Electroplating solution for rare-earth metal electrodeposition and preparation method for and use of electroplating solution

Abstract

An electroplating solution for rare-earth metal electrodeposition and a preparation method for and a use of the electroplating solution. The electroplating solution comprises the following raw materials: a rare-earth metal salt, a complexing agent and water, wherein the content of the rare-earth metal salt in the electroplating solution is 0.15-0.55 mol / L, and the molar ratio of the complexing agent to the rare-earth metal salt in the electroplating solution is 1:(1.5-5). The preparation method comprises: putting water and the complexing agent in an electroplating bath, uniformly stirring, and adjusting the pH value to a first preset value; adding the rare-earth metal salt into the electroplating bath, uniformly stirring, and adjusting the pH value to a second preset value; and adding water to the electroplating bath to the required volume to obtain the electroplating solution for rare-earth metal electrodeposition. The electroplating solution for rare-earth metal electrodeposition is a simple and effective aqueous solution, the raw materials are easy to obtain, the costs are low, the preparation process is simple, high environmental protection and high safety are achieved, and a deposited rare-earth metal layer has uniform crystal grains.

Description

Electrodeposition rare earth metal plating solution and preparation method and application thereof Technical Field

[0001] The invention belongs to the technical field of electroplating, and in particular relates to an electrodeposition rare earth metal plating solution and a preparation method and application thereof. Background Art

[0002] Due to their unique electronic structure, rare earth elements have the effects of refining grains of metals or alloys, reducing surface defects, and improving wear resistance and corrosion resistance.

[0003] Existing studies have reported that rare earth samarium films can effectively prevent the corrosion of base metals. When steel or aluminum-based materials containing coatings are immersed in a samarium salt bath or polarized as a cathode, their corrosion rate will be greatly reduced. Therefore, the utilization of rare earth metals has attracted the attention of more and more scholars in various metal materials fields.

[0004] However, due to the very negative deposition potential of rare earth metals, the current preparation of rare earth films mostly uses deposition methods such as molten salt and sputtering, which have disadvantages such as harsh production and preparation conditions, high costs, and environmental and safety risks.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a simple and effective aqueous solution electrodeposition rare earth metal plating solution and its preparation method and application, which has readily available raw materials, low cost, simple preparation process, strong environmental protection, high safety, and the deposited rare earth metal layer has uniform grains.

[0007] The present invention provides the following technical solutions:

[0008] In a first aspect, a rare earth metal electrodeposition plating solution is provided, wherein the plating solution raw materials include: a rare earth metal salt, a complexing agent and water;

[0009] The content of the rare earth metal salt in the plating solution is 0.15-0.55 mol / L, and the molar ratio of the complexing agent to the rare earth metal salt in the plating solution is 1:(1.5-5).

[0010] Furthermore, the rare earth metal salt includes one of rare earth metal chloride, rare earth metal nitrate, and rare earth metal acetate, preferably rare earth metal chloride.

[0011] Furthermore, the rare earth metal in the rare earth metal salt includes one of lanthanum, samarium and cerium.

[0012] Furthermore, the complexing agent includes one of citric acid, ethylenediaminetetraacetic acid, tartaric acid, sodium salt or potassium salt of citric acid, sodium salt or potassium salt of ethylenediaminetetraacetic acid, and sodium salt or potassium salt of tartaric acid.

[0013] Furthermore, the complexing agent includes a combination of any one of citric acid, ethylenediaminetetraacetic acid, and tartaric acid and any one of sodium salt or potassium salt of citric acid, sodium salt or potassium salt of ethylenediaminetetraacetic acid, and sodium salt or potassium salt of tartaric acid.

[0014] Preferably, the complexing agent is a combination of citric acid and its sodium salt or potassium salt, a combination of ethylenediaminetetraacetic acid and its sodium salt or potassium salt, or a combination of tartaric acid and its sodium salt or potassium salt. The combination of the two can form a more stable buffer system, which is more conducive to the stability of the plating solution.

[0015] Furthermore, the molar ratio of any one of citric acid, ethylenediaminetetraacetic acid, and tartaric acid to the sodium salt or potassium salt of citric acid, the sodium salt or potassium salt of ethylenediaminetetraacetic acid, and the sodium salt or potassium salt of tartaric acid is (1-5):1. A ratio that is too high or too low is not conducive to the stability of the buffer system.

[0016] Furthermore, the plating solution raw materials also include a pH regulator; the pH regulator includes a pH increase regulator and a pH decrease regulator; the pH increase regulator includes one of ammonia water, potassium hydroxide, and sodium hydroxide, preferably ammonia water; the pH decrease regulator includes one of hydrochloric acid, perchloric acid, nitric acid, and acetic acid, preferably the corresponding acid corresponding to the rare earth metal salt.

[0017] In a second aspect, a method for preparing the electrodeposited rare earth metal plating solution of the first aspect is provided, comprising:

[0018] Put water and complexing agent into the plating tank, stir evenly, and adjust the pH to a first preset value;

[0019] Adding rare earth metal salt to the plating tank, stirring evenly, and adjusting the pH to a second preset value;

[0020] Add water to the plating tank to the required volume to obtain an electrodeposition rare earth metal plating solution.

[0021] Furthermore, the first preset value of the pH is 4 to 5; the second preset value of the pH is 1.5 to 3.0, which is the pH of the final plating solution. If the pH of the plating solution is too high, it will be detrimental to the stability of the rare earth metal ions in the plating solution, and if the pH of the plating solution is too low, it will be detrimental to the precipitation of rare earth metal elements.

[0022] In a third aspect, an application of the electrodeposition rare earth metal plating solution of the first aspect is provided, comprising: using an insoluble anode, taking the workpiece to be electroplated as the cathode, and electroplating in the electrodeposition rare earth metal plating solution, wherein the electroplating current density is ≤10A / dm 2 , filtering, reflux and stirring are continuously performed during the electroplating process.

[0023] Furthermore, a barrel plating process is adopted.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The electrodeposition rare earth metal plating solution provided by the present invention comprises raw materials including a rare earth metal salt, a complexing agent, and water. It is a simple and effective plating solution formula for depositing a rare earth metal layer from an aqueous solution. The raw materials are readily available, and there is no reliance on organic solvents. The solution is low in cost, highly environmentally friendly, greatly reduces the complexity of the equipment, and is highly safe.

[0026] (2) The content of rare earth metal salt in the electrodeposition rare earth metal plating solution provided by the present invention is 0.15-0.55 mol / L, and the molar ratio of the complexing agent to the rare earth metal salt is 1:(1.5-5). The plating solution has high stability, and the deposited rare earth metal layer has uniform grains, which can be used for barrel plating. If the rare earth metal salt content is too high, the rare earth metal elements in the plating solution are more easily hydrolyzed, resulting in instability of the plating solution. If the rare earth metal salt content is too low, the rare earth metal elements are not easily plated. If the complexing agent content is too low, no complexing effect is achieved. If the complexing agent content is too high, the rare earth metal elements are more difficult to precipitate.

[0027] (3) The preparation method of the electrodeposited rare earth metal plating solution provided by the present invention is simple to operate and highly safe. In addition, the present invention stipulates that the order of adding the rare earth metal salt and the complexing agent must be to first dissolve the complexing agent in pure water and then add the rare earth metal salt. If the rare earth metal salt is dissolved first and then the complexing agent is added, it is easy to cause the rare earth metal ions in the plating solution to become emulsified, thereby causing the plating solution to be turbid. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a SEM morphology of a samarium metal layer deposited on the outer surface of a steel wire in Example 1 of the present invention;

[0029] FIG2 is a SEM morphology of rare earth metal salt precipitated on the outer surface of the steel wire in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] Example 1

[0032] A certain amount of pure water, citric acid and sodium citrate are placed in a plating tank, wherein the molar ratio of citric acid to sodium citrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of citric acid and sodium citrate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0033] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 The plating process lasted for 30 seconds, with continuous filtration, reflux, and stirring during the electroplating process to obtain the desired samarium metal layer. The morphology of the samarium layer is shown in Figure 1. The grains in the samarium layer are evenly distributed on the copper-based steel wire.

[0034] Example 2

[0035] A certain amount of pure water, citric acid and sodium citrate are placed in a plating tank, wherein the ratio of citric acid to sodium citrate is 5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.0; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 3.0. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of citric acid and sodium citrate in the plating solution is 0.11 mol / L, and the content of samarium chloride is 0.55 mol / L.

[0036] Steel wire is used as cathode and insoluble titanium plate is used as anode, and the current density is 10A / dm 2 , plating for 16 seconds, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0037] Example 3

[0038] A certain amount of pure water, citric acid and sodium citrate are placed in a plating tank, wherein the ratio of citric acid to sodium citrate is 1:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 5.0; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 1.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of citric acid and sodium citrate in the plating solution is 0.10 mol / L, and the content of samarium chloride is 0.15 mol / L.

[0039] Steel wire was used as cathode and insoluble titanium plate as anode, with a current density of 0.8A / dm 2 , plating for 2 minutes, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0040] Example 4

[0041] A certain amount of pure water and citric acid are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; samarium chloride is then added, stirred thoroughly to dissolve, and the pH is fine-tuned to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of citric acid in the plating solution is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0042] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0043] Example 5

[0044] A certain amount of pure water, tartaric acid and potassium tartrate are placed in a plating tank, wherein the ratio of tartaric acid to potassium tartrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of tartaric acid and potassium tartrate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0045] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0046] Example 6

[0047] A certain amount of pure water, tartaric acid and potassium tartrate are placed in a plating tank, wherein the ratio of tartaric acid to potassium tartrate is 5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.0; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 3.0. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of tartaric acid and potassium tartrate in the plating solution is 0.11 mol / L, and the content of samarium chloride is 0.55 mol / L.

[0048] Steel wire is used as cathode and insoluble titanium plate is used as anode, and the current density is 10A / dm 2 , plating for 16 seconds, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0049] Example 7

[0050] A certain amount of pure water, tartaric acid and potassium tartrate are placed in a plating tank, wherein the ratio of tartaric acid to potassium tartrate is 1:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 5.0; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 1.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of tartaric acid and potassium tartrate in the plating solution is 0.10 mol / L, and the content of samarium chloride is 0.15 mol / L.

[0051] Steel wire was used as cathode and insoluble titanium plate as anode, with a current density of 0.8A / dm 2 , plating for 2 minutes, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0052] Example 8

[0053] A certain amount of pure water and tartaric acid are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; samarium chloride is then added, stirred thoroughly to dissolve, and the pH is fine-tuned to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of tartaric acid in the plating solution is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0054] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0055] Example 9

[0056] A certain amount of pure water, ethylenediaminetetraacetic acid, and sodium ethylenediaminetetraacetate are placed in a plating tank, wherein the ratio of ethylenediaminetetraacetic acid to sodium ethylenediaminetetraacetate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of ethylenediaminetetraacetic acid and sodium ethylenediaminetetraacetate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0057] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0058] Example 10

[0059] A certain amount of pure water, ethylenediaminetetraacetic acid, and sodium ethylenediaminetetraacetate are placed in a plating tank, wherein the ratio of ethylenediaminetetraacetic acid to sodium ethylenediaminetetraacetate is 5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.0; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 3.0. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of ethylenediaminetetraacetic acid and sodium ethylenediaminetetraacetate in the plating solution is 0.11 mol / L, and the content of samarium chloride is 0.55 mol / L.

[0060] Steel wire is used as cathode and insoluble titanium plate is used as anode, and the current density is 10A / dm 2 , plating for 16 seconds, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0061] Example 11

[0062] A certain amount of pure water, ethylenediaminetetraacetic acid, and sodium ethylenediaminetetraacetate are placed in a plating tank, wherein the ratio of ethylenediaminetetraacetic acid to sodium ethylenediaminetetraacetate is 1:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 5.0; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 1.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of ethylenediaminetetraacetic acid and sodium ethylenediaminetetraacetate in the plating solution is 0.10 mol / L, and the content of samarium chloride is 0.15 mol / L.

[0063] Steel wire was used as cathode and insoluble titanium plate as anode, with a current density of 0.8A / dm 2 , plating for 2 minutes, filtering, refluxing and stirring continuously during the electroplating period to obtain the required metal samarium layer.

[0064] Example 12

[0065] A certain amount of pure water and ethylenediaminetetraacetic acid are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added, stirred thoroughly to dissolve, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of ethylenediaminetetraacetic acid in the plating solution is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0066] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0067] Example 13

[0068] A certain amount of pure water and potassium EDTA are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; samarium chloride is then added, stirred thoroughly to dissolve, the pH is slightly adjusted to 2.5, and finally pure water is added to the required volume to obtain the required plating solution, in which the content of potassium EDTA in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0069] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0070] Example 14

[0071] A certain amount of pure water and potassium citrate are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; samarium chloride is then added, stirred thoroughly to dissolve, and the pH is fine-tuned to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of potassium citrate in the plating solution is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0072] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0073] Example 15

[0074] A certain amount of pure water and sodium tartrate are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; samarium chloride is then added, stirred thoroughly to dissolve, and the pH is fine-tuned to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of sodium tartrate is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0075] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0076] Example 16

[0077] A certain amount of pure water, citric acid and sodium tartrate are placed in a plating tank, wherein the ratio of citric acid to sodium tartrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the total content of citric acid and sodium tartrate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0078] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0079] Example 17

[0080] A certain amount of pure water, ethylenediaminetetraacetic acid, and potassium citrate are placed in a plating tank, wherein the ratio of ethylenediaminetetraacetic acid to potassium citrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and fully stirred to dissolve it, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of ethylenediaminetetraacetic acid and potassium citrate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0081] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, refluxing and stirring continuously during the electroplating period to obtain the desired metal samarium layer.

[0082] Comparative Example 1

[0083] A certain amount of pure water, citric acid and sodium citrate are placed in a plating tank, wherein the ratio of citric acid to sodium citrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of citric acid and sodium citrate in the plating solution is 0.07 mol / L, and the content of samarium chloride is 0.1 mol / L.

[0084] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 The plating was carried out for 30 seconds. During the electroplating period, the system was continuously filtered, refluxed and stirred. During the electroplating process, hydrogen was vigorously released from the cathode, and almost no samarium layer was deposited on the steel wire.

[0085] Comparative Example 2

[0086] A certain amount of pure water, tartaric acid and sodium citrate are placed in a plating tank, wherein the ratio of tartaric acid to sodium citrate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, in which the total content of tartaric acid and sodium citrate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.6 mol / L.

[0087] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 30s, filtering, reflux and stirring continuously during the electroplating period, and rare earth salts adhere to the surface of the steel wire after the electroplating is completed, as shown in Figure 2.

[0088] Comparative Example 3

[0089] A certain amount of pure water, tartaric acid and potassium ethylenediaminetetraacetate are placed in a plating tank, wherein the ratio of tartaric acid to potassium ethylenediaminetetraacetate is 2.5:1, and they are fully stirred to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added thereto, and it is fully stirred to dissolve, and the pH is slightly adjusted to 2.5. Finally, pure water is added to the required volume to obtain the required plating solution, wherein the total content of tartaric acid and potassium ethylenediaminetetraacetate in the plating solution is 0.12 mol / L, and the content of samarium chloride is 0.3 mol / L.

[0090] Steel wire was used as cathode and insoluble titanium plate as anode, with a current density of 15.0A / dm 2 , plating for 30s, filtering, reflux and stirring continuously during the electroplating process, the cathode vigorously releases hydrogen during the electroplating process, and almost no samarium layer is deposited on the steel wire.

[0091] Comparative Example 4

[0092] Place a certain amount of pure water and 0.12 mol / L citric acid in a plating tank, stir thoroughly to dissolve and homogenize, and adjust the pH to 4.5; then add 0.3 mol / L samarium chloride, stir thoroughly to dissolve, and fine-tune the pH to 3.5. The plating solution is turbid and cannot be electroplated.

[0093] Comparative Example 5

[0094] A certain amount of pure water and ethylenediaminetetraacetic acid are placed in a plating tank, stirred thoroughly to dissolve and homogenize, and the pH is adjusted to 4.5; then samarium chloride is added, stirred thoroughly to dissolve, and the pH is slightly adjusted to 1.2. Finally, pure water is added to the required volume to obtain the required plating solution, in which the content of ethylenediaminetetraacetic acid in the plating solution is 0.12 mol / L and the content of samarium chloride is 0.3 mol / L.

[0095] Steel wire is used as cathode and insoluble titanium plate is used as anode, with a current density of 6.0A / dm 2 , plating for 1 minute, filtering, reflux and stirring continuously during the electroplating process, the cathode vigorously releases hydrogen during the electroplating process, and almost no samarium layer is deposited on the steel wire.

[0096] Comparative Example 6

[0097] Place a certain amount of pure water and 0.12 mol / L tartaric acid in a plating tank, stir thoroughly to dissolve and homogenize, and adjust the pH to 5.5; then add 0.3 mol / L samarium chloride and stir thoroughly to dissolve it. During the dissolution process of samarium chloride, the plating solution becomes turbid and cannot be electroplated.

[0098] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electrodeposition rare earth metal plating solution, characterized in that: The raw materials of the plating solution include: rare earth metal salt, complexing agent and water; The content of the rare earth metal salt in the plating solution is 0.15-0.55 mol / L, and the molar ratio of the complexing agent to the rare earth metal salt in the plating solution is 1:(1.5-5).

2. The electrodeposition rare earth metal plating solution according to claim 1, characterized in that: The rare earth metal salt includes one of rare earth metal chloride, rare earth metal nitrate and rare earth metal acetate.

3. The electrodeposition rare earth metal plating solution according to claim 1, characterized in that: The rare earth metal in the rare earth metal salt includes one of lanthanum, samarium and cerium.

4. The electrodeposition rare earth metal plating solution according to claim 1, characterized in that: The complexing agent includes one of citric acid, ethylenediaminetetraacetic acid, tartaric acid, sodium salt or potassium salt of citric acid, sodium salt or potassium salt of ethylenediaminetetraacetic acid, and sodium salt or potassium salt of tartaric acid.

5. The electrodeposition rare earth metal plating solution according to claim 1, characterized in that: The complexing agent includes a combination of any one of citric acid, ethylenediaminetetraacetic acid, and tartaric acid and any one of sodium salt or potassium salt of citric acid, sodium salt or potassium salt of ethylenediaminetetraacetic acid, and sodium salt or potassium salt of tartaric acid.

6. The electrodeposition rare earth metal plating solution according to claim 5, characterized in that: The molar ratio of any one of citric acid, ethylenediaminetetraacetic acid, and tartaric acid to any one of sodium salt or potassium salt of citric acid, sodium salt or potassium salt of ethylenediaminetetraacetic acid, and sodium salt or potassium salt of tartaric acid is (1-5):

1.

7. The electrodeposition rare earth metal plating solution according to claim 1, characterized in that: The plating solution raw materials also include a pH adjuster; the pH adjuster includes a pH upward adjuster and a pH downward adjuster; the pH upward adjuster includes one of ammonia water, potassium hydroxide, and sodium hydroxide, and the pH downward adjuster includes one of hydrochloric acid, perchloric acid, nitric acid, and acetic acid.

8. A method for preparing the electrodeposition rare earth metal plating solution according to any one of claims 1 to 7, characterized in that: include: Put water and complexing agent in the plating tank, stir evenly, and adjust the pH to a first preset value; Adding rare earth metal salt into the plating tank, stirring evenly, and adjusting the pH to a second preset value; Add water to the plating tank to the required volume to obtain an electrodeposition rare earth metal plating solution.

9. The method for preparing the electrodeposition rare earth metal plating solution according to claim 8, characterized in that: The first preset value of pH is 4-5, and the second preset value of pH is 1.5-3.

0.

10. Use of the rare earth metal electrodeposition plating solution according to any one of claims 1 to 7, characterized in that: include: An insoluble anode is used, and the workpiece to be electroplated is used as the cathode. Electroplating is carried out in the electrodeposition rare earth metal plating solution, and the current density of the electroplating is ≤10A / dm 2 , filtering, reflux and stirring are continuously performed during the electroplating process.

Images