Corrosion-resistant high-conductivity nickel-coated copper core and method for preparing same

Abstract

The present application relates to a kind of corrosion-resistant high-conductive nickel-coated copper core and its preparation method, belong to nickel-coated copper core technical field.The present application is uniformly coated with a dense nickel layer on the surface of copper core, and further coated with a layer of corrosion-resistant coating outside the nickel layer, the corrosion-resistant coating is obtained by corrosion-resistant coating material coating solidification, the formula of the corrosion-resistant coating material is as follows, by weight parts, epoxy resin emulsion 70~90 parts, composite filler 10~20 parts, polytetrafluoroethylene emulsion 5~10 parts, curing agent 3~5 parts, polydimethylsiloxane 1~2 parts.The nickel-coated copper core obtained by the present application can maintain high conductivity while significantly improving corrosion resistance and impact resistance.The preparation method of the present application is simple, easy to industrial production, and the performance of the obtained product is stable, suitable for application in various special environments.

Description

Technical Field

[0001] This invention belongs to the field of nickel-clad copper core technology, and relates to a corrosion-resistant, highly conductive nickel-clad copper core and its preparation method. Background Technology

[0002] Copper, as a metal with excellent electrical conductivity, has wide applications in electrical and electronic fields. However, its corrosion resistance and solderability are relatively poor, especially in harsh environments where the performance of copper materials degrades rapidly, leading to a shortened product lifespan. In traditional applications, steel-clad copper core materials are widely used due to their good conductivity and mechanical strength. However, with the development of modern industry, especially in some special environments, the corrosion resistance of steel-clad copper core materials can no longer meet practical requirements, which limits the further expansion of its application range. Nickel, on the other hand, is known for its excellent corrosion resistance and solderability, but its relatively weak conductivity limits its application in situations requiring high conductivity.

[0003] Therefore, coating a copper core with a layer of nickel can retain the excellent electrical conductivity of copper while significantly improving the material's corrosion resistance and solderability. This nickel-clad copper composite material has broad application prospects in electrical connections, communication equipment, aerospace, and other fields. However, the corrosion resistance of nickel-clad copper materials still needs improvement. Especially in some extreme environments, such as corrosive media like strong acids and alkalis, corrosion may still occur even with nickel coating technology, affecting the product's service life and reliability. Therefore, how to further improve the corrosion resistance of nickel-clad copper materials has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a corrosion-resistant, highly conductive nickel-clad copper core and its preparation method, which maintains the high conductivity of the copper core while having excellent corrosion resistance and good impact resistance.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A corrosion-resistant, highly conductive nickel-clad copper core, comprising, from the inside out, a copper core, a nickel plating layer, and a corrosion-resistant coating.

[0007] The corrosion-resistant coating is obtained by applying and curing a corrosion-resistant paint. The formulation of the corrosion-resistant paint is as follows (by weight): 70-90 parts epoxy resin emulsion, 10-20 parts composite filler, 5-10 parts polytetrafluoroethylene emulsion, 3-5 parts curing agent, and 1-2 parts polydimethylsiloxane.

[0008] The preparation method of the composite filler is as follows:

[0009] S1-1: Place 20-30 parts of diatomaceous earth in 100 parts of sodium hydroxide solution, sonicate at 60-80℃ for 20-40 min, then wash with deionized water, and then dry in a vacuum drying oven for 6-8 h to obtain powder A;

[0010] S1-2: Add 15-25 parts of powder A to 50-60 parts of deionized water and stir for 30 minutes. Then add 3-5 parts of ammonium molybdate and continue stirring for 2 hours. Remove the deionized water by rotary evaporation at 60°C, and then calcine in a muffle furnace to obtain powder B.

[0011] S1-3: Add 10-20 parts of powder B to 30-40 parts of phytic acid solution, sonicate at 40-50℃ for 10 min, then stir at room temperature at 550-650 r / min for 1-2 h, wash with deionized water, and then freeze dry in a freeze dryer for 8-12 h to obtain powder C.

[0012] S1-4: Mix powder C with glass flakes at a mass ratio of (1-2):1, place in a ball mill and ball mill for 40-60 minutes at a speed of 150 r / min, then add silane coupling agent KH570 and continue ball milling for 1-3 hours while maintaining the speed to obtain the composite filler.

[0013] As a preferred embodiment of the present invention, the method for preparing the corrosion-resistant coating is as follows:

[0014] The epoxy resin emulsion, composite filler, and polytetrafluoroethylene emulsion are mixed according to the formula ratio and stirred at a speed of 700-800 r / min for 30-50 min. Then, polydimethylsiloxane is added and the stirring is continued at the same speed for 20 min. Finally, the curing agent is added and the mixture is stirred at a speed of 800-900 r / min for 5-10 min to obtain the corrosion-resistant coating.

[0015] In a preferred embodiment of the present invention, the curing agent is an amine-based curing agent.

[0016] As a preferred embodiment of the present invention, the concentration of the sodium hydroxide solution in S1-1 is 0.2M.

[0017] As a preferred embodiment of the present invention, the roasting temperature in S1-2 is 600-800℃ and the roasting time is 1-2h.

[0018] In a preferred embodiment of the present invention, the phytic acid solution in S1-3 has a mass fraction of 10-20%.

[0019] As a preferred embodiment of the present invention, the amount of silane coupling agent KH570 added in S1-4 is 3% of the total weight of powder C and glass flakes.

[0020] A method for preparing a corrosion-resistant, highly conductive nickel-clad copper core, the specific steps of which are as follows:

[0021] S8-1: Immerse the copper core in degreasing solution, sonicate at 60-80℃ for 5-15 min, wash the copper core with deionized water at 80-90℃, then acid wash in 0.2M hydrochloric acid solution for 5-15 s, wash with deionized water at 20-40℃, and then dry in a vacuum drying oven at 60℃ for 6-8 h to obtain the pretreated copper core;

[0022] S8-2: Place the pretreated copper core in an electrolyte solution for electroplating. The electroplating temperature is 45–55℃, the electroplating time is 8–10 min, the voltage is 3–4V, and the current density is 1–2 A / dm³. 2 A nickel plating layer is obtained;

[0023] S8-3: Apply a corrosion-resistant coating to the surface of the nickel plating layer and cure it at 75-85℃ for 1-2 hours to obtain the corrosion-resistant, highly conductive nickel-coated copper core.

[0024] As a preferred embodiment of the present invention, the degreasing solution in S8-1 consists of 20-30 g / L sodium carbonate, 40-60 g / L sodium phosphate, and 1-3 g / L sodium dodecyl sulfonate, with deionized water as the solvent.

[0025] As a preferred embodiment of the present invention, the electrolyte in S8-2 consists of 230-250 g / L nickel sulfate, 4-6 g / L sodium chloride, 20-30 g / L boric acid, and 5-10 g / L sodium citrate, with deionized water as the solvent.

[0026] Copper is a highly conductive metal, capable of effectively transmitting current and ensuring the high conductivity of the nickel-clad copper core. Nickel plating on the copper core significantly enhances its corrosion resistance; the nickel plating layer prevents corrosive media from directly contacting the copper core, while nickel itself also possesses excellent corrosion resistance.

[0027] Epoxy resin emulsion, as the main component of the coating, possesses excellent waterproof, moisture-proof, and corrosion-resistant properties. It effectively isolates the entry of oxygen or moisture, reducing the oxidation and corrosion rate of the nickel-plated copper core surface. The epoxy resin emulsion exhibits good adhesion, bonding tightly to the nickel plating layer, ensuring the stability and durability of the coating and helping to prevent peeling or damage during transportation, installation, and maintenance. The coating formed after the epoxy resin emulsion cures has high mechanical strength and can withstand certain shear, bending, and impact forces.

[0028] In the preparation of the composite filler, diatomaceous earth is treated with sodium hydroxide. Sodium hydroxide effectively interacts with the silicate structure on the surface of diatomaceous earth, removing impurities and promoting the formation and exposure of hydroxyl functional groups, thus increasing the number of active sites on the surface. During calcination, ammonium molybdate decomposes at high temperature to generate molybdenum oxides. These oxides possess high chemical stability and activity, enabling them to form chemical bonds with hydroxyl and other functional groups on the diatomaceous earth surface. This not only enhances the bonding force between diatomaceous earth and molybdenum oxides but also makes the entire composite structure more stable and durable. Furthermore, the high hardness and wear resistance of molybdenum oxides further improve the mechanical properties of the coating. Furthermore, the porous cage-like structure of diatomaceous earth is conducive to the adsorption and storage of molybdenum oxide and other substances, significantly increasing the content of effective components in the coating; the pores of diatomaceous earth form a complex network in the coating, and when corrosive media attempt to penetrate into the interior of the coating, these pore structures act as a physical barrier, increasing the diffusion path and difficulty of the corrosive media; when the coating is eroded by corrosive media, molybdenum oxide can be released from the pores of diatomaceous earth to react with the corrosive media or form a protective layer.

[0029] The carboxyl groups in phytic acid can chelate with metal ions to form stable chelates, thereby improving the chemical stability of the coating. After reacting with metal ions, phytic acid can form a dense protective layer on the coating surface, which can further prevent corrosive media from contacting the coating substrate and enhance the coating's corrosion resistance.

[0030] Glass flakes are inorganic materials with a lamellar structure. Adding glass flakes to composite fillers can enhance coating toughness. The lamellar structure of glass flakes can create a "maze effect" within the coating, increasing the diffusion path of corrosive media. Simultaneously, glass flakes themselves possess high toughness, improving the coating's impact resistance and crack resistance. When combined with components such as phytic acid, diatomaceous earth, and molybdenum oxide, glass flakes can form a multi-layered protective structure within the coating, more effectively blocking the penetration of corrosive media and improving the coating's corrosion resistance. Furthermore, the addition of glass flakes can improve the appearance of the coating, making it smoother and more even.

[0031] Silane coupling agent KH570 acts as a bridge, tightly binding composite fillers and organic resins together, thereby improving the interfacial adhesion and overall stability of the coating. The addition of KH570 also improves the hydrophobicity of the coating surface, reducing moisture erosion and thus enhancing the coating's water resistance and corrosion resistance.

[0032] Polytetrafluoroethylene (PTFE) emulsions exhibit excellent resistance to strong acids, strong alkalis, oxidants, and most solvents, demonstrating superior chemical stability and weather resistance. Adding PTFE emulsions to coating formulations enables the resulting coatings to remain stable in various corrosive environments, further extending the service life of both the coating and the substrate.

[0033] The beneficial effects of this invention are:

[0034] The nickel plating layer significantly enhances the corrosion resistance of the copper core while maintaining its high conductivity. Epoxy resin emulsion, as the main component of the coating, not only possesses excellent waterproof, moisture-proof, and corrosion-resistant properties but also adheres tightly to the nickel plating layer, ensuring the coating's stability and durability. In the preparation of the composite filler, specific treatments enhance the bonding force between diatomaceous earth and molybdenum oxide, improving the coating's corrosion resistance. The addition of phytic acid further enhances the coating's chemical stability and corrosion resistance. The introduction of glass flakes enhances the coating's toughness, forming a multi-layered protective structure that more effectively blocks the penetration of corrosive media. The silane coupling agent KH570 improves the coating's interfacial bonding and overall stability. The addition of polytetrafluoroethylene emulsion enables the coating to remain stable in various corrosive environments, extending the service life of the nickel-clad copper core. Detailed Implementation

[0035] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0036] Example 1

[0037] A corrosion-resistant, highly conductive nickel-clad copper core, comprising, from the inside out, a copper core, a nickel plating layer, and a corrosion-resistant coating.

[0038] The corrosion-resistant coating is obtained by applying and curing a corrosion-resistant paint. The formulation of the corrosion-resistant paint is as follows (by weight): 80 parts epoxy resin emulsion, 15 parts composite filler, 7 parts polytetrafluoroethylene emulsion, 4 parts ethylenediamine, and 1.5 parts polydimethylsiloxane.

[0039] The preparation method of the composite filler is as follows:

[0040] S1-1: Place 25 parts of diatomaceous earth in 100 parts of 0.2M sodium hydroxide solution, sonicate at 70℃ for 30 min, then wash with deionized water, and then dry in a vacuum drying oven for 7 h to obtain powder A;

[0041] S1-2: Add 20 parts of powder A to 55 parts of deionized water and stir for 30 min. Then add 4 parts of ammonium molybdate and continue stirring for 2 h. Remove the deionized water by rotary evaporation at 60 °C. Then place it in a muffle furnace for calcination at 700 °C for 1.5 h to obtain powder B.

[0042] S1-3: Add 15 parts of powder B to 35 parts of phytic acid solution with a mass fraction of 15%, sonicate at 45℃ for 10 min, then stir at room temperature at 600 r / min for 1.5 h, wash with deionized water, and then freeze dry in a freeze dryer for 10 h to obtain powder C.

[0043] S1-4: Mix powder C and glass flakes at a mass ratio of 1.5:1, place them in a ball mill and ball mill for 50 minutes at a speed of 150 r / min, then add silane coupling agent KH570, the amount of silane coupling agent KH570 added is 3% of the total weight of powder C and glass flakes, and continue ball milling for 2 hours at the same speed to obtain the composite filler.

[0044] The preparation method of the corrosion-resistant coating is as follows:

[0045] The epoxy resin emulsion, composite filler, and polytetrafluoroethylene emulsion were mixed according to the proportion of Formula 1 and stirred at 750 r / min for 40 min. Then, polydimethylsiloxane was added and stirred for another 20 min while maintaining the stirring speed. Finally, ethylenediamine was added and stirred at 850 r / min for 8 min to obtain the corrosion-resistant coating.

[0046] A method for preparing a corrosion-resistant, highly conductive nickel-clad copper core, the specific steps of which are as follows:

[0047] S8-1: Immerse the copper core in a degreasing solution consisting of 25 g / L sodium carbonate, 50 g / L sodium phosphate, and 2 g / L sodium dodecyl sulfonate, with deionized water as the solvent. Sonicate at 70°C for 10 min, wash the copper core with 85°C deionized water, then acid wash in 0.2M hydrochloric acid solution for 10 s, wash with 30°C deionized water, and then dry in a 60°C vacuum drying oven for 7 h to obtain the pretreated copper core.

[0048] S8-2: The pretreated copper core is placed in an electrolyte solution for electroplating. The electrolyte solution consists of 240 g / L nickel sulfate, 5 g / L sodium chloride, 25 g / L boric acid, and 7 g / L sodium citrate. The solvent is deionized water. The electroplating temperature is 50℃, the electroplating time is 9 min, the voltage is 3.5V, and the current density is 1.5 A / dm³. 2 A nickel plating layer is obtained;

[0049] S8-3: Apply a corrosion-resistant coating to the surface of the nickel plating layer and cure it at 80°C for 1.5 hours to obtain the corrosion-resistant, highly conductive nickel-coated copper core.

[0050] Example 2

[0051] A corrosion-resistant, highly conductive nickel-clad copper core, comprising, from the inside out, a copper core, a nickel plating layer, and a corrosion-resistant coating.

[0052] The corrosion-resistant coating is obtained by applying and curing a corrosion-resistant paint. The formulation 2 of the corrosion-resistant paint is as follows: by weight, 70 parts epoxy resin emulsion, 10 parts composite filler, 5 parts polytetrafluoroethylene emulsion, 3 parts ethylenediamine, and 1 part polydimethylsiloxane.

[0053] The preparation method of the composite filler is as follows:

[0054] S1-1: Place 20 parts of diatomaceous earth in 100 parts of 0.2M sodium hydroxide solution, sonicate at 60℃ for 20 min, then wash with deionized water, and dry in a vacuum drying oven for 6 h to obtain powder A;

[0055] S1-2: Add 15 parts of powder A to 50 parts of deionized water and stir for 30 minutes. Then add 3 parts of ammonium molybdate and continue stirring for 2 hours. Remove the deionized water by rotary evaporation at 60°C. Then place it in a muffle furnace for calcination at 600°C for 1 hour to obtain powder B.

[0056] S1-3: Add 10 parts of powder B to 30 parts of phytic acid solution with a mass fraction of 10%, sonicate at 40℃ for 10 min, then stir at room temperature at 550 r / min for 1 h, wash with deionized water, and then freeze dry in a freeze dryer for 8 h to obtain powder C.

[0057] S1-4: Mix powder C and glass flakes at a mass ratio of 1:1, place them in a ball mill and ball mill for 40 minutes at a speed of 150 r / min, then add silane coupling agent KH570, the amount of silane coupling agent KH570 added is 3% of the total weight of powder C and glass flakes, and continue ball milling for 1 hour while maintaining the speed to obtain the composite filler.

[0058] The preparation method of the corrosion-resistant coating is as follows:

[0059] The epoxy resin emulsion, composite filler, and polytetrafluoroethylene emulsion were mixed according to the ratio of Formula 2 and stirred at 700 r / min for 30 min. Then, polydimethylsiloxane was added and stirred for another 20 min while maintaining the stirring speed. Finally, ethylenediamine was added and stirred at 800 r / min for 5 min to obtain the corrosion-resistant coating.

[0060] A method for preparing a corrosion-resistant, highly conductive nickel-clad copper core, the specific steps of which are as follows:

[0061] S8-1: Immerse the copper core in a degreasing solution consisting of 20 g / L sodium carbonate, 40 g / L sodium phosphate, and 1 g / L sodium dodecyl sulfonate, with deionized water as the solvent. Sonicate at 60°C for 5 min, wash the copper core with 80°C deionized water, then acid wash in 0.2M hydrochloric acid solution for 5 s, wash with 20°C deionized water, and then dry in a 60°C vacuum drying oven for 6 h to obtain the pretreated copper core.

[0062] S8-2: The pretreated copper core is placed in an electrolyte solution for electroplating. The electrolyte solution consists of 230 g / L nickel sulfate, 4 g / L sodium chloride, 20 g / L boric acid, and 5 g / L sodium citrate. The solvent is deionized water. The electroplating temperature is 45℃, the electroplating time is 8 min, the voltage is 3V, and the current density is 1 A / dm³. 2 A nickel plating layer is obtained;

[0063] S8-3: Apply corrosion-resistant coating to the surface of the nickel plating layer and cure at 75°C for 2 hours to obtain the corrosion-resistant, highly conductive nickel-coated copper core.

[0064] Example 3

[0065] A corrosion-resistant, highly conductive nickel-clad copper core, comprising, from the inside out, a copper core, a nickel plating layer, and a corrosion-resistant coating.

[0066] The corrosion-resistant coating is obtained by applying and curing a corrosion-resistant paint. The formulation of the corrosion-resistant paint is as follows: by weight, 90 parts epoxy resin emulsion, 20 parts composite filler, 10 parts polytetrafluoroethylene emulsion, 5 parts ethylenediamine, and 2 parts polydimethylsiloxane.

[0067] The preparation method of the composite filler is as follows:

[0068] S1-1: Place 30 parts of diatomaceous earth in 100 parts of 0.2M sodium hydroxide solution, sonicate at 80℃ for 40 min, then wash with deionized water, and dry in a vacuum drying oven for 8 h to obtain powder A;

[0069] S1-2: Add 25 parts of powder A to 60 parts of deionized water and stir for 30 minutes. Then add 5 parts of ammonium molybdate and continue stirring for 2 hours. Remove the deionized water by rotary evaporation at 60°C. Then place it in a muffle furnace for calcination at 800°C for 2 hours to obtain powder B.

[0070] S1-3: Add 20 parts of powder B to 40 parts of phytic acid solution with a mass fraction of 20%, sonicate at 50℃ for 10 min, then stir at room temperature at 650 r / min for 2 h, wash with deionized water, and then freeze dry in a freeze dryer for 12 h to obtain powder C.

[0071] S1-4: Mix powder C and glass flakes at a mass ratio of 2:1, place them in a ball mill and ball mill for 60 minutes at a speed of 150 r / min, then add silane coupling agent KH570, the amount of silane coupling agent KH570 added is 3% of the total weight of powder C and glass flakes, and continue ball milling for 3 hours at the same speed to obtain the composite filler.

[0072] The preparation method of the corrosion-resistant coating is as follows:

[0073] The epoxy resin emulsion, composite filler, and polytetrafluoroethylene emulsion were mixed according to the ratio of Formula 3 and stirred at 800 r / min for 50 min. Then, polydimethylsiloxane was added and stirred for another 20 min while maintaining the stirring speed. Finally, ethylenediamine was added and stirred at 900 r / min for 10 min to obtain the corrosion-resistant coating.

[0074] A method for preparing a corrosion-resistant, highly conductive nickel-clad copper core, the specific steps of which are as follows:

[0075] S8-1: The copper core is immersed in a degreasing solution consisting of 30 g / L sodium carbonate, 60 g / L sodium phosphate, and 3 g / L sodium dodecyl sulfonate, with deionized water as the solvent. The copper core is ultrasonicated at 80°C for 15 min, washed with deionized water at 90°C, then acid-washed in 0.2 M hydrochloric acid solution for 15 s, washed with deionized water at 40°C, and then dried in a vacuum drying oven at 60°C for 8 h to obtain the pretreated copper core.

[0076] S8-2: The pretreated copper core is placed in an electrolyte solution for electroplating. The electrolyte solution consists of 250 g / L nickel sulfate, 6 g / L sodium chloride, 30 g / L boric acid, and 10 g / L sodium citrate. The solvent is deionized water. The electroplating temperature is 55℃, the electroplating time is 10 min, the voltage is 4V, and the current density is 2A / dm³. 2 A nickel plating layer is obtained;

[0077] S8-3: Apply corrosion-resistant coating to the surface of the nickel plating layer and cure at 85°C for 2 hours to obtain the corrosion-resistant, highly conductive nickel-coated copper core.

[0078] Comparative Example 1

[0079] Ammonium molybdate was not added during the preparation of the composite filler, and the remaining steps were the same as in Example 1.

[0080] Comparative Example 2

[0081] Phytic acid solution was not added during the preparation of the composite filler, and the remaining steps were the same as in Example 1.

[0082] Comparative Example 3

[0083] Glass flakes were not added during the preparation of the composite filler, and the remaining steps were the same as in Example 1.

[0084] Comparative Example 4

[0085] In the preparation of the corrosion-resistant coating, polytetrafluoroethylene emulsion is not added, and the remaining steps are the same as in Example 1.

[0086] Comparative Example 5

[0087] Without the nickel plating step, the remaining steps are the same as in Example 1.

[0088] The resistivity of Examples 1 to 3 was measured in accordance with the GB / T 1424-1996 standard, and the experimental data are summarized in the table below.

[0089] Resistivity (Ω·m) Example 1 0.062538 Example 2 0.062680 Example 3 0.062595

[0090] Corrosion resistance tests were conducted on Examples 1-3 and Comparative Examples 1-5 according to GB / T 10125-2021 standard, and the experimental data are summarized in the table below.

[0091] Corrosion resistance (h) Example 1 2200 Example 2 2100 Example 3 2150 Comparative Example 1 1900 Comparative Example 2 1800 Comparative Example 3 1700 Comparative Example 4 1850 Comparative Example 5 2000

[0092] The impact resistance of the corrosion-resistant, highly conductive nickel-clad copper cores prepared in Examples 1-3 and Comparative Example 3 was tested according to IEC 60068-2-27 standard. The experimental data are summarized in the table below.

[0093] Impact resistance (h) Example 1 5100 Example 2 4950 Example 3 5030 Comparative Example 3 4520

[0094] As can be seen from the examples and comparative data, the nickel-clad copper core prepared by the present invention maintains the high conductivity of the copper core, while also having excellent corrosion resistance and impact resistance.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A corrosion-resistant, highly conductive nickel-clad copper core, characterized in that, The corrosion-resistant, highly conductive nickel-clad copper core comprises, from the inside out, a copper core, a nickel plating layer, and a corrosion-resistant coating. The corrosion-resistant coating is obtained by applying and curing a corrosion-resistant paint. The formulation of the corrosion-resistant paint is as follows (by weight): 70-90 parts epoxy resin emulsion, 10-20 parts composite filler, 5-10 parts polytetrafluoroethylene emulsion, 3-5 parts curing agent, and 1-2 parts polydimethylsiloxane. The preparation method of the composite filler is as follows: S1-1: Place 20-30 parts of diatomaceous earth in 100 parts of sodium hydroxide solution, sonicate at 60-80℃ for 20-40 min, then wash with deionized water, and then dry in a vacuum drying oven for 6-8 h to obtain powder A; S1-2: Add 15-25 parts of powder A to 50-60 parts of deionized water and stir for 30 minutes. Then add 3-5 parts of ammonium molybdate and continue stirring for 2 hours. Remove the deionized water by rotary evaporation at 60°C, and then calcine in a muffle furnace to obtain powder B. S1-3: Add 10-20 parts of powder B to 30-40 parts of phytic acid solution, sonicate at 40-50℃ for 10 min, then stir at room temperature at 550-650 r / min for 1-2 h, wash with deionized water, and then freeze dry in a freeze dryer for 8-12 h to obtain powder C. S1-4: Mix powder C with glass flakes at a mass ratio of (1-2):1, place in a ball mill and ball mill for 40-60 minutes at a speed of 150 r / min, then add silane coupling agent KH570 and continue ball milling for 1-3 hours while maintaining the speed to obtain the composite filler.

2. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The preparation method of the corrosion-resistant coating is as follows: The epoxy resin emulsion, composite filler, and polytetrafluoroethylene emulsion are mixed according to the formula ratio and stirred at a speed of 700-800 r / min for 30-50 min. Then, polydimethylsiloxane is added and the stirring is continued at the same speed for 20 min. Finally, the curing agent is added and the mixture is stirred at a speed of 800-900 r / min for 5-10 min to obtain the corrosion-resistant coating.

3. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The curing agent is an amine-based curing agent.

4. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The concentration of sodium hydroxide solution in S1-1 is 0.2M.

5. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The roasting temperature in S1-2 is 600-800℃, and the roasting time is 1-2h.

6. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The phytic acid solution in S1-3 has a mass fraction of 10-20%.

7. The corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The amount of silane coupling agent KH570 added in S1-4 is 3% of the total weight of powder C and glass flakes.

8. A method for preparing a corrosion-resistant, highly conductive nickel-clad copper core as described in any one of claims 1 to 7, characterized in that, The specific steps of the preparation method are as follows: S8-1: Immerse the copper core in degreasing solution, sonicate at 60-80℃ for 5-15 min, wash the copper core with deionized water at 80-90℃, then acid wash in 0.2M hydrochloric acid solution for 5-15 s, wash with deionized water at 20-40℃, and then dry in a vacuum drying oven at 60℃ for 6-8 h to obtain the pretreated copper core; S8-2: Place the pretreated copper core in an electrolyte solution for electroplating. The electroplating temperature is 45–55℃, the electroplating time is 8–10 min, the voltage is 3–4V, and the current density is 1–2 A / dm³. 2 A nickel plating layer is obtained; S8-3: Apply a corrosion-resistant coating to the surface of the nickel plating layer and cure it at 75-85℃ for 1-2 hours to obtain the corrosion-resistant, highly conductive nickel-coated copper core.

9. The method for preparing a corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The degreasing solution in S8-1 consists of 20-30 g / L sodium carbonate, 40-60 g / L sodium phosphate, and 1-3 g / L sodium dodecyl sulfonate, with deionized water as the solvent.

10. The method for preparing a corrosion-resistant, highly conductive nickel-clad copper core according to claim 1, characterized in that, The electrolyte in S8-2 consists of 230–250 g / L nickel sulfate, 4–6 g / L sodium chloride, 20–30 g / L boric acid, and 5–10 g / L sodium citrate, with deionized water as the solvent.