CN106119914B - A kind of cobalt manganese alloy electroplate liquid and its application - Google Patents

Abstract

The present invention provides a kind of cobalt manganese alloy electroplate liquids, include each component of following concentration：Cobalt ions source 0.01mol/L~0.05mol/L, manganese ion source 0.35mol/L~0.7mol/L, chelating agent 20g/L~40g/L, conductive salt 30g/L~50g/L, stabilizer 250g/L~450g/L, surplus is solvent.The present invention also provides a kind of methods that cobalt manganese alloy coating is prepared using the electroplate liquid, include the following steps：First, oil removing and activation；2nd, it is electroplated.Inventive formulation is reasonable, and technological operation is simple, environmental-friendly, and obtained cobalt manganese alloy coating is uniformly, bright, ingredient is controllable.

Description

A kind of cobalt-manganese alloy electroplating solution and its application

technical field

The invention belongs to the technical field of electrochemistry, and in particular relates to a cobalt-manganese alloy electroplating solution and an application thereof.

Background technique

Electroplating is a traditional method for preparing coatings. The properties of coatings can be strictly controlled by controlling parameters and other conditions. The preparation cost is low, and it can adapt to the shape of complex substrates, so it is widely used. Recently, electroplating Mn or Mn alloys has attracted attention. Among them, Co-Mn alloy can be transformed into cobalt-manganese spinel through heat treatment, which can be used for solid oxide metal connector coating, which can improve the electrical conductivity and high temperature resistance of the connector, and prevent "Cr poisoning" from occurring. However, in the cobalt-manganese alloy electroplating system, the standard potential of Co ²⁺ /Co is -0.277V _H , and the standard potential of Mn ²⁺ /Mn is -1.18V _H . It is the metal with the most negative standard potential among the metals that can be electroplated in aqueous solution, so it is very difficult to electroplate cobalt-manganese alloy. Agladaz et al. electroplated cobalt-manganese alloy in a sulfate plating solution, but the manganese content of the cobalt-manganese alloy coating was only 2%. Only MnCo ₂ O ₄ or Mn _1.5 Co _1.5 O ₄ in cobalt-manganese spinel has a thermal expansion coefficient and electrical conductivity that meet the requirements of the connector coating, so the manganese content in the cobalt-manganese coating cannot be lower than 20%, otherwise it is difficult to obtain the required performance Cobalt-manganese spinel coating is required, so it is necessary to add a suitable complexing agent to shorten the deposition potential of the cobalt-manganese alloy to increase the manganese content in the cobalt-manganese alloy coating. Wu et al. used glucose as a complexing agent to prepare cobalt-manganese alloys by DC electroplating and pulse electroplating methods. The results showed that the coatings obtained by DC electroplating were porous and thin, and there were cracks on the surface of the coatings obtained by pulse electroplating. Therefore, it is necessary to invent a New cobalt-manganese alloy plating solution.

Contents of the invention

The technical problem to be solved by the present invention is to provide a cobalt-manganese alloy electroplating solution that has stable chemical properties, does not volatilize harmful gases, and uses chemicals that are harmless to the environment. The preparation process of the electroplating solution is simple, the cost is low, and the manganese content is as high as more than 20wt%.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is: a cobalt-manganese alloy electroplating solution, which is characterized in that, each component comprising the following concentrations:

Cobalt ion source 0.01mol/L～0.05mol/L;

Manganese ion source 0.35mol/L～0.7mol/L;

Chelating agent 20g/L～40g/L;

Conductive salt 30g/L～50g/L;

Stabilizer 250g/L～450g/L;

The balance is solvent.

Above-mentioned a kind of cobalt-manganese alloy electroplating solution is characterized in that, comprises each component of following concentration:

Cobalt ion source 0.01mol/L;

Manganese ion source 0.59mol/L;

Chelating agent 30g/L;

Conductive salt 36g/L;

Stabilizer 400g/L;

The balance is solvent.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the cobalt ion source is cobaltous chloride.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the source of manganese ions is manganous chloride.

The aforementioned cobalt-manganese alloy electroplating solution is characterized in that the chelating agent is ammonium chloride.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the conductive salt is sodium chloride or potassium chloride.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the stabilizer is N,N-dimethylformamide.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the solvent is deionized water.

The above-mentioned cobalt-manganese alloy electroplating solution is characterized in that the pH value of the electroplating solution is 1-4.

The present invention also provides a method for preparing a cobalt-manganese alloy coating using the cobalt-manganese alloy electroplating solution, characterized in that the method comprises the following steps:

Step 1, pre-plating treatment, including degreasing treatment and activation treatment, the specific process is:

Step 101, degreasing treatment: heat the alkaline degreasing agent to 80°C-90°C, then soak the metal parts to be plated in the heated alkaline degreasing agent for 30 minutes, take it out, clean it and dry it; Said alkaline degreasing agent comprises each component of following concentration: trisodium phosphate 30g/L～45g/L, sodium carbonate 35g/L～50g/L, sodium hydroxide 50g/L～60g/L, sodium silicate 4g /L～6g/L, the balance is deionized water;

Step 102, activation treatment: soak the metal parts to be plated after the degreasing treatment in step 101 in the activation treatment solution at a temperature of 15°C to 60°C for 60s, take them out and clean them; Concentrated sulfuric acid less than 98% and deionized water are uniformly mixed in a volume ratio (0.015-0.04): 1;

Step 2, electroplating treatment: place the metal piece to be plated after the activation treatment in step 102 in a plating tank filled with a cobalt-manganese alloy plating solution, use the metal piece to be plated as the cathode, and use the graphite plate as the anode. Plating solution temperature 20 ℃ ~ 25 ℃, current density of 20mA cm ^-2 ~ 200mA cm ^-2 electroplating 5min ~ 10min, then take out the metal parts after electroplating, clean with deionized water, dry, and place on the metal Cobalt-manganese alloy coating is obtained on the surface of the workpiece.

Compared with the prior art, the present invention has the following advantages:

1. The formula of the present invention is reasonable, and NH ₄ Cl is used as a chelating agent, which can shorten the deposition potential of cobalt and manganese and realize co-deposition of cobalt and manganese. DMF can effectively prevent Co ²⁺ and Mn ²⁺ in the solution from being transformed into high-priced oxides Co ₂ O ₃ and Mn ₂ O ₃ , and can effectively prevent the generation of chlorine gas at the anode. The cobalt-manganese alloy plating process using the electroplating solution composition is simple to operate and environmentally friendly, and the obtained plating layer is bright and the composition is controllable.

2. The cobalt-manganese alloy electroplating solution of the present invention has a simple preparation process and low cost, and the manganese content is as high as 20wt% or more; the electroplating solution has stable chemical properties, does not volatilize harmful gases, and the medicine used is harmless to the environment.

3. After the cobalt-manganese alloy electroplating solution of the present invention is oxidized, a cobalt-manganese spinel coating can be obtained, and the obtained cobalt-manganese spinel coating has excellent adhesion performance to the metal part substrate.

4. The process of the present invention is simple, the conditions are controllable, the coating is uniform and dense, and it has good adhesion to the metal substrate. It is suitable for depositing on the surface of solid oxide metal connectors, and can be converted into cobalt-manganese spinel coating after oxidation treatment. .

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

Description of drawings

Fig. 1 is the SEM photograph of the surface of the cobalt-manganese alloy coating prepared by using the cobalt-manganese alloy electroplating solution of Example 6 of the present invention.

Detailed ways

Example 1

The present embodiment cobalt-manganese alloy electroplating solution comprises each component of following concentration:

Cobalt ion source 0.01mol/L; The cobalt ion source is cobaltous chloride;

Manganese ion source 0.59mol/L; Described manganese ion source is manganous chloride;

Chelating agent 30g/L; Described chelating agent is ammonium chloride;

Conductive salt 36g/L; Described conductive salt is potassium chloride;

Stabilizer 400g/L; The stabilizer is N,N-dimethylformamide;

Surplus is solvent; Described solvent is deionized water;

The pH value of the electroplating solution is 2.5.

The preparation method of electroplating solution described in the present embodiment is:

Step 1. Take part of the deionized water, add the chelating agent to the deionized water, mix and dissolve completely, add the cobalt ion source to the solution in which the chelating agent is dissolved while stirring, and stir evenly to obtain solution A;

Step 2, take part of the deionized water again, dissolve the manganese ion source in the taken deionized water, then add conductive salt and stabilizer in turn, and obtain solution B after stirring evenly;

Step 3: After stirring solution A for 1 hour, mix it with solution B evenly, stir for 2 hours, adjust the pH value with dilute hydrochloric acid, and finally add remaining deionized water to constant volume to obtain a cobalt-manganese electroplating solution.

In this embodiment, the method for preparing a cobalt-manganese alloy coating using the above-mentioned cobalt-manganese alloy electroplating solution comprises the following steps:

Step 1, pre-plating treatment, including degreasing treatment and activation treatment, the specific process is:

Step 101, degreasing treatment: heat the alkaline degreasing agent to 85°C, then soak the metal piece to be plated in the heated alkaline degreasing agent for 30 minutes, take it out, clean it and dry it; the alkaline The degreasing agent includes the following components at the following concentrations: trisodium phosphate 35g/L, sodium carbonate 35g/L, sodium hydroxide 55g/L, sodium silicate 5g/L, and the balance is deionized water;

Step 102, activation treatment: soak the metal piece to be plated after the degreasing treatment in step 101 in the activation treatment solution at a temperature of 50° C. for 60 seconds, take it out and clean it; the activation treatment consists of a concentration of not less than 98% Concentrated sulfuric acid and deionized water are uniformly mixed at a volume ratio of 0.03:1;

Step 2, electroplating treatment: place the metal piece to be plated after the activation treatment in step 102 in a plating tank filled with a cobalt-manganese alloy plating solution, use the metal piece to be plated as the cathode, and use the graphite plate as the anode. The temperature of the electroplating solution was 22°C, and the current density was 100mA cm ^-2 for 8 minutes. After that, the metal parts after electroplating were taken out, cleaned with deionized water and dried, and finally a cobalt-manganese alloy coating was obtained on the surface of the metal parts. The coating is dense and well combined with the substrate, wherein the atomic percentage [Co]/[Mn]=1.23.

Example 2

The present embodiment cobalt-manganese alloy electroplating solution comprises each component of following concentration:

Cobalt ion source 0.03mol/L; The cobalt ion source is cobaltous chloride;

Manganese ion source 0.45mol/L; Described manganese ion source is manganese chloride;

Chelating agent 26g/L; Described chelating agent is ammonium chloride;

Conductive salt 38g/L; Described conductive salt is sodium chloride;

Stabilizer 290g/L; The stabilizer is N,N-dimethylformamide;

Surplus is solvent; Described solvent is deionized water;

The pH value of the electroplating solution is 3.

The preparation method of electroplating solution described in the present embodiment is:

Step 1. Take part of the deionized water, add the chelating agent to the deionized water, mix and dissolve completely, add the cobalt ion source to the solution in which the chelating agent is dissolved while stirring, and stir evenly to obtain solution A;

Step 2, take part of the deionized water again, dissolve the manganese ion source in the taken deionized water, then add conductive salt and stabilizer in turn, and obtain solution B after stirring evenly;

Step 3: After stirring solution A for 1 hour, mix it with solution B evenly, stir for 2 hours, adjust the pH value with dilute hydrochloric acid, and finally add remaining deionized water to constant volume to obtain a cobalt-manganese electroplating solution.

In this embodiment, the method for preparing a cobalt-manganese alloy coating using the above-mentioned cobalt-manganese alloy electroplating solution comprises the following steps:

Step 1, pre-plating treatment, including degreasing treatment and activation treatment, the specific process is:

Step 101, degreasing treatment: heat the alkaline degreasing agent to 88°C, then soak the metal piece to be plated in the heated alkaline degreasing agent for 30 minutes, take it out, clean it and dry it; the alkaline The degreaser includes the following components: trisodium phosphate 35g/L, sodium carbonate 45g/L, sodium hydroxide 55g/L, sodium silicate 5g/L, and the balance is deionized water;

Step 102, activation treatment: soak the metal piece to be plated after the degreasing treatment in step 101 in the activation treatment solution at a temperature of 50° C. for 60 seconds, take it out and clean it; the activation treatment consists of a concentration of not less than 98% Concentrated sulfuric acid and deionized water are uniformly mixed at a volume ratio of 0.02:1;

Step 2, electroplating treatment: place the metal piece to be plated after the activation treatment in step 102 in a plating tank filled with a cobalt-manganese alloy plating solution, use the metal piece to be plated as the cathode, and use the graphite plate as the anode. The temperature of the electroplating solution was 25°C, and the current density was 25mA cm ^-2 for 8 minutes. After that, the metal parts after electroplating were taken out, cleaned with deionized water, and then dried. Finally, a cobalt-manganese alloy coating was obtained on the surface of the metal parts. The plating layer is uniform, wherein the atomic percentage [Co]/[Mn]=4.73.

Example 3

The present embodiment cobalt-manganese alloy electroplating solution comprises each component of following concentration:

Cobalt ion source 0.03mol/L; The cobalt ion source is cobaltous chloride;

Manganese ion source 0.5mol/L; Described manganese ion source is manganous chloride;

Chelating agent 28g/L; Described chelating agent is ammonium chloride;

Conductive salt 40g/L; Described conductive salt is potassium chloride;

Stabilizer 300g/L; The stabilizer is N,N-dimethylformamide;

Surplus is solvent; Described solvent is deionized water;

The pH value of the electroplating solution is 4.

Step 1. Take part of the deionized water, add the chelating agent to the deionized water, mix and dissolve completely, add the cobalt ion source to the solution in which the chelating agent is dissolved while stirring, and stir evenly to obtain solution A;

Step 2, take part of the deionized water again, dissolve the manganese ion source in the taken deionized water, then add conductive salt and stabilizer in turn, and obtain solution B after stirring evenly;

Step 3: After stirring solution A for 1 hour, mix it with solution B evenly, stir for 2 hours, adjust the pH value with dilute hydrochloric acid, and finally add remaining deionized water to constant volume to obtain a cobalt-manganese electroplating solution.

In this embodiment, the method for preparing a cobalt-manganese alloy coating using the above-mentioned cobalt-manganese alloy electroplating solution comprises the following steps:

Step 1, pre-plating treatment, including degreasing treatment and activation treatment, the specific process is:

Step 101, degreasing treatment: heat the alkaline degreasing agent to 80°C, then soak the metal piece to be plated in the heated alkaline degreasing agent for 30 minutes, take it out, clean it and dry it; the alkaline The degreasing agent includes the following components at the following concentrations: trisodium phosphate 45g/L, sodium carbonate 35g/L, sodium hydroxide 60g/L, sodium silicate 4g/L, and the balance is deionized water;

Step 102, activation treatment: soak the metal piece to be plated after the degreasing treatment in step 101 in the activation treatment solution at a temperature of 60°C for 60 seconds, take it out and clean it; Concentrated sulfuric acid and deionized water are uniformly mixed at a volume ratio of 0.015:1;

Step 2, electroplating treatment: place the metal piece to be plated after the activation treatment in step 102 in a plating tank filled with a cobalt-manganese alloy plating solution, use the metal piece to be plated as the cathode, and use the graphite plate as the anode. The temperature of the electroplating solution was 25°C, and the current density was 20mA cm ^-2 for 5 minutes. After that, the metal parts after electroplating were taken out, cleaned with deionized water and dried, and finally a cobalt-manganese alloy coating was obtained on the surface of the metal parts. The coating is uniform and dense, and the atomic percentage [Co]/[Mn]=4.05.

Example 4

The present embodiment cobalt-manganese alloy electroplating solution comprises each component of following concentration:

Cobalt ion source 0.05mol/L; The cobalt ion source is cobaltous chloride;

Manganese ion source 0.7mol/L; Described manganese ion source is manganous chloride;

Chelating agent 30g/L; Described chelating agent is ammonium chloride;

Conductive salt 50g/L; Described conductive salt is sodium chloride;

Stabilizer 400g/L; The stabilizer is N,N-dimethylformamide;

Surplus is solvent; Described solvent is deionized water;

The pH value of the electroplating solution is 1.

Step 1. Take part of the deionized water, add the chelating agent to the deionized water, mix and dissolve completely, add the cobalt ion source to the solution in which the chelating agent is dissolved while stirring, and stir evenly to obtain solution A;

Step 2, take part of the deionized water again, dissolve the manganese ion source in the taken deionized water, then add conductive salt and stabilizer in turn, and obtain solution B after stirring evenly;

Step 3: After stirring solution A for 1 hour, mix it with solution B evenly, stir for 2 hours, adjust the pH value with dilute hydrochloric acid, and finally add remaining deionized water to constant volume to obtain a cobalt-manganese electroplating solution.

In this embodiment, the method for preparing a cobalt-manganese alloy coating using the above-mentioned cobalt-manganese alloy electroplating solution comprises the following steps:

Step 1, pre-plating treatment, including degreasing treatment and activation treatment, the specific process is:

Step 101, degreasing treatment: heat the alkaline degreasing agent to 90°C, then soak the metal piece to be plated in the heated alkaline degreasing agent for 30 minutes, take it out, clean it and dry it; the alkaline The degreaser includes the following components: trisodium phosphate 30g/L, sodium carbonate 50g/L, sodium hydroxide 50g/L, sodium silicate 6g/L, and the balance is deionized water;

Step 102, activation treatment: soak the metal piece to be plated after the degreasing treatment in step 101 in the activation treatment solution at a temperature of 15°C for 60s, take it out and clean it; Concentrated sulfuric acid and deionized water are uniformly mixed at a volume ratio of 0.04:1;

Step 2, electroplating treatment: place the metal piece to be plated after the activation treatment in step 102 in a plating tank filled with a cobalt-manganese alloy plating solution, use the metal piece to be plated as the cathode, and use the graphite plate as the anode. The temperature of the electroplating solution was 20°C, and the current density was 200mA cm ^-2 for 5 minutes. After that, the metal parts after electroplating were taken out, cleaned with deionized water and dried, and finally a cobalt-manganese alloy coating was obtained on the surface of the metal parts. The coating is uniform and dense, and has strong bonding force with the substrate, wherein the atomic percentage [Co]/[Mn]=2.75.

In addition, in order to determine the optimal ratio of the cobalt-manganese alloy electroplating solution, the applicant of the present invention has carried out a large number of experimental verifications, optimized the amount of the developed basic formula, and adjusted the main salt concentration and pH value in the formula successively. The details are as follows: In the test, 430 stainless steel substrates of the same size were used for electroplating, the electroplating temperature was 25°C, and the addition amount of chelating agent, conductive salt and stabilizer remained unchanged, which were 30g/L, 36g/L and 400g/L respectively . The pretreatment method is the same as in Example 1. Table 1 shows the test results of the influence of the electroplating solution composition, pH value and current density on the coating composition ([Co]/[Mn] atomic ratio) and appearance.

Table 1 The influence of the selection of electroplating solution components, pH value and current density on the coating

As can be seen from Table 1, comparing Examples 5, 6, 7 and 8, it can be seen that the optimum concentration of the cobalt-manganese coating with a higher manganese content is Example 6. Fig. 1 is the surface SEM photo of the cobalt-manganese alloy coating prepared by using the cobalt-manganese alloy electroplating solution of embodiment 6. It can be seen from Figure 1 that the coating is uniform and dense, with strong bonding force and good quality, wherein the atomic percentage [Co]/[Mn]=1.69. After the coating is oxidized, a uniform layer of Mn _1.5 Co _1.5 O ₄ spinel coating is formed on the surface of the metal parts, which meets the design requirements and provides technical support for the development of protective coatings on the surface of SOFC connectors.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent changes made to the above embodiments according to the technical essence of the invention still belong to the protection scope of the technical solution of the invention.

Claims (8)

1. a kind of cobalt manganese alloy electroplate liquid, which is characterized in that include each component of following concentration：

Cobalt ions source 0.01mol/L~0.05mol/L；

Manganese ion source 0.35mol/L~0.7mol/L；

Chelating agent 20g/L~40g/L；The chelating agent is ammonium chloride；

Conductive salt 30g/L~50g/L；

Stabilizer 250g/L~450g/L；The stabilizer is N,N-dimethylformamide；

Surplus is solvent.

2. a kind of cobalt manganese alloy electroplate liquid according to claim 1, which is characterized in that include each component of following concentration：

Cobalt ions source 0.01mol/L；

Manganese ion source 0.59mol/L；

Chelating agent 30g/L；

Conductive salt 36g/L；

Stabilizer 400g/L；

Surplus is solvent.

3. a kind of cobalt manganese alloy electroplate liquid according to claim 1 or 2, which is characterized in that the cobalt ions source is chlorination Sub- cobalt.

4. a kind of cobalt manganese alloy electroplate liquid according to claim 1 or 2, which is characterized in that the manganese ion source is chlorination Sub- manganese.

5. a kind of cobalt manganese alloy electroplate liquid according to claim 1 or 2, which is characterized in that the conductive salt is sodium chloride Or potassium chloride.

6. a kind of cobalt manganese alloy electroplate liquid according to claim 1 or 2, which is characterized in that the solvent is deionized water.

7. a kind of cobalt manganese alloy electroplate liquid according to claim 1 or 2, which is characterized in that the pH value of the electroplate liquid is 1 ~4.

8. a kind of method for preparing cobalt manganese alloy coating using cobalt manganese alloy electroplate liquid as claimed in claim 1 or 2, feature exist In this method includes the following steps：

Step 1: treatment before plating, including oil removal treatment and activation process, detailed process is：

Step 101, oil removal treatment：Alkaline degreaser is heated to 80 DEG C~90 DEG C, after plating metal part then is placed in heating Alkaline degreaser in impregnate 30min, clean up and dry after taking-up；The alkaline degreaser includes each group of following concentration Point：Tertiary sodium phosphate 30g/L~45g/L, sodium carbonate 35g/L~50g/L, sodium hydroxide 50g/L~60g/L, sodium metasilicate 4g/L~ 6g/L, surplus are deionized water；

Step 102, activation process：It is 15 DEG C~60 DEG C that plating metal part after oil removal treatment in step 101 is placed in temperature 60s is impregnated in activation process liquid, is cleaned up after taking-up；The activation process is dense not less than 98% by mass percent concentration Sulfuric acid and deionized water be by volume (0.015~0.04): 1 is uniformly mixed；

Step 2: electroplating processes：Plating metal part after activation process in step 102 is placed in and is loaded with cobalt manganese alloy electroplate liquid Coating bath in, using plating metal part as cathode, using graphite cake as anode, in 20 DEG C~25 DEG C of cobalt manganese alloy temperature of electroplating solution, electricity Current density is 20mA cm^-2~200mA cm^-2Under conditions of be electroplated 5min~10min, later by after plating metalwork take out, It is dried up after being cleaned up with deionized water, cobalt manganese alloy coating is obtained on metalwork surface.