Nickel alloy electroplating solution and electroplating process

Abstract

The invention provides a nickel alloy electroplating solution and an electroplating process. The nickel alloy electroplating solution comprises the following components: 150-250 g / L of nickel sulfate; boric acid: 30-50 g / L; 80 to 130 mL / L of mixed organic acid; 15 to 30 mL / L of a metal blackening agent; and 3-10 mL / L of an organic dispersant. According to the environment-friendly electroplating liquid, an alloy coating comparable to highly toxic hexavalent chromium black chromium can be obtained, a traditional hexavalent chromium black chromium electroplating process can be replaced according to the requirements of products in some fields, and an implementation scheme capable of achieving the purposes of reducing pollution, improving efficiency, reducing cost and expanding production benefits is provided for customers; and the product competitiveness and the product diversity of enterprises can be improved. The invention further provides a preparation method and an electroplating method of the nickel alloy electroplating solution.

Description

Technical Field

[0001] The invention belongs to the technical field of nickel alloy electroplating, and in particular relates to a nickel alloy electroplating solution and an electroplating process. Background Art

[0002] With the development of industrial technology, the demand for functional and decorative surface treatment processes is growing. Black chrome plating has been widely used in various fields due to its unique optical properties and appearance characteristics. Hexavalent black chrome plating has excellent selective light absorption ability, which can almost completely absorb visible light and near-infrared light waves, making it an ideal choice for products such as solar absorbers, optical instruments, military weapons, and high-end cameras. In addition, the solemn and elegant black appearance of black chrome plating is also popular in areas such as automotive decorative parts, daily hardware and tools. However, chromic acid (CrO3), the core component of hexavalent chromium black chrome plating solution, is extremely carcinogenic and toxic, posing a serious threat to the health of operators and causing persistent pollution to the environment. With increasingly stringent global environmental regulations, such as the EU RoHS Directive and REACH regulations, have imposed strict restrictions on the use of hexavalent chromium. Therefore, the development of environmentally friendly alternative processes has become an urgent need in the industry.

[0003] Currently, the main alternatives to hexavalent chromium black chrome on the market include organic coating technologies such as electrophoretic black paint and spray black paint. Although these methods can simulate the black appearance of black chrome plating to a certain extent, there are still obvious gaps in terms of metallic texture, blackness and wear resistance. The electrophoretic black paint coating lacks the gloss and hardness unique to metal plating, while the spraying process with the addition of black slurry is prone to color difference and surface unevenness, making it difficult to meet the requirements of high-end decorative coatings. In addition, the weather resistance and corrosion resistance of organic coatings are usually inferior to those of metal plating, and fading or peeling may occur after long-term use. Therefore, it is difficult to completely replace the comprehensive performance of hexavalent chromium black chrome plating by relying solely on organic coating technology. There is an urgent need to explore a new surface treatment technology that can meet environmental protection requirements while retaining the excellent properties of black chrome plating.

[0004] In recent years, researchers have attempted to replace the hexavalent chromium black chromium process through alloy electroplating, trivalent chromium electroplating, and other methods, but most solutions still have problems such as insufficient blackness, poor bonding strength, or poor process stability. For example, although the trivalent chromium black chromium plating process has low toxicity, the blackness and uniformity of the coating are often difficult to reach the level of hexavalent chromium plating; and although some alloy electroplating processes can achieve a darker black color, they are difficult to apply on a large scale due to complex components or high costs. Therefore, the development of a new environmentally friendly black chromium plating solution and supporting electroplating process, so that the coating is close to the traditional hexavalent chromium black chromium plating in terms of blackness, metallic texture, wear resistance and corrosion resistance, while complying with environmental protection regulations, has become a key technical issue that needs to be urgently addressed in the current surface treatment field. This breakthrough will not only promote the advancement of green manufacturing technology, but also provide a more sustainable solution for the high-end decorative and functional coating market. Summary of the Invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a nickel alloy electroplating solution that can produce an alloy layer with properties similar to those of conventional hexavalent chromium black chrome plating in terms of blackness, metallic texture, wear resistance, and corrosion resistance.

[0006] The invention also provides a method for preparing the nickel alloy electroplating solution.

[0007] The invention also provides a nickel alloy plating method.

[0008] A first aspect of the present invention provides a nickel alloy electroplating solution, comprising:

[0009] Nickel sulfate: 150-250 g / L;

[0010] Boric acid: 30-50 g / L;

[0011] Mixed organic acids: 80-130 mL / L;

[0012] Metal blackening agent: 15-30mL / L;

[0013] Organic dispersant: 3-10 mL / L.

[0014] One of the technical solutions of the present invention regarding the nickel alloy electroplating solution has at least the following beneficial effects:

[0015] The present invention uses an environmentally friendly electroplating solution to obtain an alloy coating comparable to the highly toxic hexavalent chromium black chromium. It can replace the traditional hexavalent chromium black chromium electroplating process to meet the needs of products in certain fields, providing customers with an implementation plan that can reduce pollution, increase efficiency, lower costs, and maximize production benefits. It can also improve the company's own product competitiveness and product diversity.

[0016] The electroplating solution of the present invention can replace the highly toxic and polluting hexavalent chromium black chromium electroplating process in certain fields. Moreover, because the electroplating solution can directly electroplate a black coating on iron or stainless steel, it can also replace traditional surface treatment processes such as high-temperature blackening of iron or stainless steel, thereby having the advantages of reducing production costs, pollutant emissions, and production energy consumption.

[0017] In the electroplating solution of the present invention, the mixed organic acid serves as a chelating agent, which functions to stabilize the metal ions in the plating solution.

[0018] The function of the metal blackening agent is to co-deposit with metallic nickel to form a deep black alloy coating.

[0019] The function of organic dispersants is to reduce the surface tension of the plating solution, which is conducive to uniform coating.

[0020] According to some embodiments of the present invention, the mixed organic acid is at least two of malic acid, citric acid, aminosulfonic acid, aspartic acid, glycine and potassium thionine.

[0021] According to some embodiments of the present invention, the mixed organic acid is a mixed acid of aminosulfonic acid and glycine.

[0022] According to some embodiments of the present invention, the mixed organic acid is a mixed acid of aminosulfonic acid and glycine, with a mass ratio of 7 to 10:1.

[0023] According to some embodiments of the present invention, the metal blackening agent is at least two of zinc sulfate, zinc chloride, zinc acetate, stannous chloride, stannous sulfate, manganese sulfate, potassium antimony tartrate and potassium fluorozirconate.

[0024] According to some embodiments of the present invention, the metal blackening agent is a mixture of stannous sulfate and potassium fluorozirconate.

[0025] According to some embodiments of the present invention, the metal blackening agent is a mixture of stannous sulfate and potassium fluorozirconate in a mass ratio of 4 to 6:1.

[0026] According to some embodiments of the present invention, the organic dispersant is at least one of polyethylene glycol and fatty alcohol polyoxyethylene ether.

[0027] According to some embodiments of the present invention, the polyethylene glycol is polyethylene glycol 600 to polyethylene glycol 2000.

[0028] According to some embodiments of the present invention, the polyethylene glycol has a molecular weight between 600 and 2000.

[0029] According to some embodiments of the present invention, in the nickel alloy electroplating solution, the solvent is water.

[0030] According to some embodiments of the present invention, the nickel alloy electroplating solution contains nickel sulfate: 150-250 g / L.

[0031] According to some embodiments of the present invention, the nickel alloy electroplating solution contains any value of nickel sulfate 150g / L, 160g / L, 170g / L, 180g / L, 190g / L, 200g / L, 210g / L, 220g / L, 230g / L, 240g / L, 250g / L or a range formed by any two of them, such as 200g / L to 220g / L.

[0032] According to some embodiments of the present invention, the nickel alloy electroplating solution contains 30-50 g / L of boric acid.

[0033] According to some embodiments of the present invention, the nickel alloy electroplating solution contains any one of 30 g / L, 35 g / L, 40 g / L, 45 g / L, and 50 g / L of boric acid, or a range formed by any two of the values, such as 40 g / L to 45 g / L.

[0034] According to some embodiments of the present invention, the nickel alloy electroplating solution contains 80-130 mL / L of mixed organic acid.

[0035] According to some embodiments of the present invention, the nickel alloy electroplating solution contains any value of 80 mL / L, 90 mL / L, 100 mL / L, 110 mL / L, 120 mL / L, 130 mL / L of mixed organic acid or a range formed by any two of them, such as 100 mL / L to 120 mL / L.

[0036] According to some embodiments of the present invention, the nickel alloy electroplating solution contains 15 to 30 mL / L of a metal blackening agent.

[0037] According to some embodiments of the present invention, the nickel alloy electroplating solution contains any one of 15 mL / L, 20 mL / L, 25 mL / L, and 30 mL / L of metal blackening agent, or a range formed by any two of them, such as 20 mL / L to 25 mL / L.

[0038] According to some embodiments of the present invention, the nickel alloy electroplating solution contains 3 to 10 mL / L of an organic dispersant.

[0039] According to some embodiments of the present invention, the nickel alloy electroplating solution contains any value of 3 mL / L, 4 mL / L, 5 mL / L, 6 mL / L, 7 mL / L, 8 mL / L, 9 mL / L, 10 mL / L of organic dispersant or a range of values formed by any two of them, such as 6 mL / L to 8 mL / L.

[0040] The second aspect of the present invention provides a method for preparing the nickel alloy electroplating solution of the first aspect of the present invention, comprising the following steps: adding the nickel sulfate and boric acid to water, stirring and dissolving, adding the mixed organic acid, metal blackening agent and organic dispersant, adjusting the pH and then fixing the volume.

[0041] The method for preparing the nickel alloy electroplating solution does not require expensive equipment and complicated process control, has undemanding reaction conditions, readily available raw materials, low production cost, and is easy to industrialize.

[0042] According to some embodiments of the present invention, the pH is adjusted to 2-3 before constant volume in order to obtain a stable and uniform black alloy coating.

[0043] The third aspect of the present invention provides a method for plating nickel alloy, which includes the steps of electroplating a workpiece to be plated using the nickel alloy electroplating solution of the first aspect of the present invention to form a nickel alloy layer on the surface of the workpiece to be plated.

[0044] The nickel alloy plating method of the present invention has at least the following beneficial effects:

[0045] 1. As a safe alternative, more environmentally friendly, specifically:

[0046] It can replace the highly polluting hexavalent chromium black chrome plating or high-temperature blackening process, eliminate the use of highly toxic substances (such as hexavalent chromium), and significantly reduce environmental, energy consumption and health risks.

[0047] Avoiding the generation of harmful substances such as chromic acid mist and chromium-containing wastewater is in line with the trend of green manufacturing.

[0048] 2. Simplified the process and optimized the cost. Specifically:

[0049] No pretreatment is required (such as high-temperature oxidation or passivation of iron / stainless steel), and a black coating can be formed directly on iron or stainless steel, reducing process and equipment investment.

[0050] It eliminates the energy consumption of high-temperature blackening process (traditional process requires above 100℃), thus saving production costs.

[0051] The components of the plating solution are all conventional chemicals, without any scarce or expensive materials, and the cost is controllable.

[0052] 3. The coating performance is better. The black alloy coating obtained by the system is close to hexavalent chromium coating in color, uniformity and decorativeness, meeting the high-end appearance requirements (such as electronic products and automotive parts) and comparable to traditional black chrome.

[0053] Due to the high stability of the plating solution, the mixed organic acid chelates the metal ions and reduces the impact of impurities; the organic dispersant improves the wettability of the plating solution to ensure that the coating is dense and defect-free.

[0054] 4. Improved production efficiency. Diversified applications broaden product design possibilities (such as deep black exterior parts) and enhance market competitiveness. Simplified processes shorten production cycles. The use of dispersants reduces coating defect rates, resulting in overall increased production capacity.

[0055] 5. Complying with relevant regulations and sustainability requirements, it avoids increasingly stringent chromium pollution restrictions (such as RoHS and REACH), helping companies pass environmental certifications, promoting the industry's transition to low-toxicity and low-energy technologies, and enhancing the company's social image.

[0056] The nickel plating method of the present invention achieves a balance between performance, cost, and environmental protection through an environmentally friendly formula and a simplified process. It is particularly suitable for fields such as hardware, electronics, and automotive parts that require black plating, and has both economic benefits and social value.

[0057] According to some embodiments of the present invention, the workpiece to be plated includes an electroplated workpiece having a nickel-plated surface, an electroplated workpiece having a copper-plated surface, a copper alloy electroplated workpiece, or an iron electroplated workpiece.

[0058] According to some embodiments of the present invention, the nickel plating method of the present invention has a temperature of 45-55°C.

[0059] According to some embodiments of the present invention, the nickel plating method of the present invention has a temperature of any one of 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, and 55°C, or a range formed by any two of them, such as 48°C to 50°C.

[0060] According to some embodiments of the present invention, in the nickel plating method of the present invention, the pH value of the plating solution is 2-3.

[0061] According to some embodiments of the present invention, in the nickel plating method of the present invention, the pH of the plating solution is any one of 2, 2.2, 2.4, 2.6, 2.8, and 3.0, or a range formed by any two of them, such as 2.4 to 2.6.

[0062] According to some embodiments of the present invention, in the nickel plating method of the present invention, the cathode current density is 1.0 to 2.0 ASD.

[0063] According to some embodiments of the present invention, in the nickel plating method of the present invention, the cathode current density is any value among 1.0ASD, 1.2ASD, 1.4ASD, 1.6ASD, 1.8ASD, 2.0ASD, or a range formed by any two of them, such as 1.6 to 1.8ASD.

[0064] According to some embodiments of the present invention, in the nickel plating method of the present invention, the electroplating time is 3 to 10 minutes.

[0065] According to some embodiments of the present invention, in the nickel plating method of the present invention, the electroplating time is any value among 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min or a range formed by any two of them, such as 5min to 7min.

[0066] According to some embodiments of the present invention, in the nickel alloy plating method of the present invention, the electroplating method is static electroplating. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a diagram showing the effect of electroplating the nickel alloy Hastelloy slot standard sheet in Example 1.

[0068] Figure 2 This is a comparison chart of the effect of electroplating the nickel alloy to-be-plated part with pores in Example 2 and the effect of traditional hexavalent chromium and black chromium electroplating. DETAILED DESCRIPTION

[0069] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0070] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0071] Unless otherwise specified, "room temperature" in the present invention means 25°C±5°C.

[0072] Unless otherwise specified, “about” in the present invention means that the allowable error is within ±2%.

[0073] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0074] Example 1

[0075] First, a nickel alloy electroplating solution was prepared, the specific composition of which is:

[0076] Nickel sulfate: 200g / L;

[0077] Boric acid: 40g / L;

[0078] Mixed organic acids: 100mL / L;

[0079] Metal blackening agent: 20mL / L;

[0080] Organic dispersant: 6mL / L;

[0081] The solvent is water.

[0082] The mixed organic acid is a mixture of aminosulfonic acid and glycine in a mass ratio of 8:1.

[0083] The metal blackening agent is a mixture of stannous sulfate and potassium fluorozirconate with a mass ratio of 5:1.

[0084] The organic dispersant is polyethylene glycol 1000.

[0085] The preparation method of nickel alloy electroplating solution is as follows: nickel sulfate and boric acid are added to hot water according to the component ratio, and after stirring to dissolve, a mixed organic acid, metal blackening agent and organic dispersant are added, and stirring is continued for more than 30 minutes to make the plating solution uniform and chelated completely. Finally, ammonia water is used to adjust the pH value of the solution to 2.5 and then the volume is fixed.

[0086] The nickel alloy Hastelloy trough standard sheet was electroplated using the above plating solution in the following manner:

[0087] With the nickel plate as the anode and the workpiece to be plated as the cathode, in a static state, power was applied (current 0.5A) for 5 minutes under standard operating conditions (50℃, 1ASD, pH: 2.5), and a uniform dark black alloy coating was obtained. Figure 1 shown.

[0088] from Figure 1 It can be seen that, by using the plating solution of the present invention, a uniform deep black alloy coating is obtained after nickel plating, and the blackness of the coating is comparable to that of hexavalent chromium black chrome.

[0089] Example 2

[0090] First, a nickel alloy electroplating solution was prepared, the specific composition of which is:

[0091] Nickel sulfate: 200g / L;

[0092] Boric acid: 40g / L;

[0093] Mixed organic acids: 100mL / L;

[0094] Metal blackening agent: 20mL / L;

[0095] Organic dispersant: 6mL / L;

[0096] The solvent is water.

[0097] The mixed organic acid is a mixture of aminosulfonic acid and glycine in a mass ratio of 10:1.

[0098] The metal blackening agent is a mixture of stannous sulfate and potassium fluorozirconate with a mass ratio of 6:1.

[0099] The organic dispersant is polyethylene glycol 1000.

[0100] The preparation method of nickel alloy electroplating solution is as follows: nickel sulfate and boric acid are added to hot water according to the component ratio, and after stirring to dissolve, a mixed organic acid, metal blackening agent and organic dispersant are added, and stirring is continued for more than 30 minutes to make the plating solution uniform and chelated completely. Finally, ammonia water is used to adjust the pH value of the solution to 2.5 and then the volume is fixed.

[0101] The nickel alloy plated part having pores is nickel plated using the above plating solution, and the method is as follows:

[0102] With the nickel plate as the anode and the workpiece to be plated as the cathode, the electroplating was conducted for 5 minutes under standard operating conditions (50°C, 1ASD, pH: 2.5) to obtain a uniform dark black alloy coating. Figure 2 shown.

[0103] from Figure 2 It can be seen that, by using the plating solution of the present invention, a uniform deep black alloy coating is obtained after nickel plating, and the blackness of the coating is comparable to that of hexavalent chromium black chrome.

[0104] Comparative Example 1

[0105] The nickel alloy electroplating solution of this comparative example is different from that of Example 1 in that the organic acid is only aminosulfonic acid and no glycine is added.

[0106] The nickel alloy Hastelloy trough standard sheet is nickel plated using the above plating solution in the following manner:

[0107] Using a nickel plate as the anode and the workpiece to be plated as the cathode, in a static state, power is applied (current 0.5A) for 5 minutes under standard operating conditions (50°C, 1ASD, pH: 2.5). Only a dark black alloy coating with poor uniformity and slightly poor blackness can be obtained.

[0108] Comparative Example 2

[0109] The nickel alloy electroplating solution of this comparative example is different from that of Example 1 in that the metal blackening agent is stannous sulfate and potassium fluorozirconate is not added.

[0110] The nickel alloy Hastelloy trough standard sheet is nickel plated using the above plating solution in the following manner:

[0111] Using a nickel plate as the anode and the workpiece to be plated as the cathode, in a static state, power was applied (current 0.5A) for 5 minutes under standard operating conditions (50°C, 1ASD, pH: 2.5), and a dark black alloy coating with poor covering ability was obtained.

[0112] Comparative Example 3

[0113] A commercially available traditional hexavalent black chromium-plated wrench was selected as a control for subsequent measurements.

[0114] Performance Testing

[0115] The color difference and glossiness values of the plated parts of Example 1, Example 2 and Comparative Examples 1 to 3 were tested, and the results are shown in Table 1.

[0116] Table 1

[0117]

[0118] From the data in Table 1, it can be seen that the coating of Comparative Example 1 has a slightly poor blackness and is yellowish, and the color difference L value and a value are both high; while the coating of Comparative Example 2 is rougher and the color difference L value is lower. Specifically:

[0119] The L values of Example 1 and Example 2 (17.1 / 17.8) are close to the L value of Comparative Example 3 (hexavalent chromium black chrome) (16.5), indicating that the blackness of the coating of the present invention is comparable to that of conventional hexavalent chromium black chrome, verifying its substitutability.

[0120] The a / b values of Example 1 and Example 2 (0.58 / 1.7, 0.50 / 1.6) are close to neutral, indicating that the coating color is pure without obvious red / green or yellow / blue color shift.

[0121] The a value (0.85) and b value (2.4) of Comparative Example 3 (hexavalent chromium) are higher, indicating that the conventional process has a slight reddish-yellow cast, while the coating of the present invention has a more neutral color.

[0122] Comparative Example 1 (single aminosulfonic acid) has a higher L value (19.5) and insufficient blackness, indicating that the synergistic effect of the mixed organic acid (aminosulfonic acid + glycine) on blackness is crucial.

[0123] Comparative Example 2 (single stannous sulfate) has the lowest L value (15.2), higher blackness, but poor glossiness and uniformity, indicating that a single blackening agent can enhance blackness but sacrifices other properties.

[0124] Glossiness:

[0125] The glossiness of Example 1 and Example 2 at a low angle (20°) (0.15 / 0.12) is significantly lower than that of Comparative Example 3 (0.40), indicating that the coating surface of the present invention is more matte and better meets the low-reflection requirements of high-end decorative parts.

[0126] Comparative Example 1 (single organic acid) has a higher gloss (20°: 0.22), which proves that mixed organic acids can improve the uniformity of the coating and reduce the gloss.

[0127] The 85° glossiness (68) of Comparative Example 2 (single blackening agent) is low, indicating that the coating is rough, which further verifies that the compounding of stannous sulfate and potassium fluorozirconate can improve the surface smoothness.

[0128] The present invention achieves blackness (L value ≤ 18), neutral color and matte effect (low gloss) comparable to traditional black chrome without hexavalent chromium through the synergistic effect of mixed organic acid (aminosulfonic acid + glycine) and composite blackening agent (stannous sulfate + potassium fluorozirconate).

[0129] The absence of the mixed organic acid (Comparative Example 1) will lead to a decrease in blackness and an increase in glossiness; the absence of the composite blackening agent (Comparative Example 2) can improve the blackness but sacrifice uniformity.

[0130] In terms of process advantages, the coatings of Example 1 and Example 2 are more effective in complex channel parts (such as Figure 2 ), which proves that the organic dispersant (polyethylene glycol) effectively improves the wettability of the plating solution and is suitable for precision components.

[0131] Using the plating solution of the present invention, with a nickel plate as the anode and a nickel coating, copper coating, copper alloy, iron, or other material as the cathode, and applying power for 5 minutes under standard operating conditions in a static state, a uniform, deep black alloy coating can be obtained, with a blackness comparable to hexavalent chromium black chrome. Furthermore, after the coating is baked and painted, a 100-grid test demonstrates excellent adhesion between the coating and the paint layer, reaching level 0, meeting the application requirements of most fields.

[0132] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the spirit of the present invention.

Claims

1. A nickel alloy electroplating solution, characterized in that The nickel alloy electroplating solution comprises: Nickel sulfate: 150-250 g / L; Boric acid: 30-50 g / L; Mixed organic acids: 80-130 mL / L; Metal blackening agent: 15-30mL / L; Organic dispersant: 3-10 mL / L.

2. The nickel alloy electroplating solution according to claim 1, characterized in that The mixed organic acid is at least two of malic acid, citric acid, aminosulfonic acid, aspartic acid, glycine and potassium thionine.

3. The nickel alloy electroplating solution according to claim 2, characterized in that The mixed organic acid is a mixed acid of aminosulfonic acid and glycine.

4. The nickel alloy electroplating solution according to claim 1, characterized in that The metal blackening agent is at least two of zinc sulfate, zinc chloride, zinc acetate, stannous chloride, stannous sulfate, manganese sulfate, potassium antimony tartrate and potassium fluorozirconate.

5. The nickel alloy electroplating solution according to claim 4, characterized in that The metal blackening agent is a mixture of stannous sulfate and potassium fluorozirconate.

6. The nickel alloy electroplating solution according to claim 1, characterized in that The organic dispersant is at least one of polyethylene glycol and fatty alcohol polyoxyethylene ether.

7. The nickel alloy electroplating solution according to claim 6, characterized in that The polyethylene glycol is polyethylene glycol 600 to polyethylene glycol 2000.

8. A method for preparing the nickel alloy electroplating solution according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: adding the nickel sulfate and boric acid into water, stirring and dissolving them, adding the mixed organic acid, metal blackening agent and organic dispersant, adjusting the pH and then fixing the volume.

9. A nickel alloy plating method, characterized in that: The nickel alloy plating method comprises the steps of electroplating a workpiece to be plated using the nickel alloy electroplating solution according to any one of claims 1 to 6 to form a nickel plating layer on the surface of the workpiece to be plated.

10. The nickel alloy plating method according to claim 9, characterized in that: The workpiece to be plated includes an electroplated workpiece with a nickel-plated surface, an electroplated workpiece with a copper-plated surface, a copper alloy electroplated workpiece or an iron electroplated workpiece.

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