Preparation method of copper-clad aluminum slot wire WIC superconducting wire

Abstract

The invention belongs to the technical field of superconducting material processing, and discloses a preparation method of a copper-clad aluminum slot wire WIC superconducting wire, and the method comprises the steps: obtaining a to-be-processed workpiece which comprises a copper-clad aluminum rod and a copper matrix round wire; the copper-clad aluminum rod is sequentially subjected to drawing, annealing, rolling and forming, and the copper-clad aluminum groove wire is prepared; the copper-clad aluminum slot wire and the copper matrix round wire are respectively cleaned and coated with a soldering flux, and then are simultaneously immersed into a tin bath filled with tin liquor to be matched with an inlaying mold to carry out inlaying welding for at least 1000m, so that the copper-clad aluminum slot wire WIC wire is obtained; and surface layer and deep layer welding defect characterization is carried out on the obtained copper-clad aluminum slot wire WIC, and it is ensured that the number of the surface layer and the number of the deep layer welding defects of the copper-clad aluminum slot wire WIC are both zero. According to the method, inlay welding is carried out in the mode that copper-clad aluminum is matched with dip soldering, and the problems that in the traditional technology, the labor cost is high, the welding quality is not stable, and the productivity is insufficient can be solved at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of superconducting material processing, in particular to a method for preparing a copper-clad aluminum slot wire WIC superconducting wire. Background Art

[0002] Aluminum slot wire WIC (Wire in channel) superconducting wire is a high-performance wire that combines aluminum slot wire design and superconducting technology. It uses the zero resistance characteristics of superconducting materials to achieve efficient and lossless transmission of current. This material not only has excellent electrical conductivity, but also has high strength, lightness and good stability due to its structure and material composition. It is mainly used in the field of magnetic levitation transportation and in the manufacture of superconducting magnets. It is a key material for magnetic levitation trains to achieve efficient and stable suspension and propulsion. It is also used in energy, communications and other fields.

[0003] The traditional aluminum slot wire WIC superconducting wire is prepared by embedding the superconducting round wire into the aluminum slot wire trough and performing argon arc welding under argon conditions. After welding, the welding points are polished and cleaned. The disadvantages of this method are: poor welding stability, prone to defects such as raised welding points, pores and inclusions at the weld, very dependent on operator experience, and high labor costs; the welding process is unstable, which can easily cause local performance degradation of the superconducting wire, and higher performance superconducting round wire must be used, with high raw material costs; low degree of automation and slow welding speed, resulting in extremely low production efficiency and inability to carry out mass production; the aluminum slot wire is directly in contact with the external environment, has poor corrosion resistance, and requires a higher storage and working environment.

[0004] In view of this, a method for preparing a copper-clad aluminum slot wire WIC superconducting wire is proposed. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a copper-clad aluminum slot wire WIC superconducting wire to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a copper-clad aluminum slot wire WIC superconducting wire comprises the following steps: S1: Obtain a workpiece to be processed, wherein the workpiece to be processed includes a copper-clad aluminum rod and a copper-based round wire; S2: The copper-clad aluminum rod is sequentially drawn, annealed, rolled and formed to obtain a copper-clad aluminum slotted wire; S3: After cleaning and applying flux to the copper-clad aluminum slot wire and the copper matrix round wire respectively, they are immersed in a tin bath filled with tin liquid and inlaid with an inlay mold for at least 1000m to obtain the copper-clad aluminum slot wire WIC wire; S4: Characterize the surface and deep welding defects of the obtained copper-clad aluminum slotted wire WIC wire to ensure that the number of surface and deep welding defects of the copper-clad aluminum slotted wire WIC wire is 0.

[0007] Further preferably, in S1, the copper-clad aluminum rod is obtained by coating a copper strip onto an aluminum ingot by argon arc welding, and then sequentially performing hot extrusion and cold drawing on the aluminum ingot coated with the copper strip; the copper volume ratio of the copper-clad aluminum rod is 1% to 30%.

[0008] Further preferably, in S1, the copper-based round wire includes copper-based NbTi / Cu superconducting round wire, Nb3Sn / Cu superconducting round wire, NbTi / Cu superconducting cable or Nb3Sn / Cu superconducting cable and copper-based ordinary round wire or cable and round wire with surface copper plating.

[0009] Further preferably, in S2, the obtained copper-clad aluminum slot wire has a wide side dimension of 1-10 mm and a narrow side dimension of 0.5-5 mm.

[0010] Further preferably, in S4, when characterizing the surface welding defects of the obtained copper-clad aluminum slotted wire WIC wire, the surface tin accumulation defects of the copper-clad aluminum slotted wire WIC wire are characterized by a particle detector.

[0011] Further preferably, in S3, after the copper-clad aluminum slot wire and the copper matrix round wire are cleaned and coated with flux respectively, they are immersed in a tin bath filled with tin liquid and matched with an inlay mold for inlay welding for at least 1000m, the inlay welding temperature is 250~450℃, and the inlay welding speed is 20~100m / min.

[0012] Further preferably, in said S4, when characterizing the inner layer welding defects of the obtained copper-clad aluminum slotted wire WIC wire, the cold welding defects between the copper-clad aluminum slotted wire and the copper base round wire constituting the copper-clad aluminum slotted wire WIC wire are characterized by an eddy current flaw detector.

[0013] Compared with the prior art, the present invention has the following beneficial effects: Since a dense oxide film is easily formed on the surface of aluminum slot wire, it is impossible to directly use solder for welding. However, adding a thin copper layer on the surface of aluminum slot wire and superconducting round wire can be embedded and welded by dip soldering. In this application, copper-clad aluminum is embedded and welded by dip soldering, which can solve the problems of high labor cost, unstable welding quality, insufficient production capacity, etc. in traditional processes. In addition, the solder layer on the surface of copper-clad aluminum slot wire WIC wire can also solve the problem of poor corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a cross-sectional view of a copper-based superconducting round wire in the present invention; Figure 2 This is a schematic diagram of the copper-clad aluminum slotted wire in the present invention; Figure 3 It is a schematic diagram of dip welding of the copper-clad aluminum slot wire WIC superconducting wire in the present invention; Figure 4 This is a surface quality diagram of the copper-clad aluminum slot wire WIC superconducting wire in the present invention; In the figure: 1. Copper clad aluminum slot wire; 2. Copper matrix superconducting round wire; 3. Tin bath; 4. Inlay mold; 5. Copper clad aluminum slot wire WIC superconducting wire. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] See also Figure 1-4 , the present invention provides a technical solution: A method for preparing a copper-clad aluminum slot wire WIC superconducting wire comprises the following steps: S1: Obtain a workpiece to be processed, the workpiece to be processed includes a copper-clad aluminum rod and a copper-based round wire; S2: The copper-clad aluminum rod is sequentially drawn, annealed, rolled and formed to obtain a copper-clad aluminum slotted wire; S3: After cleaning and applying flux to the copper-clad aluminum slot wire and the copper matrix round wire respectively, they are immersed in a tin bath filled with tin liquid and inlaid with an inlay mold for at least 1000m to obtain the copper-clad aluminum slot wire WIC wire; S4: Characterize the surface and deep welding defects of the obtained copper-clad aluminum slotted wire WIC wire to ensure that the number of surface and deep welding defects of the copper-clad aluminum slotted wire WIC wire is 0.

[0017] In the present invention, in S1, the copper-clad aluminum rod is obtained by coating a copper strip onto an aluminum ingot by argon arc welding, and then sequentially subjecting the aluminum ingot coated with the copper strip to hot extrusion and cold drawing; the copper volume ratio of the copper-clad aluminum rod is 1% to 30%.

[0018] In the present invention, in S1, the copper-based round wire includes copper-based NbTi / Cu superconducting round wire, Nb3Sn / Cu superconducting round wire, NbTi / Cu superconducting cable or Nb3Sn / Cu superconducting cable and copper-based ordinary round wire or cable and round wire with copper-plated surface.

[0019] In the present invention, in S2, the copper-clad aluminum slot wire obtained has a wide side dimension of 1-10 mm and a narrow side dimension of 0.5-5 mm.

[0020] In the present invention, in S4, when characterizing the surface welding defects of the obtained copper-clad aluminum slotted wire WIC wire, the surface tin accumulation defects of the copper-clad aluminum slotted wire WIC wire are characterized by a particle detector.

[0021] In the present invention, in S3, the copper-clad aluminum slot wire and the copper matrix round wire are cleaned and coated with flux respectively, and then immersed in a tin bath filled with tin liquid and matched with an inlay mold for inlay welding for at least 1000m, the inlay welding temperature is 250~450℃, and the inlay welding speed is 20~100m / min.

[0022] In the present invention, in S4, when the inner layer welding defects of the obtained copper clad aluminum slotted wire WIC wire are characterized, the cold welding defects between the copper clad aluminum slotted wire and the copper base round wire constituting the copper clad aluminum slotted wire WIC wire are characterized by an eddy current flaw detector.

[0023] Example 1: According to the copper-clad aluminum slot wire WIC superconducting wire preparation process, the workpiece to be processed is obtained, and the workpiece to be processed includes a copper-clad aluminum rod and a copper matrix round wire, wherein the copper-clad aluminum rod has a diameter of 6.0 mm, a copper volume ratio of 2%, and a length of 350 m; the copper matrix round wire is a NbTi / Cu superconducting round wire with a diameter of 1.5 mm and a length of 1200 m.

[0024] The copper-clad aluminum rod is sequentially drawn, annealed, rolled and formed to prepare a copper-clad aluminum slotted wire with a length of 1100 m, a width of 5.01 mm, a height of 2.12 mm and a slot width of 1.51 mm.

[0025] The copper-clad aluminum slot wire and NbTi / Cu superconducting round wire were cleaned and coated with flux respectively, and then immersed in a tin bath filled with tin liquid and inlaid with an inlay mold for 1000m. The inlay welding temperature was 420℃ and the inlay welding speed was 20m / min. A copper-clad aluminum slot wire WIC superconducting wire with a width of 4.95mm and a height of 2.05mm was obtained. The surface tinning and solder filling of the copper-clad aluminum slot wire WIC superconducting wire were very smooth.

[0026] The obtained copper-clad aluminum slotted wire WIC superconducting wire was passed through a particle detector and an eddy current flaw detector in turn to characterize the surface and deep welding defects. The number of surface tin accumulation defects of the copper-clad aluminum slotted wire WIC superconducting wire was 0; the number of cold welding defects between the copper-clad aluminum slotted wire and the copper base round wire of the copper-clad aluminum slotted wire WIC superconducting wire was 0.

[0027] Example 2: According to the copper-clad aluminum slot wire WIC superconducting wire preparation process, the workpiece to be processed is obtained, and the workpiece to be processed includes a copper-clad aluminum rod and a copper matrix round wire, wherein the copper-clad aluminum rod has a diameter of 2.0 mm, a copper volume ratio of 1.5%, and a length of 500 m; the copper matrix round wire selects 1200 m of NbTi / Cu superconducting round wire with a diameter of 0.5 mm.

[0028] The copper-clad aluminum rod is sequentially drawn, annealed, rolled and formed to prepare a copper-clad aluminum slotted wire with a length of 1200 m, a width of 1.5 mm, a height of 0.9 mm and a slot width of 0.51 mm.

[0029] The copper-clad aluminum slot wire and NbTi / Cu superconducting round wire were cleaned and coated with flux respectively, and then immersed in a tin bath filled with tin liquid and inlaid with an inlay mold for 1000m. The inlay welding temperature was 260℃, and the inlay welding speed was 80m / min. A copper-clad aluminum slot wire WIC superconducting wire with a width of 1.45mm and a height of 0.85mm was obtained. The surface tinning and solder filling of the copper-clad aluminum slot wire WIC superconducting wire were very smooth.

[0030] The obtained copper-clad aluminum slotted wire WIC superconducting wire was passed through a particle detector and an eddy current flaw detector in turn to characterize the surface and deep welding defects. The number of surface tin accumulation defects of the copper-clad aluminum slotted wire WIC superconducting wire was 0; the number of cold welding defects between the copper-clad aluminum slotted wire and the copper base round wire of the copper-clad aluminum slotted wire WIC superconducting wire was 0.

[0031] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0032] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a copper-clad aluminum slot wire WIC superconducting wire, characterized in that: The following steps are involved: S1: Obtain a workpiece to be processed, wherein the workpiece to be processed includes a copper-clad aluminum rod and a copper-based round wire; S2: The copper-clad aluminum rod is sequentially drawn, annealed, rolled and formed to obtain a copper-clad aluminum slotted wire; S3: After cleaning and applying flux to the copper-clad aluminum slot wire and the copper matrix round wire respectively, they are immersed in a tin bath filled with tin liquid and inlaid with an inlay mold for at least 1000m to obtain the copper-clad aluminum slot wire WIC wire; S4: Characterize the surface and deep welding defects of the obtained copper-clad aluminum slotted wire WIC wire to ensure that the number of surface and deep welding defects of the copper-clad aluminum slotted wire WIC wire is 0.

2. The method for preparing a copper-clad aluminum slot wire WIC superconducting wire according to claim 1, characterized in that: In S1, the copper-clad aluminum rod is obtained by coating a copper strip onto an aluminum ingot by argon arc welding, and then sequentially subjecting the aluminum ingot coated with the copper strip to hot extrusion and cold drawing; the copper volume ratio of the copper-clad aluminum rod is 1% to 30%.

3. The method for preparing a copper-clad aluminum slot wire WIC superconducting wire according to claim 1, characterized in that: In S1, the copper-based round wire includes copper-based NbTi / Cu superconducting round wire, Nb3Sn / Cu superconducting round wire, NbTi / Cu superconducting cable or Nb3Sn / Cu superconducting cable and copper-based ordinary round wire or cable and round wire with copper-plated surface.

4. The method for preparing a copper-clad aluminum slotted wire WIC superconducting wire according to claim 1, characterized in that: In S2, the obtained copper-clad aluminum slot wire has a wide side dimension of 1-10 mm and a narrow side dimension of 0.5-5 mm.

5. The method for preparing a copper-clad aluminum slot wire WIC superconducting wire according to claim 1, characterized in that: In the above S4, when characterizing the surface welding defects of the obtained copper-clad aluminum slotted wire WIC wire, the surface tin accumulation defects of the copper-clad aluminum slotted wire WIC wire are characterized by a particle detector.

6. The method for preparing a copper-clad aluminum slotted wire WIC superconducting wire according to claim 1, characterized in that: In S3, the copper-clad aluminum slot wire and the copper-based round wire are cleaned and coated with flux respectively, and then immersed in a tin bath filled with tin liquid and matched with an inlay mold for inlay welding for at least 1000m, the inlay welding temperature is 250-450°C, and the inlay welding speed is 20-100m / min.

7. The method for preparing a copper-clad aluminum slot wire WIC superconducting wire according to claim 1, characterized in that: In the above S4, when the inner layer welding defects of the obtained copper clad aluminum slotted wire WIC wire are characterized, the cold welding defects between the copper clad aluminum slotted wire and the copper base round wire constituting the copper clad aluminum slotted wire WIC wire are characterized by an eddy current flaw detector.

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