed difference;

[0017] In a possible design, the guiding mechanism adopts a plurality of sets of position-limiting guide wheels, or a combination of a plurality of sets of position-limiting guide wheels and a distributed vibration table.

[0018] The moving speed of the core wire is equal to the hot drawing speed of the drawing die, and the moving speed of the core wire is greater than the moving speed of the tube sleeve, and the moving speed of the tube sleeve is 5-50mm / s.

[0019] In a possible design, the guiding mechanism uses multiple sets of limiting guide wheels.

[0020] In a possible design, the length of the heating zone of the heating box is 2%-3% of the length of the assembly, and the longest heating time of the heating box heating the same position of the core wire is no more than 10 minutes.

[0021] In a possible design, a vibration module is provided on the heating box, or a vibrator is provided adjacent to the heating box.

[0022] In one possible design, the angle between the drawing die and the horizontal line is 5°-90°;

[0023] A gap is left between the core wire and the sleeve, and the gap forms a liquid zone for accumulating liquid filler above the inlet of the drawing die. Correspondingly, the heating zone of the heating box is located above the liquid zone;

[0024] Preheating of the drawing die: before the step of assembly feeding is implemented, the drawing die is preheated, and the temperature of the drawing die is 10-20°C higher than the melting point of the filler; after the step of assembly feeding is implemented, the drawing die stops heating and dissipates heat through the cooling box.

[0025] In a possible design, the cooling port of the cooling box faces the outlet of the drawing die, and when the cooling box uses an air knife, the wind speed of the air knife is 10-50 m / s, and the cooling length is 2-5 cm.

[0026] In a second aspect, the present invention provides a composite wire made by the high-temperature superconducting composite wire forming method.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] Through vacuum, local heating vibration, inclined hot drawing and rapid cooling technology, the internal solder is in liquid state while the tube sleeve is reduced in diameter, which greatly shortens the heating time, avoids excessive extrusion stress on the high-temperature superconducting tape during the forming process, and greatly reduces the superconductivity degradation caused by high temperature and stress strain during the forming process. At the same time, the vibration, inclined over-molding and rapid cooling process form a continuous casting effect under gravity and rapid air cooling, which can reduce or even eliminate the problem of filler voids in the prior art, and the low porosity helps to improve the strength of the cable. Based on this, the composite wire has higher mechanical properties and electromagnetic comprehensive properties than the cables prepared by the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0030] Figure 1 The present invention is a flow chart of a method for forming a high-temperature superconducting composite wire.

[0031] Figure 2 It is a schematic diagram of the structure of the assembly.

[0032] Figure 3 It is a structural schematic diagram of the forming processing line.

[0033] Figure 4 for Figure 3 Schematic diagram of the enlarged structure of the drawing die.

[0034] 1. Core wire; 2. Tube sleeve; 3. Filler; 4. Guide mechanism; 5. Heating box; 6. Drawing die; 7. Cooling box; 8. Winder; 9. Composite wire. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0036] Embodiment 1:

[0037] like Figure 1-Figure 4 As shown, a high temperature superconducting composite wire forming method comprises the following steps:

[0038] S100 Pipe threading: the core wire 1 coated with the filler 3 is inserted into the pipe sleeve 2 to obtain an assembly;

[0039] S200 vacuum seal: the cleaning gas is blown into the tube sleeve 2, the front end of the tube sleeve 2 is sealed and then vacuumed, and the rear end of the tube sleeve 2 is sealed after the vacuum reaches the standard;

[0040] S300 Heating and Vibrating: The assembly moves along the forming processing line to the heating box 5, where it is heated and vibrated, and the filler 3 melts into liquid and falls off and accumulates at the front end of the drawing die 6;

[0041] S400 tilting over-molding: the assembly is tilted through the drawing die 6, the outer periphery of the core wire 1 is coated with liquid filler 3, and the tube sleeve 2 is reduced in diameter;

[0042] S500 rapid cooling: the assembly passes through a cooling box 7 and is cooled, the liquid filler 3 solidifies and connects the core wire 1 and the sleeve 2 to obtain a composite wire 9;

[0043] S600 Coiling: Applying a drawing and reducing force through the coiler 8 and coiling the composite wire 9.

[0044] The core wire 1 is coated with a filler 3, and the forming processing line includes a guide mechanism 4, a heating box 5, a drawing die 6, a cooling box 7 and a winding device 8 which are arranged in sequence.

[0045] The high-temperature superconducting composite wire forming method allows the heated and melted filler 3 to remain in liquid state by tilting the mold, and the liquid filler 3 can be quickly coated on the core wire 1, which greatly reduces the heating temperature and shortens the heating time, and also avoids the extrusion stress on the core wire 1 during the drawing process, and greatly reduces the superconductivity degradation that may be caused by heating and stress strain during the forming process. After tilting the mold, rapid cooling is achieved by cooling to form a continuous casting effect, which reduces the problem of insufficient filling between the sleeve 2 and the core wire 1 due to the solidification of the filler 3 and the cold shrinkage of the material during the cooling process, and reduces the porosity inside the composite wire 9.

[0046] After the assembly of step S100 is completed, Figure 2 As shown, the core wire 1 is inserted into the tube sleeve 2, and an annular gap is formed between the core wire 1 and the tube sleeve 2, which reserves storage space for the melted filler 3 and effectively reduces the extrusion of the core wire 1 when the tube sleeve 2 shrinks.

[0047] It is easy to understand that the filler 3 is preferably solder, such as low-temperature solder and medium-temperature solder, and any suitable commercially available filler material may also be selected.

[0048] For the assembly, the core wire 1 is made of a plurality of REBCO high temperature superconducting tapes connected in parallel, or any other suitable commercially available tapes.

[0049] The sleeve 2 is made of copper, aluminum and its alloy, annealed or semi-annealed, with an elongation better than 30%. The wall thickness of the sleeve 2 is 10%-40% of the diameter of the core wire 1, and the length is 1.1-1.2 times the diameter of the core wire 1.

[0050] The filler 3 of this embodiment is a low-temperature solder with a maximum melting point of 220° C., and the solder coating amount of the core wire 1 is 74%-80% of the cross-sectional area of ​​the core wire 1 .

[0051] The forming processing line includes a guiding mechanism 4, a heating box 5, a drawing die 6, a cooling box 7 and a reel 8 which are arranged in sequence; technical personnel in this field appropriately increase or decrease the feed speed according to specific processing conditions, and the speeds of the drawing die 6 and the reel 8 are also adaptively adjusted, which will not be repeated here.

[0052] When the assembly is fed to the drawing die 6, the diameter of the tube sleeve 2 will shrink when passing through the drawing die 6, that is, the length of the tube sleeve 2 will be extended, while the length of the core wire 1 will not be extended. Therefore, before the step S500 tilting over the die, there should be a speed difference between the core wire 1 and the tube sleeve 2, that is, the core wire 1 and the tube sleeve 2 can slide relative to each other to ensure that the step S500 tilting over the die is implemented smoothly.

[0053] Further, after the tilting over the mold in step S500, the core wire 1 and the sleeve 2 are connected by the solidified filler 3 to obtain the composite wire 9. At this time, the composite wire 9 is pulled and wound by the winder 8, and the core wire 1 and the sleeve 2 move synchronously without any speed difference between the two.

[0054] Further, after the assembly is completed, step S200 can be performed to clean and seal the assembly to ensure that oxidation does not occur during subsequent processing and to ensure processing quality. Specifically, the vacuum sealing in step S200 includes the following steps:

[0055] S210: Blowing cleaning gas into the assembly from one end of the assembly until the oxygen content of the gas discharged from the other end of the assembly is less than 0.1%;

[0056] S220: Squeeze the front end 3-5 cm of the tube sleeve 2 and apply vacuum sealing grease, and evacuate the assembly from the front end of the assembly. When the vacuum degree is lower than 500 Pa, extrude the rear end 3-5 cm of the tube sleeve 2 and apply vacuum sealing grease to seal the assembly.

[0057] Based on the above design scheme, step S210 is used to clean the assembly and reduce the oxygen content, and the sealing of step 220 is used to avoid oxidation during the subsequent forming process, thereby ensuring that the formed composite wire 9 has excellent mechanical and electrical connectivity.

[0058] Before implementing step S200, considering that the assembly is long, the assembly should be placed on relevant equipment before vacuum sealing to facilitate related operations. Preferably, one end of the assembly is placed on the forming processing line, which is convenient for subsequent vacuum sealing related operations and for feeding the assembly into the forming processing line to facilitate steps S300-S600.

[0059] Furthermore, in theory, the vacuum sealing can be completed on equipment other than the forming processing line and then the assembly can be sent to the forming processing line. However, the assembly needs to be disassembled and assembled many times, and the assembly is prone to damage during the disassembly and assembly process. Considering that the length of the assembly is long, the related risks are further increased. Therefore, it is preferred to put the assembly on the forming processing line and then perform step S200 and subsequent steps.

[0060] Optionally, the cleaning gas includes, but is not limited to, argon, krypton, neon, helium and xenon.

[0061] In a possible implementation, the guide mechanism 4 is used to install and transport the assembly so that the assembly moves along the forming processing line, and one end of the sleeve 2 is connected to the reel 8 and pulled by the reel 8 so that the core wire 1 and the sleeve 2 have a speed difference.

[0062] Based on the above design scheme, the feeding of the assembly is achieved through the guiding mechanism 4, so that the sleeve 2 remains straight, reducing the friction resistance between the core wire 1 and the sleeve 2, and cooperating with the traction of the reel 8 to drive the core wire 1 to move, so that the core wire 1 and the sleeve 2 can slide relative to each other, avoiding the breakage of the core wire 1 or the sleeve 2 due to synchronous movement. At the same time, the sleeve 2 is moved by the reel 8 to ensure that the two can slide relative to each other.

[0063] Specifically, the moving speed of the core wire 1 is equal to the hot drawing speed of the drawing die 6, and the moving speed of the core wire 1 is greater than the moving speed of the tube sleeve 2, and the moving speed of the tube sleeve 2 is 5-50 mm / s. Based on this, those skilled in the art appropriately increase or decrease the moving speed of the tube sleeve 2 according to actual processing conditions, and on the basis of this speed, set the moving speed of the core wire 1 according to the reduction amount of the tube sleeve 2.

[0064] Preferably, the assembly before processing can be arranged in a non-powered straight line or a distributed vibration table, so that the assembly can be arranged in a straight line, a circle with a large bending radius, or any other suitable shape, to ensure that under the action of traction power, the core wire 1 and the sleeve 2 of the assembly are fed forward within the elastic stretching range, and relative slip occurs between the core wire 1 and the sleeve 2 when feeding forward.

[0065] In a possible implementation, the guide mechanism adopts a combination of multiple sets of limit guide wheels, or multiple sets of limit guide wheels and a distributed vibration table. Based on this, it is ensured that the pipe sleeve 2 enters the heating box 5 in a smooth posture, so that the heating box 5 maintains the same inclination angle as the drawing die 6.

[0066] Specifically, for an assembly with a shorter length, the pipe sleeve 2 is straightened or fixed in a smooth curve through multiple sets of limiting guide wheels, the pipe sleeve 2 is fixed when the pipe is inserted, and the pipe sleeve 2 is ensured to move under less resistance when winding and pulling, thereby reducing the movement resistance of the pipe sleeve 2 and the relative sliding resistance between the pipe sleeve 2 and the core wire 1; when the length of the assembly is longer, multiple sets of limiting guide wheels can also be fixed on the distributed vibration table to realize the movement of the assembly.

[0067] It is easy to understand that the multiple sets of limit guide wheels and distributed vibration tables can be selected from any suitable existing models. Those skilled in the art are aware of their working principles, which will not be elaborated here.

[0068] In the heating and vibration step S400, the heating box 5 is used to supply heat to melt the filler 3, and because the drawing die 6 is inclined, the sleeve 2 and the core wire 1 in the heating box 5 will maintain the same inclination angle as the drawing die 6. Therefore, under the combined action of gravity and vibration, the liquid filler 3 forms a liquid area at the inlet of the drawing die 6, and the core wire 1 moves through the liquid area. The liquid filler 3 fully coats the outer periphery of the core wire 1, thereby increasing the coating amount of the filler 3, which helps to improve the performance of the composite wire 9 so that the composite wire 9 obtains high mechanical strength.

[0069] At the same time, vibration is used to accelerate the speed of the liquid filler 3 falling off, and the phenomenon of liquefied filler 3 adhering to the core wire 1 is avoided as much as possible, ensuring that there is sufficient liquid filler 3 in the liquid area, effectively ensuring the quality of subsequent filler 3 fully coating the core wire 1.

[0070] In a possible implementation, the length of the heating zone of the heating box 5 is 2%-3% of the length of the assembly, and the longest heating time of the heating box 5 heating the same position of the core wire 1 is no more than 10 minutes.

[0071] Based on the above design scheme, the length of the heating zone is ensured, on the one hand, a sufficient amount of liquid filler 3 is generated, and on the other hand, the time for the core wire 1 to pass through the liquid zone is shortened, and the amount of filler 3 coated on the core wire 1 is increased. The heating temperature of the heating box 5 is adapted to the melting point of the filler 3, ensuring that the filler 3 can be melted quickly. At the same time, by limiting the heating time of the heating box 5 heating the same position of the core wire 1, it is avoided that the superconductivity decreases due to continuous high temperature, affects the current-carrying performance of the composite wire 9 after forming, and ensures that the diameter reduction of the sleeve 2 meets the design requirements.

[0072] In step S500, in the tilting die, the core wire 1 and the sleeve 2 are pulled through the drawing die 6, the sleeve 2 is reduced in diameter, and the liquid filler 3 squeezed out by the reduced diameter of the sleeve 2 flows back to the liquid area and is stored in the area. It is easy to understand that as the forming length of the composite wire 9 increases, the liquid filler 3 in the liquid area gradually increases.

[0073] In a possible implementation, a vibration module is provided on the heating box 5, or a vibrator is provided near the heating box 5. Based on the above design, the vibration function is realized by the vibration module or the vibrator to accelerate the speed at which the liquid filler 3 falls off the core wire 1. According to factors such as the diameter of the core wire 1, the type of filler 3, the heating temperature, and the position of the vibrator, those skilled in the art can obtain the preferred vibration frequency through a limited number of experiments to improve the processing quality. Based on this, the vibration frequency is not limited in any way in this embodiment.

[0074] It is easy to understand that the heating box 5 can be any suitable existing model, and the vibrator can be any suitable existing equipment.

[0075] In a possible implementation, the angle between the drawing die 6 and the horizontal line is 5°-90°. Based on the above design, the liquid area is formed by tilting, so as to store the liquid filler 3 and coat the core wire 1 with the liquid filler 3. Further, if the tilt angle of the drawing die 6 is increased, it is theoretically feasible, but too large a tilt angle increases the difficulty of laying out the forming processing line, especially making it difficult to lay out a horizontal processing line. Therefore, in order to reduce the processing difficulty, the tilt angle of the drawing die 6 is preferably 5°-10° during actual use.

[0076] In a possible implementation, a gap is left between the core wire 1 and the sleeve 2, and the gap forms a liquid area for accumulating liquid filler 3 above the inlet of the drawing die 6. Accordingly, the heating area of ​​the heating box 5 is located above the liquid area. Based on the above design scheme, the liquid area is an irregular area, which changes accordingly according to the amount of liquid filler 3. The heating box 5 is heated to supplement the heat to ensure that the filler 3 in the liquid area remains in liquid state. It is easy to understand that since the drawing die 6 is placed at an angle, the heating area is located obliquely above the liquid area.

[0077] In a possible implementation, the drawing die 6 is preheated: before the assembly feeding is implemented, the drawing die 6 is preheated, and the temperature of the drawing die 6 is 10-20° C. higher than the melting point of the filler 3 ; after the assembly feeding is implemented, the drawing die 6 stops heating and dissipates heat through the cooling box 7 .

[0078] Based on the above design scheme, the temperature of the drawing die 6 is increased by preheating the drawing die 6, so that the temperature of the drawing die 6 is adapted to the forming temperature of the composite wire 9, and the superconductivity degradation caused by the temperature difference during the drawing process is reduced. For the heat dissipation of the cooling box 7, the temperature of the drawing die 6 can be reduced to about the melting point of the filler 3 by controlling the heat dissipation parameters of the cooling box 7, so as to avoid excessive temperature difference.

[0079] In the cooling step S600, the assembly is rapidly cooled by the cooling box 7, and the liquid filler 3 is rapidly solidified to form the composite wire 9. Preferably, the cooling port of the cooling box 7 is toward the outlet of the drawing die 6. Based on this, the assembly is cooled before it leaves the drawing die 6, and then during the cooling process, the drawing die 6 squeezes out the excess liquid filler 3 in the feeding direction of the assembly, thereby increasing the amount of liquid filler 3, effectively offsetting the voids caused by the solidification of the filler 3 and the cold shrinkage of the material, and reducing the porosity of the composite wire 9.

[0080] In a possible implementation, when the cooling box 7 uses an air knife, the wind speed of the air knife is 10-50 m / s. Based on the above design, in addition to the air knife, the cooling box 7 can also select other suitable commercially available cooling equipment, and those skilled in the art can adjust the working parameters of the cooling equipment according to the actual processing conditions.

[0081] Furthermore, this embodiment also discloses a composite wire 9, which is made by the high-temperature superconducting composite wire forming method.

[0082] Based on this, the composite wire 9 realizes the continuous preparation of high-strength seamless armored high-temperature superconducting cables through vacuum, local heating vibration, inclined hot drawing and rapid cooling technology, and has higher mechanical properties and electromagnetic comprehensive properties than the cables prepared by the prior art. In addition, the composite wire 9 can be widely used in electric power, magnetic confinement fusion reactors, scientific research equipment, magnetic resonance imaging, large motors, magnetic levitation and other fields, with a wide range of applications and good practicality.

[0083] Embodiment 2:

[0084] This embodiment provides a practical and feasible technical solution based on Embodiment 1:

[0085] The core wire 1 is a high temperature superconducting core wire, the tube sleeve 2 is a copper tube, the filler 3 is a low temperature solder, the heating box 5 is a circulating hot air box with a maximum heating temperature of 200°C-210°C, and the cooling box 7 is an air knife.

[0086] Furthermore, the diameter of the high-temperature superconducting core wire coated with low-temperature solder is 3.1±0.1mm, the melting point of the low-temperature solder is 183°C, the side length of the high-temperature superconducting core wire is 2±0.1mm, the inner diameter of the tube sleeve 2 is 5mm, the wall thickness is 0.5mm, and the diameter of the processed composite wire 9 is 4mm. The specific processing process of the 100-meter-long composite wire 9 is as follows:

[0087] Step 1, core wire 1 through the tube: insert the high-temperature superconducting core wire coated with solder into the copper tube, and insert the high-temperature superconducting core wire until it is flush with the other end of the copper tube to form an assembly, and pass the front end of the assembly through the guide mechanism 4, the circulating hot air box, the drawing die 6 and the air knife in sequence.

[0088] Step 2: Vacuum sealing: Use high-pressure and high-purity argon gas to purge the assembly from the front end to the rear end until the oxygen content of the outlet gas at the end is reduced to 0.1%, then stop, squeeze and deform the front end of the copper tube, apply vacuum grease to seal it and fix it on the reel 8, evacuate the tube sleeve 2 from the rear end, and after the vacuum degree is lower than 500Pa, squeeze the rear end 3-5cm of the copper tube and apply vacuum sealing grease to seal it.

[0089] Step 3, heating and vibration: the copper tube moves forward at 20 mm / s under the traction of the winding and pulling device 8, and the copper tube and the high-temperature superconducting core wire enter the circulating hot air box under traction, and the temperature rises rapidly under the heating of the circulating hot air at 200℃-210℃, and the low-temperature solder melts into liquid, and the length of the liquid zone is 3m; a vibration module is installed in the circulating hot air box, and the vibration module applies 50Hz vertical vibration to the copper tube, and the vibration accelerates the liquid solder to gather at the front end of the drawing die 6; the circulating hot air box is arranged obliquely, coaxial with the drawing die 6 and the wind knife, and forms an angle of 5° with the horizontal line. The wind knife is at the bottom, and the liquid solder accumulates at the front end of the die under the action of gravity.

[0090] Step 4: Tilt over the die: The copper tube and the high-temperature superconducting core wire are pulled through the drawing die 6, and the copper tube is reduced to an outer diameter of 4 mm. The axis of the drawing die 6 is inclined at a 5° angle to the horizontal line. The liquid solder extruded by the copper tube is returned to and stored in the liquid area. As the forming length increases, the liquid solder in the liquid area gradually increases.

[0091] Step 5, rapid cooling: The wire after shrinkage is rapidly cooled by the wind knife at the exit of the drawing die 6, with a wind speed of 30m / s and a cooling length of 4cm. During the cooling process, at the exit of the drawing die 6, the liquid solder squeezed by the shrinkage moves forward to fill the gaps caused by the solidification of the solder and the cold shrinkage of the material.

[0092] Step 6: Coiling: The cooled composite wire 9 is coiled by the coiler 8 .

[0093] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for forming a high-temperature superconducting composite wire, characterized in that: The following steps are involved: Pipe insertion: the core wire (1) coated with a filler (3) is inserted into the pipe sleeve (2) to obtain an assembly; Vacuum sealing: the cleaning gas is blown into the interior of the tube sleeve (2), the front end of the tube sleeve (2) is sealed and then vacuum is drawn, and the rear end of the tube sleeve (2) is sealed after the vacuum reaches the standard; Heating and vibration: the assembly moves along the forming processing line to the heating box (5), where it is heated and vibrated, and the filler (3) melts into a liquid state and falls off and accumulates at the front end of the drawing die (6); Tilt over-molding: the assembly is tilted through the drawing die (6), the outer periphery of the core wire (1) is coated with liquid filler (3), and the diameter of the tube sleeve (2) is reduced; Rapid cooling: the assembly passes through a cooling box (7) and is cooled, the liquid filler (3) solidifies and connects the core wire (1) and the sleeve (2) to obtain a composite wire (9); Coiling: A drawing and shrinking force is applied by a coiler (8) to coil the composite wire (9).

2. The high temperature superconducting composite wire forming method according to claim 1, characterized in that: A filling material (3) is coated on the core wire (1), and the forming processing line comprises a guiding mechanism (4), a heating box (5), a drawing die (6), a cooling box (7) and a winding device (8) which are arranged in sequence.

3. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: Steps Vacuum sealing includes the following steps: Blow cleaning gas into the assembly from one end until the oxygen content of the gas at the other end of the assembly is less than 0.1%; The front end 3-5 cm of the tube sleeve (2) is squeezed and coated with vacuum sealing grease, and the assembly is evacuated from the front end of the assembly. When the vacuum degree is lower than 500 Pa, the rear end 3-5 cm of the tube sleeve (2) is squeezed and coated with vacuum sealing grease to seal the assembly.

4. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: The guide mechanism (4) is used to install and transport the assembly so that the assembly moves along the forming processing line, and one end of the sleeve (2) is connected to the reel (8) and pulled by the reel (8) so that the core wire (1) and the sleeve (2) have a speed difference; The moving speed of the core wire (1) is equal to the hot drawing speed of the drawing die (6), and the moving speed of the core wire (1) is greater than the moving speed of the tube sleeve (2), and the moving speed of the tube sleeve (2) is 5-50 mm / s.

5. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: The guiding mechanism (4) is selected from a plurality of sets of position-limiting guide wheels, or a combination of a plurality of sets of position-limiting guide wheels and a distributed vibration table.

6. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: The length of the heating zone of the heating box (5) is 2%-3% of the length of the assembly, and the longest heating time of the heating box (5) heating the same position of the core wire (1) is no more than 10 minutes.

7. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: A vibration module is provided on the heating box (5), or a vibrator is provided adjacent to the heating box (5).

8. The method for forming a high temperature superconducting composite wire according to claim 1 or 6, characterized in that: The angle between the drawing die (6) and the horizontal line is 5°-90°; A gap is left between the core wire (1) and the sleeve (2), and the gap forms a liquid zone for accumulating liquid filler (3) above the inlet of the drawing die (6). Accordingly, the heating zone of the heating box (5) is located above the liquid zone; Preheating of the drawing die (6): before the assembly feeding is implemented, the drawing die (6) is preheated, and the temperature of the drawing die (6) is 10-20°C higher than the melting point of the filler (3); after the assembly feeding is implemented, the drawing die (6) stops heating and dissipates heat through the cooling box (7).

9. The method for forming a high temperature superconducting composite wire according to claim 1, characterized in that: The cooling port of the cooling box (7) faces the outlet of the drawing die (6), and when the cooling box (7) uses an air knife, the wind speed of the air knife is 10-50m / s.

10. A composite wire, characterized in that: The high temperature superconducting composite wire is manufactured by the high temperature superconducting composite wire forming method according to any one of claims 1 to 9.

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