A method for manufacturing a spliced copper / nickel clad strip

Abstract

The application discloses a kind of preparation methods of splicing structure copper / nickel composite strip, which comprises the following steps: one, copper assembly and nickel assembly are spliced and assembled to obtain copper / nickel assembly after processing;Two, copper / nickel composite block is obtained by pressure and heat preservation;Three, copper / nickel composite sheet is obtained by slicing and finishing;Four, copper / nickel composite sheet is obtained by hot rolling and thinning;Five, copper / nickel composite strip blank is obtained by cold rolling and thinning;Six, copper / nickel composite strip is obtained by slitting and coiling.The application uses pressure and heat preservation combined with rolling, improves the copper / nickel interface organization density in copper / nickel composite strip, thereby improves the quality stability of copper / nickel composite strip, guarantees the conductivity of copper / nickel composite strip as electrode terminal connecting piece, so that the size specification of copper / nickel composite strip is no longer limited, reduces processing cost, improves production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of composite material processing technology, specifically relating to a method for preparing spliced ​​copper / nickel composite strips. Background Technology

[0002] Lithium-ion batteries possess advantages such as high voltage platform, high energy density, low self-discharge rate, and long service life, making them the preferred power source for electric vehicles. In practical applications, lithium-ion battery packs are formed by connecting the electrode terminals of individual lithium-ion batteries to meet the diverse power requirements of electric vehicles. The components used to connect the battery electrode terminals in this process are called metal connectors. Experience has shown that the performance of these metal connectors, such as conductivity, solderability, corrosion resistance, and mechanical properties, significantly impacts the power output performance of the lithium-ion battery pack.

[0003] Copper, with its excellent electrical conductivity, good machinability, and low cost, is a primary material for manufacturing metal connectors. However, copper itself has relatively low strength and poor corrosion resistance, which negatively impacts the discharge characteristics and reliability of battery packs. Nickel, on the other hand, possesses good electrical conductivity, high strength, and chemical stability. Its excellent weldability improves the strength and lifespan of connectors, enhances the stability of battery pack discharge processes, and provides strong, aesthetically pleasing welds with excellent corrosion resistance. Through technical means, copper and nickel are joined and processed into specific shapes and sizes, creating copper / nickel connectors.

[0004] In practical applications, copper / nickel connectors come in a variety of forms and sizes. Common copper / nickel connectors currently include... Figure 1 As shown, its characteristics are as follows: (1) The copper is pure copper, with grades TU1, TU2, T1 or T2; the nickel is pure nickel, with grades N4 or N6. (2) The copper / nickel connecting strip is in the form of foil strip, with a total thickness of 0.1mm to 1.0mm and a total width of 10mm to 400mm, wherein the ratio of the width occupied by the copper side and the nickel side is arbitrary. (3) The connection form of copper and nickel is splicing, and the connection interface is parallel to the length direction of the connecting strip.

[0005] From a materials processing perspective, copper / nickel connecting strips are essentially spliced ​​copper / nickel composite strips. Currently, methods for preparing spliced ​​copper / nickel composite strips include: fusion welding-grinding, explosive rolling, and extrusion rolling. The fusion welding-grinding method involves connecting copper and nickel strips using tungsten inert gas welding with wire, followed by mechanical grinding to obtain the copper / nickel composite strip. While flexible and convenient, this method is manual, resulting in low production efficiency, unstable quality, and pinhole defects at the copper / nickel interface, affecting the conductivity of the connecting strip. Furthermore, the composite strip has poor flatness, making subsequent welding to electrode terminals difficult. The explosive rolling method involves first processing a copper / nickel composite plate using explosive welding, then slicing the composite plate, and finally rolling the sliced ​​sheets to thin them, thus obtaining the copper / nickel composite strip. This method boasts high production efficiency but also high processing costs. However, pinhole defects easily form at the copper / nickel interface, affecting the conductivity of the connecting piece. Furthermore, due to the limitations of explosive welding on the thickness of the cladding material, this method cannot produce composite strips with a nickel or copper side width exceeding 30mm. The extrusion-rolling method involves first extruding copper / nickel composite strips using a large deformation rate, then slicing the composite strips, and finally rolling the sliced ​​sheets to thin them, thus obtaining copper / nickel composite strips. This method produces copper / nickel composite strips with a dense interface structure, stable and reliable quality, high production efficiency, and low processing costs, but it requires a dedicated production line with a significant initial investment. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a method for preparing a spliced ​​copper / nickel composite strip, addressing the shortcomings of the prior art. This method achieves diffusion bonding by pressurizing and heat-insulating the copper / nickel assembly, combined with a hot-rolling followed by cold-rolling process. This improves the density of the copper / nickel interface structure in the copper / nickel composite strip, thereby enhancing its quality stability and ensuring its conductivity as an electrode terminal connector. The method boasts high production efficiency and low cost, solving the problems of interface bonding defects, limited dimensions, and high costs associated with existing copper / nickel composite strips.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a spliced ​​copper / nickel composite strip, characterized in that the method includes the following steps:

[0008] Step 1: Prepare materials: Level and cut the copper and nickel plates respectively, then machine them into rectangular blocks, and clean them with ethanol or acetone to obtain copper and nickel assemblies. Then assemble the copper and nickel assemblies to obtain a copper / nickel assembly.

[0009] Step 2, diffusion bonding: The copper / nickel composite obtained in Step 1 is placed in a vacuum hot pressing sintering furnace and pressurized and kept at a constant temperature to allow the copper and nickel to diffusely bond in a planar manner, thus obtaining a copper / nickel composite block.

[0010] Step 3, Slicing and Finishing: Slice the copper / nickel composite block obtained in Step 2 along the cutting direction perpendicular to the copper / nickel bonding surface, and then perform dimensional and surface finishing to obtain a copper / nickel composite sheet;

[0011] Step 4, Hot Rolling Thinning: The copper / nickel composite sheet obtained in Step 3 is hot rolled and combined with an intermediate vacuum annealing process to obtain a copper / nickel composite thin sheet.

[0012] Step 5, Cold rolling thinning: The copper / nickel composite sheet obtained in step 4 is cold rolled and combined with an intermediate vacuum annealing process to obtain copper / nickel composite strip billet;

[0013] Step 6: Slitting and coiling: The copper / nickel composite strip blank is slitted and coiled to obtain copper / nickel composite strip.

[0014] The method for preparing a spliced ​​copper / nickel composite strip described above is characterized in that the surface roughness of the copper and nickel components in step one is not less than Ra0.8. This invention, by controlling the surface roughness of the copper and nickel components, ensures a tight bond after splicing and assembly, which is beneficial for planar diffusion bonding between the two components after subsequent pressurization and heat preservation.

[0015] The above-mentioned method for preparing a spliced ​​copper / nickel composite strip is characterized in that, in step one, the copper assembly includes a thin copper assembly with dimensions of δ1mm×Wmm×Lmm and a thick copper assembly with dimensions of 2δ1mm×Wmm×Lmm, and the nickel assembly has dimensions of δ2mm×Wmm×Lmm; the splicing assembly process is as follows: taking the thick copper assembly as the center, the nickel assembly and the thin copper assembly obtained in step one are stacked sequentially on the upper and lower surfaces of the thick copper assembly, respectively, ensuring that the outermost layer is the nickel assembly. The structure of the copper / nickel assembly of the present invention is as follows: Figure 2a As shown, the three-layer structure, consisting of a thick copper assembly and a nickel assembly stacked on the upper and lower surfaces of the thick copper assembly, can also be described as follows: Figure 2b As shown, it consists of a multi-layer structure consisting of a thick copper assembly and nickel assemblies and thin copper assemblies stacked sequentially on the upper and lower surfaces of the thick copper assembly.

[0016] Due to the significant difference in deformation resistance between copper and nickel, copper elongates much more than nickel during plastic processing at the same temperature. This inevitably leads to bending deformation of the copper / nickel composite strip, making the plastic processing process difficult to continue. To address this technical challenge, this invention uses symmetrical assembly of copper and nickel components, i.e., a Ni / Cu / Ni three-layer structure or a Ni / Cu / … / Ni / Cu / Ni / … / Cu / Ni multi-layer structure. The deformation balancing force generated during rolling deformation ensures a straight copper / nickel interface, thus guaranteeing smooth plastic processing and improving the quality of the copper / nickel composite strip. Furthermore, this invention uses a thick copper component, twice the thickness of the thin copper component, as the center. This facilitates the subsequent separation along the center of the thick copper component to obtain two sets of copper / nickel composite strips, improving preparation efficiency. Compared to the three-layer structure, the multi-layer structure offers higher production efficiency and lower cost.

[0017] The method for preparing a spliced ​​copper / nickel composite strip described above is characterized in that the pressurization and heat preservation process in step two is as follows: a vacuum is drawn from the vacuum hot-pressing sintering furnace, and the pressure of the residual gas inside the furnace is reduced to 5.0 × 10⁻⁶. -2 When the pressure is below Pa, the heating system is started. Once the furnace temperature reaches 760℃~820℃, the hydraulic system is activated, and the system pressure is adjusted to ensure the pressure P on the copper / nickel contact surface is 1.2MPa~2.6MPa. This temperature and pressure are maintained for 90min~120min. After the holding period, the copper / nickel composite block is removed from the furnace after cooling to below 100℃. This invention uses a vacuum diffusion welding method to join copper and nickel. By controlling process parameters such as vacuum degree, system pressure, heating temperature, and holding time during the vacuum diffusion welding process, physical changes such as metal reduction, plastic creep, atomic diffusion, and recrystallization occur at the copper / nickel interface, thereby forming a reliable metallurgical bond.

[0018] The above-mentioned method for preparing a spliced ​​copper / nickel composite strip is characterized in that, in step three, the copper / nickel composite block is sliced ​​using a saw, and then machined for dimensional and surface finishing; or the copper / nickel composite block is sliced ​​using wire cutting, and then surface polished for dimensional and surface finishing. In this invention, the slicing positions include cut surface 1 and cut surface 2, such as... Figure 3 As shown.

[0019] The above-mentioned method for preparing a spliced ​​copper / nickel composite strip is characterized in that the thickness of the copper / nickel composite sheet in step three is 2mm to 20mm.

[0020] The above-mentioned method for preparing a spliced ​​copper / nickel composite strip is characterized in that the hot rolling process in step four is as follows: the copper / nickel composite sheet is placed in an air heating furnace and heated to 240℃~280℃ and held at that temperature, and then subjected to multi-pass rolling, wherein the single-pass reduction of the multi-pass rolling does not exceed 25%, the final rolling temperature is not lower than 150℃, and intermediate vacuum annealing is performed when the total reduction exceeds 37%.

[0021] The above-mentioned method for preparing a spliced ​​copper / nickel composite strip is characterized in that the thickness of the copper / nickel composite sheet in step four does not exceed 1.8 mm.

[0022] The above-mentioned method for preparing spliced ​​copper / nickel composite strip is characterized in that the cold rolling process in step five is as follows: the copper / nickel composite sheet is subjected to tension rolling at room temperature using an uncoiling and tension rolling mill auxiliary equipment, and the single-pass reduction of tension rolling does not exceed 20%, to obtain copper / nickel composite strip blank. When the total reduction is more than 60%, intermediate vacuum annealing is performed.

[0023] The method for preparing a spliced ​​copper / nickel composite strip described above is characterized in that the intermediate vacuum annealing process in steps four and five is performed with a vacuum degree of not less than 5.0 × 10⁻⁶. -2 Pa, hold at 600℃~650℃ for 60min~90min, then cool with the furnace to below 150℃ before unloading.

[0024] In the rolling process of this invention, as the rolling reduction increases, the number of defects near the copper / nickel interface of the copper / nickel composite sheet gradually increases, increasing the risk of interface delamination and ultimately affecting the conductivity of the copper / nickel composite strip. Simultaneously, the dislocation density in the copper and nickel matrices continuously increases, making further deformation more difficult, and the conductivity of the matrix metal also significantly decreases. Therefore, this invention controls the process parameters of hot rolling to control the thickness of the copper / nickel composite sheet while ensuring its quality. Furthermore, this invention incorporates an intermediate vacuum annealing process during rolling, which largely eliminates the structural defects caused by rolling deformation, restores the properties of the matrix metal, and improves its conductivity. This invention employs a hot-rolling followed by cold-rolling process. On the one hand, hot rolling achieves a large reduction deformation; on the other hand, cold rolling improves the surface condition and dimensional accuracy of the hot-rolled product, thus enhancing the quality of the copper / nickel composite strip.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This invention achieves diffusion bonding by pressurizing and heat-insulating the copper / nickel composite obtained by splicing copper and nickel components, combined with a rolling process of hot rolling followed by cold rolling, thereby improving the density of the copper / nickel interface structure in the copper / nickel composite strip, thus improving the quality stability of the copper / nickel composite strip and ensuring the conductivity of the copper / nickel composite strip as an electrode terminal connecting piece.

[0027] 2. This invention uses a combination of pressure insulation and rolling to achieve a tight bond between the copper and nickel components, which makes the size and specifications of the copper / nickel composite strip, especially the width ratio of copper and nickel in the copper / nickel composite strip, no longer limited. This results in a wide range of product specifications and effectively improves production efficiency.

[0028] 3. The preparation process of this invention can be completed on general material processing equipment, avoiding large one-time investment, reducing processing costs and improving production efficiency.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a copper / nickel connector in the prior art.

[0031] Figure 2a This is a schematic diagram of the copper / nickel composite with a three-layer structure according to the present invention.

[0032] Figure 2b This is a schematic diagram of the copper / nickel composite with a multilayer structure according to the present invention.

[0033] Figure 3 This is a schematic diagram of the slicing method in this invention.

[0034] Figure 4 This is a partial physical image of the copper / nickel composite strip prepared in Example 3 of the present invention.

[0035] Figure 5 This is a cross-sectional microstructure diagram of the copper / nickel composite strip prepared in Example 3 of the present invention. Detailed Implementation

[0036] Example 1

[0037] This embodiment includes the following steps:

[0038] Step 1: Material Preparation: The copper and nickel plates are leveled and cut, then machined into rectangular blocks. These blocks are then cleaned with ethanol to obtain copper and nickel assemblies. The copper and nickel assemblies are then assembled to form a copper / nickel composite. The surface roughness of both the copper and nickel assemblies is Ra0.8. The copper assembly includes a thin copper component measuring 20mm × 120mm × 160mm and a thick copper component measuring 40mm × 120mm × 160mm. The nickel assemblies are 20mm × 120mm × 160mm in size. The assembly process involves placing a layer of nickel assemblies on the upper and lower surfaces of the thick copper component, using the thick copper component as the center, to obtain a three-layer copper / nickel composite.

[0039] Step 2, Diffusion Bonding: Place the copper / nickel assembly obtained in Step 1 into a vacuum hot-pressing sintering furnace. Evacuate the furnace until the residual gas pressure inside drops to 5.0 × 10⁻⁶. -2 When Pa, start the heating system. When the furnace temperature rises to 820℃, start the hydraulic system and adjust the system pressure so that the pressure P on the copper / nickel contact surface is 1.2MPa. Then maintain this temperature and pressure for 120 minutes. After the heat preservation is completed, cool down to 100℃ with the furnace and take it out of the furnace to achieve planar diffusion connection between copper and nickel and obtain copper / nickel composite block.

[0040] Step 3, Slicing and Finishing: The copper / nickel composite block obtained in Step 2 is sliced ​​using a saw along the cutting direction perpendicular to the copper / nickel bonding surface to obtain a sheet with a thickness of 22mm. Then, the dimensions and surface are finished by machining to obtain a copper / nickel composite sheet with a thickness of 20mm.

[0041] Step 4, Hot Rolling Thinning: The copper / nickel composite sheet obtained in Step 3 is placed in an air-heated furnace and heated to 150℃~280℃ and held therefore, then subjected to 8 passes of rolling. The reduction amount for each pass is as follows: Both intermediate vacuum annealing processes involved a vacuum level of 5.0 × 10⁻⁶. -2 Pa, held at 650℃ for 60 min, and then cooled in the furnace to below 150℃ to obtain a copper / nickel composite sheet with a thickness of 1.8 mm;

[0042] Step 5, Cold Rolling Thinning: The copper / nickel composite sheet obtained in Step 4 is subjected to 6 passes of tension cold rolling using an uncoiling and tensioning mill auxiliary equipment. The reduction amount for each pass is as follows: The intermediate vacuum annealing process involves a vacuum degree of 5.0 × 10⁻⁶. -2Pa, held at 650℃ for 60 min, then cooled in the furnace to 150℃ and removed from the furnace to obtain a copper / nickel composite strip billet with a thickness of 0.1 mm;

[0043] Step 6, Slitting and Coiling: The copper / nickel composite strip blank obtained in Step 5 is slitting using a slitting machine. During the slitting process, the cutter cuts along the length of the copper / nickel composite strip blank at a designated position. Then, the strip is coiled using a winding machine to obtain copper / nickel composite strip.

[0044] Example 2

[0045] This embodiment includes the following steps:

[0046] Step 1: Material Preparation: The copper and nickel plates are leveled and cut, then machined into rectangular blocks. These blocks are then cleaned with ethanol to obtain copper and nickel assemblies. The copper and nickel assemblies are then assembled to form a copper / nickel composite. The surface roughness of both the copper and nickel assemblies is Ra0.4. The copper assembly includes a thin copper component measuring 30mm × 160mm × 200mm and a thick copper component measuring 60mm × 160mm × 200mm. The nickel assemblies are 40mm × 160mm × 200mm in size. The assembly process involves stacking the nickel and thin copper assemblies sequentially on the upper and lower surfaces of the thick copper assembly, with the outermost layer being the nickel assemblies, resulting in a 7-layer copper / nickel composite.

[0047] Step 2, Diffusion Bonding: Place the copper / nickel composite obtained in Step 1 into a vacuum hot-pressing sintering furnace. Evacuate the furnace until the residual gas pressure inside drops to 8.0 × 10⁻⁶. -3 When the temperature reaches 760℃, start the heating system. When the furnace temperature reaches 760℃, start the hydraulic system and adjust the system pressure so that the pressure P on the copper / nickel contact surface is 2.6MPa. Then maintain this temperature and pressure for 90 minutes. After the heat preservation is completed, cool down the furnace to below 50℃ and take it out of the furnace. This allows the copper and nickel to diffusely bond in a plane, thus obtaining a copper / nickel composite block.

[0048] Step 3, Slicing and Finishing: The copper / nickel composite block obtained in Step 2 is sliced ​​using a saw along the cutting direction perpendicular to the copper / nickel bonding surface to obtain a sheet with a thickness of 22mm. Then, the dimensions and surface are finished by machining to obtain a copper / nickel composite sheet with a thickness of 18mm.

[0049] Step 4, Hot Rolling Thinning: The copper / nickel composite sheet obtained in Step 3 is placed in an air heating furnace and heated to 160℃~240℃ and held at that temperature. Then, it is rolled in 8 passes, with the reduction amount distributed in each pass as follows: Both intermediate vacuum annealing processes involved a vacuum level of 8.0 × 10⁻⁶. -3 Pa, held at 600℃ for 90 min, then cooled to 60℃ in the furnace and removed from the furnace to obtain a copper / nickel composite sheet with a thickness of 1.6 mm;

[0050] Step 5, Cold Rolling Thinning: The copper / nickel composite sheet obtained in Step 4 is subjected to 4 passes of tension cold rolling using an uncoiling and tensioning mill auxiliary equipment. The reduction amount for each pass is as follows: A copper / nickel composite strip blank with a thickness of 1.04 mm was obtained;

[0051] Step 6, Slitting and Coiling: The copper / nickel composite strip blank obtained in Step 5 is slitting using a slitting machine. During the slitting process, the cutter cuts along the length of the copper / nickel composite strip blank at a designated position. Then, the strip is coiled using a winding machine to obtain copper / nickel composite strip.

[0052] Example 3

[0053] This embodiment includes the following steps:

[0054] Step 1: Material Preparation: The copper and nickel plates are leveled and cut, then machined into rectangular blocks. After cleaning with acetone, copper and nickel assemblies are obtained. These are then assembled to form a copper / nickel composite. The surface roughness of both the copper and nickel assemblies is Ra0.8. The copper assembly includes a thin copper component measuring 12mm × 120mm × 200mm and a thick copper component measuring 24mm × 120mm × 200mm. The nickel component measures 10mm × 120mm × 200mm. The assembly process involves stacking the nickel and thin copper components sequentially on the upper and lower surfaces of the thick copper component, with the outermost layer being the nickel component, resulting in an 11-layer copper / nickel composite.

[0055] Step 2, Diffusion Bonding: Place the copper / nickel composite obtained in Step 1 into a vacuum hot-pressing sintering furnace, evacuate the furnace, and wait until the residual gas pressure inside the furnace drops to 1.0 × 10⁻⁶. -2 When Pa, start the heating system. When the furnace temperature rises to 800℃, start the hydraulic system and adjust the system pressure so that the pressure P on the copper / nickel contact surface is 1.0MPa. Then maintain this temperature and pressure for 100min. After the heat preservation is completed, cool down the furnace to below 30℃ and take it out of the furnace to achieve planar diffusion connection between copper and nickel and obtain copper / nickel composite block.

[0056] Step 3, Slicing and Finishing: The copper / nickel composite block obtained in Step 2 is sliced ​​by wire cutting along the cutting direction perpendicular to the copper / nickel bonding surface to obtain a sheet with a thickness of 2.1mm. Then, surface polishing is used to finish the dimensions and surface to obtain a copper / nickel composite sheet with a thickness of 2mm.

[0057] Step 4, Hot Rolling Thinning: The copper / nickel composite sheet obtained in Step 3 is placed in an air heating furnace and heated to 180℃~260℃ and held at that temperature. Then, it is rolled in 3 passes, with the reduction amount distributed in each pass as follows: A copper / nickel composite sheet with a thickness of 1.5 mm was obtained;

[0058] Step 5, Cold Rolling Thinning: The copper / nickel composite sheet obtained in Step 4 is subjected to 7 passes of tension cold rolling using an uncoiling and tensioning mill auxiliary equipment. The reduction amount for each pass is as follows: A copper / nickel composite strip blank with a thickness of 0.3 mm was obtained, wherein the intermediate vacuum annealing process was performed with a vacuum degree of 2.0 × 10⁻⁶. -2 Pa, hold at 630℃ for 80 minutes, then cool in the furnace to 30℃ and remove from the furnace;

[0059] Step Six: Slitting and Coiling: The copper / nickel composite strip blank obtained in Step Five is slitting using a slitting machine. During the slitting process, the cutter cuts along the length of the copper / nickel composite strip blank at a designated position. Then, a winding machine is used to coil the strip into a coil to obtain the copper / nickel composite strip. A partial photograph of the actual product is shown below. Figure 4 As shown.

[0060] Figure 5 This is a cross-sectional microstructure image of the copper / nickel composite strip prepared in this embodiment. Figure 5 It can be seen that the copper / nickel interface in this copper / nickel composite strip is well bonded, without microstructural defects such as cracks, pores, inclusions, and second phases. The matrix metal structure is dense and maintains a relatively coarse annealed state morphology. This structure ensures that the copper / nickel composite strip has good electrical conductivity.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a spliced ​​copper / nickel composite strip, characterized in that, The method includes the following steps: Step 1: Material Preparation: The copper and nickel plates are leveled and cut, then machined into rectangular blocks. These blocks are then cleaned with ethanol or acetone to obtain copper and nickel assemblies. The copper and nickel assemblies are then assembled to form a copper / nickel assembly. The copper assembly includes a thin copper component with dimensions δ1mm×Wmm×Lmm and a thick copper component with dimensions 2δ1mm×Wmm×Lmm. The nickel assembly has dimensions δ2mm×Wmm×Lmm. The assembly process is as follows: using the thick copper assembly as the center, the nickel and thin copper assemblies obtained in Step 1 are stacked sequentially on the upper and lower surfaces of the thick copper assembly, ensuring that the outermost layer is the nickel assembly. Step 2, Diffusion Bonding: The copper / nickel composite obtained in Step 1 is placed in a vacuum hot-pressing sintering furnace and pressurized and kept at a constant temperature to allow the copper and nickel to diffusely bond in a planar manner, thus obtaining a copper / nickel composite block. The pressurization and heat-keeping process is as follows: the vacuum hot-pressing sintering furnace is evacuated until the residual gas pressure inside the furnace drops to 5.0 × 10⁻⁶. -2 When the temperature is below Pa, start the heating system. When the furnace temperature rises to 760℃~820℃, start the hydraulic system and adjust the system pressure so that the pressure P on the copper / nickel contact surface is 1.2MPa~2.6MPa. Then maintain this temperature and pressure for 90min~120min. After the holding period, cool down the furnace to below 100℃ and remove it from the furnace to obtain a copper / nickel composite block. Step 3, Slicing and Finishing: Slice the copper / nickel composite block obtained in Step 2 along the cutting direction perpendicular to the copper / nickel bonding surface, and then perform dimensional and surface finishing to obtain a copper / nickel composite sheet; Step 4, Hot Rolling Thinning: The copper / nickel composite sheet obtained in Step 3 is hot rolled and combined with an intermediate vacuum annealing process to obtain a copper / nickel composite thin sheet. Step 5, Cold rolling thinning: The copper / nickel composite sheet obtained in step 4 is cold rolled and combined with an intermediate vacuum annealing process to obtain copper / nickel composite strip billet; Step 6: Slitting and coiling: The copper / nickel composite strip blank is slitted and coiled to obtain copper / nickel composite strip.

2. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The surface roughness of the copper and nickel assemblies mentioned in step one shall not be less than Ra0.

8.

3. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, In step three, the copper / nickel composite block is sliced ​​using a saw, and then machined for dimensional and surface finishing; or the copper / nickel composite block is sliced ​​using wire cutting, and then polished for dimensional and surface finishing.

4. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The thickness of the copper / nickel composite sheet mentioned in step three is 2mm to 20mm.

5. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The hot rolling process described in step four is as follows: the copper / nickel composite sheet is placed in an air heating furnace and heated to 240℃~280℃ and held at that temperature. Then, it is rolled in multiple passes, and the reduction of each single pass in the multi-pass rolling does not exceed 25%. The final rolling temperature is not lower than 150℃, and intermediate vacuum annealing is performed when the total reduction exceeds 37%.

6. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The thickness of the copper / nickel composite sheet mentioned in step four shall not exceed 1.8 mm.

7. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The cold rolling process described in step five is as follows: copper / nickel composite sheets are subjected to tension rolling at room temperature using uncoiling and tension rolling mill auxiliary equipment, and the single-pass reduction of tension rolling does not exceed 20% to obtain copper / nickel composite strip billet. When the total reduction is more than 60%, intermediate vacuum annealing is performed.

8. The method for preparing a spliced ​​copper / nickel composite strip according to claim 1, characterized in that, The intermediate vacuum annealing process described in steps four and five both require a vacuum level of not less than 5.0 × 10⁻⁶. -2 Pa, hold at 600℃~650℃ for 60min~90min, then cool with the furnace to below 150℃ before unloading.

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