CN108866605A - A kind of Zn-Ni-Al2O3Electroplate liquid, preparation method and application - Google Patents

Abstract

The invention discloses a Zn-Ni-Al ₂ O ₃ electroplating solution, a preparation method and an application thereof. The electroplating solution is composed of a main complexing agent, an auxiliary complexing agent, zinc sulfate, nickel sulfate, potassium carbonate, additives, Al ₂ O ₃ Nanoparticle suspension and water are prepared; the contents of each component in the electroplating solution are: main complexing agent 20-400g/L, auxiliary complexing agent 5-300g/L, zinc sulfate 10-300g/L, nickel sulfate 5 ～200g/L, potassium carbonate 10～500g/L, additive 0.1～20g/L, Al ₂ O ₃ nanoparticle suspension 1～100ml/L; the additive is prepared from ultrapure water. The invention optimizes the performance by screening and using the additives. The obtained coating has a bright appearance, is uniform and flat, is compact, has no pores and cracks, and has significantly improved corrosion resistance and wear resistance.

Description

A kind of Zn-Ni-Al2O3 electroplating solution, preparation method and application

technical field

The invention belongs to the technical field of electroplating Zn-Ni-Al ₂ O ₃ composite coatings, and relates to a Zn-Ni-Al ₂ O ₃ electroplating solution, a preparation method and an application.

Background technique

With the development of science and technology and modern industry, the quality requirements for protective coatings are getting higher and higher. Zinc-based alloy coating, as an anodic coating, can play a very good role in protecting the steel substrate and is widely used. At present, due to the advantages of high stability, good corrosion resistance, high hardness, and no pollution, Zn-Ni-Al ₂ O ₃ composite coatings are used as protective materials, and have great potential in automotive, aerospace, and electronic machinery products. Great application.

At present, the cyanide-free electrodeposition Zn-Ni-Al ₂ O ₃ composite coating technology has made great progress, but compared with the traditional cyanide Zn-Ni-Al ₂ O ₃ composite coating, there is still a certain gap in performance. Especially in the stability of the plating solution, the corrosion resistance of the coating and the bright appearance, its application is limited. Adding a certain amount of additives in the plating solution can obviously improve the performance of the plating solution and the coating, and the stability and corrosion resistance are all improved. Most of the existing additives can improve some aspects of the performance of the plating solution or coating, but at the same time cause the decline of other properties, and cannot take into account all properties at the same time. Therefore, the present invention provides an additive that simultaneously improves performance, can completely replace the traditional technology, and makes it have very important technical application value and far-reaching historical significance.

Contents of the invention

The invention mainly provides a Zn-Ni-Al ₂ O ₃ electroplating solution, a preparation method and an application. The plating solution is optimized through the screening and addition of additives, and the resulting plating solution has the characteristics of high current efficiency, high stability, and good dispersion. As a result, the composite coating with bright appearance, high hardness and good corrosion resistance has been obtained, which has been paid attention to in industrialization.

Concrete technical scheme of the present invention is:

A Zn-Ni-Al ₂ O ₃ electroplating solution prepared from a main complexing agent, an auxiliary complexing agent, zinc sulfate, nickel sulfate, potassium carbonate, additives, Al ₂ O ₃ nano particle suspension and water; electroplating The contents of each component in the liquid are: main complexing agent 20-400g/L, auxiliary complexing agent 5-300g/L, zinc sulfate 10-300g/L, nickel sulfate 5-200g/L, potassium carbonate 10-500g/L L, additive 0.1～20g/L, Al ₂ O ₃ nano particle suspension 1～100ml/L; said additive is alkyl hydrazide, 3-alkyl-2-cycloethylene, aminoacetamide, alkyl trimethyl ammonium bromide, adenine, guanine, cytosine, thymine, tetraethylenepentamine, saccharin, gum arabic, 3-methylquinoline, 2,3-dichloroquinoxaline, pyridine, cinnamon acetic acid, 5, 6-Dichloronicotinic acid, uric acid, ascorbic acid, sodium dodecylsulfonate, dodecylphenol, ammonium alkylsulfonate, alkyl glycoside, dialkyldiphenylamine, sulfurized calcium alkylphenate, alkylbenzene One or a mixture of calcium sulfonate, succinic acid, dimethylamine borane, and antimony trichloride. Due to the addition of additives, the wear resistance and corrosion resistance of the coating are improved, the appearance is bright, and the property of the coating is obviously improved. Among them, a small amount of additives can change the performance of the plating solution, so the concentration of additives should not be too high.

Further, the above-mentioned main complexing agent is one or a mixture of hydantoin or hydantoin derivatives.

Further, the above hydantoin derivatives are 3-hydroxymethyl-5,5-diphenylhydantoin, 5,5-diphenylhydantoin, 1,3-dichloro-5, 5-Diphenylhydantoin, 1-aminohydantoin, 5,5-dimethylhydantoin, 2-thiohydantoin, 1,3-dibromo-5,5- Dimethylhydantoin, 1,3-dimethylol-5,5-dimethylhydantoin or 2-thio-5,5-dimethylhydantoin.

Further, the above-mentioned auxiliary complexing agent is dimethylamine, ethylenediamine, triethanolamine, triethylenetetramine, tetraethylenepentamine, glycine, potassium tartrate, potassium sodium tartrate, sodium citrate, ammonium citrate, malic acid , polyethylene glycol, hydroxyethylidene diphosphonic acid, sodium pyrophosphate, potassium pyrophosphate, oxalic acid, urea, sodium formate, ammonium formate, sodium acetate, ammonium acetate, sodium sulfite, ammonium sulfite, potassium sulfite, sodium thiosulfate , One or two or more of thioureas.

The above-mentioned Zn-Ni _{- Al2O3} electroplating solution preparation method comprises the following steps:

Step ₁ , preparation of _Al2O3 nanoparticle suspension:

Add absolute ethanol to the aluminum sec-butoxide reagent, fully dissolve the reagent, perform magnetic stirring, slowly add ultrapure water, the molar ratio of the aluminum sec-butoxide reagent to ultrapure water is 0.01:1.24, and obtain solution A; Add 10-20ml of nitric acid solution with a mass concentration of 30% to liter solution A to make the pH value reach 3-5, and white precipitates will appear at this time; continue stirring at 60°C until all the precipitates are dissolved to obtain Al ₂ O ₃ nanoparticle suspension;

Step 2, Prepare Additive Solution

According to the target concentration of the additive in the electroplating solution, the raw material of the additive is prepared into a clarified solution with ultrapure water and then stored at a constant volume;

Step 3, configure the plating solution:

According to the target content of each component in the electroplating solution, first the main complexing agent is mixed with zinc sulfate and water to obtain No. 1 clarified solution; the auxiliary complexing agent is mixed with nickel sulfate and added with water to obtain No. 2 clarified solution; secondly, potassium carbonate and Al ₂ O ₃ nanoparticle suspensions were added to No. 1 and No. 2 solutions respectively and stirred; finally, after No. 1 and No. 2 solutions were clarified, the two solutions were mixed, and the additive solution prepared in step 2 was added and mixed evenly to obtain Zn-Ni-Al ₂ O ₃ electroplating solution.

The method for preparing a composite coating with the above Zn-Ni-Al ₂ O ₃ electroplating solution includes the following steps: the substrate is first degreased, pickled, rinsed with distilled water and ultrapure water; then directly put the substrate into the -In the plating tank of Al ₂ O ₃ electroplating solution, perform electroplating; after the electroplating is completed, take the sample out of the electroplating solution, wash the surface with ultrapure water, and dry it with cold air to obtain the coating; the current density during the electroplating process is 1～5A/ dm ² , the temperature of the plating solution is 20-60°C, the pH value is between 7-11, the distance between cathode and anode is 1-30cm, the stirring speed of the plating solution is 0-3000rpm, and the electroplating time is 10-120min.

Further, the above-mentioned substrate is a sheet or an iron sheet; the anode is a Pt sheet.

The beneficial effect of the invention is that one or more additives are used in the plating solution, which greatly changes the properties of the plating solution and the plating layer. When the Zn-Ni-Al ₂ O ₃ composite coating is electroplated, the electroplating process is stable, and the plating solution does not decompose, precipitate, or change color. And the additives play a synergistic role in the plating solution without doping. The crystallization of the coating is fine, flat and free of pores and cracks, and the brightness is improved. At the same time, the corrosion resistance and wear resistance are also greatly improved, further improving the feasibility of industrialization.

Description of drawings

Fig. 1 is the SEM figure obtained before and after adding the additive obtained in specific example 5; (a) before adding, (b) after adding.

Fig. 2 is the Tafel graph obtained before and after adding additives obtained in specific example 5.

Fig. 3 is the SEM figure obtained before and after adding the additive obtained in specific example 7; (a) before adding, (b) after adding.

Fig. 4 is the Tafel graph obtained before and after adding additives obtained in specific embodiment 7.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 15cm, bath temperature is 50°C, pH value is 8, current density is 4A/dm ² , stirring speed is 1100rpm, electroplating The time is 40 minutes.

Example 2:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 5cm, bath temperature is 30°C, pH value is 7, current density is 3A/dm ² , stirring speed is 700rpm, electroplating The time is 30 minutes.

Example 3:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 10cm, bath temperature is 45°C, pH value is 9, current density is 5A/dm ² , stirring speed is 800rpm, electroplating The time is 45 minutes.

Example 4:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 12cm, bath temperature is 40°C, pH value is 10, current density is 1A/dm ² , stirring speed is 900rpm, electroplating The time is 50 minutes.

Example 5:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 7cm, bath temperature is 30°C, pH value is 10, current density is 6A/dm ² , stirring speed is 900rpm, electroplating The time is 40 minutes.

Embodiment 6:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 6cm, bath temperature is 35°C, pH value is 11, current density is 6A/dm ² , stirring speed is 900rpm, electroplating The time is 30 minutes.

Embodiment 7:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 4cm, bath temperature is 45°C, pH value is 10, current density is 5A/dm ² , stirring speed is 1000rpm, electroplating The time is 55 minutes.

Embodiment 8:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 5cm, bath temperature is 55°C, pH value is 11, current density is 7A/dm ² , stirring speed is 900rpm, electroplating The time is 30 minutes.

Embodiment 9:

Electroplating process conditions: copper sheet is the cathode, Pt sheet is the anode, the distance between the cathode and the anode is 6cm, the temperature of the plating solution is 50°C, the pH value is 10, the current density is 8A/dm ² , the stirring speed is 1000rpm, the electroplating The time is 35 minutes.

Example 10:

Electroplating process conditions: copper sheet as cathode, Pt sheet as anode, distance between cathode and anode is 6cm, bath temperature is 50°C, pH value is 9, current density is 4A/dm ² , stirring speed is 1000rpm, electroplating The time is 30 minutes.

Example 11: The composition and concentration of the plating solution are the same as in Example 8, the iron sheet is the cathode, the Pt sheet is the anode, the distance between the cathode and the anode is 5cm, the temperature of the plating solution is 55°C, the pH value is 11, and the current density is 7A /dm ² , the stirring speed is 900rpm, and the electroplating time is 30min.

Embodiment 12: The composition and concentration of the plating solution are the same as in Example 9, the iron sheet is the cathode, the Pt sheet is the anode, the distance between the cathode and the anode is 6cm, the temperature of the plating solution is 50°C, the pH value is 10, and the current density is 8A /dm ² , the stirring speed is 1000rpm, and the electroplating time is 35min.

Example 13: The composition and concentration of the plating solution are the same as in Example 10, the iron sheet is the cathode, the Pt sheet is the anode, the distance between the cathode and the anode is 6cm, the temperature of the plating solution is 50°C, the pH value is 9, and the current density is 4A /dm ² , the stirring speed is 1000rpm, and the electroplating time is 30min.

The obtained coating has a bright appearance, is uniform and flat, is compact, has no pores and cracks, and has significantly improved corrosion resistance and wear resistance.

Claims (7)

1. a kind of Zn-Ni-Al₂O₃Electroplate liquid, which is characterized in that by main complexant, auxiliary complexing agent, zinc sulfate, nickel sulfate, carbon Sour potassium, additive, Al₂O₃Nano granule suspension and water are formulated；Each component content is respectively in electroplate liquid：Main complexant 20~400g/L, 5~300g/L of auxiliary complexing agent, 10~300g/L of zinc sulfate, 5~200g/L of nickel sulfate, potassium carbonate 10~ 500g/L, 0.1~20g/L of additive, Al₂O₃1~100ml/L of nano granule suspension；The additive is alkyl hydrazine, 3- Alkyl -2- cyclic ethylene, amino acetamide, alkyl trimethyl ammonium bromide, adenine, guanine, cytimidine, thymidine, tetrem Five amine of alkene, saccharin, gum arabic, 3- methylquinoline, 2,3- dichloro-quinoxaline, pyridine, cortex cinnamomi acetic acid, 5,6- dichloro-nicotinic acid, Uric acid, ascorbic acid, dodecyl sodium sulfate, dodecylphenol, alkyl sulfonic acid ammonium, alkyl glycosides, dialkyl diphenylamine, vulcanization One of alkyl phenol calcium, alkyl benzene calcium sulfonate, succinic acid, dimethyamine borane, antimony trichloride or two or more mixing Object.

2. electroplate liquid according to claim 1, which is characterized in that the main complexant is that hydantoins or hydantoins spread out One or more kinds of mixtures of biology.

3. electroplate liquid according to claim 2, which is characterized in that the hydantoin derivatives are 3- methylol -5,5- Diphenyl hydantoin, 5,5- diphenyl hydantoin, the chloro- 5,5- diphenyl hydantoin of 1,3- bis-, 1- amido glycolyurea, 5,5- dimethyl hydantoin, 2- thio-hydantoin, the bromo- 5,5- dimethyl hydantoin of 1,3- bis-, dihydroxymethyl -5 1,3-, 5- dimethyl hydantoin or the thio -5,5- dimethyl hydantoin of 2-.

4. electroplate liquid according to claim 1 or 2 or 3, which is characterized in that the auxiliary complexing agent is dimethylamine, second two Amine, triethanolamine, triethylene tetramine, tetraethylenepentamine, amion acetic acid, potassium tartrate, sodium potassium tartrate tetrahydrate, sodium citrate, lemon Sour ammonium, malic acid, polyethylene glycol, 1-hydroxy ethylidene-1,1-diphosphonic acid, sodium pyrophosphate, potassium pyrophosphate, oxalic acid, urea, sodium formate, formic acid One or both of ammonium, sodium acetate, ammonium acetate, sodium sulfite, ammonium sulfite, potassium sulfite, sodium thiosulfate, thiocarbamide with On.

5. any Zn-Ni-Al of Claims 1 to 4₂O₃Liquid and preparation method thereof is electroplated, which is characterized in that include the following steps：

Step 1, Al is prepared₂O₃Nano granule suspension：

Dehydrated alcohol is added in aluminium secondary butylate reagent, reagent is sufficiently dissolved, carries out magnetic agitation, is slowly added to ultrapure water, The molar ratio of aluminium secondary butylate reagent and ultrapure water is 0.01:1.24, obtain solution A；10-20ml matter is added into every liter of solution A The nitric acid solution that concentration is 30% is measured, so that pH value is reached 3-5, there is white precipitate generation at this time；Continue to stir at 60 DEG C, until All precipitatings dissolve to arrive Al₂O₃Nano granule suspension；

Step 2, additive solution is prepared

According to the aimed concn of additive in electroplate liquid, constant volume is protected after additive raw material is configured to clear solution with ultrapure water It deposits；

Step 3, electroplate liquid is configured：

According to the target content of ingredient each in electroplate liquid, add water to mix with zinc sulfate main complexant first, obtains No.1 clarification Solution；Auxiliary complexing agent adds water to mix with nickel sulfate, obtains No. two clear solutions；Secondly, by potassium carbonate and Al₂O₃Nano particle Suspension is added separately in No.1 and No. two solution and stirs；Finally, by two kinds of solution after No.1 and No. two solution clarifications Additive solution prepared by step 2 is added in mixing, is uniformly mixed, obtains Zn-Ni-Al₂O₃Electroplate liquid.

6. applying any Zn-Ni-Al of Claims 1 to 4₂O₃The method that electroplate liquid prepares composite deposite, including walk as follows Suddenly：Matrix carries out oil removing, pickling first, is rinsed with distilled water and ultrapure water；Then directly matrix is put into containing Zn- Ni-Al₂O₃In the coating bath of electroplate liquid, it is electroplated；After completing plating, sample is taken out from electroplate liquid, cleans table with ultrapure water Face, cold air drying obtain coating；It is characterized in that, current density is 1~5A/dm in electroplating process², bath temperature be 20~ 60 DEG C, for pH value between 7~11, anode cathode separation is 1~30cm, and plating solution mixing speed is 0~3000rpm, electroplating time For 10~120min.

7. according to the method described in claim 6, it is characterized in that, matrix is using piece or iron plate；Anode is Pt piece.