CN106987863A - The preparation technology of the bimodal nano-crystal nickel cobalt alloy of single pulse electrodpositing light two-phase - Google Patents

Abstract

The invention relates to a preparation process of single-pulse electrodeposited bright double-phase double-peak nanocrystalline nickel-cobalt alloy. The specific steps are as follows: prior to electroplating, the electroplating solution is subjected to activated carbon adsorption and electrolytic decontamination, and then a pre-plating test is carried out in a Hall cell device to determine the conditions of the bright dual-phase bimodal nickel-cobalt alloy coating. Electroplating is carried out in a plating solution with a pH value between 2 and 5, a concentration of nickel sulfate 50-70g/L, nickel chloride 40-60g/L, and cobalt sulfate 40-50g/L as the main salt. The plate is used as the anode after surface treatment, and the stainless steel is used as the cathode after surface treatment. The coating of bright dual-phase bimodal nanocrystalline nickel-cobalt alloy is deposited by single pulse electrodeposition. The electrodeposition time is 2h~4h, and the pulse current density is 2.5~3A. /dm ² , the duty ratio is 20%-40%, the period is 1-2ms, and the stirring speed is 100-500r/min. The nickel-cobalt alloy coating prepared by the method has bright surface, compact structure, fine crystallization, good flatness, no cracks, good corrosion resistance, high strength and plasticity.

Description

Preparation process of bright dual-phase bimodal nanocrystalline nickel-cobalt alloy by single-pulse electrodeposition

technical field

The invention relates to a preparation process of a single-pulse electrodeposited bright dual-phase bimodal nano-crystalline nickel-cobalt alloy, belonging to the field of electroplating alloys.

technical background

Nickel is a silver-white metal with a density of 8.9, a melting point of 1455°C and a boiling point of 2915°C. Nickel has good mechanical strength, ductility and corrosion resistance, and is widely used in military manufacturing, civil industry, machinery manufacturing, petroleum industry, etc.; nickel-cobalt alloy is a permanent magnetic material, widely used in electronic remote control, atomic energy, etc. Industrial and ultrasonic technology and other fields.

The electrochemical deposition method, commonly known as electroplating, is a method in which the conductive part to be plated is used as the cathode in a plating solution containing a metal plating compound, and through electrolysis, it is expected to obtain a firm bond, a uniform coating, and a fine surface on the surface of the part. The electrochemical processing method of metal film is also one of the most widely used surface treatment technologies at present. According to the way the power supply provides voltage and current, it can be divided into ordinary DC electroplating, AC-DC superimposed electroplating, pulse electroplating, etc., and pulse electroplating is further divided into single pulse electroplating and double pulse electroplating. According to the type of electroplating metal elements, it is divided into single metal electroplating and alloy electroplating.

With the development of science and technology and modern industry, various new requirements are put forward for the performance of functional materials and structural materials, and the quality requirements for protective coatings are also getting higher and higher. The traditional electroplating single metal nickel coating is due to:( 1) The bonding strength of the coating is poor (2) The dispersion ability of the coating is poor (3) The brightness of the coating is poor (4) The current efficiency is low, the deposition rate is slow, etc. (5) The factors such as acid resistance, alkali resistance, and wear resistance are not high enough. Certain special requirements. Therefore, using a metal nickel as the substrate, the co-deposition of metal nickel and metal cobalt is obtained by electrodeposition method, and it has high hardness, temperature resistance, acid resistance, alkali resistance, wear resistance, self-lubricating property, and corrosion resistance. Nickel-cobalt alloy coatings with corrosion resistance, special decorative appearance, electrical contact function, electrocatalysis and other functions have attracted much attention.

In addition to some basic conditions for single metal deposition, alloy electroplating should also have the following two elements:

(1) Of the two metals to be electroplated by the alloy, at least one of the metals must be able to deposit from an aqueous solution of its salt. In particular, it should be emphasized that although some special metals such as tungsten and molybdenum cannot be deposited from the aqueous solution of their salts, they can co-deposit with iron group elements, so the necessary conditions for metal co-deposition do not necessarily require that the components can be deposited from water alone.

(2) The co-deposition of two metals must meet their deposition potentials to be similar. If the potential difference between the two metals is large, the metal with a relatively positive potential will be deposited first, and will even repel the deposition of another metal later.

Compared with DC electroplating nickel-cobalt alloy, pulse electroplating nickel-cobalt alloy has the following performances:

(1) A dense, high-conductivity deposition layer can be obtained;

(2) Reduce concentration polarization and increase cathode current density;

(3) Reduce or eliminate oxygen embrittlement and improve the physical and mechanical properties of the coating;

(4) Reduce the amount of additives and improve the purity of the coating;

(5) Reduce porosity and improve the protective performance of the coating.

(6) The pulse electric bond can significantly improve the performance of the coating, which opens up a new way for the development of electroplating technology.

In short, the temperature resistance, acid resistance, alkali resistance, wear resistance, welding, toughness, plasticity, strength, anti-corrosion, electrical conductivity, anti-discoloration, smoothness and other performance indicators of single-pulse electroplating bright dual-phase nanocrystalline nickel-cobalt alloy coating have been greatly improved. At the same time, the use of single-pulse electrodeposition of nickel-cobalt alloy can avoid many shortcomings of traditional processes.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for single-pulse electrodeposition of bright dual-phase bimodal nanocrystalline nickel-cobalt alloy in view of the deficiencies in the prior art. The nickel-cobalt alloy coating obtained by this method has a bright surface and a compact structure. Good flatness, no cracks, good corrosion resistance, high strength and plasticity. When the cobalt content is 66.7% (mass fraction), it presents a dual-phase structure containing face-centered cubic and close-packed hexagonal crystal structures. At the same time, the grains also present a special bimodal distribution, that is, the grains present a large and small grain distribution, that is, at the same time Large grains and small grains can be observed within a field of view (the size of large grains can reach more than 100nm, and the size of small grains can reach tens of nanometers).

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

The preparation technology of single-pulse electrodeposited bright dual-phase bimodal nanocrystalline nickel-cobalt alloy is characterized in that: it comprises the following process steps: prior to electroplating, the electroplating solution is first subjected to active carbon adsorption and electrolytic removal of impurities, and then in the Hall cell device The pre-plating test is carried out to determine the additive range of the bright dual-phase nickel-cobalt alloy coating, and then the pH value is stabilized between 2 and 5, and the concentration is 50-70g/L of nickel sulfate and 40-60g/L of nickel chloride. , cobalt sulfate 40 ~ 50g/L electroplating in the main salt plating solution, the soluble nickel plate is used as the anode after surface treatment, and the stainless steel after surface treatment is used as the cathode, and the single pulse electrodeposition process is used to electroplate bright biphasic bimodal nanometer Crystalline nickel-cobalt alloy coating, wherein the electrodeposition time is 2h~4h, the pulse current density is 2.5~3A/dm ² , the duty ratio is 20%~40%, the cycle is 1~2ms, and the stirring speed is 100~500r/min .

According to the above scheme, the plating solution also includes 20-30 g/L of sodium sulfate as a supporting electrolyte, 0.1-0.5 g/L of saccharin, 0.01-0.05 g/L of 1,4-butynediol, 0.5 g/L sodium lauryl sulfate.

According to the above scheme, each component and its content in the described plating solution are:

The preparation steps of the electroplating solution are as follows:

(1) Take quantitative nickel sulfate with analytical balance, join in the beaker that deionized water is housed prepared in advance, heat to dissolve;

(2) Add quantitative nickel chloride and cobalt sulfate to the solution in step (1) respectively with an analytical balance, and heat to dissolve it.

The slow-release acid used to regulate pH in the described electroplating solution is boric acid, and its preparation process is as follows:

(1) Add quantitative deionized water to the cleaned beaker;

(2) the deionized water in step (1) is put on the heating furnace that is cushioned with asbestos net and boiled, then the quantitative boric acid that weighs is added into the deionized water that boils and boric acid is dissolved completely;

(3) Pour all the boric acid dissolved in the step (2) into the configured plating solution rapidly.

The anionic surfactant sodium lauryl sulfate of 0.5-0.6g/L is also included in the described plating solution as a wetting agent, and the preparation process of the wetting agent used is as follows:

(1) take by weighing a certain amount of sodium lauryl sulfate earlier with analytical balance and be placed in clean beaker;

(2) Then add a small amount of deionized water to adjust the sodium lauryl sulfate in the step (1) into a paste;

(3) Finally, pour deionized water boiled in an electric furnace into a beaker filled with pasty sodium lauryl sulfate, boil for 30 minutes to fully dissolve, and finally pour it into the prepared plating solution.

The plating solution should be adsorbed and removed before electroplating. Use an analytical balance to weigh 3g/L granular activated carbon and add it to the prepared plating solution. Stir and adsorb for 1h under the action of magnetic stirring, and then take out the granular activated carbon. , and finally remove the powdery activated carbon remaining in the plating solution by vacuum filtration;

The plating solution will also be electrolytically decontaminated after being adsorbed and decontaminated by activated carbon. The condition of electrolytic decontamination is low current, that is, usually 0.1A, the electrolysis time is 6h, and the anode is still a soluble nickel plate with a purity of more than 99.99%. It is a thin steel plate folded into a corrugated shape.

Carry out pre-plating test by Hall cell to determine the condition of electroplating bright nickel-cobalt alloy, Hall cell pre-plating test includes the following steps:

Step 1: Use a graduated cylinder to measure 250ml of the test plating solution, without adding saccharin and 1,4-butynediol, and adjust the pH value to be stable between 2 and 5;

Step 2: heating the plating solution to 45-65°C through the heating rod in the Hall tank;

Step 3: Put the specific copper sheet used for the Hall cell test with the surface treated and cleaned into the Hall cell;

Step 4: Start trial plating. The trial plating current is DC and constant at 1A. During the trial plating process, manually stir with a glass rod to adjust the pH at any time to stabilize it within the range required by step 1. The trial plating time is 10 minutes. ;

Step 5: Clean and dry the copper sheet after trial plating, and observe with the naked eye whether there is a large area of bright area on the surface; then place it on a table with a flat surface and observe the curling around the copper sheet , so as to determine the magnitude of the stress in the coating;

Step 6: If the bright area on the surface of the copper plated after the trial plating is not large and the four corners are warped, it is necessary to re-measure 250ml of the plating solution, and then continuously change the saccharin and 1 , The amount of 4-butynediol, so as to determine the conditions for adding bright coating additives.

The plating solution is stirred by an electric stirring paddle, so that the composition of each part of the plating solution is uniform.

The purity of the soluble nickel plate for the anode is above 99.99%, the electrode spacing between the anode and the cathode is 15-20cm, the specifications are 10cm×10cm×0.2cm, and the area ratio of the anode and the cathode is greater than or equal to 4 :1.

The cathode stainless steel is sequentially polished to a mirror effect by metallographic sandpaper of 120 mesh, 220 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1500 mesh, 2000 mesh, and 3000 mesh. Carry out decontamination and degreasing treatment for 8 to 10 minutes, then put the degreasing treated substrate into deionized water at 80°C for ultrasonic treatment for 2 minutes, remove the alkali washing solution remaining on the surface of the stainless steel substrate, and finally put the substrate into dilute sulfuric acid solution Medium ultrasonic vibration for 30-60s for rust removal and surface activation treatment.

Beneficial effects of the present invention:

1. The present invention utilizes porous activated carbon to have better adsorption capacity to absorb some impurities in the plating solution to purify the plating solution.

2. In this electroplating process, after removing impurities by activated carbon, the impurities in the plating solution are further removed by electrolytic removal under low current, making the plating solution more pure, thereby ensuring the purity and surface smoothness of the alloy coating.

3. In this electroplating process, before the actual electroplating, the Hall cell test is carried out to determine the additive range of the electroplating bright nickel-cobalt alloy coating, so as to ensure the brightness of the alloy coating.

4. The acid used for pickling in this electroplating process is dilute sulfuric acid with a volume fraction of 10%, which avoids the pollution to the environment caused by dilute hydrochloric acid.

5. In this electroplating process, ultrasonic vibration is used in the three-step washing process of alkali washing, water washing and pickling, so as to make the washing effect better.

6. The coating of this electroplating process is bright, uniform in composition, high in strength, hardness and plasticity, and its acid and alkali resistance and wear resistance have also been greatly improved. In terms of microstructure, it shows a dual-phase structure with both FCC and HCP, as well as a bimodal structure with grain size distribution.

Description of drawings

Figure 1 is a TEM image of a single-pulse electrodeposited bimodal nickel-cobalt alloy coating

Fig. 2 is the TEM image of the nanocrystalline nickel-cobalt alloy coating of 50% cobalt content

Fig. 3 is the TEM image of the nanocrystalline nickel-cobalt alloy coating of 70% cobalt content

Fig. 4 is the energy spectrogram of the nanocrystalline nickel-cobalt alloy coating of 50% for cobalt content

Fig. 5 is the energy spectrum diagram of the nanocrystalline nickel-cobalt alloy coating of 70% cobalt content

Fig. 6 is the XRD figure of the nanocrystalline nickel-cobalt alloy coating of different cobalt content

detailed description

Example 1

A preparation process of single-pulse electrodeposited bright dual-phase bimodal nanocrystalline nickel-cobalt alloy, comprising the following steps:

A. The preparation of plating solution: add the boric acid of 50g/L in the plating solution of nickel sulfate 60g/L, nickel chloride 50g/L, cobalt sulfate 45g/L main salt, then add deionized water to balance the plating solution to 5L (4L is used for formal electroplating, 1L is used for trial plating test).

B. Adsorption and impurity removal: add 3g/L activated carbon to the prepared plating solution without additives and put it into a magnet, stir and adsorb at room temperature for 1h. Finally, the activated carbon remaining in the plating solution was removed by suction filtration.

C. Electrolytic impurity removal: Electrolytic adsorption and impurity removal were performed on the filtered plating solution under a pulse power supply with an average current of 0.1A, and electrolysis was performed for 6 hours.

D. Pre-plating test:

Step 1: Measure 250ml of the plating solution from the 5L of the electrolytic plating solution, add only 0.5g/L sodium lauryl sulfate, without adding saccharin and 1,4-butynediol. The temperature of the plating solution in the Hall cell was heated to 55° C. by a heating rod and kept constant.

Step 2: Pre-plating is carried out under the condition of a DC power supply and a constant current of 1A. During the test plating process, the pH value was stable at 3.8, and the plating solution was continuously stirred, and the test plating time was 10 minutes.

Step 3: Rinse the plated parts with deionized water, and then blow dry.

Step 4: Place the blow-dried plated parts on a table with a flat surface and observe the angle of the four corners of the copper sheet. At the same time, observe the brightness of the surface of the copper sheet.

Step 5: If the four corners of the above-mentioned plated parts are slightly lifted or the surface of the plated parts is not bright enough. Re-measure 250ml of plating solution and constantly change the amount of saccharin and 1,4-butynediol on the basis of the plating solution in step 1 to obtain the range of additives for bright plating.

E. Cleaning: Put the base stainless steel into the alkali washing solution at 80°C, ultrasonicate for 10min in an ultrasonic machine with an ultrasonic frequency of 30kHz, and then put it into deionized water at 80°C for 2min (f=30kHz) to remove Alkaline cleaning solution remaining on the surface of the substrate. Finally, put the substrate into 10% dilute sulfuric acid for ultrasonic pickling for 30s.

F. Formal electroplating: Add the amount of additives determined in the pre-plating stage to the 4L plating solution, and at the same time put the treated substrate into the 4L plating solution to start electroplating. The electroplating conditions are: single pulse electroplating, average current 0.4A, t _on = 0.2ms, t _off = 0.8ms, duty cycle 20%, electroplating time 2h, thickness 25um, bath temperature stable at 55°C, pH value stable at 3.8.

G. Post-plating treatment: Rinse the plated piece with deionized water and dry it to get the test piece.

Example 2

A preparation process of single-pulse electrodeposited bright dual-phase nanocrystalline nickel-cobalt alloy, comprising the following steps:

A. Preparation of plating solution: Add 40g/L boric acid to the plating solution of nickel sulfate 50g/L, nickel chloride 40g/L, and cobalt sulfate 40g/L as the main salt, then add deionized water to balance the plating solution to 5L (4L is used for formal electroplating, 1L is used for trial plating test).

B. Adsorption and impurity removal: add 3g/L activated carbon to the prepared plating solution without additives and put it into a magnet, stir and adsorb at room temperature for 1h. Finally, the activated carbon remaining in the plating solution was removed by suction filtration.

C. Electrolytic impurity removal: Electrolytic adsorption and impurity removal were performed on the filtered plating solution under a pulse power supply with an average current of 0.1A, and electrolysis was performed for 6 hours.

D. Pre-plating test:

Step 1: Measure 250ml of the plating solution from the 5L of the electrolytic plating solution, add only 0.5g/L sodium lauryl sulfate, without adding saccharin and 1,4-butynediol. The temperature of the plating solution in the Hall cell was heated to 45° C. by a heating rod and kept constant.

Step 2: Pre-plating is carried out under the condition of a DC power supply and a constant current of 1A. During the test plating process, the pH value was stable at 4.5, and the plating solution was continuously stirred, and the test plating time was 10 minutes.

Step 3: Rinse the plated parts with deionized water, and then blow dry.

Step 4: Place the blow-dried plated parts on a table with a flat surface and observe the angle of the four corners of the copper sheet. At the same time, observe the brightness of the surface of the copper sheet.

Step 5: If the four corners of the above-mentioned plated parts are slightly lifted or the surface of the plated parts is not bright enough. Re-measure 250ml of plating solution and constantly change the amount of saccharin and 1,4-butynediol on the basis of the plating solution in step 1 to obtain the range of additives for bright plating.

E. Cleaning: Put the base stainless steel into the alkali washing solution at 60°C, ultrasonicate it in an ultrasonic machine with an ultrasonic frequency of 35kHz for 8min, and then put it into deionized water at 60°C and oscillate ultrasonically for 2min (f=30kHz) to remove Alkaline cleaning solution remaining on the surface of the substrate. Finally, put the substrate into 10% dilute sulfuric acid for ultrasonic pickling for 45s.

F. Formal electroplating: Add the amount of additives determined in the pre-plating stage to the 4L plating solution, and at the same time put the treated substrate into the 4L plating solution to start electroplating. The electroplating conditions are: single pulse electroplating, average current 0.6A, t _on = 0.8ms, t _off = 1.2ms, duty cycle 40%, electroplating time 3h, thickness 35um, bath temperature stable at 45°C, pH value stable at 4.5.

G. Post-plating treatment: Rinse the plated piece with deionized water and dry it to get the test piece.

Example 3

A preparation process of single-pulse electrodeposited bright dual-phase nanocrystalline nickel-cobalt alloy, comprising the following steps:

A. The preparation of plating solution: add the boric acid of 45g/L in the plating solution of nickel sulfate 70g/L, nickel chloride 60g/L, cobalt sulfate 50g/L main salt, then add deionized water to balance the plating solution to 5L (4L is used for formal electroplating, 1L is used for trial plating test).

B. Adsorption and impurity removal: add 3g/L activated carbon to the prepared plating solution without additives and put it into a magnet, stir and adsorb at room temperature for 1h. Finally, the activated carbon remaining in the plating solution was removed by suction filtration.

C. Electrolytic impurity removal: Electrolytic adsorption and impurity removal were performed on the filtered plating solution under a pulse power supply with an average current of 0.1A, and electrolysis was performed for 6 hours.

D. Pre-plating test:

Step 1: Measure 250ml of the plating solution from the 5L of the electrolytic plating solution, add only 0.5g/L sodium lauryl sulfate, without adding saccharin and 1,4-butynediol. The temperature of the plating solution in the Hall cell was heated to 65° C. by a heating rod and kept constant.

Step 2: Pre-plating is carried out under the condition of a DC power supply and a constant current of 1A. During the test plating process, the pH value was stable at 5, and the plating solution was continuously stirred, and the test plating time was 10 minutes.

Step 3: Rinse the plated parts with deionized water, and then blow dry.

Step 4: Place the blow-dried plated parts on a table with a flat surface and observe the angle of the four corners of the copper sheet. At the same time, observe the brightness of the surface of the copper sheet.

Step 5: If the four corners of the above-mentioned plated parts are slightly lifted or the surface of the plated parts is not bright enough. Re-measure 250ml of plating solution and constantly change the amount of saccharin and 1,4-butynediol on the basis of the plating solution in step 1 to obtain the range of additives for bright plating.

E. Cleaning: Put the base stainless steel into the alkali washing solution at 40°C, ultrasonicate it in an ultrasonic machine with an ultrasonic frequency of 40kHz for 6min, and then put it into deionized water at 40°C and oscillate ultrasonically for 2min (f=30kHz) to remove Alkaline cleaning solution remaining on the surface of the substrate. Finally, put the substrate into 10% dilute sulfuric acid for ultrasonic pickling for 60s.

F. Formal electroplating: Add the amount of additives determined in the pre-plating stage to the 4L plating solution, and at the same time put the treated substrate into the 4L plating solution to start electroplating. The electroplating conditions are: single pulse electroplating, average current 0.4A, t _on = 0.2ms, t _off = 0.8ms, duty cycle 20%, electroplating time 4h, thickness 40um, bath temperature stable at 65°C, pH value stable at 5.

G. Post-plating treatment: Rinse the plated piece with deionized water and dry it to get the test piece.

Claims (10)

1. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of single pulse electrodpositing light two-phase, it is characterised in that including following work Skill step：First by electroplate liquid through charcoal absorption removal of impurities and electrolysis removal of impurities before plating, then carried out again in Hall slot device Preplating experiment determines the condition of bright biphase nanocrystalline nickel-cobalt alloy plating, then in stable between 2~5, the concentration with pH value To be electroplated in 50~70g/L of nickel sulfate, 40~60g/L of nickel chloride, the plating solution that 40~50g/L of cobaltous sulfate is main salt, with can As anode after dissolubility nickel plate surface treated, as negative electrode after stainless steel surface treated, using single pulse electrodpositing technique The bimodal nickel-cobalt alloy plating of electroplating bright Nanocrystalline Two-phase, wherein electrodeposition time be 2h~4h, pulse current density be 2.5~ 3A/dm², dutycycle be 20%~40%, the cycle be 1~2ms, electrodeposition temperature be 45~65 DEG C, mixing speed be 100~ 500r/min。

2. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1, its It is characterised by：The also sodium sulphate including 20~30g/L is as supporting electrolyte in the plating solution, and 0.1~0.5g/L saccharin is made For primary brightener, 0.01~0.05g/L Isosorbide-5-Nitrae-butynediols is used as second-class brightener.

3. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1 or 2, It is characterized in that：The electroplate liquid preparation steps are as follows：

(1) quantitative nickel sulfate is weighed with assay balance, is added in beaker of the preprepared equipped with deionized water, heating Dissolving；

(2) weigh with assay balance quantitative nickel chloride respectively again and cobaltous sulfate is added separately in the solution in step (1), plus Heat dissolves it.

4. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 3, its It is characterised by：The sustained-release acid for being used to adjust PH in described electroplate liquid is boric acid, and its process for preparation is as follows：

(1) clean beaker is added to quantitative deionized water；

(2) deionized water in step (1) is put on the heating furnace for be lined with asbestos gauge and boiled, then by the quantitative boron weighed up Acid, which is added in the deionized water boiled, is completely dissolved boric acid；

(3) boric acid all dissolved in step (2) is poured into rapidly in configured plating solution.

5. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 3, its It is characterised by：Also the anionic surfactant so lauryl sulfate including 0.5-0.6g/L is used as profit in described plating solution Humectant, the process for preparation of wetting agent used is as follows：

(1) first a certain amount of lauryl sodium sulfate is weighed with assay balance to be placed in clean beaker；

(2) then add minimal amount of deionized water the lauryl sodium sulfate in step (1) is tuned into starchiness；

(3) finally the deionized water boiled with electrothermal furnace is poured into the beaker equipped with starchy lauryl sodium sulfate, boiled 30min makes it fully dissolve, finally in configured plating solution is poured into.

6. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 3, its It is characterised by：The plating solution will carry out adsorption-edulcoration before plating, and the granular active carbon that 3g/L is weighed with assay balance is added Into the plating solution of the preparation, then the stirring and adsorbing 1h under magneton stirring action takes out granular activated carbon, finally by Vacuum filtration removes the powdered activated carbon of residual in the plating solution；

The plating solution will also carry out electrolysis removal of impurities after charcoal absorption removal of impurities, and the condition of electrolysis removal of impurities is that low current is to lead to It is often 0.1A, electrolysis time is 6h, anode or the soluble nickel plate that purity is more than 99.99%, and negative electrode is to be converted into corrugated Thin steel plate.

7. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1, its It is characterised by：The condition that preplating experiment determines electroplating bright nickel cobalt (alloy) is carried out by Hull cell, Hull cell preplating experiment is included Following steps：

Step one：250ml examination plating solution is measured with graduated cylinder, saccharin and Isosorbide-5-Nitrae-butynediols is not added with, regulate pH value it is stable 2~ Between 5；

Step 2：Plating solution therein is heated to 45~65 DEG C by the heating rod in Hull cell；

Step 3：The specific copper sheet for Hull cell test that surface is cleaned by processing is put into Hull cell；

Step 4：Start examination plating, examination plating electric current be direct current and it is constant be 1A, examination plating during stirred manually by using glass bar Mix, the size that PH is adjusted at any time is stabilized it in the scope required by step one, try plating time 10min；

Step 5：Dried up after the copper sheet for trying to have plated is cleaned, visually observe whether its surface has the lighted region of larger area；So The situation that copper sheet surrounding is tilted is observed on the desktop for placing it in surfacing afterwards and being laid flat, so as to judge the big of stress in coating It is small；

Step 6：If the copper sheet surface-brightening region that examination has been plated is less and there is the situation of tilting at four angles, it need to measure again 250ml plating solution, then try at upper one to be constantly changing the consumption of saccharin and Isosorbide-5-Nitrae-butynediols on the basis of plating piece, so that really Determine the condition of the addition of bright coating additive.

8. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1, its It is characterised by：Plating solution process is stirred by electric stirring oar, so that the composition uniformity at each position of plating solution.

9. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1, its It is characterised by：The purity of the soluble nickel plate of described anode is more than 99.99%, and the electrode spacing of the anode and negative electrode is 15~20cm, specification is the ㎝ of the ㎝ of 10 ㎝ × 10 × 0.2, and the area ratio of anode and negative electrode is more than or equal to 4:1.

10. the preparation technology of the bimodal nano-crystal nickel cobalt alloy of the bright two-phase of single pulse electrodpositing according to claim 1, its It is characterised by：Negative electrode stainless steel sequentially passes through 120 mesh, 220 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1500 mesh, 2000 Mesh, the abrasive paper for metallograph of 3000 mesh is polishing to mirror effect, puts it into 8~10min of ultrasound in 80 DEG C of alkali wash waters and is decontaminated Oil removal treatment, is then put into ultrasonically treated 2min in 80 DEG C of deionized water by the matrix that oil removal treatment is crossed, and removing is remained in The alkali wash water on stainless steel base surface, is finally put into 30~60s of ultrasonic vibration in dilution heat of sulfuric acid by matrix and is derusted and table Face activation process.