阅读说明：本技术 一种电镀工艺 (Electroplating process ) 是由 戴燕江 于 2021-07-28 设计创作，主要内容包括：本发明提出了一种电镀工艺,涉及电镀工艺技术领域。一种电镀工艺,包括前处理、活化、镀锌、镀镍、镀银和钝化步骤。本发明通过先在前处理步骤对工件超声清洗,除去工件表面的污渍,再用电解液除去表面的油污,使得工件表面干净,便于后续处理,可以保证在后续的电镀过程中,阳离子附着于工件表面结合牢固紧密。(The invention provides an electroplating process, and relates to the technical field of electroplating processes. An electroplating process comprises the steps of pretreatment, activation, zinc plating, nickel plating, silver plating and passivation. The invention removes stains on the surface of the workpiece by ultrasonic cleaning of the workpiece in the pretreatment step, and removes oil stains on the surface by using the electrolyte, so that the surface of the workpiece is clean, the subsequent treatment is convenient, and the cation can be ensured to be attached to the surface of the workpiece and firmly and tightly combined in the subsequent electroplating process.)

1. An electroplating process, comprising the steps of:

pretreatment: ultrasonically cleaning a workpiece, taking out, treating the workpiece in electrolyte, cleaning the workpiece with water, and drying the workpiece to obtain a pretreated workpiece;

and (3) activation: placing the pretreatment piece into HCl solution, treating at 25-35 ℃, washing with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activation treated piece in a first plating solution, stirring for 130-160s, cleaning with water, and drying to obtain a first plated piece;

nickel plating: placing the first plated part in a second plating solution, stirring for 70-90s, washing with water, and drying to obtain a second plated part;

silver plating: weighing silver nitrate, potassium cyanide and deionized water, mixing the potassium cyanide into the deionized water, stirring for dissolving, adding the silver nitrate, stirring for dissolving, performing stirring treatment for 150 seconds and 200 seconds, then cleaning with water, and drying to obtain a third plated part;

passivation: and passivating and drying the third plated part.

2. An electroplating process according to claim 1, wherein the ultrasonic cleaning in the pretreatment step is carried out by placing the workpiece in absolute ethyl alcohol for 15-20 min.

3. An electroplating process according to claim 1, wherein the workpiece removed in the pre-treatment step is placed in an electrolyte at a temperature of 55-75 ℃ and a current density of 4.5-9.5A/m²And (3) under the condition, after treating for 1-2min, cleaning with water and drying to obtain a pretreatment piece.

4. An electroplating process according to claim 1, wherein the electrolyte comprises 95-105g/L alkaline degreasing powder.

5. The electroplating process as claimed in claim 1, wherein the activating step comprises disposing the pre-treated part in 150-250ml/L HCl solution, treating at 25-35 deg.C for 5-10min, washing with water, and drying to obtain the activated part.

6. An electroplating process according to claim 1, wherein the galvanising step is carried out by subjecting the activated part to a first bath at a temperature of 60-70 ℃ and a current density of 2-4A/m²Under the condition, stirring at the speed of 50-200r/min for 130-160s, then washing with water and drying to obtain the first plating piece.

7. An electroplating process according to claim 1, wherein the pH of the first bath is from 10.2 to 10.7.

8. The electroplating process as claimed in claim 1, wherein the first plating solution of the galvanizing step contains zinc sulfate with a concentration of 50-80g/L and potassium sulfate with a concentration of 150-160 g/L.

9. An electroplating process according to claim 1, wherein the nickel plating step comprises placing the first plated part in a second plating solution at a temperature of 15-30 ℃ and a current density of 3-6.5A/m²Under the condition, stirring for 70-90s at the speed of 50-200r/min, then washing with water and drying to obtain a second plating piece; the second plating solution comprises nickel chloride with the concentration of 90-120g/L and H with the concentration of 15-25g/L₃BO₃。

10.An electroplating process according to claim 1, wherein the silver plating step is in particular according to (4-6): (6-8): weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and controlling the temperature to be 15-30 ℃ and the current density to be 0.7-1.5A/m²Under the condition, after stirring treatment is carried out for 150-200s at the speed of 50-200r/min, the third plating piece is obtained after being cleaned by water and dried.

Technical Field

The invention relates to the technical field of electroplating processes, in particular to an electroplating process.

Background

Electroplating is a process of plating a thin layer of other metals or alloys on the surface of some metals by using the principle of electrolysis, and is a process of attaching a layer of metal film on the surface of a metal or other material workpiece by using the action of electrolysis, thereby preventing the oxidation of the metals, improving the wear resistance, the conductivity, the light reflection performance, the corrosion resistance, the beauty and the like.

The plating performance is different from that of the base metal, and has new characteristics. The coating can be divided into protective coating, decorative coating and other functional coatings according to the functions of the coatings.

The product obtained by the existing electroplating process often has the condition of uneven coating thickness, so that the problem of poor quality of the workpiece in subsequent use is solved.

Disclosure of Invention

The invention aims to provide an electroplating process which has the advantage of uniform film coating.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The embodiment of the application provides an electroplating process, which comprises the following steps:

pretreatment: ultrasonically cleaning a workpiece, taking out, treating the workpiece in electrolyte, cleaning the workpiece with water, and drying the workpiece to obtain a pretreated workpiece;

and (3) activation: placing the pretreatment piece into HCl solution, treating at 25-35 ℃, washing with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activation treated piece in a first plating solution, stirring for 130-160s, cleaning with water, and drying to obtain a first plated piece;

nickel plating: placing the first plated part in a second plating solution, stirring for 70-90s, washing with water, and drying to obtain a second plated part;

silver plating: weighing silver nitrate, potassium cyanide and deionized water, mixing the potassium cyanide into the deionized water, stirring for dissolving, adding the silver nitrate, stirring for dissolving, performing stirring treatment for 150 seconds and 200 seconds, then cleaning with water, and drying to obtain a third plated part;

passivation: and passivating and drying the third plated part.

Compared with the prior art, the embodiment of the invention has at least the following advantages or beneficial effects:

according to the invention, the workpiece is ultrasonically cleaned in the pretreatment step to remove stains on the surface of the workpiece, and the electrolyte is used for removing oil stains on the surface, so that the surface of the workpiece is clean, the subsequent treatment is convenient, and the cation can be attached to the surface of the workpiece and firmly and tightly combined in the subsequent electroplating process; the surface of the pretreatment piece is further cleaned through an activation step, because the metal with high surface activity can be subjected to oxidation reaction in the air to form an oxide film when the pretreatment piece is exposed for a long time, the oxide layer on the surface and some impurities attached to the surface of the pretreatment piece can be removed under the treatment of HCl solution, so that the surface of the pretreatment piece is clean, the subsequent treatment is facilitated, and the condition that cations are attached to the surface of a workpiece and are firmly and tightly combined in the subsequent electroplating process can be ensured; in the step of galvanizing, the activation processing piece is placed in a first plating solution and is processed under the condition of stirring, the first plating solution can flow under the stirring, metal ions near a cathode cannot be reduced rapidly, a compact plating layer can be obtained, meanwhile, the defects of pockmarks and the like caused by hydrogen gas staying on the surface of the activation processing piece can be prevented, and after the reaction is carried out for 70-90s, a compact plating film can be formed on the surface of the activation processing piece, so that the surface oxidation of the activation processing piece can be prevented, the conductivity of the surface of the activation processing piece can be improved, and firmer combination can be obtained in the subsequent step of nickel plating; in the nickel plating step, the first plating piece is placed in the second plating solution, stirring treatment is carried out, high-pressure impact is formed, metal ions of a cathode are quickly supplemented, the upper limit of current density can be improved by three to five times, the uniformity of a plating layer is improved, the compactness of the plating layer is improved, and the first plating piece has better corrosion resistance and decorative effect after being plated with nickel on the surface; in the silver plating step, the third plated part can be polished easily by plating silver on the surface of the second plated part, so that the third plated part has strong light reflection capability and good heat conduction, electric conduction and welding performance.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to specific examples.

The invention provides an electroplating process which is characterized by comprising the following steps:

pretreatment: ultrasonically cleaning a workpiece, taking out, treating the workpiece in electrolyte, cleaning the workpiece with water, and drying the workpiece to obtain a pretreated workpiece;

and (3) activation: placing the pretreatment piece into HCl solution, treating at 25-35 ℃, washing with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activation treated piece in a first plating solution for treatment for 130-160s, then cleaning with water and drying to obtain a first plated piece;

nickel plating: placing the first plated part in a second plating solution for treatment for 70-90s, then washing with water and drying to obtain a second plated part;

silver plating: weighing silver nitrate, potassium cyanide and deionized water, mixing the potassium cyanide into the deionized water, stirring for dissolving, adding the silver nitrate, stirring for dissolving, performing stirring treatment for 150 seconds and 200 seconds, then cleaning with water, and drying to obtain a third plated part;

passivation: and passivating and drying the third plated part.

The workpiece is ultrasonically cleaned in the pretreatment step to remove stains on the surface of the workpiece, and only the electrolyte is used for removing oil stains on the surface, so that the surface of the workpiece is clean, the subsequent treatment is convenient, and the cation can be attached to the surface of the workpiece and firmly and tightly combined in the subsequent electroplating process; the surface of the pretreatment piece is further cleaned through an activation step, because the metal with high surface activity can be subjected to oxidation reaction in the air to form an oxide film when the pretreatment piece is exposed for a long time, the oxide layer on the surface and some impurities attached to the surface of the pretreatment piece can be removed under the treatment of HCl solution, so that the surface of the pretreatment piece is clean, the subsequent treatment is facilitated, and the condition that cations are attached to the surface of a workpiece and are firmly and tightly combined in the subsequent electroplating process can be ensured; in the step of galvanizing, the activation processing piece is placed in a first plating solution and is processed under the condition of stirring, the first plating solution can flow under the stirring, metal ions near a cathode cannot be reduced rapidly, a compact plating layer can be obtained, meanwhile, the defects of pockmarks and the like caused by hydrogen gas staying on the surface of the activation processing piece can be prevented, and after the reaction is carried out for 70-90s, a compact plating film can be formed on the surface of the activation processing piece, so that the surface oxidation of the activation processing piece can be prevented, the conductivity of the surface of the activation processing piece can be improved, and firmer combination can be obtained in the subsequent step of nickel plating; in the nickel plating step, the first plating piece is placed in the second plating solution, stirring treatment is carried out, high-pressure impact is formed, metal ions of a cathode are quickly supplemented, the upper limit of current density can be improved by three to five times, the uniformity of a plating layer is improved, the compactness of the plating layer is improved, and the first plating piece has better corrosion resistance and decorative effect after being plated with nickel on the surface; in the silver plating step, the third plated part can be polished easily by plating silver on the surface of the second plated part, so that the third plated part has strong light reflection capability and good heat conduction, electric conduction and welding performance. Therefore, the current electroplating technology adopts common mechanical stirring and compressed air stirring as the cathode, and tests prove that the stirring can not achieve the optimal effect because a vacuum layer of 0.5mm is formed by the deposition of metal ions on the surface of the cathode. At present, through experiments, high-voltage impact is formed on an electroplating product (cathode) in a tank cylinder by using tank liquor circulating equipment, and a cathode vacuum layer is broken, so that metal ions of the cathode are quickly supplemented, the upper limit of current density can be improved by three to five times, the uniformity of a coating is improved, and the compactness of the coating is improved.

In some embodiments of the present invention, the ultrasonic cleaning in the pretreatment step is to place the workpiece in absolute ethanol for ultrasonic cleaning for 15-20 min. Based on the solubility of absolute ethyl alcohol, the ultrasonic treatment is carried out in the absolute ethyl alcohol, so that stains on the surface of the workpiece can be oscillated and dissolved in the absolute ethyl alcohol.

In some embodiments of the present invention, the workpiece taken out in the pretreatment step is placed in an electrolyte at a temperature of 55-75 ℃ and a current density of 4.5-9.5A/m²And (3) under the condition, after treating for 1-2min, cleaning with water and drying to obtain a pretreatment piece. The pretreatment is carried out under the condition, so that the oil stains on the surface of the workpiece can be fully removed.

In some embodiments of the present invention, the electrolyte contains 95-105g/L alkaline degreasing powder.

In some embodiments of the present invention, the activating step is to put the pre-treated part into HCl solution with concentration of 150-250ml/L, treat the pre-treated part at 25-35 ℃ for 5-10min, clean the pre-treated part with water, and blow-dry the pre-treated part to obtain the activated treated part. Under the condition, the difficult dirt and oxide attached to the surface of the pretreatment piece can be separated and removed by HCl.

In some embodiments of the present invention, the zinc plating step is performed by placing the activated workpiece in a first plating solution at a temperature of 60-70 deg.C and a current density of 2-4A/m²Under the condition, stirring at the speed of 50-200r/min for 130-160s, then washing with water and drying to obtain the first plating piece. The galvanizing is carried out under the condition, so that the surface coating is uniform and firmly adhered, and the stirring is carried out at the speed, so that the metal ions near the cathode can be prevented from being rapidly reduced, a compact coating can be obtained, and the defects of pits and the like caused by the retention of hydrogen on the surface of an activation treatment member can be prevented.

In some embodiments of the present invention, the pH of the first plating solution is 10.2 to 10.7.

In some embodiments of the present invention, the first plating solution of the aforementioned zinc plating step contains zinc sulfate with a concentration of 50-80g/L and potassium sulfate with a concentration of 150-160 g/L.

In some embodiments of the present invention, the nickel plating step is to put the first plated part into the second plating solution at a temperature of 15-30 ℃ and a current density of 3-6.5A/m²Under the condition, stirring for 70-90s at the speed of 50-200r/min, then washing with water and drying to obtain a second plating piece; the second plating solution comprises nickel chloride with the concentration of 90-120g/L and H with the concentration of 15-25g/L₃BO₃. The nickel plating is carried out under the condition, so that the surface coating is uniform and firmly adhered, and the stirring treatment is carried out at the speed to form high-voltage impact, so that metal ions of the cathode are quickly supplemented, the upper limit of the current density can be improved by three to five times, the uniformity of the coating is improved, and the compactness of the coating is improved.

In some embodiments of the present invention, the silver plating step is performed according to (4-6): (6-8): weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, adding the silver nitrate, stirring for dissolving, and carrying out current flow at the temperature of 15-30 DEG CThe density is 0.7-1.5A/m²Under the condition, after stirring treatment is carried out for 150-200s at the speed of 50-200r/min, the third plating piece is obtained after being cleaned by water and dried. The silver plating operation is carried out under the condition, and a layer of silver can be uniformly plated on the surface of the second plated part, so that the plated part can be polished easily, and has strong light reflection capability, and good heat conduction, electric conduction and welding performances.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 15min, taking out, placing in electrolyte at 55 deg.C and current density of 4.5A/m²Under the condition, after the treatment is carried out for 1min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 95g/L of alkaline degreasing powder;

and (3) activation: placing the pretreatment piece into HCl solution with concentration of 150ml/L, treating for 5min at 25 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 60 deg.C and current density 2A/m²Under the condition, stirring for 130s at the speed of 50r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 50g/L and potassium sulfate with the concentration of 150 g/L;

nickel plating: placing the first plating piece in a second plating solution at 15 deg.C and current density of 3A/m²Under the condition, stirring for 70s at the speed of 50r/min, then washing with water and drying to obtain a second plating part, wherein the second plating solution comprises 90g/L nickel chloride and 15g/L H₃BO₃；

Silver plating step: according to the following steps of 4: 6: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 15 ℃ and the current density of 0.7A/m²Stirring at 50r/min for 150sThen, cleaning with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Example 2

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after the treatment is carried out for 1.5min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 3A/m²Under the condition, stirring for 145s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 65g/L and potassium sulfate with the concentration of 155 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Under the condition, stirring for 80s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 105g/L and H with the concentration of 20g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1A/m²Under the condition, stirring at the speed of 100r/min for 175s, then washing with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Example 3

An electroplating process comprising the steps of:

pretreatment: will be provided withUltrasonic cleaning the workpiece in anhydrous ethanol for 20min, taking out, placing in electrolyte at 75 deg.C with current density of 9.5A/m²Under the condition, after the treatment is carried out for 2min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 105g/L of alkaline degreasing powder;

and (3) activation: placing the pretreatment piece into HCl solution with the concentration of 250ml/L, treating for 10min at 35 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 70 deg.C and current density 4A/m²Under the condition, stirring for 160s at the speed of 200r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 80g/L and potassium sulfate with the concentration of 160 g/L;

nickel plating: placing the first plating piece in a second plating solution at 30 deg.C and current density of 6.5A/m²Under the condition, stirring for 90s at 200r/min, cleaning with water, and blow-drying to obtain a second plating solution, wherein the second plating solution comprises nickel chloride with the concentration of 120g/L and H with the concentration of 25g/L₃BO₃；

Silver plating step: according to the following steps of 6: 8: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 30 ℃ and the current density of 1.5A/m²Under the condition, stirring for 200s at the speed of 200r/min, then washing with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Example 4

This example is different from example 2 in that the current density is the maximum value.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 9.5A/m²Treating for 1.5min under the condition, cleaning with water, and blow-drying to obtain a pretreated part, wherein the pretreated part is preparedThe electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 4A/m²Under the condition, stirring for 145s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 65g/L and potassium sulfate with the concentration of 155 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 6.5A/m²Under the condition, stirring for 80s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 105g/L and H with the concentration of 20g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1.5A/m²Under the condition, stirring at the speed of 100r/min for 175s, then washing with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Example 5

This example is different from example 2 in that the concentrations of the first plating solution and the second plating solution are the minimum values.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after the treatment is carried out for 1.5min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 3A/m²Under the condition, stirring for 145s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating piece, wherein the first plating solution contains zinc sulfate with the concentration of 50g/L and potassium sulfate with the concentration of 150 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Under the condition, stirring for 80s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 90g/L and H with the concentration of 15g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1A/m²Under the condition, stirring at the speed of 100r/min for 175s, then washing with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Example 6

This example is different from example 2 in that the concentrations of the first plating solution and the second plating solution are maximum values.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after the treatment is carried out for 1.5min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density3A/m²Under the condition, stirring for 145s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating piece, wherein the first plating solution contains zinc sulfate with the concentration of 80g/L and potassium sulfate with the concentration of 160 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Under the condition, stirring for 80s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 120g/L and H with the concentration of 25g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1A/m²Under the condition, stirring at the speed of 100r/min for 175s, then washing with water and drying to obtain a third plated part;

passivation: and passivating the third plated part and drying.

Comparative example 1

This comparative example differs from example 2 in that: the plating time is less than the range value.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 10min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after treatment for 0.5min, cleaning with water and drying by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline degreasing powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 3A/m²Under the condition, stirring for 100s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 65g/L and potassium sulfate with the concentration of 155 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Under the condition, stirring for 50s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 105g/L and H with the concentration of 20g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1A/m²Under the condition, stirring for 100s at the speed of 100r/min, then washing with water and drying to obtain a third plating piece;

passivation: and passivating the third plated part and drying.

Comparative example 2

This comparative example differs from example 2 in that: the zinc and nickel plating steps were not stirred.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after the treatment is carried out for 1.5min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 3A/m²Under the condition, after standing for 145s, cleaning with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 65g/L and potassium sulfate with the concentration of 155 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Standing for 80s under the condition, cleaning with water, and blow-drying to obtain the second platingThe second plating solution comprises nickel chloride with the concentration of 105g/L and H with the concentration of 20g/L₃BO₃；

Silver plating step: according to the following steps: 7: weighing silver nitrate, potassium cyanide and deionized water according to the weight ratio of 1000, mixing the potassium cyanide into the deionized water, stirring for dissolving, then adding the silver nitrate, stirring for dissolving, and carrying out the processes of weighing the silver nitrate, the potassium cyanide and the deionized water at the temperature of 25 ℃ and the current density of 1A/m²Under the condition, stirring for 100s at the speed of 100r/min, then washing with water and drying to obtain a third plating piece;

passivation: and passivating the third plated part and drying.

Comparative example 3

This comparative example differs from example 2 in that: no silver plating step was performed.

An electroplating process comprising the steps of:

pretreatment: ultrasonic cleaning the workpiece in anhydrous ethanol for 18min, taking out, placing in electrolyte at 65 deg.C with current density of 7A/m²Under the condition, after the treatment is carried out for 1.5min, the workpiece is cleaned by water and dried by blowing to obtain a pretreatment piece, wherein the electrolyte contains 100g/L of alkaline oil removal powder;

and (3) activation: placing the pretreatment piece into an HCl solution with the concentration of 200ml/L, treating for 8min at 30 ℃, cleaning with water, and drying to obtain an activation treatment piece;

galvanizing: placing the activated part in a first plating solution at pH 10.2-10.7, temperature 65 deg.C and current density 3A/m²Under the condition, stirring for 145s at the speed of 150r/min, then washing with water and drying by blowing to obtain a first plating part, wherein the first plating solution contains zinc sulfate with the concentration of 65g/L and potassium sulfate with the concentration of 155 g/L;

nickel plating: placing the first plating piece in a second plating solution at 25 deg.C and current density of 4.8A/m²Under the condition, stirring for 80s at the speed of 150r/min, then washing with water and drying by blowing to obtain a second plating part, wherein the second plating solution comprises nickel chloride with the concentration of 105g/L and H with the concentration of 20g/L₃BO₃；

Passivation: and passivating the second plated part and drying.

Examples of the experiments

First, the condition of good coating

The plated articles having a size of 50mm × 50mm obtained in examples 1 to 6 and comparative examples 1 to 3 were examined, and the plating condition of the plated articles was examined by visual inspection and observation with a microscope.

According to detection, the plated parts prepared in examples 1-6 have no pinholes, peeling, bubbling, streaks, irregularities and shedding phenomena in appearance, complete and uniform coating coverage, sufficient brightness and qualified detection.

The plated article prepared in comparative example 1 had pinholes and pocks in appearance, and it can be seen that it was partially uncovered and that there were protrusions in part due to the short plating time, which resulted in the surface not being uniformly covered with the plating layer.

The plated article prepared in comparative example 2 apparently had unevenly distributed plating layers, pockmarks and pinholes, and was locally thick and locally thin, and it can be seen that metal ions in the vicinity of the cathode were drastically reduced, and hydrogen gas remained on the surface of the activated article to cause pockmarks, etc., because stirring was not performed during the galvanization and nickel plating.

The plated article prepared in comparative example 3 had a surface with uneven distribution of plating, pockmarks and pinholes, and had poor surface brightness, and it can be seen that the surface of the plated article was uneven and lacked brightness because the silver plating operation was not performed.

(II) corrosion resistance

The plated articles having a size of 50mm × 50mm obtained in examples 1 to 6 and comparative examples 1 to 2 were examined, subjected to a neutral salt spray test in an oven at 120 ℃ for 1 hour at a baking port, and subjected to continuous spraying for 288 hours to confirm the conditions of the plated articles, as shown in Table 1.

TABLE 1

From the conditions of table 1, it can be seen that the corrosion resistance of the plated articles prepared in examples 2 to 4 and 6 is the best, and in particular, in comparison, the plated article of example 2 is the best; the corrosion resistance of the plated articles of comparative examples 1 to 3 was poor.

In conclusion, the workpiece is ultrasonically cleaned in the pretreatment step to remove stains on the surface of the workpiece, and the electrolyte is used for removing oil stains on the surface, so that the surface of the workpiece is clean, the subsequent treatment is convenient, and the cation can be firmly and tightly attached to the surface of the workpiece in the subsequent electroplating process; the surface of the pretreatment piece is further cleaned through an activation step, because the metal with high surface activity can be subjected to oxidation reaction in the air to form an oxide film when the pretreatment piece is exposed for a long time, the oxide layer on the surface and some impurities attached to the surface of the pretreatment piece can be removed under the treatment of HCl solution, so that the surface of the pretreatment piece is clean, the subsequent treatment is facilitated, and the condition that cations are attached to the surface of a workpiece and are firmly and tightly combined in the subsequent electroplating process can be ensured; in the step of galvanizing, the activation processing piece is placed in a first plating solution and is processed under the condition of stirring, the first plating solution can flow under the stirring, metal ions near a cathode cannot be reduced rapidly, a compact plating layer can be obtained, meanwhile, the defects of pockmarks and the like caused by hydrogen gas staying on the surface of the activation processing piece can be prevented, and after the reaction is carried out for 70-90s, a compact plating film can be formed on the surface of the activation processing piece, so that the surface oxidation of the activation processing piece can be prevented, the conductivity of the surface of the activation processing piece can be improved, and firmer combination can be obtained in the subsequent step of nickel plating; in the nickel plating step, the first plating piece is placed in the second plating solution, stirring treatment is carried out, high-pressure impact is formed, metal ions of a cathode are quickly supplemented, the upper limit of current density can be improved by three to five times, the uniformity of a plating layer is improved, the compactness of the plating layer is improved, and the first plating piece has better corrosion resistance and decorative effect after being plated with nickel on the surface; in the silver plating step, the third plated part can be polished easily by plating silver on the surface of the second plated part, so that the third plated part has strong light reflection capability and good heat conduction, electric conduction and welding performances.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.