A silicon carbide particle reinforced gradient nickel-tungsten alloy coating and its preparation method

Abstract

The present invention provides a silicon carbide particle-reinforced gradient nickel-tungsten alloy coating and a preparation method thereof. The preparation method comprises the following steps: 1) preparing a base nickel-tungsten alloy plating solution; 2) preparing nickel-tungsten alloy plating solutions containing low-concentration silicon carbide particles, medium-concentration silicon carbide particles, and high-concentration silicon carbide particles, respectively; and 3) sequential electroplating. Compared with conventional nickel-tungsten alloys, the silicon carbide particle-reinforced gradient nickel-tungsten alloy coating prepared by the preparation method provided by the present invention has higher hardness and better resistance to high-temperature oxidation and wear. Compared with conventional spray coatings and metal ceramics, it has better toughness and higher hardness than chrome plating, and has broad application prospects in the fields of aerospace and military equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of surface engineering, and in particular relates to a high-temperature wear-resistant silicon carbide particle-reinforced gradient nickel-tungsten alloy coating and a preparation method thereof. Background Art

[0002] Mechanical components used in aviation, aerospace, and military equipment are often subject to the dual effects of high temperatures and wear, which shortens their lifespan. Coatings, such as thermal spraying WC-Co, NiCr, and Al2O3, are effective methods for improving material surface properties and are often used to enhance their resistance to high-temperature wear. Cermets, due to their self-lubricating and high-temperature resistance, are often used to protect products prone to high-temperature wear, such as bearings and hot-rolled rollers. However, their poor toughness and impact resistance limit their application in military equipment and other fields.

[0003] Nickel-tungsten alloys have broad application prospects due to their excellent corrosion and wear resistance. They are often used to protect mechanical parts and possess better overall performance than conventional chrome and nickel plating. Tungsten in nickel-tungsten alloys is the metallic element with the highest melting point, and its content has a significant impact on the high-temperature resistance of the coating. A higher tungsten content improves the coating's high-temperature resistance. However, an increase in tungsten content increases internal stress in the coating. When internal stress accumulates to a certain level, cracks and pores are more likely to form in the coating, affecting its protective performance against the substrate, thus limiting the application of nickel-tungsten alloys.

[0004] Therefore, it is an urgent problem to provide a new particle-reinforced nickel-tungsten alloy coating that does not affect the toughness of the coating and is resistant to high-temperature wear. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating.

[0006] Another object of the present invention is to provide a silicon carbide particle reinforced gradient nickel-tungsten alloy coating, which is resistant to high temperature wear.

[0007] In order to achieve the above object, the present invention provides a method for preparing a high-temperature wear-resistant silicon carbide particle reinforced gradient nickel-tungsten alloy coating, comprising the following steps:

[0008] 1) Prepare nickel-tungsten alloy plating solution base:

[0009] Nickel sulfate, sodium tungstate, sodium pyrophosphate, and stabilizer are dissolved in deionized water to prepare a nickel-tungsten alloy plating solution base solution; wherein the concentration of sodium tungstate is 30-40 g / L, the concentration of nickel sulfate is 20-25 g / L, the molar concentration of sodium pyrophosphate is 3 times the molar concentration of nickel sulfate, the concentration of stabilizer is 0.05 g / L, and the pH is 7.5-8.5;

[0010] 3) Prepare nickel-tungsten alloy plating solutions containing low-concentration silicon carbide particles, medium-concentration silicon carbide particles, and high-concentration silicon carbide particles respectively

[0011] The nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles is prepared by measuring silicon carbide particles, washing them with deionized water 5-10 times their mass by stirring for 30-40 minutes, and filtering them through 2-3 layers of filter paper. The filtered silicon carbide particles are then repeatedly washed 1-2 times and added to a mother solution of nickel-tungsten alloy plating solution to adjust the volume. The plating solution is then circulated by mechanical stirring, magnetic stirring, or a pump, and the plating solution is continuously stirred to keep the silicon carbide particles uniformly suspended, thereby obtaining a nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles. The concentration of the silicon carbide particles is 1-10 g / L.

[0012] The nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles is prepared by measuring silicon carbide particles, washing them with 5-10 times the mass of deionized water under stirring for 30-40 minutes, filtering them through 2-3 layers of filter paper, repeatedly washing the filtered silicon carbide particles 1-2 times, and then adding them to a nickel-tungsten alloy plating solution mother liquor to adjust the volume. The plating solution is then continuously stirred by mechanical stirring, magnetic stirring, or circulating the plating solution with a pump to uniformly suspend the silicon carbide particles, thereby obtaining a nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles. The silicon carbide content is 11-40 g / L.

[0013] The nickel-tungsten alloy plating solution containing a high concentration of silicon carbide particles is prepared by measuring silicon carbide particles, washing them with deionized water 5-10 times their mass by stirring for 30-40 minutes, and filtering them through 2-3 layers of filter paper. The filtered silicon carbide particles are then repeatedly washed 1-2 times and added to a mother solution of nickel-tungsten alloy plating solution to adjust the volume. The plating solution is then continuously stirred by mechanical stirring, magnetic stirring, or circulating the plating solution with a pump to uniformly suspend the silicon carbide particles, thereby obtaining a nickel-tungsten alloy plating solution containing a high concentration of silicon carbide particles. The silicon carbide content is 50-300 g / L.

[0014] 3) Sequential electroplating:

[0015] The workpiece is electroplated in a nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles, a nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles, and a nickel-tungsten alloy plating solution containing high-concentration silicon carbide particles in sequence to obtain a three-layer structure of silicon carbide-enhanced gradient nickel-tungsten alloy plating.

[0016] Furthermore, the stabilizer is inositol.

[0017] Furthermore, the silicon carbide particles are green silicon carbide particles with a particle size ranging from 0.5 to 5 μm.

[0018] Furthermore, in step 1), the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles is 2-10 g / L; the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles is 15-30 g / L; and the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing high-concentration silicon carbide particles is 50-200 g / L.

[0019] Furthermore, in step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing low concentration silicon carbide particles are as follows: electroplating temperature 60-70°C, current density 5-10A / dm 2 , electroplating time 10-60min.

[0020] Furthermore, in step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles are as follows: electroplating temperature 60-70°C, current density 5-10A / dm 2 , electroplating time 30-90min.

[0021] Furthermore, in step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing high concentration of silicon carbide particles are as follows: electroplating temperature 60-70°C, current density 5-10A / dm 2 , electroplating time 30-120min.

[0022] Furthermore, in step 2), before electroplating in the nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles, the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles, and the nickel-tungsten alloy plating solution containing high-concentration silicon carbide particles, the workpiece or the coating is activated with 1:1 hydrochloric acid for 1 to 2 minutes, and the electroplating interval time for each layer is controlled at 1 to 10 minutes.

[0023] By activating with hydrochloric acid and controlling the interval time, surface oxidation of the workpiece or coating is avoided, thereby ensuring the bonding strength between the workpiece and the coating or between the coatings.

[0024] Silicon carbide particles have a hardness of around 3000 HV and exhibit excellent thermal conductivity and oxidation resistance at high temperatures. When added to a coating, they significantly enhance the coating's hardness and high-temperature wear resistance. Low-content silicon carbide coatings offer good toughness, while high-content silicon carbide coatings exhibit both high hardness and high brittleness. Medium-content silicon carbide coatings offer a performance intermediate between the two, serving as a transitional layer. Therefore, the present invention utilizes a multi-layer, gradient-structured nickel-tungsten alloy coating with varying silicon carbide contents, ensuring both coating toughness and enhanced high-temperature wear resistance.

[0025] The silicon carbide particles used in the present invention have a particle size range of 0.5 to 5 μm. At this point, the particles are dispersed evenly in the coating, resulting in a smooth coating with low roughness and better wear reduction. If the silicon carbide particle size is too small (less than 0.5 μm), it is easy to agglomerate, resulting in uneven dispersion in the plating solution, and deposition in the coating also degrades the coating uniformity. If the silicon carbide particle size is too large (greater than 5 μm), the large particles accumulate on the sample surface due to gravity, making it difficult for the flow of the plating solution and the erosion of bubbles to carry away ions, hindering ion diffusion on the electrode surface and the deposition of the alloy coating. The particles cannot be effectively embedded, resulting in poor coating density and affecting the coating quality.

[0026] The present invention provides a method for preparing a three-layer silicon carbide particle-reinforced nickel-tungsten alloy coating with high-temperature wear resistance. A three-layer coating is formed between the prepared nickel-tungsten alloy coating and the steel substrate. The first layer of silicon carbide, close to the substrate, has the lowest silicon carbide content and the best coating toughness. The silicon carbide content of the second and third layers increases successively, improving the hardness and thereby improving properties such as wear resistance and high-temperature oxidation resistance. The preparation method provided by the present invention fully utilizes the hardness and high-temperature resistance of silicon carbide particles and the high density and good toughness of nickel-tungsten alloy, complementing each other's advantages and significantly improving the high-temperature wear performance of the coating. It can make up for the shortcomings of conventional metal ceramic coatings and chrome plating, and has good application value in special equipment used in some high-temperature and friction environments.

[0027] The present invention also provides a three-layer silicon carbide reinforced gradient nickel-tungsten alloy coating prepared by the preparation method of the above-mentioned high-temperature wear-resistant silicon carbide reinforced gradient nickel-tungsten alloy coating, wherein the silicon carbide content in the first layer from the substrate to the surface of the three-layer silicon carbide reinforced gradient nickel-tungsten alloy coating is 2-10wt%, the silicon carbide content in the second layer is 10-20wt%, and the third layer has a high silicon carbide content of 20-50wt%.

[0028] The present invention also provides a three-layer silicon carbide reinforced gradient nickel-tungsten alloy coating prepared by the preparation method of the above-mentioned high-temperature wear-resistant silicon carbide reinforced gradient nickel-tungsten alloy coating. The three-layer silicon carbide reinforced gradient nickel-tungsten alloy coating has a first layer thickness of 5-25 μm from the substrate to the surface, a second layer thickness of 10-40 μm, and a third layer thickness of 10-50 μm. The coating thickness is determined according to the specific requirements of the size and performance of the specific product, while ensuring that all three layers can play an effective role.

[0029] The beneficial effects of the present invention are:

[0030] The present invention provides a silicon carbide particle reinforced gradient nickel-tungsten alloy coating and a preparation method thereof. Compared with conventional nickel-tungsten alloys, the silicon carbide particle reinforced gradient nickel-tungsten alloy coating has higher coating hardness and better resistance to high-temperature oxidation and wear; compared with conventional spray coatings and metal ceramics, it has better toughness and higher hardness than chrome plating, and has broad application prospects in the fields of aerospace and military equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A The figure is a surface morphology diagram of a particle-reinforced gradient nickel-tungsten alloy coating with a silicon carbide content of 7.7 wt % prepared by the method of the present invention.

[0032] Figure 1B This is a surface morphology diagram of a particle-reinforced gradient nickel-tungsten alloy coating with a silicon carbide content of 15.3 wt % prepared by the method of the present invention.

[0033] Figure 1C This is a surface morphology diagram of a particle-reinforced gradient nickel-tungsten alloy coating with a silicon carbide content of 34.1 wt % prepared by the method of the present invention.

[0034] Figure 2 The present invention provides cross-sectional and line scanning EDS curves of a silicon carbide particle reinforced gradient nickel-tungsten alloy coating prepared by the method of the present invention.

[0035] Figure 3A This is the friction coefficient curve of the pin-on-disc friction and wear test of the chrome-plated sample at 800℃ and a loading force of 100N.

[0036] Figure 3B This is a friction coefficient curve of the pin-on-disc friction and wear test of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating sample prepared in Example 1 under a high temperature environment of 800°C and a loading force of 100N.

[0037] Figure 4A This is the wear scar width measurement diagram of the chrome-plated specimen after the pin-on-disc friction and wear test at 800°C and a loading force of 100N.

[0038] Figure 4B This is the wear scar depth measurement diagram of the chrome-plated specimen after the pin-on-disc friction wear test at 800℃ and a loading force of 100N.

[0039] Figure 4C This is the wear scar width measurement diagram of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating specimen after the pin-on-disc friction and wear test at 800℃ and a loading force of 100N.

[0040] Figure 4D This is the wear scar depth measurement diagram of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating specimen after the pin-on-disc friction and wear test at a high temperature of 800℃ and a loading force of 100N.

[0041] Figure 5 This is a microscopic morphology of the three-layer silicon carbide reinforced gradient composite coating obtained in Example 2.

[0042] Figure 6This is a wear scar depth measurement diagram of the three-layer silicon carbide reinforced gradient composite coating sample obtained in Example 2 after the pin-on-disc friction wear test under a high temperature environment of 800°C and a loading force of 100N. DETAILED DESCRIPTION

[0043] The embodiments of the present invention will be described in detail and comprehensively below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0044] Adding hard SiC particles to the nickel-tungsten alloy electrolyte and uniformly dispersing them throughout the nickel-tungsten composite coating produces a dispersion strengthening effect, significantly improving the hardness and wear resistance of the nickel-tungsten coating. Simultaneously, the large-scale and sequential adsorption and deposition of solid particles onto the nickel-tungsten coating effectively controls the growth of nickel-tungsten crystal nuclei, contributing to improved coating density. The introduction of these particles also helps release internal stresses in the coating, significantly reducing its brittleness and inhibiting crack formation. Therefore, nickel-tungsten alloys reinforced with hard SiC particles are beneficial for improving their high-temperature wear resistance, while the SiC content significantly influences the coating's toughness and hardness.

[0045] The raw materials used in the following examples are all commercially available products.

[0046] Example 1

[0047] Sodium tungstate, sodium pyrophosphate, nickel sulfate, and stabilizer inositol were dissolved in deionized water to prepare a nickel-tungsten alloy plating solution with a concentration of 30 g / L sodium tungstate, a molar concentration of sodium pyrophosphate that is 3 times the molar concentration of nickel sulfate, 20 g / L nickel sulfate, and 0.05 g / L stabilizer inositol. The pH was then adjusted to 7.5 with aqueous ammonia to obtain a nickel-tungsten alloy plating solution base solution.

[0048] 8 g / L of 0.5 μm silicon carbide, 20 g / L of 0.5 μm silicon carbide, and 50 g / L of 5 μm silicon carbide, which were washed with 5 times the mass of deionized water, were added respectively to obtain three kinds of silicon carbide particle-reinforced nickel-tungsten alloy plating solutions with low, medium, and high concentrations. The solutions were stirred evenly and fixed to volume with water to obtain nickel-tungsten alloy plating solutions containing low, medium, and high concentrations of silicon carbide particles.

[0049] A carbon steel test block was used as the cathode, the bath temperature was 65°C, the bath was continuously stirred, and the cathode current density was 7A / dm 2 The electroplating surface of the test block is parallel to the stirring or flowing direction of the plating solution (horizontal or horizontal electroplating), and three kinds of silicon carbide particle reinforced nickel-tungsten alloy coating samples are obtained by electroplating. The silicon carbide contents in the coatings are 7.7wt%, 15.3wt%, and 34.1wt%, respectively. The micromorphology is as follows Figure 1A 、 Figure 1B 、 Figure 1C shown.

[0050] By adjusting the amount of silicon carbide of different particle sizes added to the plating solution, as well as the current density during electroplating, the silicon carbide content in the coating can be changed. Through experiments, it was found that the content of silicon carbide in the particle-reinforced nickel-tungsten alloy coating increases with the particle size (in the range of 0.5 to 5 μm) or concentration of green silicon carbide added to the plating solution, decreases with the increase of current density, and has little to do with the basic nickel-tungsten alloy plating solution parameters. Therefore, nickel-tungsten alloy coatings with different silicon carbide contents can be obtained by adjusting the particle size, concentration and electroplating current density of silicon carbide. Silicon carbide of different particle sizes can be freely combined to meet the particle content requirements in the coating, and large-particle silicon carbide can obtain a higher silicon carbide content coating in a high-concentration plating solution, making the coating surface harder and more resistant to high temperatures.

[0051] The pre-treated carbon steel test piece was electroplated in the above three plating solutions in the order of silicon carbide concentration from low to high for 30 minutes, 60 minutes and 120 minutes respectively by horizontal electroplating. Each layer was activated with 1:1 hydrochloric acid for 1 to 2 minutes before plating, with an interval of no more than 10 minutes. A three-layer structure of silicon carbide particle reinforced gradient nickel-tungsten alloy coating was obtained. The cross-sectional line scanning energy spectrum (EDS) diagram is shown as follows: Figure 2 As shown. Figure 2 It can be seen that there are three layers of coating structure with different silicon carbide contents; from the surface to the substrate, according to Figure 2 The middle white line is scanned from left to right, and the Si content is 23.9wt%, 10.7wt%, and 5.4wt%, respectively. The corresponding SiC content is 34.1wt%, 15.3wt%, and 7.7wt%, respectively. The thickness of the three coatings are 10μm, 20μm, and 40μm, respectively.

[0052] The high-temperature wear performance of the coating was tested using a high-temperature friction and wear tester (MMQ-02G). The heat-resistant alloy GH4214 was used as the wear pin. The experimental conditions were a constant temperature of 800°C, a friction speed of 100 r / min, a load of 100 N, and a time of 3600 s. The specimens were chrome-plated test blocks and prepared silicon carbide particle reinforced gradient nickel-tungsten alloy coating test blocks. The friction coefficient curve of the chrome-plated test block is shown in Figure 2. Figure 3A As shown in the figure, the friction coefficient curve of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating test block is as follows Figure 3B As shown. Figure 3A and Figure 3B Calculations show that the average friction coefficient of the chrome-plated sample is 0.38, while the average friction coefficient of the silicon carbide particle-reinforced gradient nickel-tungsten alloy coating is 0.28. The average friction coefficient of the silicon carbide particle-reinforced gradient nickel-tungsten alloy coating is significantly lower than that of the chrome-plated sample, indicating better self-lubrication and greater wear resistance.

[0053] Then the wear scar width and depth of chromium plating and silicon carbide particle reinforced gradient nickel-tungsten alloy coating were measured. Figures 4A to 4D As shown, the wear scar width and depth of chrome plating are Figure 4A 、 Figure 4B The wear scar width and depth of the SiC particle reinforced gradient Ni-T alloy coating are Figure 4C 、 Figure 4D .from Figure 4A 、 Figure 4B It can be seen that the width of the chrome wear scar is 4083.75 μm and the depth is 76.98 μm. Figure 4C 、 Figure 4D It can be seen that the wear scar width of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating is 3579.80μm and the depth is 10.65μm. Calculation of the wear scar depth shows that the wear loss of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating is less than 1 / 7 of that of chrome plating, and its high-temperature wear resistance is more than 7 times that of chrome plating. The surface microhardness of the silicon carbide particle reinforced gradient nickel-tungsten alloy coating can reach above 1136HV, and the hardness is 785HV at 800℃, achieving high-temperature wear resistance.

[0054] Example 2

[0055] Sodium tungstate, sodium pyrophosphate, nickel sulfate, and stabilizer inositol are dissolved in deionized water to prepare a nickel-tungsten alloy plating solution with a concentration of 40 g / L sodium tungstate, a molar concentration of sodium pyrophosphate that is 3 times the molar concentration of nickel sulfate, 25 g / L nickel sulfate, and a stabilizer inositol of 0.05 g / L. Then, ammonia water is used to adjust the pH to 8.5 to obtain a nickel-tungsten alloy plating solution base solution.

[0056] Then, green silicon carbide with a particle size of 1 μm was washed with 5 times the mass of deionized water at a concentration of 2 g / L, 15 g / L, and green silicon carbide with a particle size of 3 μm was washed with 150 g / L, and then added to the nickel-tungsten alloy plating solution base solution. After stirring, water was added to the fixed volume to obtain nickel-tungsten alloy plating solutions containing three concentrations of silicon carbide particles: low, medium, and high.

[0057] A carbon steel test block was used as the cathode, the bath temperature was 70°C, the bath was stirred magnetically, and the cathode current density was 10A / dm 2 The plating surface of the test piece is parallel to the stirring direction of the plating solution (horizontal or horizontal electroplating), and is electroplated in low, medium and high concentration plating solutions for 10 minutes, 30 minutes and 60 minutes respectively. Each layer is activated with 1:1 hydrochloric acid for 1 to 2 minutes before electroplating, and the interval time is not more than 10 minutes. A three-layer structure of silicon carbide particle reinforced gradient nickel-tungsten alloy coating is obtained. The thickness of the three coatings is 5μm, 15μm and 30μm respectively. The content of silicon carbide in the coating is 4.1wt%, 18.4wt% and 40.5wt% respectively. The surface morphology is as follows: Figure 5 As shown, the high temperature wear test was carried out under the same conditions as in Example 1, and the results are as follows Figure 6As shown in the figure, the wear depth of the coating is 12.68 μm, and the wear resistance is good.

[0058] It can be seen from the above embodiments that the three-layer silicon carbide reinforced gradient nickel-tungsten alloy coating prepared by the preparation method of the silicon carbide reinforced gradient nickel-tungsten alloy coating provided by the present invention forms a multi-layer structure. On the basis of improving the hardness of the coating, it still maintains good coating toughness, and improves the oxidation resistance of the surface coating. It is resistant to high-temperature wear of 800°C, which is significantly better than chrome plating, and achieves the effect of high-temperature wear resistance.

[0059] The above-described embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating, characterized in that: The steps include: 1) Prepare nickel-tungsten alloy plating solution base: Dissolve nickel sulfate, sodium tungstate, sodium pyrophosphate, and stabilizer in deionized water to prepare a nickel-tungsten alloy plating solution base solution; wherein the concentration of sodium tungstate is 30-40 g / L, the concentration of nickel sulfate is 20-25 g / L, the molar concentration of sodium pyrophosphate is 3 times the molar concentration of nickel sulfate, the concentration of stabilizer is 0.05 g / L, and the pH is 7.5-8.5; 2) Prepare nickel-tungsten alloy plating solutions containing low-concentration silicon carbide particles, medium-concentration silicon carbide particles, and high-concentration silicon carbide particles respectively The nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles is prepared by measuring silicon carbide particles, washing them with 5-10 times the mass of deionized water under stirring for 30-40 minutes, filtering them through 2-3 layers of filter paper, repeatedly washing the filtered silicon carbide particles 1-2 times, and then adding them to a nickel-tungsten alloy plating solution mother solution to adjust the volume. The plating solution is then circulated by mechanical stirring, magnetic stirring, or a pump, and the plating solution is continuously stirred to keep the silicon carbide particles uniformly suspended, thereby obtaining a nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles. The concentration of the silicon carbide particles is 1-10 g / L. The nickel-tungsten alloy plating solution containing a medium concentration of silicon carbide particles is prepared by measuring silicon carbide particles, washing them with 5-10 times the mass of deionized water under stirring for 30-40 minutes, filtering them through 2-3 layers of filter paper, repeatedly washing the filtered silicon carbide particles 1-2 times, and then adding them to a nickel-tungsten alloy plating solution mother liquor to a constant volume. The plating solution is then circulated by mechanical stirring, magnetic stirring, or a pump, and the plating solution is continuously stirred to uniformly suspend the silicon carbide particles, thereby obtaining a nickel-tungsten alloy plating solution containing a medium concentration of silicon carbide particles. The silicon carbide content is 11-40 g / L. The nickel-tungsten alloy plating solution containing a high concentration of silicon carbide particles is prepared by measuring silicon carbide particles, washing them with 5-10 times the mass of deionized water under stirring for 30-40 minutes, and filtering them through 2-3 layers of filter paper. The filtered silicon carbide particles are then repeatedly washed 1-2 times and added to a mother solution of nickel-tungsten alloy plating solution to adjust the volume. The plating solution is then circulated by mechanical stirring, magnetic stirring, or a pump, and the plating solution is continuously stirred to uniformly suspend the silicon carbide particles, thereby obtaining a nickel-tungsten alloy plating solution containing a high concentration of silicon carbide particles. The silicon carbide content is 50-300 g / L. 3) Sequential electroplating: The workpiece is electroplated in a nickel-tungsten alloy plating solution containing a low concentration of silicon carbide particles, a nickel-tungsten alloy plating solution containing a medium concentration of silicon carbide particles, and a nickel-tungsten alloy plating solution containing a high concentration of silicon carbide particles in sequence to obtain a three-layer structure of a silicon carbide particle-reinforced gradient nickel-tungsten alloy coating; Wherein, the stabilizer is inositol.

2. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: The silicon carbide particles are green silicon carbide particles with a particle size range of 0.5 to 5 μm.

3. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: In step 1), the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles is 2-10 g / L; the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles is 15-30 g / L; and the concentration of silicon carbide in the nickel-tungsten alloy plating solution containing high-concentration silicon carbide particles is 50-200 g / L.

4. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: In step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing low concentration of silicon carbide particles are: electroplating temperature 60-70℃, current density 5-10A / dm 2 The electroplating time is 10-60min. During electroplating, mechanical stirring, magnetic stirring or a pump is used to circulate the plating solution and continuously stir the plating solution to make the silicon carbide particles evenly suspended.

5. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: In step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles are: electroplating temperature 60-70°C, current density 5-10A / dm 2 The electroplating time is 30-90 minutes. Mechanical stirring, magnetic stirring or a pump is used to circulate the plating solution and continuously stir the plating solution to make the silicon carbide particles evenly suspended.

6. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: In step 2), the electroplating conditions in the nickel-tungsten alloy plating solution containing high concentration of silicon carbide particles are: electroplating temperature 60~70℃, current density 5-10A / dm 2 The electroplating time is 30-120 minutes. Mechanical stirring, magnetic stirring or a pump is used to circulate the plating solution and continuously stir the plating solution to make the silicon carbide particles evenly suspended.

7. The method for preparing a silicon carbide particle reinforced gradient nickel-tungsten alloy coating according to claim 1, wherein: In step 2), before electroplating in the nickel-tungsten alloy plating solution containing low-concentration silicon carbide particles, the nickel-tungsten alloy plating solution containing medium-concentration silicon carbide particles, and the nickel-tungsten alloy plating solution containing high-concentration silicon carbide particles, the workpiece or the coating is activated with 1:1 hydrochloric acid for 1 to 2 minutes, and the electroplating interval for each layer is 1 to 10 minutes.

8. A silicon carbide particle reinforced gradient nickel-tungsten alloy coating prepared by the preparation method according to any one of claims 1 to 7.

Images