Micro-arc oxidation cathode discharge area enhancement method and device based on ultrasonic vibration

Abstract

The invention discloses a micro-arc oxidation cathode discharge area enhancing method and device based on ultrasonic vibration, and relates to the technical field of metal material surface machining. A valve metal workpiece is connected with an anode of a micro-arc oxidation power source, and a cathode of the micro-arc oxidation power source is connected with a stainless steel material to serve as a counter electrode; the space between the valve metal workpiece and the stainless steel material is filled with electrolyte, and an ultrasonic vibrator is connected with a counter electrode to drive the counter electrode to vibrate at the same frequency and high speed. The device comprises a working solution tank which is used for filling electrolyte; the ultrasonic vibrator is arranged in the electrolyte of the working solution tank; the cathode counter electrode is arranged at the top of the ultrasonic vibrator and is positioned in the electrolyte; the valve metal workpiece is arranged on the inner side of the cathode counter electrode; an anode of the micro-arc oxidation power supply is connected with the valve metal workpiece, and a cathode of the micro-arc oxidation power supply is connected with the cathode counter electrode and the ultrasonic vibrator. The surface of the cathode is subjected to vibration impact, so that bubbles attached to the surface of the cathode are separated from the surface of the cathode and overflow into the electrolyte, and the effective discharge area of the cathode is further increased.

Description

Technical Field

[0001] The present invention relates to the technical field of surface processing of metal materials, and more specifically to a method and device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration. Background Technique

[0002] The micro-arc oxidation technology develops from the traditional anodic oxidation technology and is a surface modification technology for in-situ growth of ceramic film layers on the surface of valve metals and their alloys. The generated ceramic film layer has excellent properties such as good bonding force with the substrate, high hardness, corrosion resistance, wear resistance, high insulation resistance, heat shock resistance, and good thermal stability. It has broad application prospects in the fields of aerospace, equipment manufacturing, textile machinery, and electronic communication. The traditional micro-arc oxidation cathode device is a square working liquid tank. In order to make the electric field on the surface of the workpiece uniform, an auxiliary cathode needs to be designed to make the electric field on the surface of the workpiece uniform, the discharge consistent, and facilitate the entry and exit of the working liquid, the discharge of gas and heat, and improve the efficiency and quality of micro-arc oxidation.

[0003] During the micro-arc oxidation process, reactions of oxygen evolution at the anode and hydrogen evolution at the cathode will occur. After these gases are evolved, they are first adsorbed on the electrode surface. The bubbles evolved at the anode are beneficial to the micro-arc oxidation discharge, while the bubbles evolved at the cathode cause the cathode surface to be blocked due to slow overflow. Bubbles are poor conductors of electricity, resulting in a reduction in the actual conductive area of the cathode.

[0004] The micro-arc oxidation treatment has certain requirements for the cathode area, that is, there is a minimum value for the cathode area in the micro-arc oxidation treatment. To ensure the treatment quality of the film layer, it is objectively required to maintain a certain cathode-anode area ratio. Due to the attachment of bubbles, the actual value of the current passing through the workpiece is smaller than the observed value, and further reduces the effective discharge area of the micro-arc oxidation cathode. It is severely restricted in terms of improving the film formation efficiency, expanding the treatment area, and improving the film layer quality, which is particularly prominent in the use of auxiliary cathodes.

[0005] Therefore, how to increase the effective discharge area of the cathode and improve the film layer quality is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a method and device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, aiming to solve the above technical problems.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration. A ceramic film layer can be in-situ grown on the surface of a valve metal workpiece through micro-arc oxidation by inter-electrode discharge. During the treatment, the valve metal workpiece is connected to the anode of the micro-arc oxidation power supply, and the cathode of the micro-arc oxidation power supply is connected to a stainless steel material as the counter electrode. The space between the valve metal workpiece and the stainless steel material is filled with an electrolyte. An ultrasonic vibrator is connected to the counter electrode to drive the counter electrode to vibrate at the same frequency and at high speed. The cathode surface is impacted by the vibration, causing the bubbles attached to the cathode surface to detach from its surface and overflow into the electrolyte, thereby increasing the effective discharge area of the cathode.

[0009] Through the above technical solution, in the present invention, the ultrasonic vibrator drives the counter electrode to vibrate at the same frequency and at high speed, causing the bubbles attached to the cathode surface to detach, thereby increasing the effective discharge area of the cathode. The increase in the effective discharge area makes the micro-arc oxidation reaction more sufficient, improving the growth rate and quality of the ceramic film layer. The shielding of the cathode surface by bubbles is reduced, making the electric field distribution more uniform, thereby improving the uniformity and densification of the generated ceramic film layer.

[0010] Preferably, in the above method for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, the following steps are specifically included:

[0011] Step 1, surface treatment: cleaning the valve metal workpiece to obtain the treated valve metal workpiece;

[0012] Step 2, adding an electrolyte into the electrolytic cell, and placing the valve metal workpiece to be treated and the cathode together in the electrolyte;

[0013] Step 3, turning on the power supply to perform a micro-arc oxidation reaction. During the reaction, turn on the ultrasonic vibrator to drive the cathode to vibrate at the same frequency and at high speed, forcing the bubbles generated by the reaction and attached to the cathode surface to detach from the cathode surface, increasing the actual area of the cathode participating in the micro-arc oxidation reaction, that is, the effective discharge area.

[0014] The present invention also provides a device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, including:

[0015] A working liquid tank for filling the electrolyte;

[0016] An ultrasonic vibrator placed in the electrolyte of the working liquid tank;

[0017] A cathode counter electrode placed on the top of the ultrasonic vibrator and located in the electrolyte;

[0018] A valve metal workpiece placed inside the cathode counter electrode;

[0019] Micro-arc oxidation power supply, the anode of the micro-arc oxidation power supply is connected to the valve metal workpiece, and the cathode of the micro-arc oxidation power supply is connected to the cathode counter electrode and the ultrasonic vibrator.

[0020] Through the above technical solutions, the device provided by the present invention includes a working liquid tank, an ultrasonic vibrator, a cathode counter electrode, a valve metal workpiece and a micro-arc oxidation power supply. The structure is reasonably designed, facilitating operation and maintenance. It is applicable to the micro-arc oxidation treatment of various valve metal workpieces, and the shape and size of the cathode counter electrode can be adjusted according to the workpiece requirements.

[0021] Preferably, in the above device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, a working liquid cooler is further included, and the working liquid cooler is connected to the working liquid tank through a circulation pipeline. By connecting the working liquid cooler to the working liquid tank, the working temperature of the electrolyte can be effectively controlled, preventing the stability of the micro-arc oxidation reaction and the film layer quality from being affected due to excessive temperature. A stable temperature environment helps to extend the service life of equipment such as the ultrasonic vibrator and the micro-arc oxidation power supply.

[0022] Preferably, in the above device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, the working liquid cooler drives the liquid circulation through a working liquid circulation pump. The working liquid cooler is internally provided with a cooling water channel and an electrolyte channel. The electrolyte flows through the working liquid cooler during the circulation process and exchanges heat with the cooling water. The cooling water channel is connected to the cooling water through an external cooling water pipeline. By driving the liquid circulation through the working liquid circulation pump, the electrolyte exchanges heat with the cooling water during the circulation process to achieve efficient cooling, ensuring that the temperature of the electrolyte always remains within a reasonable range. The design of the cooling water channel and the electrolyte channel enables more sufficient heat exchange and further optimizes the thermal management performance of the device.

[0023] Preferably, in the above device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, the cathode counter electrode is of a stainless steel cylinder structure and is mechanically connected to the ultrasonic vibrator. The cathode counter electrode adopts a stainless steel cylinder structure and is mechanically connected to the ultrasonic vibrator, enhancing the structural stability of the device and ensuring that the position and vibration effect of the counter electrode are not affected during the vibration process.

[0024] Preferably, in the above device for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, a horizontal partition is provided inside the stainless steel cylinder structure, and the valve metal workpiece is placed on the horizontal partition. The horizontal partition provides stable support and positioning for the valve metal workpiece, ensuring that the workpiece remains fixed during the micro-arc oxidation process and avoiding workpiece displacement caused by vibration. It helps the electrolyte to be evenly distributed around the workpiece, further improving the uniformity of the micro-arc oxidation reaction.

[0025] Preferably, in the above-mentioned micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration, the electrolyte is composed of deionized water, sodium hydroxide, potassium fluoride, and sodium tetraborate; the concentration of sodium hydroxide in the electrolyte is 5 g / L; the concentration of potassium fluoride in the electrolyte is 2 mL / L; the concentration of sodium tetraborate in the electrolyte is 3 g / L. The specific electrolyte composition and concentration (sodium hydroxide, potassium fluoride, sodium tetraborate) provide an optimal chemical environment for the micro-arc oxidation reaction, which helps to generate a high-quality ceramic film layer. By precisely controlling the chemical composition of the electrolyte, the properties such as the hardness, density, and wear resistance of the film layer can be adjusted to meet different application requirements.

[0026] Preferably, in the above-mentioned micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration, the micro-arc oxidation power supply is a bipolar pulse power supply, with a forward voltage of 540 V - 550 V, a reverse voltage of 85 V - 90 V, and a current density of 2.0 A / dm 2 - 2.5 A / dm 2 , a frequency of 2000 Hz - 2500 Hz, and a duty cycle of 15% - 20%. The parameters of the bipolar pulse power supply (forward voltage, reverse voltage, current density, frequency, duty cycle) are optimized, which can precisely control the process of the micro-arc oxidation reaction, ensuring the stability and uniformity of the film layer growth. Reasonable power supply parameter settings help to generate a thicker, denser, and harder ceramic film layer while reducing defects.

[0027] Preferably, in the above-mentioned micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration, the working temperature of the electrolyte is maintained below 90 °C. Keeping the working temperature of the electrolyte below 90 °C avoids the adverse effects of high temperature on the film layer quality and equipment performance, while ensuring the stable progress of the reaction. The reasonable temperature control range improves the safety and reliability of the entire micro-arc oxidation device and reduces the operation risk.

[0028] Through the above technical solutions, compared with the prior art, the present invention discloses a micro-arc oxidation cathode discharge area enhancement method and device based on ultrasonic vibration, which has the following beneficial effects:

[0029] 1. Improve the micro-arc oxidation efficiency and quality: Increase the effective cathode discharge area: Drive the counter electrode to vibrate through the ultrasonic vibrator, so that the bubbles attached to the cathode surface are detached, thereby significantly increasing the effective cathode discharge area and improving the efficiency of the micro-arc oxidation reaction. The thickness of the generated ceramic film layer increases, the thickness of the dense layer improves, the microhardness increases, and the surface roughness decreases. The overall film layer quality is significantly better than the traditional method.

[0030] 2. Optimize the device structure and performance: The device is reasonably designed, including a working fluid tank, an ultrasonic vibrator, a cathode counter electrode, a valve metal workpiece, and a micro-arc oxidation power supply. It has a compact structure, facilitating operation and maintenance. The device is applicable to various valve metal workpieces. The shape and size of the cathode counter electrode can be adjusted according to the workpiece requirements, showing wide applicability. Through the working fluid cooler and the circulation system, the electrolyte temperature can be effectively controlled, preventing the adverse effects of high temperature on the reaction and the equipment, extending the equipment life, and ensuring the stable progress of the reaction at the same time.

[0031] 3. Improve the process stability and reliability: The optimized electrolyte composition and concentration, as well as the parameter settings of the bipolar pulse power supply, provide the best chemical and electrical environment for the micro-arc oxidation reaction, ensuring the stability and uniformity of the film growth. By removing bubbles through ultrasonic vibration, combined with the optimized power supply parameters and electrolyte formula, the film defects are reduced, and the uniformity and compactness of the film are improved.

[0032] 4. Economic benefits and environmental friendliness: By increasing the effective discharge area of the cathode and optimizing the reaction conditions, the film formation time is shortened, the production efficiency is improved, and the production cost is reduced. No harmful substances are mentioned in the whole process. Moreover, by optimizing the temperature and reaction conditions, the energy consumption and waste liquid discharge are reduced, meeting the environmental protection requirements.

[0033] 5. Improve the versatility and flexibility of the device: The design of the stainless steel cylinder structure and the horizontal partition enhances the structural stability of the device. At the same time, it can adapt to workpieces of different shapes and sizes, improving the versatility and flexibility of the device. The operation process of the whole device is simple, easy to control and adjust, and suitable for large-scale industrial production. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0035] Figure 1 The drawings are the structural schematic diagrams of the micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration provided by the present invention.

[0036] Among them:

[0037] 1 - Working fluid tank;

[0038] 2 - Ultrasonic vibrator;

[0039] 3 - Cathode counter electrode;

[0040] 4 - Valve metal workpiece;

[0041] 5 - Micro - arc oxidation power supply;

[0042] 6 - Working fluid cooler;

[0043] 61 - Working fluid circulation pump; 62 - External cooling water pipeline;

[0044] 7 - Circulation pipeline. Specific implementation mode

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] The embodiment of the present invention discloses a method for enhancing the cathode discharge area of micro - arc oxidation based on ultrasonic vibration. A ceramic film layer can be in - situ grown on the surface of the valve metal workpiece 4 by micro - arc oxidation through inter - electrode discharge; it is characterized in that during processing, the valve metal workpiece 4 is connected to the anode of the micro - arc oxidation power supply 5, the cathode of the micro - arc oxidation power supply 5 is connected to a stainless - steel material as a counter - electrode, the electrolyte is filled between the valve metal workpiece 4 and the stainless - steel material, the ultrasonic vibrator 2 is connected to the counter - electrode, driving the counter - electrode to vibrate at the same frequency and high speed. The cathode surface is subjected to vibration impact, so that the bubbles attached to the cathode surface break away from its surface and overflow into the electrolyte, thereby increasing the effective discharge area of the cathode.

[0047] At the beginning of processing, as the inter - electrode voltage increases, a large number of bubbles are generated on the cathode surface. At this time, the ultrasonic vibration device is operated to generate ultrasonic waves. The cathode surface is subjected to vibration impact, so that the bubbles attached to the cathode surface break away from its surface and overflow into the working fluid, thereby increasing the effective discharge area of the cathode, increasing the over - current capacity of the micro - arc oxidation discharge circuit, and improving the film - forming efficiency.

[0048] The counter - electrode connected to the cathode is not limited by a specific shape. Generally, there are flat plate counter - electrodes, auxiliary cathodes, and working fluid tank bodies connected to the cathode.

[0049] To further optimize the above - mentioned technical solution, it specifically includes the following steps:

[0050] Step 1. Surface treatment: Clean the valve metal workpiece 4 to obtain the treated valve metal workpiece;

[0051] Step 2. Add electrolyte into the electrolytic cell, and place the valve metal workpiece 4 to be processed and the cathode together in the electrolyte;

[0052] Step 3: Turn on the power supply to conduct micro-arc oxidation reaction. During the reaction, turn on the ultrasonic vibrator 2 to drive the cathode to vibrate at the same frequency and high speed, forcing the bubbles generated by the reaction and attached to the cathode surface to detach from the cathode surface, increasing the actual area of the cathode participating in the micro-arc oxidation reaction, that is, the effective discharge area.

[0053] The micro-arc oxidation ceramic film layer prepared by the present invention has a high film formation efficiency and a high film layer hardness.

[0054] Moreover, the ultrasonic vibration treatment process adopted by the present invention is simple, the cathode is not restricted by the specific shape, and the bubbles attached to the cathode surface can be effectively removed, expanding the treatment area.

[0055] To implement the operation of the above method, refer to the appendix Figure 1 The embodiment of the present invention discloses a device for enhancing the discharge area of the cathode of micro-arc oxidation based on ultrasonic vibration, including:

[0056] The working liquid tank 1 is used to fill the electrolyte.

[0057] The ultrasonic vibrator 2 is placed in the electrolyte of the working liquid tank 1.

[0058] The cathode counter electrode 3 is placed on the top of the ultrasonic vibrator 2 and is located in the electrolyte.

[0059] The valve metal workpiece 4 is placed inside the cathode counter electrode 3.

[0060] The micro-arc oxidation power supply 5, the anode of the micro-arc oxidation power supply 5 is connected to the valve metal workpiece 4, and the cathode of the micro-arc oxidation power supply 5 is connected to the cathode counter electrode 3 and the ultrasonic vibrator 2.

[0061] To further optimize the above technical solution, it further includes a working liquid cooler 6, and the working liquid cooler 6 is connected to the working liquid tank 1 through a circulation pipeline 7.

[0062] To further optimize the above technical solution, the working liquid cooler 6 drives the liquid circulation through the working liquid circulation pump 61. The working liquid cooler 6 is internally provided with a cooling water channel and an electrolyte channel. The electrolyte flows through the working liquid cooler 6 during the circulation process and exchanges heat with the cooling water. The cooling water channel is connected to the cooling water through the cooling water external pipeline 62.

[0063] To further optimize the above technical solution, the cathode counter electrode 3 is of a stainless steel cylinder structure and is mechanically connected to the ultrasonic vibrator 2.

[0064] To further optimize the above technical solution, a horizontal partition is provided inside the stainless steel cylinder structure, and the valve metal workpiece 4 is placed on the horizontal partition.

[0065] To further optimize the above technical solution, the electrolyte is composed of deionized water, sodium hydroxide, potassium fluoride, and sodium tetraborate; the concentration of sodium hydroxide in the electrolyte is 5 g / L; the concentration of potassium fluoride in the electrolyte is 2 mL / L; the concentration of sodium tetraborate in the electrolyte is 3 g / L.

[0066] To further optimize the above technical solution, the micro-arc oxidation power supply 5 is a bipolar pulse power supply, with a forward voltage of 540 V - 550 V, a reverse voltage of 85 V - 90 V, and a current density of 2.0 A / dm 2 - 2.5 A / dm 2 , with a frequency of 2000 Hz - 2500 Hz and a duty cycle of 15% - 20%.

[0067] To further optimize the above technical solution, the working temperature of the electrolyte is maintained below 90°C.

[0068] Example 1:

[0069] In this example, the valve metal workpiece 4 is aluminum alloy 6061, with dimensions of 20 mm × 20 mm × 3 mm.

[0070] Using aluminum alloy 6061 as the anode and a stainless steel plate as the cathode, immerse the aluminum alloy 6061 anode in the electrolyte, then apply a bipolar pulse power supply on both sides of the cathode and anode, and under the conditions of a forward voltage of 540 V, a reverse voltage of 85 V, a current density of 2.5 A / dm 2 , a frequency of 2000 Hz, a duty cycle of 20%, and a temperature below 90°C, process for 30 minutes.

[0071] The electrolyte is composed of deionized water, sodium hydroxide, potassium fluoride, and sodium tetraborate; the concentration of sodium hydroxide in the electrolyte is 5 g / L; the concentration of potassium fluoride is 2 mL / L; the concentration of sodium tetraborate is 3 g / L.

[0072] The initial water temperature in this example is 20°C.

[0073] The thickness of the micro-arc oxidation ceramic film layer of 6061 aluminum alloy prepared in this example is 40 μm, and the film thickness of the dense layer is 26 μm.

[0074] Comparative Example 1:

[0075] When ultrasonic vibration is not applied under the same process as in Example 1:

[0076] The thickness of the micro-arc oxidation ceramic film layer of 6061 aluminum alloy prepared in this example is 31 μm, and the film thickness of the dense layer is 15 μm.

[0077] In summary, for the method for increasing the effective discharge area of the cathode of micro-arc oxidation based on ultrasonic vibration provided by the present invention, the thickness of the generated micro-arc oxidation film layer increases by 9 μm, and the thickness of the dense layer increases by 17%.

[0078] Example 2:

[0079] The valve metal workpiece 4 is aluminum alloy 2024, with dimensions of 25 mm × 25 mm × 5 mm.

[0080] Taking aluminum alloy 2024 as the anode and a stainless steel plate as the cathode, immerse the aluminum alloy 2024 anode in the electrolyte, and then apply a bipolar pulse power supply on both sides of the cathode and the anode. Under the conditions of a positive voltage of 550 V, a negative voltage of 90 V, a current density of 2.0 A / dm 2 , a frequency of 2500 Hz, a duty cycle of 15%, and a temperature below 90 °C, treat for 30 min.

[0081] The electrolyte is composed of deionized water, sodium hydroxide, potassium fluoride, and sodium tetraborate; the concentration of sodium hydroxide is 5 g / L; the concentration of potassium fluoride is 2 mL / L; the concentration of sodium tetraborate is 3 g / L.

[0082] The initial water temperature in this example is 20 °C.

[0083] The microhardness of the micro-arc oxidation ceramic film layer of 2024 aluminum alloy prepared in this example is 858 HV (load is 0.981 N), and the surface roughness Ra is 0.088 μm.

[0084] Comparative Example 2:

[0085] When ultrasonic vibration is not applied under the same process as in Example 2:

[0086] The microhardness of the micro-arc oxidation ceramic film layer of 2024 aluminum alloy prepared in this example is 657 HV (load is 0.981 N), and the surface roughness Ra is 0.149 μm.

[0087] In summary, for the method for increasing the effective discharge area of the cathode of micro-arc oxidation based on ultrasonic vibration provided by the present invention, the microhardness of the generated micro-arc oxidation film layer increases by 23%, and the surface roughness decreases by 40.1%.

[0088] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same and similar parts among the embodiments, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the description in the method part.

[0089] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration, in which a ceramic film layer can be in-situ grown on the surface of a valve metal workpiece (4) by micro-arc oxidation through inter-electrode discharge; characterized in that: During processing, the valve metal workpiece (4) is connected to the anode of the micro-arc oxidation power supply (5), the cathode of the micro-arc oxidation power supply (5) is connected to a stainless steel material as the counter electrode, the electrolyte is filled between the valve metal workpiece (4) and the stainless steel material, the ultrasonic vibrator (2) is connected to the counter electrode, driving the counter electrode to vibrate at the same frequency and at high speed. The surface of the cathode is subjected to vibration impact, causing the bubbles attached to the surface of the cathode to detach from its surface and overflow into the electrolyte, thereby increasing the effective discharge area of the cathode.

2. The method for enhancing the cathode discharge area of micro-arc oxidation based on ultrasonic vibration according to claim 1, wherein Specifically, it includes the following steps: Step 1, surface treatment: Clean the valve metal workpiece (4) to obtain the treated valve metal workpiece; Step 2, add electrolyte to the electrolytic cell, and place the valve metal workpiece (4) to be treated and the cathode in the electrolyte together; Step 3, turn on the power supply to carry out the micro-arc oxidation reaction. During the reaction process, turn on the ultrasonic vibrator (2) to drive the cathode to vibrate at the same frequency and at high speed, forcing the bubbles generated by the reaction and attached to the surface of the cathode to detach from the surface of the cathode, increasing the actual area of the cathode participating in the micro-arc oxidation reaction, that is, the effective discharge area.

3. A micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration, characterized in that, It includes: The working liquid tank (1) is used to fill the electrolyte; The ultrasonic vibrator (2) is placed in the electrolyte of the working liquid tank (1); The cathode counter electrode (3) is placed on the top of the ultrasonic vibrator (2) and is located in the electrolyte; The valve metal workpiece (4) is placed inside the cathode counter electrode (3); The micro-arc oxidation power supply (5), the anode of the micro-arc oxidation power supply (5) is connected to the valve metal workpiece (4), and the cathode of the micro-arc oxidation power supply (5) is connected to the cathode counter electrode (3) and the ultrasonic vibrator (2).

4. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 3, characterized in that, It also includes a working liquid cooler (6), and the working liquid cooler (6) is connected to the working liquid tank (1) through a circulation pipeline (7).

5. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 4, characterized in that, The working liquid cooler (6) drives the liquid to circulate through a working liquid circulation pump (61). The working liquid cooler (6) is internally provided with a cooling water channel and an electrolyte channel. The electrolyte flows through the working liquid cooler (6) during the circulation process and exchanges heat with the cooling water. The cooling water channel is connected to the cooling water through a cooling water external pipeline (62).

6. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 3, characterized in that, The cathode counter electrode (3) is of a stainless steel cylinder structure and is mechanically connected to the ultrasonic vibrator (2).

7. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 6, characterized in that A horizontal partition is provided inside the stainless steel cylinder structure, and the valve metal workpiece (4) is placed on the horizontal partition.

8. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 3, wherein The electrolyte is composed of deionized water, sodium hydroxide, potassium fluoride, and sodium tetraborate; the concentration of sodium hydroxide in the electrolyte is 5 g / L; the concentration of potassium fluoride in the electrolyte is 2 mL / L; the concentration of sodium tetraborate in the electrolyte is 3 g / L.

9. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 3, wherein The micro-arc oxidation power supply (5) is a bipolar pulse power supply, with a forward voltage of 540V - 550V, a reverse voltage of 85V - 90V, and a current density of 2.0A / dm 2 - 2.5A / dm 2 , a frequency of 2000Hz - 2500Hz, and a duty cycle of 15% - 20%.

10. The micro-arc oxidation cathode discharge area enhancement device based on ultrasonic vibration according to claim 3, wherein, The working temperature of the electrolyte is maintained below 90 °C.

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