High-corrosion-resistance porous nickel-carbon-based composite plating layer and electroplating solution

Abstract

The application provides a high-corrosion-resistance porous nickel-carbon-based composite coating and an electroplating solution, the electroplating solution comprising a porous nickel electroplating solution and a carbon-based electroplating solution, the porous nickel electroplating solution comprising a full-light nickel electroplating solution and a pore-forming agent; the pore-forming agent being selected from organic substances containing quaternary ammonium cations and halogen ions; and the carbon-based electroplating solution comprising nano-carbon materials and water. The coating and the electroplating solution provided by the application can efficiently introduce a double-element corrosion-resistant layer in a kitchen and bathroom workpiece coating. The process is easy to continuously industrialize, and the prepared workpiece has good corrosion resistance.

Description

Technical Field

[0001] This article relates to, but is not limited to, electroplated corrosion-resistant coatings, and particularly to, but is not limited to, a highly corrosion-resistant porous nickel-carbon composite coating and an electroplating solution. Background Technology

[0002] Kitchen and bathroom hardware products (such as faucets and showerheads) are used in humid and complex environments, thus requiring high corrosion resistance. Currently, the market mainly improves corrosion resistance through electroplated metal coatings (copper-semi-bright nickel-bright nickel-chromium). However, once the coating corrodes, the corrosion current concentrates on both the coating and the substrate, resulting in rapid corrosion. The presence of porous nickel effectively disperses the corrosion current, which is an important method to solve this problem.

[0003] Several methods have been developed for the preparation of porous nickel:

[0004] 1. As described in CN201710080912.8, a method and application of electroplating porous metal film by laser drilling template method is described. This method uses a laser to drill holes in a conductive substrate, fills the holes in the porous conductive substrate with insulating material, and uses the porous conductive substrate filled with insulating material as a template to electroplat a nickel film to obtain a porous nickel film.

[0005] 2. CN103243357A A method for preparing three-dimensional porous nickel films, wherein a three-dimensional porous nickel film is formed on a copper sheet by hydrogen bubble dynamic template electrodeposition.

[0006] 3. CN88102305.1 Porous nickel active cathode and its preparation method. The method uses a dealloying method to electroplate a nickel-zinc alloy coating on the surface of an iron substrate, and then dissolves the zinc in the nickel-zinc alloy coating to obtain a porous nickel layer. The method uses selective dissolution to obtain porous materials, and the dissolved components are easy to remain, resulting in impure composition of the obtained porous nickel material.

[0007] These methods have the following shortcomings:

[0008] (1) This method uses laser etching of porous conductive substrates, which is complex and expensive, and is not suitable for continuous production line production.

[0009] (2) Hydrogen bubble dynamic template electrodeposition method needs to be carried out under highly cathodic polarization conditions. It takes advantage of the severe hydrogen evolution reaction on the workpiece surface, making it difficult for the coating metal to be deposited at the bubble, thus forming a porous metal. However, this method has the disadvantage that the microstructure of the deposited layer is difficult to control.

[0010] (3) The dealloying method uses selective dissolution to obtain porous materials, but the dissolved components are easy to remain, and the resulting porous nickel materials are not pure. Summary of the Invention

[0011] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0012] This application proposes a method for preparing a porous nickel-carbon based composite coating on the surface of metal kitchen and bathroom products.

[0013] This application provides a highly corrosion-resistant porous nickel-carbon composite coating, wherein carbon material is filled into the pores of the porous nickel coating.

[0014] In one embodiment provided in this application, the average pore size of the porous nickel layer is 100 nm to 500 nm.

[0015] In one embodiment provided in this application, the carbon material is selected from any one or more of graphene oxide, graphite nanosheets, multi-walled carbon nanotubes, single-walled carbon nanotubes, graphitic carbon nitride, titanium carbide, titanium aluminum carbide, tantalum carbide, and niobium carbide.

[0016] In one embodiment of this application, the average number of pores in the porous nickel plating layer is 3,000 to 8,000 pores per square millimeter. In another embodiment of this application, electroplating in a carbon-based plating solution does not affect the pore size or the thickness of the porous nickel layer.

[0017] On the other hand, this application provides a workpiece coated with the above-mentioned highly corrosion-resistant porous nickel-carbon composite coating.

[0018] In one embodiment provided in this application, the thickness of the porous nickel layer is 15 μm to 20 μm.

[0019] On another aspect, this application provides an electroplating solution for a highly corrosion-resistant porous nickel-carbon composite coating, comprising a porous nickel electroplating solution and a carbon-based electroplating solution, wherein the porous nickel electroplating solution comprises a fully bright nickel electroplating solution and a pore-forming agent;

[0020] The pore-forming agent is selected from organic dyes (e.g., organic dyes containing quaternary ammonium cations and halide ions);

[0021] The carbon-based electroplating solution comprises nano-carbon materials and water.

[0022] In one embodiment provided in this application, the composition of the all-bright nickel plating solution may include: nickel sulfate 240 g / L to 300 g / L, nickel chloride 40 g / L to 55 g / L, boric acid 40 g / L to 50 g / L, 520 additive 5 mL / L to 15 mL / L, TRA nickel additive 3 mL / L to 5 mL / L, and the pH range of the all-bright nickel plating solution is 4.2 to 4.5.

[0023] In one embodiment provided in this application, the pore-forming agent is selected from any one or more of organic dyes containing phenazine rings, organic dyes containing thiazine rings, organic dyes containing oxazine rings, and triarylmethane dyes.

[0024] In one embodiment provided in this application, the pore-forming agent is selected from any one or more of diethylcarbosanodimethylaniline, diethylcarbosanodimethylphenol, carbosanodiphenol, basic lake blue, toluidine blue, Laureth violet, methylene green, Kerry blue, and Nile blue.

[0025] In one embodiment provided in this application, the ratio of the amount of bright nickel plating solution to the amount of pore-forming agent in the porous nickel plating solution is 0.0125g to 0.1g of pore-forming agent per liter of bright nickel plating solution.

[0026] In one embodiment provided in this application, the nano-carbon material is selected from any one or more of graphene oxide, graphite nanosheets, multi-walled carbon nanotubes, single-walled carbon nanotubes, graphitic carbon nitride, titanium carbide, titanium aluminum carbide, tantalum carbide, and niobium carbide.

[0027] In one embodiment provided in this application, the method for preparing the carbon-based electroplating solution includes weighing a certain amount of carbon-based nanomaterials and dispersing them in deionized water, ultrasonically dispersing them for 30 to 60 minutes, and then magnetically stirring them for 30 to 60 minutes to obtain a uniformly dispersed carbon-based electroplating solution.

[0028] In one embodiment provided in this application, the concentration of nano-carbon material in the carbon-based electroplating solution is 20 ppmw to 100 ppmw.

[0029] In another aspect, this application provides an electroplating method for a highly corrosion-resistant porous nickel-carbon composite coating, the electroplating method comprising:

[0030] Remove grease and dirt from the surface of the substrate to be electroplated to obtain a clean substrate;

[0031] Electroplating a porous nickel-carbon composite coating onto a clean substrate using the above-mentioned electroplating solution includes: first placing the clean substrate in the porous nickel electroplating solution for electroplating, and then electroplating it in the carbon-based electroplating solution.

[0032] In one embodiment provided in this application, the pretreatment of the metal substrate before plating is an electroplating cleaning line process, the purpose of which is to remove grease, dirt and other contaminants from the surface of the metal substrate.

[0033] In one embodiment of this application, a copper layer is pre-plated onto the clean substrate, followed by electroplating of porous nickel. Specifically, in one embodiment, the pre-treated metal workpiece is placed in an acidic copper plating solution for copper deposition. In one embodiment, the thickness of the pre-plated copper layer can be 15 μm to 20 μm. The electroplated copper may include two or more of a base copper layer, a copper pyrophosphate layer, and a copper sulfate layer. This process can refer to any of the copper plating methods in patent "CN201911282514.X A Color-Resistant Matte Black Chromium Composite Coating and Its Preparation Method". The beneficial effects of this application can also be obtained by directly electroplating a porous nickel-carbon-based composite coating on the substrate surface without pre-plating copper.

[0034] In one embodiment of this application, a decorative layer can be deposited on the surface of a highly corrosion-resistant porous nickel-carbon composite plating layer on the workpiece. In one embodiment of this application, the decorative layer can be deposited by methods such as electroplating or physical vapor deposition. In one embodiment of this application, the color of the decorative layer can be one of silver-white (trivalent white chromium), black (trivalent black chromium), or gold (TiN). In one embodiment of this application, the thickness of the decorative layer is 200 nm to 500 nm.

[0035] In one embodiment provided in this application, the electroplating process conditions in the porous nickel plating solution include: the clean substrate is the cathode, the nickel plate can be the anode, and the anode and cathode are placed parallel to each other; the current density is 5 A / dm³. 2 Up to 12A / dm 2 The electroplating time is 5 to 10 minutes, and the reaction temperature is 55°C to 65°C.

[0036] In one embodiment provided in this application, the electroplating process conditions in the carbon-based electroplating solution include: the substrate after electroplating in the porous nickel electroplating solution is the cathode, graphite can be the anode, and the cathode and anode are kept parallel to each other; the voltage is 3V to 8V; the electroplating time is 20min to 40min; and the reaction temperature can be room temperature.

[0037] In one embodiment provided in this application, the substrate is cleaned after the porous nickel layer is electroplated before subsequent operations are performed. The cleaning can be a common water washing method.

[0038] In one embodiment provided in this application, the substrate to be electroplated is a metal substrate.

[0039] In one embodiment provided in this application, the substrate to be electroplated is selected from any one or more of copper alloys, zinc alloys, and stainless steel.

[0040] In one embodiment provided in this application, the substrate to be electroplated is selected from any one or more of copper alloy (H59), zinc alloy (ZnAl4), and stainless steel (304).

[0041] The process flow incorporating the technical solution of this application can be summarized as follows: pre-plating treatment - copper plating - electroplating of a porous nickel-carbon composite corrosion-resistant layer - decorative layer. The conventionally used process flow can be summarized as: pre-plating treatment - copper plating - semi-bright nickel plating - bright nickel plating - decorative layer. The method provided in this application efficiently introduces a dual-element corrosion-resistant layer into the plating of kitchen and bathroom workpieces. This process is easy to scale up continuously for industrial application, and the prepared workpieces exhibit good corrosion resistance.

[0042] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application may be realized and obtained by means of the methods described in the description. Attached Figure Description

[0043] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0044] Figure 1A Image 1 shows the SEM image of the porous nickel plating layer on the surface of the workpiece after electroplating in a porous nickel plating solution in Example 1.

[0045] Figure 1B Image 2 shows the SEM image of the porous nickel plating layer on the surface of the workpiece after electroplating in a porous nickel plating solution in Example 1.

[0046] Figure 2A Figure 1 shows the SEM image of the coating on the surface of the workpiece after electroplating in a carbon-based electroplating solution in Example 1.

[0047] Figure 2B Image 2 shows the SEM image of the coating on the surface of the workpiece after electroplating in a carbon-based electroplating solution in Example 1.

[0048] Figure 3 This is a SEM image of the workpiece in Comparative Example 2 before electroplating in a carbon-based electroplating solution.

[0049] Figure 4 This is a SEM image of the workpiece in Comparative Example 2 after electroplating in a carbon-based electroplating solution. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application are described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0051] Example 1

[0052] The pretreated workpiece was placed in a porous nickel electroplating solution (nickel sulfate 280 g / L, nickel chloride 50 g / L, boric acid 45 g / L, 520 additive 6 mL / L, TRA nickel additive 4 mL / L, diethylsaffron azodimethylaniline 0.05 g / L, pH 4.5) and plated at 55°C with an electroplating rate of 8 A / dm³. 2 Electroplating at a current density for 5 minutes yielded a porous nickel coating (its SEM morphology is shown in Figure 1). Figure 1A and Figure 1B (As shown); then place the coating in a carbon-based nano-plating solution (20ppm graphene oxide dispersion) and maintain it at a constant voltage of 4V for 30 minutes; remove the workpiece and rinse it with deionized water for later use (its SEM morphology is shown). Figure 2A and Figure 2B As shown, from Figure 2B It can be seen that carbon materials do not change the original pore size and thickness of the porous nickel layer.

[0053] Example 2

[0054] The pretreated workpiece was placed in a porous nickel plating solution (nickel sulfate 280 g / L, nickel chloride 50 g / L, boric acid 45 g / L, 520 additive 6 mL / L, TRA nickel additive 4 mL / L, diethylsaffron azodimethylaniline 0.025 g / L, pH 4.5) and plated at 60°C with an electroplating rate of 8 A / dm³. 2 Electroplating at current density for 5 minutes yields a porous nickel coating; the coating is then placed in a carbon-based nanoplating solution (20ppm graphite nanosheet dispersion) and maintained at a constant voltage of 5V for 40 minutes; the workpiece is then removed and rinsed with deionized water for later use.

[0055] Example 3

[0056] The pretreated workpiece was placed in a porous nickel plating solution (nickel sulfate 280 g / L, nickel chloride 50 g / L, boric acid 45 g / L, 520 additive 6 mL / L, TRA nickel additive 4 mL / L, alkaline lake blue 0.1 g / L, pH 4.5) and plated at 60°C with a flux of 5 A / dm³. 2 Electroplating at current density for 10 minutes yields a porous nickel coating; the coating is then placed in a carbon-based nanoplating solution (50 ppm graphite-phase carbon nitride dispersion) and maintained at a constant voltage of 7V for 30 minutes; the workpiece is then removed and rinsed with deionized water for later use.

[0057] Example 4

[0058] The pretreated workpiece was placed in a porous nickel plating solution (nickel sulfate 280 g / L, nickel chloride 50 g / L, boric acid 45 g / L, 520 additive 6 mL / L, TRA nickel additive 4 mL / L, alkaline lake blue 0.05 g / L, pH 4.5) and plated at 65°C with a flux of 5 A / dm³. 2 Electroplating at current density for 8 minutes yields a porous nickel coating; the coating is then placed in a carbon-based nanoplating solution (50 ppm of a composite dispersion of graphitic carbon nitride and graphene oxide (mass ratio 1:1)) and kept at a constant voltage of 7V for 1 hour; the workpiece is then removed and rinsed with deionized water for later use.

[0059] Comparative Example 1

[0060] The only difference between this comparative example and Example 1 is that, after electroplating in the porous nickel plating solution, it is not electroplated in a carbon-based plating solution.

[0061] Comparative Example 2

[0062] The only difference between this comparative example and Example 1 is that electroplating is performed directly in a carbon-based electroplating solution, instead of a porous nickel plating solution. The SEM morphology of the workpiece after step S2 is as follows. Figure 3 As shown, the SEM morphology of the processed workpiece is as follows. Figure 4 As shown.

[0063] Comparative Example 3

[0064] The only difference between this comparative example and Example 1 is that, instead of using porous nickel plating solution and carbon-based plating solution, a fully bright nickel plating solution (the only difference between this and the porous nickel plating solution in Example 1 is that no pore-forming agent is added) is used for electroplating to obtain a nickel plating layer.

[0065] Test case

[0066] Examples 1 to 4 and Comparative Examples 1 to 3 were sequentially placed in a trivalent white chromium electroplating solution (KOME Kitchen & Bath Technology Co., Ltd.) (chromium chloride 25 g / L, sodium formate 50 g / L, boric acid 55 g / L, ammonium chloride 250 g / L, potassium bromide 10 g / L, sodium dodecyl sulfate 0.1 g / L), and plated at 55°C with a flux of 12 A / dm³. 2 Electroplating at current density for 1 minute yields a chromium plating layer approximately 300 nm thick. Finally, the workpiece is subjected to salt spray testing (CASS, ASS) to evaluate its corrosion resistance (according to Chinese national standard GB / T 10125-2021). Test results are evaluated every 12 hours, as detailed in Table 1.

[0067] The Vickers hardness test was performed on Examples 1 to 4 and Comparative Examples 1 to 3. The test method was as follows: the hardness of the coating was tested according to GB / T4340-2009 "Metallic Materials Vickers Hardness Test" standard, as detailed in Table 1.

[0068] The above Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to abrasion resistance tests. The test method was as follows: according to ASTM F3152-16; RCA abrasion tester (model 7-IBB, NORMAN paper tape, width 11 / 16"), a load of 175g was applied, and cyclic testing was carried out. The test was stopped when abrasion marks appeared on the sample surface. The test results were evaluated every 50 times. See Table 1 for details.

[0069] Table 1

[0070]

[0071]

[0072] As can be seen from the examples and comparative examples, the corrosion resistance, hardness and abrasion resistance of the examples are significantly higher than those of comparative examples 1 to 3.

Claims

1. A highly corrosion-resistant porous nickel-carbon composite coating, characterized in that, Carbon material fills the pores of the porous nickel layer; The carbon material is selected from any one or more of graphene oxide, graphite nanosheets, multi-walled carbon nanotubes, single-walled carbon nanotubes, graphitic carbon nitride, titanium carbide, titanium aluminum carbide, tantalum carbide, and niobium carbide. The coating is obtained by the following electroplating method: Remove grease and dirt from the surface of the substrate to be electroplated to obtain a clean substrate; Electroplating a porous nickel-carbon composite coating onto the surface of a clean substrate using an electroplating solution includes: first immersing the substrate in a porous nickel electroplating solution for electroplating, and then electroplating it in a carbon-based electroplating solution. The porous nickel plating solution includes a fully bright nickel plating solution and a pore-forming agent; The pore-forming agent is selected from organic dyes; The carbon-based electroplating solution comprises nano-carbon materials and water.

2. The coating according to claim 1, characterized in that, The average pore size of the porous nickel layer is 100 nm to 500 nm; The average pore density of the porous nickel layer is 3000 pores / mm². 2 Up to 8000 pieces / mm 2 .

3. The coating according to claim 1, characterized in that, The pore-forming agent is selected from any one or more of organic dyes containing phenazine rings, organic dyes containing thiazine rings, organic dyes containing oxazine rings, and triarylmethane dyes.

4. The coating according to claim 3, characterized in that, The pore-forming agent is selected from any one or more of diethylsaffron azodimethylaniline, diethylsaffron azodimethylphenol, saffron azophenol, basic lake blue, toluidine blue, Laureth violet, methylene green, Kerry blue, Nile blue, gentian violet, and malachite green.

5. The coating according to claim 1, characterized in that, The ratio of the amount of bright nickel plating solution to the amount of pore-forming agent in the porous nickel plating solution is from 0.0125g to 0.1g of pore-forming agent per liter of bright nickel plating solution.

6. The coating according to claim 1, characterized in that, The concentration of nano-carbon materials in the carbon-based electroplating solution is between 20 ppmw and 100 ppmw.

7. The coating according to any one of claims 3-5, characterized in that, The concentration of nano-carbon materials in the carbon-based electroplating solution is between 20 ppmw and 100 ppmw.

8. The coating according to claim 1, characterized in that, The electroplating process conditions in the porous nickel plating solution include: the clean substrate is the cathode, and the current density is 5 A / dm³. 2 Up to 12A / dm 2 The electroplating time is 5 to 10 minutes, and the reaction temperature is 55°C to 65°C.

9. The coating according to claim 1, characterized in that, The electroplating process conditions in the carbon-based electroplating solution include: the substrate after electroplating in the porous nickel electroplating solution is the cathode, the voltage is 3V to 8V, and the electroplating time is 20min to 40min.

10. The coating according to any one of claims 1 and 8-9, characterized in that, The substrate to be electroplated is a metal substrate.

11. The coating according to claim 10, characterized in that, The substrate to be electroplated is selected from any one or more of copper alloys, zinc alloys, and stainless steel.

12. The coating according to claim 11, characterized in that, The substrate to be electroplated is selected from any one or more of copper alloy H59, zinc alloy ZnAl4, and stainless steel 304.

13. A workpiece plated with the highly corrosion-resistant porous nickel-carbon composite coating as described in claim 1 or 2.

14. The workpiece according to claim 13, characterized in that, The thickness of the porous nickel layer is 15 μm to 20 μm.

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