Electroplating solution for metal parts, method for preparing the same and process for electroplating metal parts

Abstract

The present application relates to the technical field of electroplating, and particularly relates to an electroplating solution for metal parts, a preparation method thereof and a metal part electroplating process, which comprises the following raw materials in parts by weight: zinc-containing reagent 8-16 parts, nano-silicon dioxide 3-7 parts, alumina microspheres 3-7 parts, sodium hydroxide 8-12 parts, complexing agent 8-16 parts, tank opening agent 4-8 parts, cobalt salt 8-12 parts, main brightener 1-3 parts, leveler 0.01-0.03 parts, wetting agent 1-5 parts and deionized water 60-80 parts. The electroplating solution has excellent corrosion resistance, hardness, wear resistance, bright appearance, water resistance, good walking performance and salt mist resistance after plating. In combination with the brightener and the complexing agent, the gloss of the plating layer is enhanced, and the adhesion between the plating layer and the plated part is also enhanced, so that the plating layer is not easy to fade and peel off, and the practicability is better.

Description

Technical Field

[0001] This invention relates to the field of electroplating technology, specifically to an electroplating solution for metal parts, its preparation method, and an electroplating process for metal parts. Background Technology

[0002] With the development of industrial technology, increasingly higher requirements are being placed on the surface performance of metal materials. Zinc-nickel alloy is a well-known protective coating that provides the metal substrate with excellent corrosion resistance, a bright appearance, and sufficient hardness. Currently, zinc alloy zippers in metal castings are produced through casting, which often results in a rough surface and poor, unattractive color. Therefore, a protective metal layer is typically electroplated onto the surface of the zinc alloy zipper.

[0003] Electroplated zinc-nickel alloys are developed based on electroplated zinc and possess more superior properties, such as excellent corrosion resistance, thermal stability, and low hydrogen embrittlement. Compared with zinc plating, corrosion resistance can be improved by more than three times, and its thermal stability, hardness, and wear resistance are significantly improved, while its hydrogen embrittlement is greatly reduced.

[0004] Because zippers have poor chemical stability and are easily dissolved by acids and alkalis, strong alkalis cannot be used for degreasing or strong acids for etching in electroplating processes. The electroplating solution must also be formulated to be close to neutral. Otherwise, it may dissolve in the solution and undergo a displacement reaction with metals with a more positive potential, thereby affecting the adhesion of the coating and contaminating the electroplating solution. Furthermore, the current electroplating process has a fast deposition rate, resulting in a weak adhesion between the coating and the workpiece. The coating is prone to peeling off, has poor wear resistance, and when the nickel content is too high, it is also toxic to the human body, affecting human health. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the existing technology, the present invention aims to provide an electroplating solution for metal parts. After plating, the electroplating solution has excellent anti-corrosion performance, hardness, wear resistance, bright appearance, water resistance, good positioning performance, and salt spray resistance. With the cooperation of brightener and complexing agent, the gloss of the coating is enhanced, and the adhesion between the coating and the plated part is strengthened. The coating is not easy to fade or peel off, and has better practicality.

[0006] Another objective of this invention is to provide a method for preparing an electroplating solution for metal parts. This method is simple, efficient, easy to operate and control, produces high-quality products, and is conducive to industrial production.

[0007] The purpose of this invention is to provide an electroplating process for metal parts. This electroplating process is simple, has strong quality control, high bonding strength between the plating film and the zipper, high color fastness, is suitable for existing production equipment, has high production efficiency, low production cost, and few pollutants.

[0008] The objective of this invention is achieved through the following technical solution: an electroplating solution for metal parts, comprising the following raw materials in parts by weight: 8-16 parts zinc-containing reagent, 3-7 parts nano-silica, 3-7 parts alumina microspheres, 8-12 parts sodium hydroxide, 8-16 parts complexing agent, 4-8 parts plating starter, 8-12 parts cobalt salt, 1-3 parts brightener, 0.01-0.03 parts initiator, 1-5 parts wetting agent, and 60-80 parts deionized water A.

[0009] The electroplating solution of this invention produces a coating with excellent corrosion resistance, hardness, wear resistance, bright appearance, water resistance, good flow properties, and salt spray resistance. With the help of brighteners and complexing agents, the gloss of the coating is enhanced, and the adhesion between the coating and the workpiece is strengthened. The coating is not easy to fade or peel off, and its practicality is improved. The addition of nano-SiO2 increases the degree of cathodic polarization and prevents the growth of Cu-Zn alloy grains, making the coating finer and denser, reducing the porosity of the deposited layer, and forming a particle-reinforced metal matrix composite coating, thereby improving the corrosion resistance of the coating. The uniformity of the thickness and the bonding force of the zinc-cobalt alloy coating obtained after the deposition of zinc reagent and cobalt salt improve the density of the zinc-cobalt alloy coating obtained by electroplating, and can also effectively solve the above-mentioned problems in the existing technology. The alumina microspheres used as wear-resistant and corrosion-resistant reinforcing materials, due to their hollow and porous nature, can effectively composite the metal layer inside the microspheres during the electroplating process, so that the microspheres and the metal coating form a whole, which can effectively improve the wear resistance of the coating.

[0010] Preferably, the alumina microspheres comprise the following raw materials in parts by weight: 1-3 parts polyacrylamide, 10-15 parts aluminum chloride, 6-10 parts γ-alumina powder, 20-40 parts anhydrous ethanol, 2-6 parts acetic acid, 20-40 parts 1,4-epoxybutane, and 20-30 parts deionized water.

[0011] The alumina microspheres were prepared by the following steps:

[0012] (1) According to the weight parts, aluminum chloride, γ-alumina powder and 1,4-epoxybutane are added to deionized water B and dissolved. Then polyacrylamide is added and stirred evenly to obtain mixture A for later use.

[0013] (2) Transfer mixture A to a sealed container and heat it to 150-170℃ for 4-8 hours. Cool, filter, wash and dry to obtain mixture B for later use.

[0014] (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 140-160℃ and react for 8-14h to obtain the reaction system for later use;

[0015] (4) The reaction system obtained in step (3) is washed with ethanol, heated to 500-700℃ and dried for 1-3 hours, and then cooled to obtain alumina microspheres.

[0016] The alumina microspheres in this invention are prepared using the above-mentioned raw materials and methods. The alumina microspheres prepared using the above-mentioned raw materials and methods have a special micro-nano structure. The mesoporous alumina microspheres formed are wear-resistant and corrosion-resistant reinforcing materials. Due to their hollow and porous nature, metal layers can be effectively incorporated into the interior of the microspheres during the electroplating process, so that the microspheres and the metal coating form a whole, which can effectively improve the wear resistance of the coating.

[0017] Preferably, the zinc-containing reagent is one or more of zinc oxide, zinc chloride, and zinc cyanide.

[0018] Preferably, the cobalt salt is one or more of cobalt sulfate hexahydrate, cobalt sulfate heptahydrate, cobalt chloride, cobalt acetate, or cobalt nitrate.

[0019] In this invention, zinc oxide and zinc chloride are used as zinc sources, and cobalt sulfate hexahydrate, cobalt sulfate heptahydrate, cobalt chloride, cobalt acetate, or cobalt nitrate are used as cobalt sources. In addition, specific complexing agent compositions and brighteners are added to reduce the deposition rate of cobalt and allow zinc, which has a more negative electrode potential, to be preferentially deposited. The resulting zinc-cobalt alloy coating can be uniformly deposited in both high and low current density regions, avoiding the coating thickness being significantly higher than that in low regions due to excessively rapid cobalt deposition in high regions, and also avoiding the phenomenon of easy burning in high regions.

[0020] Preferably, the complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 0.8-1.2:0.4-0.8:0.1-0.5.

[0021] The present invention prevents the decomposition of reduced cobalt, thus improving the stability of the cobalt layer formed using this electroplating solution. The complexing agent mainly complexes with zinc and cobalt ions, changing the polarization potential of zinc and cobalt ions, controlling the excessively rapid deposition of cobalt ions, improving the crystal structure of the coating, resulting in a uniform distribution of cobalt deposition on the product surface, and maintaining the alloy composition of the coating.

[0022] Preferably, the primary brightener is one or more of propynyl alcohol ethylene oxide ether, vinyl glycol propynyl alcohol ester, sodium propynyl oxyhydroxypropane sulfonate, pyridine monazine salt of hydroxypropane sulfonate, and epichlorohydrin; the primary brightener in this invention has a brightening effect, which can make the coating fuller and brighter, and the coating finer.

[0023] Preferably, the wetting agent is sodium dodecyl sulfate.

[0024] In this invention, by appropriately adding sodium dodecyl sulfate as a wetting agent, the alloy coating surface becomes smooth and bright. Sodium dodecyl sulfate can be adsorbed on the cathode surface, reducing the tension at the interface between the electrode and the plating solution, making it easier for bubbles to leave the electrode surface, and preventing pinholes in the coating.

[0025] Preferably, the initiating agent is a mixture of sodium 3-mercaptopropanesulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 0.8-1.2:0.6-1.0:0.1-0.5.

[0026] This invention specifies the composition and proportion of the initiating agent, exhibiting excellent depth-deepening and dispersing capabilities, improving the uniformity and gloss of the coating, and reducing the thickness of the intermediate and surface layers; this is achieved by controlling the amount of HSO3 present. - And OH in sodium hydroxide as a directing ion - Together, they increase the surface potential and enhance the electrostatic repulsion, which is beneficial for the dispersion of the plating solution, forming a stable protective film, enhancing corrosion resistance, and also complexing calcium and magnesium ions in water, reducing water hardness, thus making the coating surface brighter and smoother.

[0027] This invention also provides a method for preparing an electroplating solution for metal parts, which is obtained through the following steps:

[0028] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0029] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiator and wetting agent to the mixture A obtained in step 1), mix and stir continuously at a rate of 200-400 r / min until uniform to obtain electroplating solution.

[0030] The electroplating solution in this invention is prepared by the above method, and the electroplating solution prepared by the above method has excellent anti-corrosion properties, hardness, wear resistance, bright appearance, water resistance, good flow properties, and salt spray resistance. In step S2, the dissolution of sodium hydroxide is exothermic, so the solution temperature needs to be monitored and must not exceed 80°C to prevent sodium hydroxide from accumulating and agglomerating at the bottom of the tank.

[0031] This invention also provides an electroplating process for metal parts, comprising the following steps:

[0032] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0033] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0034] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0035] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0036] A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket filled with clean water and soak them for 30-150 seconds. Then remove the metal parts and blot them dry. Repeat the soaking, cleaning and drying process 2-6 times. Finally, clean with high-pressure water and dry to obtain the finished metal parts with colored non-ferrous metals.

[0037] Preferably, in step A4, the temperature of the electroplating solution is controlled at 25-30℃ and the current density is 2.0 A / dm³. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0038] The beneficial effects of the present invention are as follows: the electroplating solution of the present invention has excellent anti-corrosion performance, hardness, wear resistance, bright appearance, water resistance, good positioning performance, and salt spray resistance after coating. With the cooperation of brightener and complexing agent, the gloss of the coating is enhanced, and the adhesion between the coating and the plated part is enhanced. The coating is not easy to fade or peel off, and has better practicality.

[0039] The present invention provides a simple and efficient method for preparing an electroplating solution for metal parts, which is convenient to operate and control, produces high-quality products, and is conducive to industrial production. The electroplating process of metal parts using this solution is simple, the quality is highly controllable, the coating has high bonding strength with the zipper, and the color fastness is high. It is suitable for existing production equipment, with high production efficiency, low production cost, and few pollutants. Detailed Implementation

[0040] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0041] Example 1

[0042] An electroplating solution for metal parts comprises the following raw materials in parts by weight: 8 parts zinc reagent, 3 parts nano silica, 3 parts alumina microspheres, 8 parts sodium hydroxide, 8 parts complexing agent, 4 parts plating starter, 8 parts cobalt salt, 1 part brightener, 0.01 parts initiator, 1 part wetting agent, and 60 parts deionized water A.

[0043] The alumina microspheres comprise the following raw materials in parts by weight: 1 part polyacrylamide, 10 parts aluminum chloride, 6 parts γ-alumina powder, 20 parts anhydrous ethanol, 2 parts acetic acid, 20 parts 1,4-epoxybutane, and 20 parts deionized water B; the γ-alumina powder is γ-type alumina with CAS No.: 1344-28-1 provided by Qinghai Shengnuo Optoelectronic Technology Co., Ltd.

[0044] The alumina microspheres were prepared by the following steps:

[0045] (1) According to the weight parts, aluminum chloride, γ-alumina powder and 1,4-epoxybutane are added to deionized water B and dissolved. Then polyacrylamide is added and stirred evenly to obtain mixture A for later use.

[0046] (2) Transfer mixture A to a sealed container and heat it to 150°C for 4 hours. Then cool, filter, wash, and dry to obtain mixture B for later use.

[0047] (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 140℃ and react for 8 hours to obtain the reaction system for later use;

[0048] (4) The reaction system obtained in step (3) is washed with ethanol, heated to 500℃ and dried for 1 hour, and then cooled to obtain alumina microspheres.

[0049] The zinc-containing reagent is zinc oxide.

[0050] The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 0.8:0.4:0.1.

[0051] The starter is 1-benzyl-3-carboxypyridine chloride. The cobalt salt is cobalt sulfate hexahydrate.

[0052] The primary brightener is propynyl alcohol ethylene oxide ether. The wetting agent is sodium dodecyl sulfate.

[0053] The initiating agent is a mixture of sodium 3-mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 0.8:0.6:0.1. The sodium 3-mercaptopropane sulfonate used is sodium 3-mercaptopropane sulfonate of model number 17636-10-13-mercaptopropane sulfonate provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0054] The electroplating solution for the metal parts is prepared through the following steps:

[0055] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0056] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiating agent and wetting agent to the mixture A obtained in step 1), mix, and stir continuously at a rate of 200 r / min until uniform to obtain electroplating solution.

[0057] An electroplating process for metal parts includes the following steps:

[0058] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0059] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0060] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0061] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0062] A5. Cleaning: Place the metal parts after recovering the electroplating solution in the previous step into a bucket of clean water and soak for 30 seconds. Then take out the metal parts and dry them. Repeat the soaking, cleaning and drying process twice. Then clean with high pressure water and dry to obtain the finished metal parts with colored non-ferrous metals.

[0063] In step A4, the temperature of the electroplating solution is controlled at 25°C and the current density at 2.0 A / dm³ during electroplating. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0064] Example 2

[0065] An electroplating solution for metal parts comprises the following raw materials in parts by weight: 10 parts zinc-containing reagent, 4 parts nano-silica, 4 parts alumina microspheres, 9 parts sodium hydroxide, 10 parts complexing agent, 5 parts plating starter, 9 parts cobalt salt, 1.5 parts brightener, 0.01 parts initiator, 2 parts wetting agent, and 65 parts deionized water A.

[0066] The alumina microspheres comprise the following raw materials in parts by weight: 1.5 parts polyacrylamide, 11 parts aluminum chloride, 7 parts γ-alumina powder, 25 parts anhydrous ethanol, 3 parts acetic acid, 25 parts 1,4-epoxybutane, and 23 parts deionized water (B2). The γ-alumina powder is γ-type alumina with CAS No. 1344-28-1 provided by Qinghai Shengnuo Optoelectronic Technology Co., Ltd.

[0067] The alumina microspheres were prepared by the following steps:

[0068] (1) According to the weight parts, aluminum chloride, γ-alumina powder and 1,4-epoxybutane are added to deionized water B and dissolved. Then polyacrylamide is added and stirred evenly to obtain mixture A for later use.

[0069] (2) Transfer mixture A to a sealed container and heat it to 155°C for 5 hours. Then cool, filter, wash, and dry to obtain mixture B for later use.

[0070] (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 145℃ and react for 9 hours to obtain the reaction system for later use;

[0071] (4) The reaction system obtained in step (3) was washed with ethanol, heated to 550℃ and dried for 1.5h, and then cooled to obtain alumina microspheres.

[0072] The zinc-containing reagent is zinc chloride.

[0073] The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 0.9:0.5:0.2.

[0074] The starter is sodium allyl sulfonate. The cobalt salt is cobalt sulfate heptahydrate.

[0075] The primary brightener is vinyl glycol propargyl alcohol ester. The wetting agent is sodium dodecyl sulfate.

[0076] The initiating agent is a mixture of sodium 3-mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 0.9:0.7:0.2. The sodium 3-mercaptopropane sulfonate used is sodium 3-mercaptopropane sulfonate of model number 17636-10-13-mercaptopropane sulfonate provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0077] The electroplating solution for the metal parts is prepared through the following steps:

[0078] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0079] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiator and wetting agent to the mixture A obtained in step 1), mix and stir continuously at a rate of 250 r / min until uniform to obtain electroplating solution.

[0080] An electroplating process for metal parts includes the following steps:

[0081] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0082] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0083] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0084] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0085] A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket of clean water and soak them for 60 seconds. Then remove the metal parts and dry them. Repeat the soaking, cleaning and drying process 3 times. Then clean them with high-pressure water and dry them to obtain the finished metal parts with colored non-ferrous metals.

[0086] In step A4, the temperature of the electroplating solution is controlled at 26°C and the current density at 2.0 A / dm³ during electroplating. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0087] Example 3

[0088] An electroplating solution for metal parts comprises the following raw materials in parts by weight: 12 parts zinc-containing reagent, 5 parts nano-silica, 5 parts alumina microspheres, 10 parts sodium hydroxide, 12 parts complexing agent, 6 parts plating starter, 10 parts cobalt salt, 2 parts brightener, 0.02 parts initiator, 3 parts wetting agent, and 70 parts deionized water A.

[0089] The alumina microspheres comprise the following raw materials in parts by weight: 2 parts polyacrylamide, 12 parts aluminum chloride, 8 parts γ-alumina powder, 30 parts anhydrous ethanol, 4 parts acetic acid, 30 parts 1,4-epoxybutane, and 25 parts deionized water B; the γ-alumina powder is γ-type alumina with CAS No.: 1344-28-1 provided by Qinghai Shengnuo Optoelectronic Technology Co., Ltd.

[0090] The alumina microspheres were prepared by the following steps:

[0091] (1) According to the weight parts, aluminum chloride, γ-alumina powder and 1,4-epoxybutane are added to deionized water B and dissolved. Then polyacrylamide is added and stirred evenly to obtain mixture A for later use.

[0092] (2) Transfer mixture A to a sealed container and heat it to 160°C for 6 hours. Then cool, filter, wash, and dry to obtain mixture B for later use.

[0093] (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 150℃ and react for 10h to obtain the reaction system for later use;

[0094] (4) The reaction system obtained in step (3) was washed with ethanol, heated to 600℃ and dried for 2 hours, and then cooled to obtain alumina microspheres.

[0095] The zinc-containing reagent is a mixture of zinc oxide, zinc chloride and zinc cyanide in a weight ratio of 0.8:0.7:0.4.

[0096] The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 1.0:0.6:0.3.

[0097] The starter is a mixture of 1-benzyl-3-carboxypyridine chloride, dimethylpropynylamine, and cobalt sulfate in a weight ratio of 1.0:0.8:0.5.

[0098] The cobalt salt is a mixture of cobalt sulfate hexahydrate, cobalt sulfate heptahydrate, and cobalt nitrate in a weight ratio of 0.5:0.6:0.4.

[0099] The primary light-reflecting agent is a mixture of propynyl alcohol ethylene oxide ether, pyridine hydroxypropane sulfonate salt, and epichlorohydrin in a weight ratio of 0.6:0.4:0.7.

[0100] The wetting agent is sodium dodecyl sulfate.

[0101] The initiating agent is a mixture of sodium 3-mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 1.0:0.8:0.3. The sodium 3-mercaptopropane sulfonate used is sodium 3-mercaptopropane sulfonate of model number 17636-10-13-mercaptopropane sulfonate provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0102] The electroplating solution for the metal parts is prepared through the following steps:

[0103] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0104] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiator and wetting agent to the mixture A obtained in step 1), mix and stir continuously at a rate of 300 r / min until uniform to obtain electroplating solution.

[0105] An electroplating process for metal parts includes the following steps:

[0106] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0107] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0108] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0109] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0110] A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket of clean water and soak them for 90 seconds. Then remove the metal parts and dry them. Repeat the soaking, cleaning and drying process 4 times. Then clean them with high-pressure water and dry them to obtain the finished metal parts with colored non-ferrous metals.

[0111] In step A4, the temperature of the electroplating solution is controlled at 28°C and the current density at 2.0 A / dm³ during electroplating. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0112] Example 4

[0113] An electroplating solution for metal parts comprises the following raw materials in parts by weight: 14 parts zinc-containing reagent, 6 parts nano-silica, 6 parts alumina microspheres, 11 parts sodium hydroxide, 14 parts complexing agent, 7 parts plating starter, 11 parts cobalt salt, 2.5 parts brightener, 0.02 parts initiator, 4 parts wetting agent, and 75 parts deionized water A.

[0114] The alumina microspheres comprise the following raw materials in parts by weight: 2.5 parts polyacrylamide, 13 parts aluminum chloride, 9 parts γ-alumina powder, 35 parts anhydrous ethanol, 5 parts acetic acid, 35 parts 1,4-epoxybutane, and 28 parts deionized water (B2). The γ-alumina powder is γ-type alumina with CAS No. 1344-28-1 provided by Qinghai Shengnuo Optoelectronic Technology Co., Ltd.

[0115] The alumina microspheres were prepared by the following steps:

[0116] (5) According to the weight parts, add aluminum chloride, γ-alumina powder and 1,4-epoxybutane to deionized water B to dissolve, then add polyacrylamide and stir evenly to obtain mixture A for later use;

[0117] (6) Transfer mixture A to a sealed container and heat it to 165°C for 7 hours. Cool, filter, wash and dry to obtain mixture B for later use.

[0118] (7) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 155℃ and react for 12h to obtain the reaction system for later use;

[0119] (8) The reaction system obtained in step (3) was washed with ethanol, heated to 650℃ and dried for 2.5h, and then cooled to obtain alumina microspheres.

[0120] The zinc-containing reagent is zinc cyanide.

[0121] The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 1.1:0.7:0.4.

[0122] The starter agent is dimethylpropynylamine. The cobalt salt is cobalt acetate.

[0123] The primary brightener is propynyl alcohol ethylene oxide ether. The wetting agent is sodium dodecyl sulfate.

[0124] The initiating agent is a mixture of sodium 3-mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 1.1:0.9:0.4. The sodium 3-mercaptopropane sulfonate used is sodium 3-mercaptopropane sulfonate of model number 17636-10-13-mercaptopropane sulfonate provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0125] The electroplating solution for the metal parts is prepared through the following steps:

[0126] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0127] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiator and wetting agent to the mixture A obtained in step 1) and mix them. Stir continuously at a rate of 350 r / min until uniform to obtain the electroplating solution.

[0128] An electroplating process for metal parts includes the following steps:

[0129] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0130] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0131] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0132] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0133] A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket of clean water and soak them for 120 seconds. Then remove the metal parts and dry them. Repeat the soaking, cleaning and drying process 5 times. Then clean them with high-pressure water and dry them to obtain the finished metal parts with colored non-ferrous metals.

[0134] In step A4, the temperature of the electroplating solution is controlled at 29°C and the current density at 2.0 A / dm³ during electroplating. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0135] Example 5

[0136] An electroplating solution for metal parts comprises the following raw materials in parts by weight: 16 parts zinc-containing reagent, 7 parts nano-silica, 7 parts alumina microspheres, 12 parts sodium hydroxide, 16 parts complexing agent, 8 parts plating starter, 12 parts cobalt salt, 3 parts brightener, 0.03 parts initiator, 5 parts wetting agent, and 80 parts deionized water A.

[0137] The alumina microspheres comprise the following raw materials in parts by weight: 3 parts polyacrylamide, 15 parts aluminum chloride, 10 parts γ-alumina powder, 40 parts anhydrous ethanol, 6 parts acetic acid, 40 parts 1,4-epoxybutane, and 30 parts deionized water B; the γ-alumina powder is γ-type alumina with CAS No.: 1344-28-1 provided by Qinghai Shengnuo Optoelectronic Technology Co., Ltd.

[0138] The alumina microspheres were prepared by the following steps:

[0139] (1) According to the weight parts, aluminum chloride, γ-alumina powder and 1,4-epoxybutane are added to deionized water B and dissolved. Then polyacrylamide is added and stirred evenly to obtain mixture A for later use.

[0140] (2) Transfer mixture A to a sealed container and heat it to 170°C for 8 hours. Then cool, filter, wash, and dry to obtain mixture B for later use.

[0141] (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 160℃ and react for 14h to obtain the reaction system for later use;

[0142] (4) The reaction system obtained in step (3) was washed with ethanol, heated to 700℃ and dried for 3 hours, and then cooled to obtain alumina microspheres.

[0143] The zinc-containing reagent is zinc oxide.

[0144] The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 1.2:0.8:0.5.

[0145] The starter agent is dimethylpropynylamine. The cobalt salt is cobalt sulfate hexahydrate.

[0146] The primary brightener is propynyl alcohol ethylene oxide ether. The wetting agent is sodium dodecyl sulfate.

[0147] The initiating agent is a mixture of sodium 3-mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 1.2:1.0:0.5. The sodium 3-mercaptopropane sulfonate used is sodium 3-mercaptopropane sulfonate of model number 17636-10-13-mercaptopropane sulfonate provided by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0148] The electroplating solution for the metal parts is prepared through the following steps:

[0149] S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water A into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside.

[0150] S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiating agent and wetting agent to the mixture A obtained in step 1), mix, and stir continuously at a rate of 400 r / min until uniform to obtain electroplating solution.

[0151] An electroplating process for metal parts includes the following steps:

[0152] A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation.

[0153] A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal;

[0154] A3. Reprocessing: Deacidification, water washing, and then a second activation;

[0155] A4. Electroplating: Using the metal part as the cathode and graphite as the anode, electroplating is performed using the above-mentioned electroplating solution.

[0156] A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket of clean water and soak them for 150 seconds. Then remove the metal parts and dry them. Repeat the soaking, cleaning and drying process 6 times. Then clean them with high-pressure water and dry them to obtain the finished metal parts with colored non-ferrous metals.

[0157] In step A4, the temperature of the electroplating solution is controlled at 30℃ and the current density at 2.0 A / dm³ during electroplating. 2 Under these conditions, the ratio of anode to cathode area is 2:1.

[0158] Comparative Example 1

[0159] The difference between this comparative example and Example 3 above is that alumina microspheres were not added to the raw materials of the electroplating solution in this comparative example. The rest of the contents of this comparative example are the same as in Example 3, and will not be repeated here.

[0160] Comparative Example 2

[0161] The difference between this comparative example and Example 3 above is that no complexing agent or brightening agent was added to the raw materials of the electroplating solution in this comparative example. The rest of the contents of this comparative example are the same as in Example 3, and will not be repeated here.

[0162] The electroplating solutions prepared in Example 3 and Comparative Examples 1-2 were subjected to adhesion tests, bending adhesion tests, hot and cold adhesion tests, surface roughness tests, and phosphorus content tests.

[0163] Adhesion test: The 100-grid test is conducted using a sharp blade (blade angle 15-30°) on a test sample surface area ≥10mm². 2 Draw 10×10 small grids of 1mm×1mm in the test area (1mm spacing between lines, 11 horizontal and 11 vertical lines), each line should penetrate to the bottom layer of the coating; use a brush to clean the debris from the test area; use an adhesion strength of 350g / cm 2 -400g / cm 2 The tape (3M 600 or equivalent) is firmly adhered to the small network being tested, and the tape is vigorously rubbed with an eraser to increase the contact area and force between the tape and the test area. Hold one end of the tape and then suddenly pull the product perpendicular to the tape (for small parts, pull the tape perpendicular to the product) to quickly separate the product from the tape. Repeat the same test twice at the same location.

[0164] Wear resistance characterization: The microhardness of the coating was measured using an HXD-1000TM Vickers microhardness tester (load 120g, loading time 12s); a sand-like rubber (rubber model: LER902K) was used to apply different load weights, and the sample surface was rubbed back and forth for 1000 cycles at a speed of 60 times / minute and a stroke of about 20mm.

[0165] Corrosion resistance: Place the electroplated parts in a salt spray chamber and spray them with a 5% sodium hydroxide solution at 35°C for 2 hours. Then, take them out and place them in another constant temperature chamber at 40°C and 80% relative humidity. Observe the electroplated parts and record how long it takes for abnormalities to appear on the surface of the electroplated parts.

[0166] Salt spray resistance comparison: Salt spray resistance tests were conducted using a salt spray tester FR-1202-90 according to GB / T2423.18-2000 standard. The time the product endured salt spray was used to measure its salt spray resistance. The results are shown in Table 1.

[0167] Table 1

[0168] Example 5 ≥5 24.3 180 64 High gloss Comparative Example 1 ≥3，＜5 89.3 172 61 Average gloss Comparative Example 2 ≥2，＜4 74.1 158 43 matte finish

[0169] As can be seen from the data in the table, the cobalt plating layer obtained in Example 3 of the present invention has excellent adhesion, wear resistance, corrosion resistance and salt spray resistance, as well as surface gloss. Compared with similar products in China, the electroplating solution obtained by the present invention has superior performance in various aspects and has broad market prospects and application value.

[0170] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. An electroplating solution for metal parts, characterized in that: The raw materials include the following parts by weight: 8-16 parts zinc-containing reagent, 3-7 parts nano silica, 3-7 parts alumina microspheres, 8-12 parts sodium hydroxide, 8-16 parts complexing agent, 4-8 parts tank starter, 8-12 parts cobalt salt, 1-3 parts main brightener, 0.01-0.03 parts initiator, 1-5 parts wetting agent, and 60-80 parts deionized water; The alumina microspheres comprise the following raw materials in parts by weight: 1-3 parts polyacrylamide, 10-15 parts aluminum chloride, 6-10 parts alumina powder, 20-40 parts anhydrous ethanol, 2-6 parts acetic acid, 20-40 parts 1,4-epoxybutane, and 20-30 parts deionized water (B). The alumina microspheres were prepared by the following steps: (1) According to the weight parts, add aluminum chloride, Alumina powder and 1,4-epoxybutane were dissolved in deionized water B, then polyacrylamide was added and stirred until homogeneous to obtain mixture A, which was set aside. (2) Transfer mixture A to a sealed container and heat it to 150-170℃ for 4-8 hours. Cool, filter, wash and dry to obtain mixture B for later use. (3) Add anhydrous ethanol and acetic acid to mixture B according to the weight parts, heat to 140-160℃ and react for 8-14h to obtain the reaction system for later use; (4) Wash the reaction system obtained in step (3) with ethanol, heat to 500-700℃ and dry for 1-3 hours, and then cool to obtain alumina microspheres.

2. The electroplating solution for metal parts according to claim 1, characterized in that: The zinc-containing reagent is one or more of zinc oxide, zinc chloride, and zinc cyanide.

3. The electroplating solution for metal parts according to claim 1, characterized in that: The complexing agent is a mixture of ammonium chloride, ethanolamine and tartaric acid in a weight ratio of 0.8-1.2:0.4-0.8:0.1-0.

5.

4. The electroplating solution for metal parts according to claim 1, characterized in that: The starter is one or more of 1-benzyl-3-carboxypyridine chloride, sodium allyl sulfonate, dimethylpropynylamine, and cobalt sulfate.

5. The electroplating solution for metal parts according to claim 1, characterized in that: The cobalt salt is one or more of cobalt sulfate hexahydrate, cobalt sulfate heptahydrate, cobalt chloride, cobalt acetate, or cobalt nitrate.

6. The electroplating solution for metal parts according to claim 1, characterized in that: The primary light-reflecting agent is one or more of the following: propynyl alcohol ethylene oxide ether, vinyl glycol propynyl alcohol ester, sodium propynyl oxohydroxypropane sulfonate, pyridine monazine salt of hydroxypropane sulfonate, and epichlorohydrin.

7. The electroplating solution for metal parts according to claim 1, characterized in that: The wetting agent is sodium dodecyl sulfate.

8. The electroplating solution for metal parts according to claim 1, characterized in that: The initiating agent is made from A mixture consisting of sodium mercaptopropane sulfonate, sodium polydithiopropane sulfate, and polyethyleneimine in a weight ratio of 0.8-1.2:0.6-1.0:0.1-0.

5.

9. A method for preparing an electroplating solution for metal parts as described in any one of claims 1-8, characterized in that: It is prepared through the following steps: S1. According to the weight proportions, first add the zinc-containing reagent, nano-silica, alumina microspheres and deionized water into the reaction apparatus, then add the cobalt salt, stir evenly to obtain mixture A, and set aside. S2. According to the weight parts, add sodium hydroxide, complexing agent, plating starter, brightening agent, initiating agent and wetting agent to the mixture A obtained in step S1 and mix them. Stir continuously at a rate of 200-400 r / min until uniform to obtain the electroplating solution.

10. An electroplating process for metal parts, characterized in that: Includes the following steps: A1. Pretreatment: Degrease and wash the metal parts with water, and then perform the first activation. A2. Polishing: First polishing, then water washing and film removal, then a second polishing, then water washing and film removal; A3. Reprocessing: Deacidification, water washing, and then a second activation; A4. Electroplating: Using a metal part as the cathode and graphite as the anode, electroplating is performed using the electroplating solution described in any one of claims 1-8; A5. Cleaning: After recovering the electroplating solution in the previous step, place the metal parts in a bucket filled with clean water and soak them for 30-150 seconds. Then remove the metal parts and blot them dry. Repeat the soaking, cleaning and drying process 2-6 times. Finally, clean with high-pressure water and dry to obtain the finished metal parts with colored non-ferrous metals.