High-performance alkaline zinc-nickel alloy electroplating solution as well as preparation method and electroplating process thereof

Abstract

The invention belongs to the technical field of electroplating, and particularly relates to a high-performance alkaline zinc-nickel alloy electroplating solution and a preparation method and electroplating process thereof, and each liter of the electroplating solution comprises the following raw materials: 7-12g of zinc oxide, 1-2g of nickel sulfate, 120-140g of sodium hydroxide, 90-120g of a complexing agent, 10-18g of a nickel supplement, 1-3g of a brightener, 0.5-2g of a dispersing additive, 0.5-1g of a wetting agent and the balance of water. A plating layer obtained by the electroplating liquid and the electroplating process disclosed by the invention is high in nickel content, uniform and flat in plating layer distribution, excellent in corrosion resistance, simple and efficient in process and suitable for barrel plating and rack plating processes.

Description

Technical Field

[0001] The present invention belongs to the technical field of electroplating, and particularly relates to a high-performance alkaline zinc-nickel alloy electroplating solution, a preparation method thereof, and an electroplating process. Background Art

[0002] With the changes in application geographical conditions and requirements, traditional steel plating technologies such as phosphating, oxidation, and zinc plating can no longer meet the requirements for the protection performance of products in harsh environments. The protective performance of cyanide cadmium plating layer is better than that of cyanide zinc plating layer, but there are problems of cyanide pollution to the environment, and cadmium is highly toxic, which will cause harm to the human body and environmental pollution. Therefore, in order to find suitable coatings to replace zinc or cadmium, domestic and foreign researchers have developed zinc-nickel alloy through extensive exploration and research. The corrosion resistance of electroplated zinc-nickel alloy layer ranks first among all electroplated alloys. Under the same thickness, its anti-corrosion performance is 3-6 times that of zinc plating layer. The electroplating solution system of zinc-nickel alloy is mainly divided into two categories: acidic and alkaline. Compared with acidic plating solution, the zinc-nickel alloy coating formed in a wider current density range by alkaline plating solution is more delicate, has a higher degree of uniform composition ratio, stronger throwing power, and better corrosion resistance.

[0003] The invention patent with the publication number of CN112725852A discloses an alkaline zinc-nickel alloy electroplating solution, a preparation method thereof, and an electroplating process. In this invention, each liter of electroplating solution contains the following component raw materials: 10-20 g of zinc oxide, 120-150 g of sodium hydroxide, 15-40 g of nickel sulfate, 20-50 g of complexing agent, 8-15 g of brightener, and the balance is water; the complexing agent is at least one of triethanolamine, triethylenetetramine, potassium tartrate, sodium potassium tartrate, sodium citrate, and sodium acetate; the brightener is composed of a main brightener, a carrier, and an auxiliary brightener according to the mass ratio of (0.4-0.6):(0.2-0.3):(0.1-0.4); the main brightener is at least one of furfural, pyridine, imidazole, methylimidazole, and piperazine; the auxiliary brightener is at least one of polyethyleneimine quaternary ammonium salt, benzylpyridine carboxylate, and alkyl quaternary ammonium salt; the carrier includes polyoxyethylene ether sulfonate; this electroplating solution can be used for zinc-nickel alloy electroplating and has the advantage of good thermal stability. However, the complexing ability of the complexing agent used in this electroplating solution may be insufficient under alkaline conditions, and at the same time, there are problems of decreased uniformity and flatness of the coating due to the interaction between organic components and inorganic components. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present invention discloses a high-performance alkaline zinc-nickel alloy electroplating solution, a preparation method thereof, and an electroplating process. The coating obtained by the electroplating solution and electroplating process disclosed in the present invention has a high nickel content, uniform and flat coating distribution, excellent corrosion resistance, and is suitable for barrel plating and rack plating processes.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] In the first aspect of the present invention, a high-performance alkaline zinc-nickel alloy electroplating solution is provided. Each liter of the electroplating solution contains the following raw materials: 7-12 g of zinc oxide, 1-2 g of nickel sulfate, 120-140 g of sodium hydroxide, 90-120 g of complexing agent, 10-18 g of nickel supplement, 1-3 g of brightener, 0.5-2 g of dispersion additive, and 0.5-1 g of wetting agent, with the balance being water;

[0007] The complexing agent contains the following raw materials in parts by weight: 10-18 parts of modified aminocarboxylic acid complexing agent, 10-12 parts of second complexing agent, 10-15 parts of hydroxycarboxylic acid, and 5-18 parts of Tween 60.

[0008] In some embodiments of the present invention, the preparation steps of the modified aminocarboxylic acid complexing agent are as follows:

[0009] A1: Mix polyamine and deionized water, heat to 30-45 °C with stirring, then add epichlorohydrin, and heat to 55-60 °C, react for 1-3 h to obtain modified polyamine;

[0010] A2: Mix ethylene glycol diethyl ether diamine tetraacetic acid and glycidyl ether and add them to N,N-dimethylformamide, then add the modified polyamine obtained in step A1, add a catalyst and acetic anhydride, heat to 80-100 °C, react for 6-12 h, and after washing and drying, the modified aminocarboxylic acid complexing agent is obtained.

[0011] In some embodiments of the present invention, the preparation steps of the complexing agent are as follows:

[0012] Mix the modified aminocarboxylic acid complexing agent, the second complexing agent, hydroxycarboxylic acid, and Tween 60 to obtain the complexing agent.

[0013] Preferably, in step A1, the polyamine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0014] Preferably, in step A1, the mass ratio of the polyamine to epichlorohydrin is 1:(0.7-1.1).

[0015] Preferably, in step A2, the glycidyl ether is ethylene glycol diglycidyl ether and / or pentaerythritol tetraglycidyl ether.

[0016] Preferably, in step A2, the mass ratio of ethylene glycol diethyl ether diamine tetraacetic acid, glycidyl ether, and the modified polyamine obtained in step A1 is 1:(0.8-3):(1-5).

[0017] Preferably, the second complexing agent is sodium sulfite.

[0018] Preferably, the hydroxycarboxylic acid is at least one of citric acid, tartaric acid, and gluconic acid.

[0019] In the present invention, polyamine is modified by epichlorohydrin, and then the first complexing agent main body ethylene glycol diethylether diamine tetraacetic acid is modified together with glycidyl ether through chemical reaction to obtain a modified aminocarboxylic complexing agent. Then, the complexing agent is prepared by mixing with a second complexing agent obtained by mixing sodium sulfite and polyamine, a hydroxycarboxylic acid, and Tween 60. When it is added to this electroplating solution system as a complexing agent, compared with the complexing agent of the prior art, under the promotion of further increased polar active groups and polymer segments, the spatial ductility of the complexing agent is enhanced, and the density of functional groups is enhanced, thereby increasing its adsorption and complexing sites for metal ions; at the same time, it exhibits more excellent complexing performance under the synergistic effect of the second complexing agent; in addition, the addition of Tween 60 in the complexing agent not only further enhances its dispersion performance in the system, but the applicant also finds that metal ions in the electroplating solution tend to be more evenly distributed. This may be that when the modified aminocarboxylic complexing agent forms a stable complex with zinc-nickel metal ions in this electroplating solution system, Tween 60 synergistically plays a good adsorption role and weakens or even loses the activity of metal ions, while controlling or preventing certain possible side reactions in the electroplating solution, and assisting the complexing agent main body in the system to play a good role in stabilizing metal ions, further improving the stability and uniformity of the electroplating solution, and achieving an unexpected increase in the effect.

[0020] In some embodiments of the present invention, the nickel supplement is NI-3000 additive.

[0021] In some embodiments of the present invention, the brightener is a mixture of a main brightener, an auxiliary brightener, and a carrier.

[0022] In some embodiments of the present invention, the main brightener is at least one of piperazine, pyridine, or imidazole.

[0023] Preferably, the auxiliary brightener is a polyethyleneimine quaternary ammonium salt.

[0024] Preferably, the carrier is propargyl alcohol ethoxylate or fatty alcohol polyoxyethylene ether sulfonate.

[0025] Preferably, the mass ratio of the main brightener, the auxiliary brightener, and the carrier is 1:(0.1 - 0.3):(0.5 - 0.8).

[0026] In some embodiments of the present invention, the preparation steps of the dispersion additive are as follows:

[0027] (1) Mix a double-bond-containing epoxy group silane coupling agent and an allyl sulfonate, add them to absolute ethanol, then add an initiator, heat up to 80 - 90 °C, and react for 3 - 6 h to obtain an intermediate product;

[0028] (2) Mix polyethyleneimine with an organic solvent, then add the intermediate product from step (1), a chloroalkyl, and a catalyst, heat to 70 - 80 °C, stir and react for 1 - 3 h, then add sodium hydroxide and react for 4 - 7 h to obtain a dispersion additive.

[0029] Preferably, in step (1), the epoxy group - containing silane coupling agent with a double bond is N-(β - aminoethyl)-γ - aminopropylmethyldimethoxysilane.

[0030] Preferably, in step (1), the mass ratio of the epoxy group - containing silane coupling agent with a double bond to the allyl sulfonate is 1:(0.5 - 1).

[0031] In some embodiments of the present invention, in step (2), the mass ratio of the polyethyleneimine, the intermediate product, and the chloroalkyl is 1:(0.1 - 0.4):(0.03 - 0.06).

[0032] In the existing electroplating solutions, various additives are often added to improve the electroplating effect and ensure the quality of the coating. Aiming at the problems of poor leveling effect, insufficient dispersion ability of the additives, and possible poor compatibility with the main salt of the electroplating solution, the addition amount of the leveling agent or dispersant is often increased to activate the functions of each additive, improve the system compatibility, and then enhance the dispersion ability and covering ability of the electroplating solution. However, it may instead cause problems such as reduced coating brightness and stable nickel content distribution.

[0033] In the present invention, by further modifying polyethyleneimine, firstly, the dispersibility of polyethyleneimine itself in the electroplating solution system is improved; on the other hand, it may be that the remaining rich chelating groups form stable complexes with metal ions in the electroplating solution system, and then play a more efficient dispersion role, improving the uniformity and covering effect of the coating; on the other hand, the applicant also found that it may be that the modified polyethyleneimine and the complexing agent in the system play a good synergistic effect, inhibiting the deposition rate of the main salt in the system, avoiding its adverse effects on the flatness and brightness of the coating, ensuring the stable distribution of the brightness and nickel content in the coating, especially in the low - current area, and making the coating have excellent corrosion resistance.

[0034] In some embodiments of the present invention, the wetting agent is sodium dodecyl sulfate and / or cetyl diethanolamine polyoxyethylene ether.

[0035] On the other hand, the present invention provides a method for preparing the above - mentioned high - performance alkaline zinc - nickel alloy electroplating solution, which comprises the following steps:

[0036] While stirring, add sodium hydroxide to a part of water, then add zinc oxide and nickel sulfate, stir and mix, cool to room temperature, and then successively add a mixture of a complexing agent and a nickel supplement, a brightening agent, a dispersion additive, and a wetting agent, mix evenly, and then add the remaining water, stir and mix to obtain the electroplating solution.

[0037] On the other hand, the present invention also provides an electroplating process for an electroplating solution, comprising the following steps:

[0038] S1. Degrease, polish, and activate the workpiece to be plated to obtain a pretreated workpiece to be plated;

[0039] S2. Place the electroplating solution in a plating bath, place the pretreated workpiece to be plated therein, use the pretreated workpiece to be plated as the cathode, use a tin plate as the anode, and electroplate at a temperature of 20-40°C and a current density of 2-10 A / dm 2 for 5-20 minutes, take out and wash and dry to obtain.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The electroplating solution and electroplating process disclosed in the present invention have a high nickel content in the coating, the coating is evenly distributed and flat, and has excellent corrosion resistance, and is suitable for barrel plating and hanging plating processes.

[0042] 2. The present invention modifies polyamine with epichlorohydrin, and then modifies the main body of the first complexing agent, ethylene glycol diethyl ether diamine tetraacetic acid, together with glycidyl ether through a chemical reaction to obtain a modified aminocarboxylic acid complexing agent, and then mixes it with sodium sulfite and polyamine to obtain a second complexing agent, hydroxycarboxylic acid, and Tween 60 to prepare a complexing agent. When it is added to this electroplating solution system as a complexing agent, it exhibits more excellent complexing performance. The Tween 60 contained therein synergistically exerts a good adsorption effect and weakens or even loses the activity of metal ions. While controlling or preventing certain possible side reactions in the electroplating solution, it assists the main body of the complexing agent in the system to play a good role in stabilizing metal ions, further improving the stability and uniformity of the electroplating solution.

[0043] 2. The present invention further modifies polyethyleneimine. Firstly, it improves the dispersibility of polyethyleneimine itself in the electroplating solution system; on the other hand, it improves the uniformity and covering effect of the coating; on the other hand, the applicant also found that the modified polyethyleneimine and the complexing agent in the system play a good synergistic effect, inhibiting the deposition rate of the main salt in the system, avoiding its adverse effects on the flatness and brightness of the coating, ensuring the stable distribution of the light brightness and nickel content in the coating, especially in the low-current area, and making the coating have excellent corrosion resistance. Specific Embodiments

[0044] The present invention will be described below in conjunction with specific implementation embodiments. It should be noted that the following examples and comparative examples are only used to illustrate the present invention, and not to limit the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the gist or scope of the present invention.

[0045] For the convenience of those skilled in the art to implement the present invention, some of the raw materials and manufacturers in the following embodiments are described as follows.

[0046] Unless otherwise specified, the nickel supplement used in the following embodiments is NI-3000 additive; the brightener used is a main brightener piperazine, an auxiliary brightener polyethyleneimine quaternary ammonium salt (PNP, purchased from Wuhan Xingzhongcheng Technology Co., Ltd.), and a carrier propargyl alcohol ethoxylate, which are mixed in a mass ratio of 1:0.2:0.6; the wetting agent used is sodium dodecyl sulfate; the number average molecular weight of the polyethyleneimine used is 2500.

[0047] Preparation Example 1

[0048] The preparation steps of the dispersion additive are as follows:

[0049] (1) 1 g of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 0.7 g of allylsulfonic acid sodium are mixed and added to 10 mL of absolute ethanol, and then 0.03 g of ammonium persulfate is added. The temperature is raised to 85 °C and the reaction is carried out for 4 h to obtain an intermediate product;

[0050] (2) 10 g of polyethyleneimine and 30 mL of methanol are mixed, and then 2.5 g of the intermediate product, 0.45 g of 1-chlorobutane and 1 g of tetrabutylammonium bromide are added. The temperature is raised to 70-80 °C, and the reaction is stirred and the viscosity of the system is monitored. When the viscosity increases sharply, an isothermal 5 wt% aqueous sodium hydroxide solution is added until it dissolves, and the reaction is carried out for 5.5 h to obtain the dispersion additive.

[0051] Preparation Example 2

[0052] The preparation steps of the dispersion additive are the same as those of Preparation Example 1, except that the addition amount of allylsulfonic acid sodium in step (1) is 1.2 g.

[0053] Preparation Example 3

[0054] The preparation steps of the dispersion additive are the same as those of Preparation Example 1, except that the addition amount of the intermediate product in step (2) is 4.5 g.

[0055] Preparation Example 4

[0056] The preparation steps of the dispersion additive are the same as those of Preparation Example 1, except that the addition amount of 1-chlorobutane in step (2) is 0.7 g.

[0057] Preparation Example 5

[0058] The preparation steps of the modified aminocarboxylic complexing agent are as follows:

[0059] A1: Mix 5 g of diethylenetriamine and 20 mL of deionized water, heat up to 40 °C under stirring, then add 4.5 g of epichlorohydrin, heat up to 57 °C, and react for 2 h to obtain the modified polyamine.

[0060] A2: Mix 5 g of ethylene glycol diethyl ether diamine tetraacetic acid and 9.5 g of pentaerythritol tetraglycidyl ether, add them to 30 mL of N,N-dimethylformamide, then add 15 g of the modified polyamine obtained in step A1, add 2.5 g of pyridine and 5 g of acetic anhydride, heat up to 90 °C, and react for 9 h. After washing and drying, the modified aminocarboxylic complexing agent is obtained.

[0061] Preparation Example 6

[0062] The preparation method of the complexing agent, with the raw materials in parts by weight, includes the following steps:

[0063] Mix 14 parts of the modified aminocarboxylic complexing agent, 11 parts of the second complexing agent, 12.5 parts of citric acid and 9.8 parts of Tween 60 to obtain the complexing agent.

[0064] Among them, the modified aminocarboxylic complexing agent used in this preparation example is obtained from Preparation Example 5, and the second complexing agent is obtained by mixing sodium sulfite and triethylenetetramine in a mass ratio of 1.2:2.

[0065] Example 1

[0066] A high-performance alkaline zinc-nickel alloy electroplating solution, each liter of the electroplating solution contains the following raw materials: 10 g of zinc oxide, 1.5 g of nickel sulfate, 130 g of sodium hydroxide, 115 g of complexing agent, 15 g of nickel supplement, 2 g of brightener, 1 g of dispersion additive and 0.7 g of wetting agent, and the balance is water.

[0067] The preparation method of the high-performance alkaline zinc-nickel alloy electroplating solution in this example includes the following steps:

[0068] Under stirring, add sodium hydroxide to half of the water, then add zinc oxide and nickel sulfate, stir and mix, cool to room temperature, then sequentially add the mixture of the complexing agent and the nickel supplement, brightener, dispersion additive and wetting agent, mix evenly, and then add the remaining water, stir and mix to obtain the electroplating solution.

[0069] The dispersion additive used in this example is obtained from Preparation Example 1, and the complexing agent is obtained from Preparation Example 6.

[0070] Example 2

[0071] A high-performance alkaline zinc-nickel alloy electroplating solution comprises the following raw materials per liter of the electroplating solution: 7g zinc oxide, 1g nickel sulfate, 120g sodium hydroxide, 90g complexing agent, 10g nickel supplement, 1g brightener, 0.5g dispersing additive and 0.5g wetting agent, and the balance is water.

[0072] The method for preparing the high-performance alkaline zinc-nickel alloy electroplating solution in this embodiment has the same specific steps as in Example 1.

[0073] The dispersing additive used in this example is obtained from Preparation Example 1, and the complexing agent is obtained from Preparation Example 6.

[0074] Example 3

[0075] A high-performance alkaline zinc-nickel alloy electroplating solution comprises the following raw materials per liter of the electroplating solution: 12g of zinc oxide, 2g of nickel sulfate, 140g of sodium hydroxide, 120g of a complexing agent, 18g of a nickel supplement, 3g of a brightener, 2g of a dispersing additive and 1g of a wetting agent, with the balance being water.

[0076] The method for preparing the high-performance alkaline zinc-nickel alloy electroplating solution in this embodiment has the same specific steps as in Example 1.

[0077] The dispersing additive used in this example is obtained from Preparation Example 1, and the complexing agent is obtained from Preparation Example 6.

[0078] Example 4

[0079] A method for preparing a high-performance alkaline zinc-nickel alloy electroplating solution, the specific implementation method is the same as Example 1, the difference is that the dispersing additive used in this example is obtained from Preparation Example 2.

[0080] Example 5

[0081] A method for preparing a high-performance alkaline zinc-nickel alloy electroplating solution, the specific implementation method is the same as Example 1, the difference is that the dispersing additive used in this example is obtained from Preparation Example 3.

[0082] Example 6

[0083] A method for preparing a high-performance alkaline zinc-nickel alloy electroplating solution, the specific implementation method is the same as Example 1, the difference is that the dispersing additive used in this example is obtained from Preparation Example 4.

[0084] Example 7

[0085] A method for preparing a high-performance alkaline zinc-nickel alloy electroplating solution, the specific implementation method is the same as Example 1, the difference is that the dispersing additive used in this example is a commercially available polyethyleneimine alkyl compound (C16-PEI-PEG, purchased from Xi'an Qiyue Biotechnology Co., Ltd.).

[0086] Comparative Example 1

[0087] A preparation method of a high-performance alkaline zinc-nickel alloy electroplating solution, the specific implementation manner is the same as that of Example 1, the difference is that the complexing agent used in this example is triethylenetetramine.

[0088] Performance test:

[0089] The iron sheet (the size of the iron sheet is 10 cm × 8 cm × 0.3 mm) is degreased, polished, buffed, and activated to obtain a pre-treated workpiece to be plated; the electroplating solutions obtained in Examples 1-7 and Comparative Example 1 above are placed in a plating bath, and the pre-treated workpiece to be plated is placed therein. Using the pre-treated workpiece to be plated as the cathode and a tin plate as the anode, electroplating is carried out at a plating solution temperature of 30 °C and a current density of 6 A / dm 2 for 15 minutes, and after taking it out, cleaning and drying are carried out to obtain the coating, and the following performance tests are carried out on the coating. The specific test results are shown in Table 1:

[0090] 1. Corrosion resistance test:

[0091] The coating is subjected to a salt spray test in accordance with the neutral salt spray test standard for metallic coatings GB / T 10125-2012, and the time when red rust appears is recorded to characterize the corrosion resistance of the electroplating solution. The longer the time, the better the corrosion resistance.

[0092] 2. Coating thickness test:

[0093] On the plated workpiece, the first point is taken 1 cm from the left edge, and then points are taken every 2 cm in sequence, a total of three points are taken. The coating thickness at different points is measured using an XF-P3 coating thickness gauge of Xifan Instruments, and the ratio of the average value of the coating thickness at the three points to the thickness at the first point is the thickness dispersion. The larger the thickness dispersion value, the more uniform the coating and the higher the flatness of the coating;

[0094] 3. Nickel content test of the coating:

[0095] The nickel content of each plated workpiece is tested using an XDL-B type X-ray fluorescence thickness gauge.

[0096] The test results are shown in Table 1.

[0097] Table 1

[0098] Project Time / h Thickness dispersion / % Nickel content in coating / wt% Example 1 640 73.5 14.49 Example 2 636 72.2 14.38 Example 3 629 73.2 14.43 Example 4 620 71.7 14.17 Example 5 614 71.2 13.95 Example 6 609 70.4 13.13 Example 7 585 64.7 12.83 Comparative Example 1 637 68.3 13.31

[0099] From the comparison of the data in Examples 1-3 of Table 1, it can be seen that the nickel content of the coating obtained by the electroplating solution of the present invention is high, the distribution is uniform and flat, and it has high corrosion resistance; from the comparison of Example 4 and Example 1, it can be seen that when the addition amount of sodium allylsulfonate in step (1) is changed during the preparation of the dispersion additive, the dispersion ability of each component of the electroplating solution will decrease; from the comparison of Example 5 and Example 1, it can be seen that when the addition amount of the intermediate product in step (2) is changed during the preparation of the dispersion additive, the amphiphilicity of the dispersion additive decreases, resulting in a decrease in the corrosion resistance and the nickel content of the coating due to the decrease in the dispersion uniformity when the electroplating solution forms the coating; from the comparison of Example 6 and Example 1, it can be seen that when the addition amount of 1-chlorobutane in step (2) is changed during the preparation of the dispersion additive, the dispersion stability of the dispersion additive decreases, and then when the electroplating solution is used, affected by the dispersion effect of each component, the properties of the coating all decrease to varying degrees; from the comparison of Example 7 and Example 1, it can be seen that when a commercially available polyethyleneimine alkyl compound is used as the dispersion additive in this system, its compatibility is poor, thus affecting the effect; from the comparison of Comparative Example 1 and Example 1, it can be seen that when triethylenetetramine is used as the complexing agent in this system, the stability and uniformity of the electroplating solution are both affected, resulting in a decrease in the quality of the obtained coating.

[0100] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A high performance alkaline zinc-nickel alloy electroplating solution, characterized in that: Each liter of electroplating solution contains the following raw materials: 7-12g zinc oxide, 1-2g nickel sulfate, 120-140g sodium hydroxide, 90-120g complexing agent, 10-18g nickel supplement, 1-3g brightener, 0.5-2g dispersing additive and 0.5-1g wetting agent, and the balance is water; The complexing agent comprises the following raw materials in parts by weight: 10 to 18 parts of a modified aminocarboxylic complexing agent, 10 to 12 parts of a second complexing agent, 10 to 15 parts of hydroxycarboxylic acid and 5 to 18 parts of Tween 60.

2. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 1, characterized in that: The preparation steps of the modified aminocarboxyl complexing agent are as follows: A1: Mix the polyamine and deionized water, heat to 30-45°C while stirring, then add epichlorohydrin, heat to 55-60°C, and react for 1-3 hours to obtain the modified polyamine; A2: Mix ethylene glycol diethyl ether diamine tetraacetic acid and glycidyl ether and add them to N,N-dimethylformamide, then add the modified polyamine of step A1, add catalyst and acetic anhydride, heat to 80-100°C, react for 6-12h, wash and dry to obtain the modified aminocarboxylic complexing agent.

3. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 1, characterized in that: The second complexing agent is sodium sulfite.

4. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 1, characterized in that: The brightener is a mixture of a main brightener, an auxiliary brightener and a carrier.

5. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 4, characterized in that: The main brightener is at least one of piperazine, pyridine or imidazole.

6. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 1, characterized in that: The preparation steps of the dispersing additive are as follows: (1) Mixing a double-bond epoxy silane coupling agent and allyl sulfonate into anhydrous ethanol, then adding an initiator, heating to 80-90° C., and reacting for 3-6 hours to obtain an intermediate product; (2) Mix polyethyleneimine and an organic solvent, add the intermediate product of step (1), chloroalkyl and a catalyst, raise the temperature to 70-80° C., stir and react for 1-3 hours, then add sodium hydroxide and react for 4-7 hours to obtain a dispersing additive.

7. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 6, characterized in that: In step (2), the mass ratio of the polyethyleneimine, the modified epoxysilane coupling agent and the chloroalkyl is 1:(0.1-0.4):(0.03-0.06).

8. The high performance alkaline zinc-nickel alloy electroplating solution according to claim 1, characterized in that: The wetting agent is sodium lauryl sulfate and / or hexadecyl diethanolamine polyoxyethylene ether.

9. A method for preparing a high performance alkaline zinc-nickel alloy electroplating solution according to any one of claims 1 to 8, characterized in that: The following steps are involved: Add sodium hydroxide to part of the water under stirring, then add zinc oxide and nickel sulfate, stir and mix, cool to room temperature, then add a mixture of complexing agent and nickel supplement, brightener, dispersing additive and wetting agent in sequence, mix evenly, then add the remaining amount of water, stir and mix to obtain the electroplating solution.

10. An electroplating process comprising the electroplating solution according to any one of claims 1 to 8 or the electroplating solution obtained by the preparation method according to claim 9, characterized in that: The following steps are involved: S1, degreasing, grinding, polishing and activating the workpiece to be plated to obtain a pre-treated workpiece to be plated; S2. Place the electroplating solution in a plating tank, place the pre-treated workpiece in it, use the pre-treated workpiece as the cathode, and the tin plate as the anode. When the electroplating solution temperature is 20-40°C and the current density is 2-10A / dm 2 Electroplate for 5 to 20 minutes under the conditions, take out, clean and dry.