CN115466997A - Improved metal part surface electroplating processing method - Google Patents

Abstract

The invention discloses an improved metal piece surface electroplating processing method, and particularly relates to the technical field of electroplating, wherein a plating piece is subjected to electrolytic pickling and electrolytic activation, the electrolytic pickling peels off a peeled part on the surface of the plating piece, the surface of the plating piece is further in an activated state in an electrolytic activation mode, a protective layer is formed on the surface of the plating piece to enhance the adhesive force of an electroplated layer, the selected pickling and activation process has good effects of dissolving, inhibiting the surface layer of a titanium alloy plating piece and protecting activated titanium, an oxide film is difficult to rapidly generate on the surface of the plating piece, a pump body suction filtration mode is adopted to enable a plating solution to pass through a porous and multi-inner-cavity plating piece at a certain flow rate, the migration speed of ions is accelerated in an ultrasonic vibration mode, liquid ions are effectively diffused to the surface layer and the inner cavity of the plating piece, the concentration of cations in the inner cavity and the holes is close to the concentration of the cations outside the plating layer, and the purpose of uniform plating is achieved, and the plating quality of the plating piece is further improved.

Description

Improved metal part surface electroplating processing method

Technical Field

The invention relates to the technical field of electroplating, in particular to an improved metal piece surface electroplating processing method.

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 so as to prevent the metal from being oxidized (such as rust), improve the wear resistance, conductivity, light reflection property and corrosion resistance (such as copper sulfate) and enhance the appearance. The electroplating can enhance the corrosion resistance of the metal (the plating metal is mostly corrosion-resistant metal), increase the hardness, prevent abrasion, improve the conductivity, the smoothness, the heat resistance and the surface beauty.

At present, refractory metals such as titanium, tantalum, niobium and the like have good high-temperature strength, corrosion resistance and processing plasticity, and are industrially important high-temperature structural materials, in the application of a titanium alloy electroplating technology, the refractory metals are very active in property, and a layer of compact passive film is easily generated on the surfaces of the refractory metals in air and water, so that most of activation treatment process flows before titanium alloy electroplating comprise a sand blowing procedure, and for metal pieces containing cavities and holes, sand blowing treatment is difficult to operate and implement, so that liquid ions generated by the metal pieces are mainly diffused and transferred into bath solution in the electroplating process, the concentration of cations in the cavities and the holes is lower than that of the outside of a plating layer, the plating on the outer surface of the plating layer, the inner walls of the cavities and the holes is not uniform, and the plating quality of the plating piece is influenced, and therefore an improved metal piece surface electroplating processing method is needed to solve the problems.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides an improved metal part surface electroplating processing method, which aims to solve the technical problems that: the activation treatment process flow before the titanium alloy is electroplated mostly comprises a sand blowing process, and for metal pieces with inner cavities and holes, the sand blowing process is difficult to operate and implement, so that liquid ions generated by the metal pieces are mainly diffused and transferred into bath solution in the electroplating process, the concentration of cations in the inner cavities and the holes is lower than that of the outside of a plating layer, the plating on the outer surface of the plating layer and the inner walls of the inner cavities and the holes is uneven, and the plating quality of the plated pieces is influenced.

The purpose of the invention is as follows: the method comprises the steps of carrying out ultrasonic cleaning on a plated part to enable the surface of the plated part to be in a micro-corrosion state, carrying out electrolytic pickling and electrolytic activation, stripping off the stripped part of the surface of the plated part by the electrolytic pickling, further enabling the surface of the plated part to be in an activation state by an electrolytic activation mode, and forming a protective layer on the surface of the plated part, so that the adhesive force of an electroplated layer is enhanced, the selected pickling and activation process has good effects of dissolving, inhibiting corrosion and activating titanium alloy plated part surface and protecting activated titanium, so that an oxide film is difficult to rapidly generate on the surface of the plated part, and a pump body suction filtration mode is adopted, so that a plating solution passes through a porous and multi-cavity plated part at a certain flow rate, the migration speed of ions is accelerated by an ultrasonic vibration mode, liquid ions are effectively diffused into holes and cavities on the plated part, the concentrations of cations in the cavities and the holes are close to the concentrations of the cations outside the plated layer, the purpose of uniform plating is achieved, and the plating quality of the plated part is further improved.

In order to achieve the purpose, the invention provides the following technical scheme: an improved metal piece surface electroplating processing method comprises the following steps:

s1, base material surface pretreatment: the correct geometric shape and the normal structure of the metal of the plating part are exposed by the fine repair of a cutting machine tool or the grinding treatment of abrasive cloth and metallographic abrasive paper, and the surface roughness of the plating part after finishing is below 6 um.

S2, chemical oil removal: degreasing the plated piece by configuring a degreasing agent, placing the plated piece into a container containing the degreasing agent for ultrasonic degreasing, and heating the degreasing agent, wherein the temperature is controlled to be 70-75 ℃, and the degreasing time is controlled to be 30-40min.

S3, ultrasonic cleaning: and (3) carrying out countercurrent washing on the deoiled plated piece, then putting the washed plated piece into a washing tank with an ultrasonic generator for soaking, and then carrying out treatment in an ultrasonic cleaning mode after the plated piece is soaked.

S4, acid washing and activating: and drying the cleaned plated part, including washing and activating the holes on the plated part with acid washing solution and activating solution to strip the loose part of the plated part.

S5, chemical plating: and (3) drying the plated part after acid washing activation, performing chemical electroplating treatment after the preparation of a plating solution is completed, so that the plated part is a cathode, cations of preplated metal in the plating solution are deposited on the surface of the plated part, rinsing the electroplated finished product after the chemical electroplating process is completed, and drying.

As a further scheme of the invention: and in the S2, an ultrasonic generator is arranged in the container for containing the degreasing agent, the plating part is positioned in an electrolytic tank on the ultrasonic generator, the plating part is positioned between a positive electrode and a negative electrode in the electrolytic tank, and the ultrasonic frequency of the ultrasonic generator is 25-40kHz.

And in the S2, the current density of the anode and the cathode in the electrolytic cell is 5-20ASD, and the time is controlled to be 5-10min.

The preparation steps of the oil removing agent in the S2 are as follows:

firstly, 35g/L of sodium hydroxide, 30g/L of sodium carbonate, 30g/L of sodium phosphate, 5g/L of sodium silicate and 2g/L of sodium fluoride are selected to be mixed for 3-5min, the mixing temperature is controlled to be 35-50 ℃, and the mixing ratio of the sodium hydroxide, the sodium carbonate, the sodium phosphate, the sodium silicate and the sodium fluoride is as follows: 1.1.

As a further scheme of the invention: and the soaking time in the S3 is controlled to be 10-15min, the soaking temperature is 50-75 ℃, and the ultrasonic frequency is 20-30kHz.

As a further scheme of the invention: in the S4, the drying temperature is 80-100 ℃, the drying time is 3-8min, and the plated part is made of titanium alloy.

As a further scheme of the invention: in S4, the pickling solution is prepared by the following steps:

firstly, 20g/L hydrofluoric acid and 45g/L nitric acid are selected for mixing treatment, the mixing temperature is controlled to be 30-50 ℃, and the mixing ratio of the hydrofluoric acid to the nitric acid is 2.

As a further scheme of the invention: in S4, the preparation steps of the activating solution are as follows:

firstly, 400g/L of hydrochloric acid, 900g/L of sulfuric acid and 20g/L of corrosion inhibitor A are selected for mixing treatment, the mixing temperature is controlled to be 30-40 ℃, and the mixing ratio of the hydrochloric acid to the sulfuric acid to the corrosion inhibitor is 2.5: and 0.8, completing the preparation of the activating solution.

As a further scheme of the invention: the specific implementation steps of acid washing activation in the S4 are as follows:

s401, after drying the cleaned plating piece, firstly putting the plating piece into a pickling tank which is provided with pickling solution and is internally provided with an anode, putting the plating piece into a cathode, electrifying the pickling solution, controlling the temperature of electrolytic stripping of the pickling solution to be 20-30 ℃, controlling the current density to be 1-10ASD, and controlling the electrolytic pickling time to be 2-5min.

S402, placing the pickled plated piece into an activation tank filled with an activation solution, wherein the activation tank is also internally provided with an anode, the anode is a nickel plate, the plated piece is placed on a cathode, the activation solution is electrified, the temperature of the activation solution is 20-30 ℃, the current density is 1-10ASD, and the time of the electrolytic activation is controlled to be 10-20min.

As a further scheme of the invention: in the S5, the plating solution is prepared from 150g/L of nickel sulfate heptahydrate, 20g/L of boric acid, 85g/L of sulfate M and 5g/L of anode activating additive B.

As a further scheme of the invention: in S5, the specific implementation steps of the chemical plating are as follows:

s501, firstly, adjusting the pH value of the prepared plating solution to 5.2-5.5, and heating to 50-55 ℃.

S502, placing the plated part into an electroplating bath, wherein an electrified anode is arranged in the electroplating bath, the plated part is used as a cathode, the electrified current density is 0.5ASD, and the electroplating time is controlled to be 15-20min.

S503, simultaneously, a pump body suction filtration mode is adopted, so that the plating solution passes through the porous plating piece at a certain flow rate, the migration speed of ions is accelerated in an ultrasonic vibration mode, the flow rate of the plating solution is controlled at 35L/min, and the ultrasonic frequency is 18-25kHz.

S504, rinsing and drying the electroplated part, drying the electroplated part in a drying box at 70-90 ℃ for 20-30min, and finally completing the electroplating process to obtain a complete electroplating finished product.

The invention has the beneficial effects that: the method comprises the steps of carrying out ultrasonic cleaning on a plated part to enable the surface of the plated part to be in a micro-corrosion state, carrying out electrolytic pickling and electrolytic activation, stripping off the stripped part of the surface of the plated part by the electrolytic pickling, further enabling the surface of the plated part to be in an activation state by an electrolytic activation mode, and forming a protective layer on the surface of the plated part, so that the adhesive force of an electroplated layer is enhanced, the selected pickling and activation process has good effects of dissolving, inhibiting corrosion and activating titanium alloy plated part surface and protecting activated titanium, so that an oxide film is difficult to rapidly generate on the surface of the plated part, and a pump body suction filtration mode is adopted, so that a plating solution passes through a porous and multi-cavity plated part at a certain flow rate, the migration speed of ions is accelerated by an ultrasonic vibration mode, liquid ions are effectively diffused into holes and cavities on the plated part, the concentrations of cations in the cavities and the holes are close to the concentrations of the cations outside the plated layer, the purpose of uniform plating is achieved, and the plating quality of the plated part is further improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. 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.

An improved metal piece surface electroplating processing method comprises the following steps:

s1, base material surface pretreatment: the correct geometric shape and the normal structure of the metal of the plating part are exposed by the fine repair of a cutting machine tool or the grinding treatment of abrasive cloth and metallographic abrasive paper, and the surface roughness of the plating part after finishing is below 6 um.

S2, chemical oil removal: degreasing the plated piece by configuring a degreasing agent, placing the plated piece into a container containing the degreasing agent for ultrasonic degreasing, and heating the degreasing agent, wherein the temperature is controlled to be 70-75 ℃, and the degreasing time is controlled to be 30-40min.

S3, ultrasonic cleaning: and (3) carrying out countercurrent washing on the deoiled plated piece, then putting the washed plated piece into a washing tank with an ultrasonic generator for soaking, and then carrying out treatment in an ultrasonic cleaning mode after the plated piece is soaked.

S4, acid washing and activating: and drying the cleaned plated part, including washing each pore on the plated part, and then preparing a pickling solution and an activating solution to pickle and activate the plated part, so as to strip the loose part on the surface of the plated part.

S5, chemical plating: and (3) drying the plated part after acid washing activation, performing chemical electroplating treatment after the preparation of a plating solution is completed, so that the plated part is a cathode, cations of preplated metal in the plating solution are deposited on the surface of the plated part, rinsing the electroplated finished product after the chemical electroplating process is completed, and drying.

And S2, an ultrasonic generator is arranged in the container for containing the degreasing agent, the plating piece is positioned in an electrolytic tank on the ultrasonic generator, the plating piece is positioned between the anode and the cathode in the electrolytic tank, and the ultrasonic frequency of the ultrasonic generator is 25-40kHz.

And S2, electrifying the positive electrode and the negative electrode in the electrolytic cell at the current density of 5-20ASD for 5-10min.

The preparation steps of the oil removing agent in the S2 are as follows:

firstly, 35g/L of sodium hydroxide, 30g/L of sodium carbonate, 30g/L of sodium phosphate, 5g/L of sodium silicate and 2g/L of sodium fluoride are selected to be mixed for 3-5min, the mixing temperature is controlled to be 35-50 ℃, and the mixing ratio of the sodium hydroxide, the sodium carbonate, the sodium phosphate, the sodium silicate and the sodium fluoride is as follows: 1.1.

And S3, controlling the soaking time to be 10-15min, wherein the soaking temperature is 50-75 ℃, and the ultrasonic frequency is 20-30kHz.

And S4, drying at 80-100 ℃ for 3-8min, wherein the plated part is made of titanium alloy.

In S4, the pickling solution is prepared by the following steps:

firstly, 20g/L hydrofluoric acid and 45g/L nitric acid are selected for mixing treatment, the mixing temperature is controlled to be 30-50 ℃, and the mixing ratio of the hydrofluoric acid to the nitric acid is 2.

In S4, the preparation steps of the activating solution are as follows:

firstly, 400g/L of hydrochloric acid, 900g/L of sulfuric acid and 20g/L of corrosion inhibitor A are selected for mixing treatment, the mixing temperature is controlled to be 30-40 ℃, and the mixing ratio of the hydrochloric acid to the sulfuric acid to the corrosion inhibitor is 2.5: and 0.8, completing the preparation of the activating solution.

The specific implementation steps of acid washing activation in S4 are as follows:

s401, after drying the cleaned plated part, putting the plated part into a pickling tank which is provided with pickling solution after configuration, wherein an anode is arranged in the pickling tank, the plated part is arranged on a cathode, electrifying the pickling solution, the temperature for electrolyzing and removing the pickling solution is 20-30 ℃, the current density is 1-10ASD, and the time for electrolytic pickling is controlled to be 2-5min.

S402, placing the pickled plated piece into an activation tank filled with an activation solution, wherein the activation tank is also internally provided with an anode, the anode is a nickel plate, the plated piece is placed on a cathode, the activation solution is electrified, the temperature of the activation solution is 20-30 ℃, the current density is 1-10ASD, and the time of the electrolytic activation is controlled to be 10-20min.

In S5, the plating solution is prepared from 150g/L of nickel sulfate heptahydrate, 20g/L of boric acid, 85g/L of sulfate M and 5g/L of anode activation additive B.

In S5, the specific implementation steps of the chemical plating are as follows:

s501, firstly, adjusting the pH value of the prepared plating solution to 5.2-5.5, and heating to 50-55 ℃.

S502, placing the plated part into an electroplating bath, wherein an electrified anode is arranged in the electroplating bath, the plated part is used as a cathode, the electrified current density is 0.5ASD, and the electroplating time is controlled to be 15-20min.

S503, simultaneously, a pump body suction filtration mode is adopted, so that the plating solution passes through the porous plating piece at a certain flow rate, the migration speed of ions is accelerated in an ultrasonic vibration mode, the flow rate of the plating solution is controlled at 35L/min, and the ultrasonic frequency is 18-25kHz.

S504, rinsing and drying the electroplated part, drying the electroplated part in a drying box at 70-90 ℃ for 20-30min, and finally completing the electroplating process to obtain a complete electroplating finished product.

Example (b):

after the electroplating process was completed, the thickness of the nickel layer was measured to be about 5.3um using an XRF2000 coating thickness gauge.

Electroplating binding force: the nickel electroplating sample is placed in a constant temperature furnace at 300 ℃ for heat preservation for 1h by adopting a thermal shock test method, and is immediately placed in cold water after being taken out, so that the nickel plating layer has no phenomena of peeling, falling off and the like, which shows that the nickel plating layer is well combined with a titanium alloy plating piece, and indirectly shows that the selected acid washing and activating process has good effects of dissolving, inhibiting corrosion of the titanium alloy surface layer and protecting activated titanium, thereby ensuring that an oxide film is difficult to rapidly generate on the titanium alloy surface, and finally realizing nickel electroplating on the titanium alloy surface with higher activity.

Plating microhardness: the micro-hardness of the titanium alloy plating piece and the nickel plating layer is measured to be 310HV and 510HV respectively by using an HVS-100 digital micro-hardness meter with the loading force of 0.98N and the loading time of 10s, which shows that the micro-hardness of the titanium alloy after nickel electroplating is improved to about 1.6 times of the original micro-hardness, and the scratch resistance of the titanium alloy is obviously enhanced.

Wear resistance of the plating layer: the friction factor and the abrasion loss of a titanium alloy plated part and a coating under a dry friction condition are measured by adopting an MDW-02 mechanical reciprocating friction abrasion tester, the load is 25N, the frequency is 3Hz, the time is 60min, and a mating part is a GCrl5 bearing steel ball with the diameter of 6.35mm, and the specific table is as follows:

(1) The friction factor of the titanium alloy plated part changes along with the abrasion time:

time of wear/min	10	20	30	40	50	60
							Friction factor mu	0.3	0.36	0.38	0.37	0.38	0.39

(2) Change of plating layer friction factor with wear time:

time of wear/min	10	20	30	40	50	60
							Friction factor mu	0.18	0.2	0.22	0.23	0.19	0.2

From the above table, it can be seen that:

under the specified dry friction condition, the friction factor of the titanium alloy plated part is initially low, and is gradually stable in the later period, mainly because the titanium alloy needs to be dried after being washed and activated to prevent the titanium alloy from corroding a friction tester, a layer of thin oxide film is formed on the surface of the titanium alloy due to short-time air contact, the oxide film is mainly abraded in the early period of the friction test, the friction factor is relatively low, the measurement of the friction factor of the titanium alloy substrate in the early period of abrasion is influenced, the abrasion loss of the titanium alloy substrate is also influenced to a certain extent, after the friction test is stable, namely after a matching part is contacted with the titanium alloy plated part, the friction factor of the titanium alloy plated part is about 0.38, and the abrasion loss after 60min is 8.4mg.

The friction factor of the nickel coating is stable and is always kept at about 0.2, the abrasion loss after 60min is 1.0mg, the nickel coating is not completely abraded, and the measured friction factor and abrasion loss belong to the nickel coating.

The friction factor and the abrasion loss of the nickel-plated sample are respectively 53.8% and 13.2% of that of the titanium alloy plated part, so that after the titanium alloy is plated with nickel, the abrasion resistance of the surface of the titanium alloy is obviously improved by the antifriction effect of the nickel plating layer, and the sliding and abrasion resistance of the titanium alloy product in the transferring and assembling processes is improved.

In conclusion, the following results are obtained:

the method comprises the steps of carrying out ultrasonic cleaning on a plated part to enable the surface of the plated part to be in a micro-corrosion state, carrying out electrolytic pickling and electrolytic activation, stripping off the stripped part of the surface of the plated part by the electrolytic pickling, further enabling the surface of the plated part to be in an activation state by an electrolytic activation mode, and forming a protective layer on the surface of the plated part, so that the adhesive force of an electroplated layer is enhanced, the selected pickling and activation process has good effects of dissolving, inhibiting corrosion and activating titanium alloy plated part surface and protecting activated titanium, so that an oxide film is difficult to rapidly generate on the surface of the plated part, and a pump body suction filtration mode is adopted, so that a plating solution passes through a porous and multi-cavity plated part at a certain flow rate, the migration speed of ions is accelerated by an ultrasonic vibration mode, liquid ions are effectively diffused into holes and cavities on the plated part, the concentrations of cations in the cavities and the holes are close to the concentrations of the cations outside the plated layer, the purpose of uniform plating is achieved, and the plating quality of the plated part is further improved.

The points to be finally explained are: although the present invention has been described in detail with reference to the general description and the specific embodiments, on the basis of the present invention, the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (8)

1. An improved metal piece surface electroplating processing method is characterized by comprising the following steps:

s1, base material surface pretreatment: the accurate geometric shape and the normal structure of the metal of the plating part are exposed by the fine repair of a cutting machine tool or the polishing treatment of abrasive cloth and metallographic abrasive paper, and the surface roughness of the plating part after the finishing is below 6 um;

s2, chemical degreasing: degreasing a plated piece by configuring a degreasing agent, placing the plated piece into a container containing the degreasing agent for ultrasonic degreasing, heating the degreasing agent, controlling the temperature to be 70-75 ℃ and the degreasing time to be 30-40min;

s3, ultrasonic cleaning: carrying out countercurrent washing on the deoiled plated piece, then putting the washed plated piece into a washing tank with an ultrasonic generator for soaking, and carrying out treatment in an ultrasonic cleaning mode after the plated piece is soaked;

s4, acid washing and activating: drying the cleaned plated part, including pickling and activating the plated part with pickling solution and activating solution to strip the loose part of the plated part;

s5, chemical plating: and drying the plated part after acid washing and activation, performing chemical electroplating treatment after the preparation of a plating solution is completed, so that the plated part is a cathode, cations of pre-plated metal in the plating solution are deposited on the surface of the plated part, rinsing the electroplated finished product after the chemical electroplating process is completed, and drying.

2. The improved metal piece surface electroplating processing method according to claim 1, wherein the method comprises the following steps: and in the S2, an ultrasonic generator is arranged in the container for containing the degreasing agent, the plating piece is positioned in an electrolytic tank on the ultrasonic generator, the plating piece is positioned between the anode and the cathode in the electrolytic tank, and the ultrasonic frequency of the ultrasonic generator is 25-40kHz.

3. The improved metal piece surface electroplating processing method according to claim 1, wherein the method comprises the following steps: and the soaking time in the S3 is controlled to be 10-15min, the soaking temperature is 50-75 ℃, and the ultrasonic frequency is 20-30kHz.

4. The improved metal piece surface electroplating processing method according to claim 1, wherein the improved metal piece surface electroplating processing method comprises the following steps: and in the S4, the drying temperature is 80-100 ℃, the drying time is 3-8min, and the plated part is made of titanium alloy.

5. The improved metal piece surface electroplating processing method according to claim 1, wherein the method comprises the following steps: in S4, the pickling solution is prepared by the following steps:

firstly, 20g/L hydrofluoric acid and 45g/L nitric acid are selected for mixing treatment, the mixing temperature is controlled to be 30-50 ℃, and the mixing ratio of the hydrofluoric acid to the nitric acid is 2.

6. The improved metal piece surface electroplating processing method according to claim 5, wherein the method comprises the following steps: in S4, the preparation steps of the activating solution are as follows:

firstly, 400g/L of hydrochloric acid, 900g/L of sulfuric acid and 20g/L of corrosion inhibitor A are selected for mixing treatment, the mixing temperature is controlled to be 30-40 ℃, and the mixing ratio of the hydrochloric acid to the sulfuric acid to the corrosion inhibitor is 2.5: and 0.8, completing the preparation of the activating solution.

7. The improved metal piece surface electroplating processing method according to claim 1, wherein the method comprises the following steps: in S5, the plating solution is prepared from 150g/L of nickel sulfate heptahydrate, 20g/L of boric acid, 85g/L of sulfate M and 5g/L of anode activation additive B.

8. The improved metal piece surface electroplating processing method according to claim 6, wherein the method comprises the following steps: the specific implementation steps of acid washing activation in the S4 are as follows:

s401, after drying the cleaned plated part, firstly putting the plated part into a pickling tank which is provided with pickling solution after configuration, wherein an anode is arranged in the pickling tank, the plated part is put into a cathode, the pickling solution is electrified, the temperature for electrolytic stripping of the pickling solution is 20-30 ℃, the current density is 1-10ASD, and the time for electrolytic pickling is controlled to be 2-5min;

s402, placing the pickled plated piece into an activation tank filled with an activation solution, wherein the activation tank is also internally provided with an anode, the anode is a nickel plate, the plated piece is placed on a cathode, the activation solution is electrified, the temperature of the activation solution is 20-30 ℃, the current density is 1-10ASD, and the time of the electrolytic activation is controlled to be 10-20min.