Machining method for full-clad copper welding of copper-clad aluminum busbar composite material

Abstract

The invention relates to the technical field of copper-clad aluminum busbar composite material welding, in particular to a copper-clad aluminum busbar composite material full-copper-clad welding machining method which specifically comprises the steps that the end face of a copper-clad aluminum busbar composite raw material is polished, surface impurities are removed, and the copper-clad aluminum busbar composite material with the surface to be sprayed and brushed is formed after drying treatment; preparing a graphite coating of graphite powder and a binder, spraying or brushing the graphite coating on the to-be-sprayed surface of the copper-clad aluminum busbar composite material, drying and curing to form a to-be-welded copper-clad aluminum busbar, and selecting a copper sheet matched with the end surface of the to-be-welded copper-clad aluminum busbar for later use; a to-be-welded copper-clad aluminum busbar and a copper sheet are positioned and clamped through a clamp, the to-be-welded copper-clad aluminum busbar is preheated, welding parameters of laser welding equipment are set, the copper sheet is welded to the end face of the to-be-welded copper-clad aluminum busbar, and the copper-clad aluminum busbar composite material with full copper cladding is formed. According to the copper-clad aluminum busbar, the aluminum leakage position of the copper-clad aluminum busbar is fully clad with copper, and meanwhile the copper-clad aluminum busbar has good conductivity and good mechanical performance.

Description

Technical Field

[0001] This invention belongs to the technical field of copper-clad aluminum busbar composite materials, specifically relating to a processing method for fully copper-clad aluminum busbar composite material welding. Background Technology

[0002] Currently, copper-clad aluminum busbars suffer from aluminum leakage at the end faces or on the sides due to processing shape requirements. This leads to electrochemical corrosion during direct use. While electroplating increases costs and improves corrosion resistance at the leakage points, it is still inferior to that of copper. The current solution for electrochemical corrosion at the end faces of copper-clad aluminum busbars primarily relies on optimizing the electroplating process; however, electroplating is costly, and even after electroplating, the corrosion resistance at the leakage points remains lower than that of the copper side. Therefore, a processing method for fully copper-clad aluminum busbar composite materials with welding is proposed. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a processing method for welding copper-clad aluminum busbar composite material with full copper encapsulation, which realizes that the exposed aluminum part of the copper-clad aluminum busbar is fully encapsulated with copper, while having good electrical conductivity and good mechanical properties.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A processing method for fully copper-clad aluminum busbar composite material welding includes the following specific steps: S1. The end face of the copper-clad aluminum busbar composite material is ground, surface impurities are removed and dried to form the copper-clad aluminum busbar composite material to be sprayed on the surface. S2. Prepare a graphite coating by mixing graphite powder and binder, and spray or brush the graphite coating onto the surface of the copper-clad aluminum busbar composite material to be sprayed or brushed. After drying and curing, a copper-clad aluminum busbar to be welded is formed. Select a copper sheet that matches the end face of the copper-clad aluminum busbar to be welded for later use. S3. Position and clamp the copper-clad aluminum busbar and copper sheet to be welded using a fixture, preheat the copper-clad aluminum busbar to be welded, set the welding parameters of the laser welding equipment, and weld the copper sheet to the end face of the copper-clad aluminum busbar to be welded, forming a fully copper-clad aluminum busbar composite material.

[0005] Furthermore, the steps of grinding, removing surface impurities, and drying the end faces of the copper-clad aluminum busbar composite raw material to form the copper-clad aluminum busbar composite material surface to be sprayed also include grinding the end faces of the copper-clad aluminum busbar composite raw material with sandpaper until they are bright, so that the surface roughness of the end faces is less than 0.8. Then, clean with acetone / ethanol to remove oil, and after drying, form a copper-clad aluminum busbar composite material for the surface to be sprayed and brushed.

[0006] Furthermore, in the step of preparing the graphite coating by mixing graphite powder and binder, the graphite powder is conductive graphite powder with a particle size of less than 100 mesh and a purity of greater than or equal to 99%; the binder is water-based acrylic resin, silica sol, or alcohol-based resin; the solvent is deionized water or ethanol; wherein, the graphite powder and binder are mixed in a mass ratio of 3:1–5:1 to form the graphite coating.

[0007] Furthermore, in the step of spraying or brushing graphite coating onto the surface of the copper-clad aluminum busbar composite material, during spraying, a spray gun is used to spray the graphite coating onto the surface, with a nozzle diameter of 0.8–1.5 mm. Air pressure 0.2–0.4 10–15 cm away from the surface to be sprayed Apply 1-2 layers of graphite coating evenly to the surface to be brushed, with each layer having a thickness of approximately 5-10 mm. When brushing, use a soft brush to evenly apply the graphite coating to the surface to be sprayed, and apply 2-3 layers of graphite coating.

[0008] Furthermore, the copper sheet is made of T2 copper.

[0009] Furthermore, the copper-clad aluminum busbar and copper sheet to be welded are positioned and clamped by a fixture, with a clamping force greater than 80N.

[0010] Furthermore, the preheating temperature for the copper-clad aluminum busbar to be welded is 210℃-230℃.

[0011] Furthermore, the welding parameters of the laser welding equipment include a fiber laser power of 3000W, an output wavelength of 1080±5nm, a spot diameter of 0.3mm, a welding speed of 20-50mm / s, and a laser frequency of 4000-6000Hz.

[0012] Furthermore, when welding copper sheets to the end face of the copper-clad aluminum busbar to be welded, the laser oscillation amplitude of the fiber laser in the laser welding equipment is 0.6mm-1.2mm.

[0013] Furthermore, when welding the copper sheet to the end face of the copper-clad aluminum busbar to be welded, argon is used as the protective gas, and the argon gas flow rate is 15-20 L / min.

[0014] The beneficial effects of this invention are: (1) The surface roughness Ra of the copper-aluminum contact surface is ≤0.8μm to ensure good copper-aluminum bonding; (2) After being treated with graphite coating, the keyhole is stable and the weld transition is stable; (3) Ensure the weld penetration is stable at over 90% of the copper layer thickness of the copper-clad aluminum busbar and the weld width is 0.7-1.5 mm. Based on the entire cross-sectional area of ​​the copper-clad aluminum busbar, the tensile strength of the welded joint is 30-35 MPa, and the electrical conductivity reaches over 98% of the raw material. (4) Without affecting conductivity, the problem of aluminum leakage at the end face of copper-clad aluminum busbar is solved well, and the problem of poor corrosion resistance at the end face of copper-clad aluminum busbar is solved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the processing method for welding copper-clad aluminum busbar composite material with full copper encapsulation, as proposed in this invention.

[0016] Figure 2 This is a schematic diagram of the graphite coating process in the processing method of copper-clad aluminum busbar composite material fully encased in copper welding proposed in this invention.

[0017] Figure 3 This is a schematic diagram of the copper-aluminum interface after welding, obtained from the processing method of fully copper-clad aluminum busbar composite material welding proposed in this invention.

[0018] Figure 4 These are schematic diagrams illustrating three practical applications of the copper-clad aluminum busbar composite material welding process proposed in this invention to achieve full copper cladding. Detailed Implementation

[0019] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0020] Example 1. like Figure 1 As shown, this embodiment provides a processing method for fully copper-clad aluminum busbar composite material welding, specifically including the following steps: S1. The end face of the copper-clad aluminum busbar composite material is ground, surface impurities are removed, and it is dried to form the copper-clad aluminum busbar composite material to be sprayed.

[0021] In this embodiment, the step of grinding, removing surface impurities, and drying the end face of the copper-clad aluminum busbar composite material to form the copper-clad aluminum busbar composite material surface to be sprayed further includes grinding the end face of the copper-clad aluminum busbar composite material with sandpaper until it is bright, so that the surface roughness of the end face is less than 0.8. Then, clean with acetone / ethanol to remove oil, and after drying, form a copper-clad aluminum busbar composite material for the surface to be sprayed and brushed.

[0022] S2. Prepare a graphite coating by mixing graphite powder and binder, and spray or brush the graphite coating onto the surface of the copper-clad aluminum busbar composite material to be sprayed or brushed. After drying and curing, a copper-clad aluminum busbar to be welded is formed. Select a copper sheet that matches the end face of the copper-clad aluminum busbar to be welded for later use.

[0023] like Figure 2 As shown in this embodiment, in the step of preparing the graphite coating with graphite powder and binder, the graphite powder is conductive graphite powder with a particle size of less than 100 mesh and a purity of greater than or equal to 99%; the binder is water-based acrylic resin, silica sol or alcohol-based resin; the solvent is deionized water or ethanol; wherein, the graphite powder and binder are mixed in a mass ratio of 3:1–5:1 to form the graphite coating.

[0024] S3. Position and clamp the copper-clad aluminum busbar and copper sheet to be welded using a fixture, preheat the copper-clad aluminum busbar to be welded, set the welding parameters of the laser welding equipment, and weld the copper sheet to the end face of the copper-clad aluminum busbar to be welded, forming a fully copper-clad aluminum busbar composite material.

[0025] In this embodiment, during the step of spraying or brushing graphite coating onto the surface of the copper-clad aluminum busbar composite material, the graphite coating is applied to the surface using a spray gun with a nozzle diameter of 0.8–1.5 mm. Air pressure 0.2–0.4 10–15 cm away from the surface to be sprayed Apply 1-2 layers of graphite coating evenly to the surface to be brushed, with each layer having a thickness of approximately 5-10 mm. When brushing, use a soft brush to evenly apply the graphite coating to the surface to be sprayed, and apply 2-3 layers of graphite coating.

[0026] In this embodiment, T2 copper is used as the copper sheet, and the copper sheet is polished, surface impurities are removed and dried to ensure that the copper sheet is fully bonded to the surface of the copper-clad aluminum busbar composite material to be sprayed.

[0027] In this embodiment, the copper-clad aluminum busbar to be welded and the copper sheet are positioned and clamped by a fixture, and the clamping force of the fixture is greater than 80N.

[0028] In this embodiment, the preheating temperature for preheating the copper-clad aluminum busbar to be welded can be set to 150-300℃.

[0029] In this embodiment, the welding parameters of the laser welding equipment include a fiber laser power of 3000W, with an adjustable laser power percentage of 10%-100%. The laser power is slightly higher at the arc initiation end and slightly lower at the arc termination end to ensure penetration depth. The output laser wavelength is 1080±5nm, the spot diameter is 0.3mm, and the welding speed is 20-50mm / s depending on the thickness of the copper-clad aluminum busbar and the welding power. The laser frequency is 4000-6000Hz.

[0030] In this embodiment, when welding the copper sheet to the end face of the copper-clad aluminum busbar to be welded, in order to ensure a smooth transition of the weld and penetration depth, the laser has a certain oscillation amplitude. Depending on the welding power and welding speed, the laser oscillation amplitude of the fiber laser of the laser welding equipment is 0.6mm-1.2mm. The shielding gas is argon (≥99.99%), and the argon gas flow rate is 15-20L / min. Welding is performed around the lap or butt joint.

[0031] After welding, the tensile strength of the welded joint is 30-35 MPa, and the electrical conductivity reaches more than 98% of that of the raw material.

[0032] Example 2. This embodiment provides a processing method for fully copper-clad aluminum busbar composite material welding, which specifically includes the following steps: S1. The end face of the copper-clad aluminum busbar composite material is ground, surface impurities are removed, and it is dried to form the copper-clad aluminum busbar composite material to be sprayed.

[0033] In this embodiment, the copper-clad aluminum busbar composite material uses a copper content of 30% and dimensions of 30mm (length) × 15mm (width). A 2mm section is removed from each end face of the raw material using slow wire cutting. The end faces are then polished with sandpaper until smooth, resulting in a surface roughness Ra < 0.8. Then, clean with acetone / ethanol to remove oil, and after drying, form a copper-clad aluminum busbar composite material for the surface to be sprayed and brushed.

[0034] S2. Prepare a graphite coating by mixing graphite powder and binder, and spray or brush the graphite coating onto the surface of the copper-clad aluminum busbar composite material to be sprayed or brushed. After drying and curing, a copper-clad aluminum busbar to be welded is formed. Select a copper sheet that matches the end face of the copper-clad aluminum busbar to be welded for later use.

[0035] like Figure 2 As shown, in this embodiment, the graphite powder is conductive graphite powder with a particle size of less than 100 mesh and a purity of greater than or equal to 99%; the binder is water-based acrylic resin, silica sol, or alcohol-based resin; the solvent is deionized water or ethanol; wherein, the graphite powder and binder are mixed in a mass ratio of 3:1–5:1 to form a graphite coating.

[0036] In this embodiment, a soft brush is used to evenly apply graphite coating to the weldable surface of the copper-clad aluminum busbar composite material to form a graphite coating. It should be noted that 2-3 layers of graphite coating can be applied. After drying at room temperature for 0.5-1 hour, the coating is then baked at 80-100℃ for 1-2 hours to cure, resulting in a total thickness of <30 mm. The end faces of the copper-clad aluminum busbars to be welded are treated with a graphite coating to ensure stable keyholes and a smooth weld transition.

[0037] In this embodiment, T2 copper is selected as the copper sheet, with a specification of 2mm (thickness) × 30mm (length) × 15mm (width). At the same time, the copper sheet is polished, surface impurities are removed and dried to ensure that the copper sheet is completely bonded to the surface of the copper-clad aluminum busbar composite material to be sprayed.

[0038] S3. Position and clamp the copper-clad aluminum busbar and copper sheet to be welded using a fixture, preheat the copper-clad aluminum busbar to be welded, set the welding parameters of the laser welding equipment, and weld the copper sheet to the end face of the copper-clad aluminum busbar to be welded, forming a fully copper-clad aluminum busbar composite material.

[0039] In this embodiment, the copper-clad aluminum busbar and copper sheet to be welded are positioned and clamped by a fixture. It should be noted that the fixture used in this embodiment is a conventional fixture used for welding copper-clad aluminum busbars. This embodiment does not impose any specific limitations. The copper-clad aluminum busbar to be welded is positioned and clamped by the fixture. In this process, the positioning error is set to ≤0.02mm, and the positioning and clamping are achieved by applying a clamping force greater than 80N. At the same time, during welding, the welding gap is kept to ≤0.05mm.

[0040] In this embodiment, the preheating temperature is set to 220±10℃, the fiber laser power is 3000W, and the laser power percentile can be adjusted to 60%-70%, with slightly higher laser power at the arc initiation end and slightly lower laser power at the arc termination end to ensure penetration depth. The output laser wavelength is 1080±5nm, and the spot diameter is 0.3mm. Based on the thickness of the copper-clad aluminum busbar and the welding power, the welding speed is set to 30mm / s. Based on the welding power and welding speed, the laser oscillation amplitude of the fiber laser in the laser welding equipment is 0.8-1mm, the argon gas flow rate is 15-20L / min, and continuous welding is performed along the weld seam.

[0041] After welding, a comparison was made before and after welding. In this embodiment, the conductivity at the junction of the copper-clad aluminum busbar composite raw materials was 58.6% IACS. After welding, the conductivity at the edge of the copper-clad aluminum busbar with full copper cladding was 58.2% IACS. Based on the total cross-sectional area of ​​the copper-clad aluminum busbar, the tensile strength at the weld was calculated to be 30.7 MPa.

[0042] Example 3. This embodiment provides a processing method for fully copper-clad aluminum busbar composite material welding, which specifically includes the following steps: S1. The end face of the copper-clad aluminum busbar composite material is ground, surface impurities are removed, and it is dried to form the copper-clad aluminum busbar composite material to be sprayed.

[0043] In this embodiment, the copper-clad aluminum busbar composite material uses a copper content of 30% and dimensions of 30mm (length) × 15mm (width). CNC (Computer Numerical Control Machining) is used to mill down 2mm from both end faces of the copper-clad aluminum busbar, completely exposing the copper layer. The end faces of the copper-clad aluminum busbar composite material are then polished to a bright finish, resulting in a surface roughness Ra < 0.8. Then, clean with acetone / ethanol to remove oil, and after drying, form a copper-clad aluminum busbar composite material for the surface to be sprayed and brushed.

[0044] S2. Prepare a graphite coating by mixing graphite powder and binder, and spray or brush the graphite coating onto the surface of the copper-clad aluminum busbar composite material to be sprayed or brushed. After drying and curing, a copper-clad aluminum busbar to be welded is formed. Select a copper sheet that matches the end face of the copper-clad aluminum busbar to be welded for later use.

[0045] like Figure 2 As shown, in this embodiment, the graphite powder is conductive graphite powder with a particle size of less than 100 mesh and a purity of greater than or equal to 99%; the binder is water-based acrylic resin, silica sol, or alcohol-based resin; the solvent is deionized water or ethanol; wherein, the graphite powder and binder are mixed in a mass ratio of 3:1–5:1 to form a graphite coating.

[0046] In this embodiment, a soft brush is used to evenly apply graphite coating to the weldable surface of the copper-clad aluminum busbar composite material to form a graphite coating. It should be noted that 2-3 layers of graphite coating can be applied. After drying at room temperature for 0.5-1 hour, the coating is then baked at 80-100℃ for 1-2 hours to cure, resulting in a total thickness of <30 mm. The end faces of the copper-clad aluminum busbars to be welded are treated with a graphite coating to ensure stable keyholes and a smooth weld transition.

[0047] In this embodiment, T2 copper is selected as the copper sheet, with a size of 2mm (thickness) × 30mm (length) × 15mm (width). At the same time, the copper sheet is polished, surface impurities are removed and dried to ensure that the copper sheet is completely bonded to the surface of the copper-clad aluminum busbar composite material to be sprayed.

[0048] S3. Position and clamp the copper-clad aluminum busbar and copper sheet to be welded using a fixture, preheat the copper-clad aluminum busbar to be welded, set the welding parameters of the laser welding equipment, and weld the copper sheet to the end face of the copper-clad aluminum busbar to be welded, forming a fully copper-clad aluminum busbar composite material.

[0049] In this embodiment, the copper-clad aluminum busbar and copper sheet to be welded are positioned and clamped by a fixture. It should be noted that the fixture used in this embodiment is a conventional fixture used for welding copper-clad aluminum busbars. This embodiment does not impose any specific limitations. The copper-clad aluminum busbar to be welded is positioned and clamped by the fixture. In this process, the positioning error is set to ≤0.02mm, and the positioning and clamping are achieved by applying a clamping force greater than 80N. At the same time, during welding, the welding gap is kept to ≤0.05mm.

[0050] In this embodiment, the preheating temperature is set to 220±10℃, the fiber laser power is 3000W, and the laser power percentile can be adjusted to 60%-70%, with slightly higher laser power at the arc initiation end and slightly lower laser power at the arc termination end to ensure penetration depth. The output laser wavelength is 1080±5nm, and the spot diameter is 0.3mm. Based on the thickness of the copper-clad aluminum busbar and the welding power, the welding speed is set to 30mm / s. Based on the welding power and welding speed, the laser oscillation amplitude of the fiber laser in the laser welding equipment is 0.8-1mm, the argon gas flow rate is 15-20L / min, and continuous welding is performed along the weld seam.

[0051] After welding, a comparison was made before and after welding. In this embodiment, the conductivity at the junction of the copper-clad aluminum busbar composite raw materials was 58.6% IACS. After welding, the conductivity at the edge of the copper-clad aluminum busbar with full copper cladding was 58.4% IACS. Based on the total cross-sectional area of ​​the copper-clad aluminum busbar, the tensile strength at the weld was calculated to be 34.6 MPa.

[0052] The above embodiments realize the processing of copper-clad aluminum busbar composite material with full copper encapsulation welding, forming a fully copper-clad aluminum busbar composite material. The tensile strength of the welded joint is 30-35 MPa, and the electrical conductivity reaches more than 98% of the raw material. After welding, the copper-aluminum interface is as follows: Figure 3 As shown, without affecting conductivity, the problem of aluminum leakage at the end face of copper-clad aluminum busbars is effectively solved, as well as the problem of poor corrosion resistance at the end face of copper-clad aluminum busbars.

[0053] It should be noted that because aluminum has a much lower melting point than copper, conventional copper-to-copper welding methods can cause the aluminum layer to melt or deform. Unlike existing copper-to-copper welding methods, to ensure the aluminum layer remains unaffected, embodiments 1-3 of this invention employ a graphite coating. This coating not only improves the copper-to-copper welding effect but also ensures the stability of the aluminum layer during the welding process. Applying a graphite coating in conjunction with the laser welding process described in the above embodiments allows for copper-to-copper welding without affecting the aluminum layer's properties, achieving copper cladding at the aluminum leakage points. Figure 4 As shown, various forms of copper-clad aluminum busbars fully encased in copper are presented. Figure 4 Three methods are listed, but this embodiment is not limited to these.

[0054] Furthermore, in actual welding, due to the extremely high reflection efficiency of copper to lasers, and the jump increase in laser absorption rate as the weld temperature rises during the welding process, large heat input fluctuations can cause violent fluctuations in the copper molten pool, resulting in defects such as spatter and porosity. Therefore, the graphite coating in the above embodiments 1-3 of this invention is not a brazing filler metal, but a flux. The graphite coating used in embodiments 1-3 does not rely on graphite itself as an intermediate medium to connect the copper of the copper-aluminum busbar to the copper of the copper sheet, but is used to stabilize the laser welding effect, thereby fixing the copper to copper. The graphite will be eliminated after achieving the desired effect, and will be directly burned off during welding. It is not used to fill the weld or to connect metals after melting. It is mainly used to improve the laser absorption rate and enhance the stability of laser absorption, and has a fluxing effect. After the graphite coating treatment, the keyhole is stabilized and the weld transition is stable.

[0055] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A processing method for fully copper-clad aluminum busbar composite material welding, characterized in that, The specific steps include the following: S1. The end face of the copper-clad aluminum busbar composite material is ground, surface impurities are removed and dried to form the copper-clad aluminum busbar composite material to be sprayed on the surface. S2. Prepare a graphite coating by mixing graphite powder and binder, and spray or brush the graphite coating onto the surface of the copper-clad aluminum busbar composite material to be sprayed or brushed. After drying and curing, a copper-clad aluminum busbar to be welded is formed. Select a copper sheet that matches the end face of the copper-clad aluminum busbar to be welded for later use. S3. Position and clamp the copper-clad aluminum busbar and copper sheet to be welded using a fixture, preheat the copper-clad aluminum busbar to be welded, set the welding parameters of the laser welding equipment, and weld the copper sheet to the end face of the copper-clad aluminum busbar to be welded, forming a fully copper-clad aluminum busbar composite material.

2. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, The steps of grinding, removing surface impurities, and drying the end faces of the copper-clad aluminum busbar composite raw material to form the copper-clad aluminum busbar composite material surface to be sprayed also include grinding the end faces of the copper-clad aluminum busbar composite raw material with sandpaper until they are bright, so that the surface roughness of the end faces is less than 0.

8. Then, clean with acetone / ethanol to remove oil, and after drying, form a copper-clad aluminum busbar composite material for the surface to be sprayed and brushed.

3. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, In the step of preparing graphite coatings with graphite powder and binder, the graphite powder is conductive graphite powder with a particle size of less than 100 mesh and a purity of greater than or equal to 99%; the binder is water-based acrylic resin, silica sol, or alcohol-based resin; the solvent is deionized water or ethanol; wherein, the graphite powder and binder are mixed in a mass ratio of 3:1–5:1 to form the graphite coating.

4. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, In the step of spraying or brushing graphite coating onto the surface of the copper-clad aluminum busbar composite material, during spraying, a spray gun is used to spray the graphite coating onto the surface, with a nozzle diameter of 0.8–1.5 mm. Air pressure 0.2–0.4 10–15 cm away from the surface to be sprayed Apply 1-2 layers of graphite coating evenly to the surface to be brushed, with each layer having a thickness of approximately 5-10 mm. When brushing, use a soft brush to evenly apply the graphite coating to the surface to be sprayed, and apply 2-3 layers of graphite coating.

5. A processing method for fully copper-clad aluminum busbar composite material welding according to claim 3 or 4, characterized in that, The copper sheet is made of T2 copper.

6. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, The copper-clad aluminum busbar and copper sheet to be welded are positioned and clamped by a fixture with a clamping force greater than 80N.

7. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, The preheating temperature for the copper-clad aluminum busbar to be welded is 210℃-230℃.

8. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 1, characterized in that, The welding parameters of the laser welding equipment include a fiber laser power of 3000W, an output wavelength of 1080±5nm, a spot diameter of 0.3mm, a welding speed of 20-50mm / s, and a laser frequency of 4000-6000Hz.

9. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 8, characterized in that, When welding copper sheets to the end face of copper-clad aluminum busbars to be welded, the laser oscillation amplitude of the fiber laser in the laser welding equipment is 0.6mm-1.2mm.

10. The processing method for fully copper-clad aluminum busbar composite material welding according to claim 8, characterized in that, When welding copper sheets to the end face of the copper-clad aluminum busbar to be welded, argon is used as the protective gas, and the argon gas flow rate is 15-20 L / min.

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