Device and method for preparing CoCrFeNi series high-entropy alloy composite coating through composite plating

Abstract

The invention relates to a device and method for preparing a CoCrFeNi-series high-entropy alloy composite coating through composite plating, and relates to the technical field of metallurgical technology and material scientificity, the device comprises an electroplating liquid tank, an electroplating bath and a magnetic field generator, a dispersion assembly and a heating piece are arranged in the electroplating liquid tank, an electrode assembly is arranged in the electroplating bath, and the magnetic field generator is arranged in the electroplating bath. A circulating assembly used for circulating electroplating liquid is arranged between the electroplating liquid tank and the electroplating bath, and the magnetic field generator is arranged outside the electroplating bath. Composite electroplating is carried out on a to-be-plated metal part under the magnetic field condition, attraction of the content of components of a high-entropy alloy plating layer to ceramic particles is regulated and controlled through the interaction of the magnetic field and an electric field, so that the flatness, particle distribution and content of the plating layer are improved, meanwhile, the appearance, texture and component content of the high-entropy alloy plating layer can be regulated and controlled through application of the external magnetic field, and therefore the high-entropy alloy plating layer is obtained. Therefore, the influence on the overall performance of the coating is avoided, and the preparation efficiency of the CoCrFeNi-series high-entropy alloy composite coating is improved.

Description

Technical Field

[0001] The invention relates to the field of metallurgy technology and material science technology, and in particular to a device and a method for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating. Background Art

[0002] High entropy alloy, referred to as HEA, is an alloy formed by five or more equal or approximately equal amounts of metals. Since high entropy alloys may have many ideal properties, they are highly valued in materials science and engineering. As a new type of material, CoCrFeNi series high entropy alloys break the traditional limitation of using a single element as the main element. The simple FCC structure makes it have excellent plasticity and toughness and good corrosion resistance. It has excellent performance in high temperature thermal stability, ductility, creep resistance and corrosion resistance, and has broad application prospects. The preparation methods of high entropy alloy coatings mainly include magnetron sputtering, laser cladding, plasma cladding, thermal spraying, cold spraying, etc. The above methods still need to be further improved in terms of controllability of production process, cost and environmental protection.

[0003] Adding hard particles to the high entropy alloy coating can also significantly improve the corrosion resistance and wear resistance of the coating. In recent years, the composite electroplating technology under magnetic field has been rapidly developed. On the one hand, the electromagnetic stirring force generated by the interaction of the magnetic field and the electric field can significantly improve the mass transfer of the plating solution. At the same time, the surface morphology of the coating and the composition of the coating can also play a regulatory role, showing great application potential.

[0004] However, the interaction between the magnetic field and the electric field has limited stirring effect outside the electroplating area, and the stirring effect of the added particles outside the electroplating area and at the bottom of the electroplating tank can be ignored. In addition, due to the magnetizing force and the magnetic field energy, the coating grains can be significantly refined and even amorphous structure can be obtained, the composition of each component of the coating can be optimized, and the orientation can be preferentially oriented, thereby significantly improving the quality and performance of the coating. However, the stirring intensity generated by the interaction between the magnetic field and the electric field is still unable to make the larger particles in the plating solution evenly suspended in the plating solution, so there are still problems with the dispersion of the particles in the plating solution. At present, domestic and foreign researchers have conducted some research on the dispersion problem of the plating solution of composite electroplating under a magnetic field, such as bubble stirring, ultrasonic dispersion, mechanical stirring, etc. Although the above methods can improve the quality of the coating to a certain extent, the above methods still need to be further improved in terms of controllability of the production process and cost.

[0005] Therefore, developing a cheap and efficient method for preparing CoCrFeNi high-entropy alloy composite coatings remains a key issue that needs to be solved urgently. Summary of the invention

[0006] The object of the present invention is to provide a device and method for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating in view of the above problems.

[0007] In order to achieve its purpose, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a device for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating, which adopts the following technical solution:

[0009] A device for preparing a CoCrFeNi-based high-entropy alloy composite coating by composite plating comprises a plating liquid tank, a plating tank and a magnetic field generator, wherein a dispersion component and a heating element are arranged in the plating liquid tank, an electrode component is arranged in the plating tank, a circulation component for circulating the plating liquid is arranged between the plating liquid tank and the plating tank, and the magnetic field generator is arranged outside the plating tank.

[0010] By adopting the above technical scheme, the dispersing component stirs and disperses the plating solution so that the particles in the plating solution are evenly dispersed, the heating component keeps the plating solution at a constant temperature, the plating solution flows into the plating tank, the electrode component is started, and the magnetic field generator is cooperated to generate a magnetic field, so as to realize composite electroplating of the metal parts to be plated under magnetic field conditions, and the interaction between the magnetic field and the electric field is used to regulate the attraction of the high entropy alloy coating component content to the ceramic particles, thereby improving the flatness, particle distribution and content of the coating. At the same time, the application of an external magnetic field can regulate the morphology, texture and content of each component of the high entropy alloy coating, and then affect the overall performance of the coating. The circulation component drives the plating solution to circulate between the plating solution tank and the plating tank, reducing the probability of particles sinking to the bottom of the plating tank, so as to obtain a more stable and uniform coating, thereby improving the preparation efficiency of the CoCrFeNi-based high entropy alloy composite coating.

[0011] Optionally, the dispersing component includes an ultrasonic disperser and a mechanical agitator, wherein the ultrasonic disperser is disposed in the electroplating tank and is located at one end close to the electroplating tank, and the mechanical agitator is disposed in the electroplating tank and is located at one end away from the electroplating tank.

[0012] By adopting the above technical scheme, the ultrasonic disperser and the mechanical agitator are separately and independently arranged. The mechanical agitator is installed at the rear of the electroplating tank, which can enhance the overall stirring strength of the electroplating solution and prevent particles from settling at the bottom of the electroplating tank; the ultrasonic dispersing device is placed at the front of the electroplating tank. Due to the cavitation effect of the ultrasonic wave, the dispersing effect on the outflowing electroplating solution particles can be enhanced, allowing them to be more evenly dispersed into the electroplating tank for electroplating, thereby improving the preparation efficiency of the CoCrFeNi-based high-entropy alloy composite coating.

[0013] Optionally, the electrode assembly includes:

[0014] A cathode plate, the cathode plate comprising a cathode fixing front plate and a cathode fixing rear plate arranged opposite to each other, the cathode fixing front plate and the cathode fixing rear plate having a connected cathode hole, the cathode hole being used to install a metal piece to be plated, and a cathode conductor being further arranged in the cathode hole;

[0015] an anode plate, the anode plate comprising an anode fixing front plate and an anode fixing rear plate which are arranged opposite to each other, the anode fixing front plate and the anode fixing rear plate having a connected anode hole, the anode hole being arranged opposite to the cathode hole, the anode hole being used to install an anode material, an anode conductor being further arranged in the anode hole, and the magnetic field center generated by the magnetic field generator being located at the center of the anode plate and the cathode plate;

[0016] The electroplating power supply is arranged outside the electroplating tank, the electroplating power supply is connected to the anode conductor through the anode wire, the electroplating power supply is connected to the cathode conductor through the cathode wire, and the cathode wire and the anode wire are connected to the electroplating power supply to form a control loop.

[0017] By adopting the above technical solution, the metal part to be plated is installed in the cathode hole, the anode material is installed in the anode hole, the electroplating power supply is started and current is passed through, and the interaction between the magnetic field and the electric field generated by the magnetic field generator is coordinated to improve the performance of the CoCrFeNi high entropy alloy composite coating.

[0018] Optionally, the cathode fixing rear plate, the cathode fixing front plate, the anode fixing front plate and the anode fixing rear plate are connected together by plastic bolts and plastic nuts, and the anode fixing front plate and the cathode fixing front plate are arranged opposite to each other and have a gap.

[0019] By adopting the above technical solution, plastic screws and nuts are used to adjust the distance between the cathode and the anode, which not only improves the convenience of adjusting the distance between the anode and the cathode, but also prevents the use of metal screws and nuts from contaminating the plating solution due to corrosion by the acidic electroplating solution, and prevents the distribution of magnetic fields and electric fields on metal components during the electroplating process.

[0020] Optionally, the electroplating tank is provided with an adjusting member for adjusting the inclination angle of the electrode assembly, and the adjusting member includes a mounting member, an electrode group fixing block, a connecting member and a positioning member. The mounting member is provided in the electroplating tank, and the electrode group fixing block is rotatably provided on the mounting member. The connecting member connects the cathode fixing rear plate and the electrode group fixing block, and the positioning member is used to position the electrode group fixing block.

[0021] By adopting the above technical scheme, the anode plate and the cathode plate are first connected, and then the cathode fixed rear plate and the electrode group fixed block are connected together, and the angle of the electrode group fixed block is adjusted so that the electrode assembly can be maintained at different angles of 0 to 90° with the horizontal direction for composite electroplating. On the one hand, the content of ceramic particles in the composite coating can be regulated to a certain extent by the influence of gravity on the added particles; on the other hand, the angle between the magnetic field and the electric field is changed to regulate the influence of the electromagnetic stirring force and the magnetizing force on the migration process of metal ions near the electrode and the discharge reduction process, as well as the influence on the morphology and texture of the coating, so as to improve the performance of the CoCrFeNi-based high-entropy alloy composite coating.

[0022] Optionally, the inner bottom surface of the electroplating tank is located above the electroplating tank, and the circulation component includes:

[0023] a first circulation pipe extending from the bottom of the electroplating tank into the electroplating tank;

[0024] a second circulation pipe extending from the bottom of the electroplating tank;

[0025] A circulation pump, wherein the inlet end of the circulation pump is connected to an end of the second circulation pipe away from the electroplating tank;

[0026] The third circulation pipe is arranged on the outlet end of the circulation pump and extends into the electroplating liquid tank.

[0027] By adopting the above technical scheme, the plating solution in the plating solution tank flows into the plating solution tank through the first circulation pipe under the action of gravity after being dispersed, and the plating solution in the plating solution tank is deposited on the metal part to be plated in the cathode hole under the action of electric current and magnetic field. At the same time, the circulation pump is started, and the plating solution in the plating solution tank flows back into the plating solution tank after passing through the second circulation pipe and the third circulation pipe for heating and stirring, thereby improving the uniformity of particle distribution in the plating solution in the plating solution tank, thereby improving the preparation efficiency of the CoCrFeNi-based high-entropy alloy composite coating.

[0028] A second aspect of the present invention provides a method for preparing a CoCrFeNi-based high entropy alloy composite coating by composite plating, comprising the following steps:

[0029] S1. Prepare an electroplating solution: add a soluble nickel source, a cobalt source, an iron source, a chromium source, a buffer, a conductive salt and a complexing agent to an electroplating solvent in proportion, stir, adjust the pH to 1-3, and the temperature to 20-80° C., then add ceramic particles, stir again to obtain an electroplating solution, and add the electroplating solution to the electroplating solution tank of the above-mentioned device;

[0030] S2. Connecting the components in the device: installing the metal to be plated as the cathode material in the cathode hole, installing the graphite sheet as the anode material in the anode hole, connecting the cathode fixing rear plate, the cathode fixing front plate, the anode fixing front plate and the anode fixing rear plate together through plastic bolts and plastic nuts, maintaining the spacing between the anode plate and the cathode plate at 0.5-10 cm, and adjusting the inclination angle of the entire electrode assembly through the adjusting piece, and starting the circulation assembly to drive the electroplating solution to circulate between the electroplating solution tank and the electroplating tank;

[0031] S3, electroplating: start the electroplating power supply, and pass the current density of 0.01A ~ 100A / dm 2 A direct current electric field is applied, and a magnetic field generator is turned on to perform composite electroplating, thereby obtaining a CoCrFeNi high entropy alloy composite coating;

[0032] S4, diffusion treatment: the CoCrFeNi high entropy alloy composite coating obtained in S3 is vacuum dried and placed in a circuit with a protective gas for continuous thermal diffusion treatment to obtain a material with good bonding between the CoCrFeNi alloy coating and the substrate. The heat treatment temperature is controlled at 550-1300°C and the heat treatment time is 0.05-100h.

[0033] By adopting the above technical scheme, an electroplating solution is prepared, a buffer is used to adjust and stabilize the pH value in the electroplating solution to reduce the influence of hydrogen evolution reaction on the surface performance of the coating, and a conductive salt promotes the movement of metal ions to the cathode to improve the co-deposition efficiency. The above device is used to electroplate the metal parts to be plated under magnetic field conditions to obtain a CoCrFeNi high entropy alloy composite coating. After the preparation is completed, a proper diffusion treatment is performed to increase the interface bonding force between the coating and the substrate on the one hand, and reduce the internal stress generated by the electroplating process on the other hand. In addition, the heat treatment process can also strengthen the solid solution process of each element in the high entropy alloy coating, further improve the comprehensive performance of the coating, and thus obtain an efficient CoCrFeNi high entropy alloy composite coating.

[0034] Preferably, each liter of the electroplating solution includes the following components in weight ratio: 0.01-100g nickel source, 0.01-100g cobalt source, 0.01-100g iron source, 0.01-400g chromium source, 0.01-200g buffer, 0.01-200g conductive salt, 0.03-600g complexing agent, and 0.01-50g ceramic particles.

[0035] By adopting the above technical solution, the ratio of each component in the electroplating solution is optimized to improve the performance of the CoCrFeNi series high entropy alloy composite coating.

[0036] In the above technical scheme, S1, prepare the electroplating solution: add 40g / L nickel sulfate hexahydrate (NiSO4·6H2O), 10g cobalt sulfate hexahydrate (CoSO4·6H2O), 5g / L ferrous sulfate heptahydrate (FeSO4·7H2O), 120g / L chromium sulfate hexahydrate (CrSO4·6H2O), 50g / L boric acid, 100g / L potassium chloride, 100g / L citric acid, 20g / L sodium citrate, 5g / L saccharin sodium into deionized water in proportion, stir, adjust the pH to 1.5, the temperature to 50°C, then add 5g / L Si3N4 powder, stir again to obtain the electroplating solution, and add the electroplating solution into the electroplating tank of the device according to claim 6;

[0037] Preferably, in S2, the distance between the anode plate and the cathode plate is 2.0 cm, and the angle between the electrode assembly and the horizontal plane is 75°.

[0038] By preferably selecting nickel sulfate hexahydrate as the nickel source, cobalt sulfate hexahydrate as the cobalt source, ferrous sulfate heptahydrate as the iron source, chromium sulfate hexahydrate as the chromium source, boric acid as the buffer, potassium chloride as the conductive salt, citric acid, citrate and sodium saccharin as the complexing agent, a coordination structure is formed with chromium ions to reduce their deposition potential, and reduce the deposition potential difference with the other three metal ions, thereby achieving co-deposition of the four metal ions, and co-adjusting the position of the electrode assembly to obtain a higher performance CoCrFeNi-based high-entropy alloy composite coating.

[0039] In the above technical solution, S3, electroplating: start the electroplating power supply, and pass the current density of 3.5A / dm 2 A DC electric field was set, and the circulation component was turned on so that the flow rate of the plating solution was 10 L / min. The magnetic induction intensity generated by the magnetic field generator was maintained at 0.1 T. The magnetic field intensity was consistent with the direction of the electroplating current. The composite electroplating time was 50 min to obtain a CoCrFeNi high entropy alloy composite coating.

[0040] By controlling multiple factors such as current density, ceramic particle concentration in the electroplating solution, and magnetic field strength, the ceramic particle content and different metal element components in the composite coating can be controlled to obtain a higher performance CoCrFeNi high entropy alloy composite coating.

[0041] In summary, the present application includes at least one of the following beneficial technical effects:

[0042] 1. Electroplating is carried out under the condition of applying a constant low-intensity magnetic field, and the interaction between the magnetic field and the electric field is used to regulate the attraction of the high-entropy alloy coating component content to the ceramic particles, thereby improving the flatness, particle distribution and content of the coating; at the same time, the application of an external magnetic field can regulate the morphology, texture and content of each component of the high-entropy alloy coating, thereby affecting the overall performance of the coating.

[0043] 2. Plastic screws and nuts are used to adjust the distance between the cathode and the anode. On the one hand, this prevents the metal screws and nuts from corroding the acidic electroplating solution and contaminating the plating solution. On the other hand, it prevents the metal components from affecting the distribution of the magnetic field and electric field during the electroplating process.

[0044] 3. During the electroplating process, the cathode / anode electrode assembly can be adjusted to maintain different angles of 0 to 90° with the horizontal direction through the angle adjustment device for composite electroplating. On the one hand, the content of ceramic particles in the composite coating can be regulated to a certain extent by the influence of gravity on the added particles; on the other hand, the angle between the magnetic field and the electric field can be changed to regulate the influence of the electromagnetic stirring force and the magnetizing force on the migration process of metal ions near the electrode and the discharge reduction process, as well as the influence on the morphology and texture of the coating.

[0045] 4. After the high entropy alloy composite material is prepared, it is subjected to appropriate diffusion treatment. On the one hand, the interfacial bonding strength between the coating and the substrate is increased, and on the other hand, the internal stress generated by the electroplating process is reduced. In addition, the heat treatment process can also enhance the solid solution process of each element in the high entropy alloy coating, further improving the comprehensive performance of the coating.

[0046] 5. The reagents used in the preparation of CoCrFeNi high entropy alloy composite coatings by this method are cheap, easy to obtain, and have low consumption. The method of composite plating close to room temperature can save energy, is simple to operate, and the production process is stable and controllable.

[0047] 6. The device is simple, the separation degree is high, and it is easy to install and disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a schematic diagram of the overall structure of the device in Example 1 of the present application;

[0049] Figure 2 It is a schematic diagram of the structure of the electrode assembly in Example 1 of the present application.

[0050] Figure numerals: 1, electroplating tank; 2, electroplating tank; 3, magnetic field generator; 4, dispersion component; 41, ultrasonic disperser; 42, mechanical stirrer; 5, heating element; 51, thermocouple; 52, temperature controller; 53, electric heating tube; 6, electrode assembly; 61, cathode plate; 611, cathode fixed front plate; 612, cathode fixed rear plate; 613, cathode hole; 614, metal part to be plated; 615, cathode conductor; 616, cathode wire; 62, anode plate; 621, anode fixed front plate; 622, anode fixed rear plate; 623, anode hole; 624, anode material; 625, anode conductor; 626, anode wire; 63, electroplating power supply; 64, gasket; 7, circulation assembly; 71, first circulation pipe; 72, second circulation pipe; 73, circulation pump; 74, third circulation pipe; 75, control power supply; 76, transformer; 8, adjustment member; 81, mounting member; 811, mounting rod; 812, positioning head; 82, electrode group fixing block; 83, connecting member; 831, connecting bolt; 832, connecting nut; 84, positioning member; 841, positioning plate; 842, positioning bolt. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with examples and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Those skilled in the art will make modifications or equivalent substitutions based on the understanding of the technical scheme of the present invention, without departing from the spirit and scope of the technical scheme of the present invention, and all should be included in the protection scope of the present invention. The experimental methods in the following embodiments, unless otherwise specified, are conventional methods, and other unspecified specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0052] Example 1

[0053] Reference Figure 1 and Figure 2 A device for preparing a CoCrFeNi-based high-entropy alloy composite coating by composite plating includes a plating liquid tank 1, a plating tank 2 and a magnetic field generator 3. The plating liquid tank 1 is provided with a dispersion component 4 and a heating element 5, the plating tank 2 is provided with an electrode component 6, and a circulation component 7 for circulating the plating liquid is provided between the plating liquid tank 1 and the plating tank 2. The magnetic field generator 3 is arranged outside the plating tank 2.

[0054] Reference Figure 1 and Figure 2The dispersion component 4 includes an ultrasonic disperser 41 and a mechanical stirrer 42. The ultrasonic disperser 41, the mechanical stirrer 42 and the plating tank 1 are designed to be separated. The working element of the ultrasonic disperser 41 extends into the plating tank 1 and is located at one end close to the plating tank 2. The working element of the mechanical stirrer 42 extends into the plating tank 1 and is located at one end away from the plating tank 2. The ultrasonic disperser 41 and the mechanical stirrer 42 are both devices with corresponding functions in the prior art.

[0055] Reference Figure 1 and Figure 2 The heating element 5 includes a thermocouple 51, a temperature controller 52 and an electric heating tube 53, all of which are devices with corresponding functions in the prior art. The thermocouple 51 is located in the electroplating liquid tank 1 and is connected to the temperature controller 52. The electric heating tube 53 is arranged in the electroplating liquid tank 1 and is used to heat the electroplating liquid. The temperature of the electroplating liquid in the electroplating liquid tank 1 is controlled by the thermocouple 51, the temperature controller 52 and the electric heating tube 53.

[0056] Reference Figure 1 and Figure 2 The inner bottom surface of the electroplating tank 1 is higher than the upper surface of the electroplating tank 2. The electrode assembly 6 is arranged in the electroplating tank 2. The electrode assembly 6 includes a cathode plate 61, an anode plate 62 and an electroplating power supply 63. The cathode plate 61 includes a cathode fixed front plate 611 and a cathode fixed rear plate 612 that are relatively arranged. The cathode fixed front plate 611 and the cathode fixed rear plate 612 have connected cathode holes 613. The cathode holes 613 are used to install metal parts 614 to be plated. A cathode conductor 615 is also provided in the cathode hole 613.

[0057] Reference Figure 1 and Figure 2 The anode plate 62 includes an anode fixed front plate 621 and an anode fixed rear plate 622 which are arranged opposite to each other. The anode fixed front plate 621 and the anode fixed rear plate 622 have a connected anode hole 623. The anode hole 623 is arranged opposite to the cathode hole 613. The anode hole 623 is used to install the anode material 624. An anode conductor 625 is also arranged in the anode hole 623.

[0058] Reference Figure 1 and Figure 2 The electroplating power supply 63 is arranged outside the electroplating tank 2, and the electroplating power supply 63 is connected to the anode conductor 625 through the anode wire 626, and the electroplating power supply 63 is connected to the cathode conductor 615 through the cathode wire 616. The cathode wire 616 and the anode wire 626 are connected to the electroplating power supply 63 to form a control loop. The electroplating power supply 63 is a replicated constant DC power supply. In other feasible embodiments, the electroplating power supply 63 can also be a pulse power supply with adjustable duty cycle and frequency, or a DC power supply with reversible duty cycle, frequency and period, so as to provide currents with different characteristics for the electroplating process.

[0059] Reference Figure 1 and Figure 2 The heights of the anode fixed rear plate 622, the anode fixed front plate 621 and the cathode fixed front plate 611 are consistent, the height of the cathode fixed rear plate 612 is greater than the cathode fixed front plate 611, the anode fixed rear plate 622, the anode fixed rear plate 622, the cathode fixed front plate 611 and the cathode fixed rear plate 612 are parallel to each other, and the anode fixed rear plate 622, the anode fixed rear plate 622, the cathode fixed front plate 611 and the cathode fixed rear plate 612 are connected together by plastic bolts and plastic nuts, the anode fixed front plate 621 and the cathode fixed front plate 611 are arranged opposite to each other and have a gap, the width of the gap between the anode fixed front plate 621 and the cathode fixed front plate 611 can be adjusted by the plastic bolts and plastic nuts, and washers 64 are provided between the anode material 624 and the anode hole 623, and between the metal part 614 to be plated and the cathode hole 613.

[0060] Reference Figure 1 and Figure 2 The center of the magnetic field generated by the magnetic field generator 3 is located at the center of the anode plate 62 and the cathode plate 61. The magnetic field generator 3 is an electromagnet. In other feasible embodiments, the magnetic field generated by the magnetic field generator 3 can also be a magnetic field obtained by a permanent magnet using a magnetic circuit design, or can be a magnetic field provided by a Bitter magnet or a superconducting magnet or a hybrid magnet of a Bitter magnet and a superconducting magnet.

[0061] Reference Figure 1 and Figure 2 An adjusting member 8 for adjusting the inclination angle of the electrode assembly 6 is also provided in the electroplating tank 2. The adjusting member 8 includes a mounting member 81, an electrode group fixing block 82, a connecting member 83 and a positioning member 84. The mounting member 81 includes a mounting rod 811 fixed in the electroplating tank 2, and the electrode group fixing block 82 is rotatably disposed on the mounting rod 811.

[0062] Reference Figure 1 and Figure 2The connecting member 83 is a plastic connecting bolt 831 and a connecting nut 832. The connecting bolt 831 connects the cathode fixing rear plate 612 and the electrode group fixing block 82, and the cathode fixing rear plate 612 and the electrode group fixing block 82 are parallel to each other. The angle between the electrode group fixing block 82 and the horizontal plane is 0-90°. The connecting nut 832 is threadedly connected to the connecting bolt 831 and is used to position the cathode fixing rear plate 612. The positioning member 84 is a plastic positioning plate 841 and a positioning bolt 842. The vertical sliding sleeve on the mounting rod 811 is provided with a positioning head 812, and the positioning plate 841 is rotatably arranged on the positioning head. 812, the electrode group fixing block 82 is arranged on the positioning plate 841 through the connecting bolts 831 and is parallel to the positioning plate 841, one of the connecting nuts 832 is pressed against the outer wall of the positioning plate 841, and two positioning bolts 842 are provided, one of which passes through the connection between the positioning plate 841 and the positioning head 812 and is pressed against the positioning head 812 to limit the inclination angle of the positioning plate 841, and the other positioning bolt 842 passes through the positioning head 812 and is pressed against the mounting rod 811 to adjust the height of the positioning plate 841, thereby realizing the positioning of the electrode group fixing block 82.

[0063] Reference Figure 1 and Figure 2 The circulation component 7 includes a first circulation pipe 71, a second circulation pipe 72, a circulation pump 73 and a third circulation pipe 74. The first circulation pipe 71 extends from the bottom of the electroplating tank 1 to the electroplating tank 2, the second circulation pipe 72 extends from the bottom of the electroplating tank 2 away from the end of the electroplating tank 1, the circulation pump 73 is arranged outside the electroplating tank 2, the control end of the circulation pump 73 is connected to the control power supply 75 and the transformer 76, the inlet end of the circulation pump 73 is connected to the end of the second circulation pipe 72 away from the electroplating tank 2, and the third circulation pipe 74 is arranged on the outlet end of the circulation pump 73 and extends into the electroplating tank 1.

[0064] The working principle of Example 1 of the present application is:

[0065] The mechanical agitator strengthens the overall stirring strength of the electroplating solution to prevent the particles from settling at the bottom of the electroplating tank 1. The ultrasonic dispersion device is placed in the front of the electroplating tank 1. Due to the cavitation effect of the ultrasonic wave, the dispersion effect of the outflowing electroplating solution particles can be strengthened, so that they can be more evenly dispersed into the electroplating tank 2 for electroplating. The heating element 5 controls the temperature of the electroplating solution, and the circulating pump 73 is started. The electroplating solution circulates between the electroplating tank 1 and the electroplating tank 2. The electroplating power supply 63 and the magnetic field generator 3 are started. Electroplating is performed under the condition of applying a constant low-intensity magnetic field. The interaction between the magnetic field and the electric field is used to regulate the attraction of the high-entropy alloy coating component content to the ceramic particles, thereby improving the flatness, particle distribution and content of the coating. At the same time, the application of an external magnetic field can regulate the morphology, texture and content of each component of the high-entropy alloy coating, and thus affect the overall performance of the coating.

[0066] During the electroplating process, composite electroplating is performed by adjusting the distance between the anode and the cathode, and adjusting the angle between the electrode assembly 6 and the horizontal direction. On the one hand, the content of ceramic particles in the composite coating can be regulated to a certain extent by the influence of gravity on the added particles; on the other hand, the angle between the magnetic field and the electric field is changed to regulate the influence of the electromagnetic stirring force and the magnetizing force on the migration process of metal ions near the electrode and the discharge reduction process, as well as the influence on the morphology and texture of the coating.

[0067] Example 2

[0068] A method for preparing a CoCrFeNi-based high entropy alloy composite coating by composite plating, comprising the following steps:

[0069] S1. Prepare an electroplating solution: add a soluble nickel source, a cobalt source, an iron source, a chromium source, a buffer, a conductive salt and a complexing agent to an electroplating solvent in proportion, stir, adjust the pH to 1-3, and the temperature to 20-80°C, then add ceramic particles, stir again to obtain an electroplating solution, and add the electroplating solution to the electroplating solution tank of the device according to claim 6.

[0070] Specifically, 40 g / L nickel sulfate hexahydrate (NiSO4·6H2O), 10 g cobalt sulfate hexahydrate (CoSO4·6H2O), 5 g / L ferrous sulfate heptahydrate (FeSO4·7H2O), 120 g / L chromium sulfate hexahydrate (CrSO4·6H2O), 50 g / L boric acid, 100 g / L potassium chloride, 100 g / L citric acid, 20 g / L sodium citrate, 5 g / L saccharin were added in proportion. Sodium is added to deionized water, stirred for 5 minutes, the pH is adjusted to 1.5, the temperature is 50°C, and then 5g / L Si3N4 powder is added, the peak particle size of Si3N4 powder is 0.5μm, and the plating solution is obtained after stirring for another 5 minutes. The plating solution is added to the plating tank of the device in Example 1, the volume of the plating tank is 50L, the heating element is started to keep the temperature in the plating tank at 40°C, and the ultrasonic disperser and mechanical stirrer are started at the same time.

[0071] In other feasible embodiments, other types of salts, such as aluminum sulfate monohydrate, may be added to the electroplating solution to regulate the matrix metal of the CoCrFeNi-based high-entropy alloy composite coating; the solvent used in the electroplating solution may be a deionized water solution or an organic solvent such as N,N-dimethylformamide; the ceramic particles may also be WC, TiO2, graphene oxide and other ceramic particles (non-conductive particles), or conductive particles such as graphene and carbon nanotubes may be selected, or they may be a mixture of multiple particles.

[0072] S2. Connect the components in the device: install the metal to be plated as the cathode material in the cathode hole, install the graphite sheet as the anode material in the anode hole, connect the cathode fixing rear plate, the cathode fixing front plate, the anode fixing front plate and the anode fixing rear plate together through plastic bolts and plastic nuts, maintain the spacing between the anode plate and the cathode plate at 0.5-10cm, and adjust the inclination angle of the entire electrode assembly through the adjustment piece, start the circulation assembly to drive the electroplating solution to circulate between the electroplating solution tank and the electroplating tank.

[0073] Specifically, a pure copper strip with a thickness of 0.5 mm and a length and width of 30 mm is selected as the metal part to be plated, which is polished step by step with sandpaper, then pickled and degreased with acetone and installed in the cathode hole, a graphite sheet is selected as the anode material and installed in the anode hole, the electrode assembly is connected, the distance between the pure copper strip and the graphite sheet is adjusted to 2.0 cm by plastic bolts and plastic nuts, and the angle between the electrode assembly fixing block and the horizontal plane is adjusted to 75°; the diameters of the first circulation pipe, the second circulation pipe and the third circulation pipe are all 8 mm, the circulation pump is started, and the transformer is adjusted so that the plating solution in the plating tank enters the plating tank through the first circulation pipe, and the plating solution in the plating tank passes through the second circulation pipe and the circulation pump and then flows back to the plating tank from the third circulation pipe.

[0074] S3, electroplating: start the electroplating power supply, and pass the current density of 0.01A ~ 100A / dm 2 A direct current electric field is created and a magnetic field generator is turned on to carry out composite electroplating to obtain a CoCrFeNi high entropy alloy composite coating.

[0075] Specifically, the electroplating power supply was started and the current density was 3.5A / dm 2 The DC electric field is used to adjust the circulation pump so that the flow rate of the electroplating solution is 10 L / min. The magnetic field generator is adjusted so that the magnetic induction intensity it generates is maintained at 0.1 T. The magnetic field intensity is consistent with the direction of the electroplating current. The composite electroplating time is 50 min to obtain a CoCrFeNi high entropy alloy composite coating.

[0076] In other feasible embodiments, the ceramic content in the composite coating can be controlled by controlling the angle between the cathode plane and the horizontal plane, the current density, the concentration of ceramic particles in the electroplating solution, and the magnetic field strength, so that the particle content in the composite coating is controlled between 0-10wt% and the thickness of the composite coating is 5-1000 microns.

[0077] S4, diffusion treatment: the CoCrFeNi high entropy alloy composite coating obtained in S3 is vacuum dried and placed in a circuit with a protective gas for continuous thermal diffusion treatment to obtain a material with good bonding between the CoCrFeNi alloy coating and the substrate. The heat treatment temperature is controlled at 550-1300°C and the heat treatment time is 0.05-100h.

[0078] Specifically, the CoCrFeNi high entropy alloy composite coating obtained in S3 was dried at 50°C in vacuum for 60 min and then placed in a tubular electric furnace protected by an inert gas (argon, etc.) for continuous heat treatment and diffusion treatment to obtain a material with good bonding between the CoCrFeNi alloy coating and the substrate. The heat treatment temperature was controlled at 600°C and the heat treatment time was 10 h.

[0079] In other feasible embodiments, the protective gas of the tubular electric furnace may also be a reducing gas (carbon monoxide, hydrogen, etc.) or a mixture of an inert gas and a reducing gas.

[0080] Example 3

[0081] A method for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating, which is different from Example 2 in that each liter of the plating solution includes the following components in parts by weight: 0.01 g / L nickel sulfate hexahydrate (NiSO4·6H2O), 100 g of cobalt sulfate hexahydrate (CoSO4·6H2O), 0.01 g / L of ferrous sulfate heptahydrate (FeSO4·7H2O), 400 g / L of chromium sulfate hexahydrate (CrSO4·6H2O), 0.01 g / L of boric acid, 200 g / L of potassium chloride, 0.01 g / L of citric acid, 0.01 g / L of sodium citrate, 0.01 g / L of saccharin sodium, 0.01 g of Si3N4 powder, pH is 1, and the temperature is 20°C; the distance between the anode plate and the cathode plate is 10 cm, the angle between the electrode group fixing block and the horizontal plane is 90°, and the current density is 30 A / dm 2 , the flow rate of the plating solution is 5 L / min, the magnetic induction intensity is 1.0 T, the plating time is 5 min, the heat treatment temperature in the continuous thermal diffusion treatment is 1300 ° C, and the heat treatment time is 0.05 h.

[0082] Example 4

[0083] A method for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating, which is different from Example 2 in that each liter of the plating solution includes the following components in parts by weight: 100 g / L nickel sulfate hexahydrate (NiSO4·6H2O), 0.01 g cobalt sulfate hexahydrate (CoSO4·6H2O), 100 g / L ferrous sulfate heptahydrate (FeSO4·7H2O), 0.01 g / L chromium sulfate hexahydrate (CrSO4·6H2O), 200 g / L boric acid, 0.01 g / L potassium chloride, 200 g / L citric acid, 200 g / L sodium citrate, 200 g / L saccharin sodium, 50 g Si3N4 powder, pH 3, temperature 80°C; the distance between the anode plate and the cathode plate is 0.5 cm, the angle between the electrode group fixing block and the horizontal plane is 0°, and the current density is 0.05 A / dm2 , the flow rate of the plating solution is 5 L / min, the magnetic induction intensity is 0.01 T, the plating time is 300 min, the heat treatment temperature in the continuous thermal diffusion treatment is 550 ° C, and the heat treatment time is 100 h.

[0084] Comparative Example 1

[0085] A method for preparing a CoCrFeNi-based high-entropy alloy composite coating by composite plating is different from Example 2 in that the magnetic field generator is not turned on.

[0086] Comparative Example 2

[0087] A method for preparing a CoCrFeNi-based high-entropy alloy composite coating by composite plating is different from Example 2 in that the magnetic field generator is not turned on and the circulation pump is not started.

[0088] During the electroplating process, it was found that most of the particles in the plating solution settled to the bottom of the plating tank.

[0089] Finished product testing

[0090] The CoCrFeNi high entropy alloy composite coatings prepared by the methods of Examples 2-4 and Comparative Examples 1-2 were respectively subjected to EDS (energy dispersive spectrometry) measurement, and the results are shown in Table 1.

[0091] Table 1 Composition test table

[0092]

[0093]

[0094] It can be seen that Example 2 is the best embodiment of the preparation method of the present application. Examples 3 and 4 prove the preparation method provided by this method by changing the component ratio and operating parameters. The change trend of the coating composition in the obtained finished product is basically consistent with the proportion of the added components of the raw materials, thereby improving the raw material utilization rate and the preparation effect of the high entropy alloy composite coating. The silicon particles of the CoCrFeNi high entropy alloy composite coating prepared by this method are greatly increased, and the content of each component is evenly distributed. This proves that electroplating is carried out under the condition of applying a constant low-intensity magnetic field, and the interaction between the magnetic field and the electric field is used to regulate the attraction of the high entropy alloy coating component content to the ceramic particles, thereby improving the flatness, particle distribution and content of the coating. At the same time, the application of an external magnetic field can regulate the morphology, texture and content of each component of the high entropy alloy coating, thereby affecting the overall performance of the coating.

Claims

1. A device for preparing a CoCrFeNi series high entropy alloy composite coating by composite plating, characterized in that: The invention comprises an electroplating liquid tank (1), an electroplating tank (2) and a magnetic field generator (3); the electroplating liquid tank (1) is provided with a dispersion component (4) and a heating element (5); the electroplating tank (2) is provided with an electrode component (6); a circulation component (7) for circulating the electroplating liquid is provided between the electroplating liquid tank (1) and the electroplating tank (2); and the magnetic field generator (3) is provided outside the electroplating tank (2).

2. The device according to claim 1, characterized in that: The dispersion component (4) comprises an ultrasonic disperser (41) and a mechanical stirrer (42), wherein the ultrasonic disperser (41) is arranged in the electroplating tank (1) and is located at one end close to the electroplating tank (2), and the mechanical stirrer (42) is arranged in the electroplating tank (1) and is located at one end away from the electroplating tank (2).

3. The device according to claim 1, characterized in that: The electrode assembly (6) comprises: A cathode plate (61), the cathode plate (61) comprising a cathode fixing front plate (611) and a cathode fixing rear plate (612) arranged opposite to each other, the cathode fixing front plate (611) and the cathode fixing rear plate (612) having a connected cathode hole (613), the cathode hole (613) being used to install a metal part (614) to be plated, and a cathode conductor (615) being further provided in the cathode hole (613); an anode plate (62), the anode plate (62) comprising an anode fixing front plate (621) and an anode fixing rear plate (622) arranged opposite to each other, the anode fixing front plate (621) and the anode fixing rear plate (622) having a connected anode hole (623), the anode hole (623) being arranged opposite to the cathode hole (613), the anode hole (623) being used to install an anode material (624), an anode conductor (625) being further arranged in the anode hole (623), the magnetic field center generated by the magnetic field generator (3) being located at the center of the anode plate (62) and the cathode plate (61); The electroplating power supply (63) is arranged outside the electroplating tank (2), the electroplating power supply (63) is connected to the anode conductor (625) via the anode wire (626), the electroplating power supply (63) is connected to the cathode conductor (615) via the cathode wire (616), and the cathode wire (616) and the anode wire (626) are connected to the electroplating power supply (63) to form a control loop.

4. The device according to claim 3, characterized in that: The cathode fixing rear plate (612), the cathode fixing front plate (611), the anode fixing front plate (621) and the anode fixing rear plate (622) are connected together by plastic bolts and plastic nuts, and the anode fixing front plate (621) and the cathode fixing front plate (611) are arranged opposite to each other and have a gap.

5. The device according to claim 4, characterized in that: The electroplating tank (2) is provided with an adjusting member (8) for adjusting the inclination angle of the electrode assembly (6); the adjusting member (8) comprises a mounting member (81), an electrode group fixing block (82), a connecting member (83) and a positioning member (84); the mounting member (81) is arranged in the electroplating tank (2); the electrode group fixing block (82) is rotatably arranged on the mounting member (81); the connecting member (83) connects the cathode fixing rear plate (612) and the electrode group fixing block (82); and the positioning member (84) is used to position the electrode group fixing block (82).

6. The device according to claim 5, characterized in that: The inner bottom surface of the electroplating liquid tank (1) is located above the electroplating tank (2), and the circulation component (7) comprises: A first circulation pipe (71), the first circulation pipe (71) extending from the bottom of the electroplating liquid tank (1) into the electroplating tank (2); A second circulation pipe (72), the second circulation pipe (72) extending from the bottom of the electroplating tank (2); A circulation pump (73), wherein the inlet end of the circulation pump (73) is connected to an end of the second circulation pipe (72) away from the electroplating tank (2); A third circulation pipe (74), wherein the third circulation pipe (74) is arranged on the outlet end of the circulation pump (73) and extends into the electroplating liquid tank (1).

7. A method for preparing a CoCrFeNi-based high entropy alloy composite coating by composite plating, characterized in that: The following steps are involved: S1. Prepare an electroplating solution: add a soluble nickel source, a cobalt source, an iron source, a chromium source, a buffer, a conductive salt and a complexing agent to an electroplating solvent in proportion, stir, adjust the pH to 1 to 3, and the temperature to 20 to 80° C., then add ceramic particles, stir again to obtain an electroplating solution, and add the electroplating solution to the electroplating solution tank of the device according to claim 6; S2. Connecting the components in the device: installing the metal to be plated as the cathode material in the cathode hole, installing the graphite sheet as the anode material in the anode hole, connecting the cathode fixing rear plate, the cathode fixing front plate, the anode fixing front plate and the anode fixing rear plate together through plastic bolts and plastic nuts, maintaining the spacing between the anode plate and the cathode plate at 0.5-10 cm, and adjusting the inclination angle of the entire electrode assembly through the adjusting piece, and starting the circulation assembly to drive the electroplating solution to circulate between the electroplating solution tank and the electroplating tank; S3, electroplating: start the electroplating power supply, and pass the current density of 0.01A ~ 100A / dm 2 A direct current electric field is applied, and a magnetic field generator is turned on to perform composite electroplating, thereby obtaining a CoCrFeNi high entropy alloy composite coating; S4, diffusion treatment: the CoCrFeNi high entropy alloy composite coating obtained in S3 is vacuum dried and placed in a circuit with a protective gas for continuous thermal diffusion treatment to obtain a material with good bonding between the CoCrFeNi alloy coating and the substrate. The heat treatment temperature is controlled at 550-1300°C and the heat treatment time is 0.05-100h.

8. The method according to claim 7, characterized in that: Each liter of the electroplating solution includes the following components in weight ratio: 0.01-100g nickel source, 0.01-100g cobalt source, 0.01-100g iron source, 0.01-400g chromium source, 0.01-200g buffer, 0.01-200g conductive salt, 0.03-600g complexing agent, and 0.01-50g ceramic particles.

9. The method according to claim 8, characterized in that: S1. Prepare a plating solution: add 40 g / L nickel sulfate hexahydrate (NiSO4·6H2O), 10 g cobalt sulfate hexahydrate (CoSO4·6H2O), 5 g / L ferrous sulfate heptahydrate (FeSO4·7H2O), 120 g / L chromium sulfate hexahydrate (CrSO4·6H2O), 50 g / L boric acid, 100 g / L potassium chloride, 100 g / L citric acid, 20 g / L sodium citrate, and 5 g / L saccharin sodium to deionized water in proportion, stir, adjust the pH to 1.5, and the temperature to 50°C, then add 5 g / L Si3N4 powder, stir again to obtain a plating solution, and add the plating solution to the plating solution tank of the device according to claim 6; Preferably, in S2, the distance between the anode plate and the cathode plate is 2.0 cm, and the angle between the electrode assembly and the horizontal plane is 75°.

10. The method according to claim 8, characterized in that: S3, electroplating: start the electroplating power supply, and pass the current density to 3.5A / dm 2 A DC electric field was set, and the circulation component was turned on so that the flow rate of the plating solution was 10 L / min. The magnetic induction intensity generated by the magnetic field generator was maintained at 0.1 T. The magnetic field intensity was consistent with the direction of the electroplating current. The composite electroplating time was 50 min to obtain a CoCrFeNi high entropy alloy composite coating.

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