A sealed micro-arc oxidation device with uniform circulation control

Abstract

This invention discloses a closed-loop, uniformly circulated micro-arc oxidation device. The overall design employs a closed structure, comprising five subsystems: an anode device, a lifting device, a cathode device, a liquid supply device, and an electrical system. These subsystems work together to achieve functions such as workpiece clamping and disassembly, solution temperature control and delivery, and uniform electric field discharge during the micro-arc oxidation process. Using this device for micro-arc oxidation effectively solves the problems of poor stability, poor uniformity, and poor consistency in traditional micro-arc oxidation devices regarding solution, temperature, current density, and electric field control. It achieves precise control of process parameters in each stage of micro-arc oxidation, improving product quality consistency and overall performance stability. It possesses advantages such as small size, modularity, integrated automation, high efficiency, and precision, and can be widely promoted for engineering applications. It has practical guiding significance for the process promotion and intelligent development of micro-arc oxidation equipment.

Description

Technical Field

[0001] This invention relates to the field of micro-arc oxidation surface treatment technology for lightweight alloys (aluminum, magnesium, titanium and their alloys), and in particular to a closed-loop uniform circulation controlled micro-arc oxidation device. Background Technology

[0002] Micro-arc oxidation utilizes the instantaneous high temperature and pressure generated by electric arc discharge to grow a ceramic film mainly composed of base metal oxides on the surface of metals such as aluminum, magnesium, and titanium and their alloys in situ. This significantly improves the surface hardness, wear resistance, and corrosion resistance of the material. At the same time, the electrolyte is environmentally friendly and does not pollute the environment, making it a green and environmentally friendly surface treatment technology.

[0003] Currently, micro-arc oxidation devices mainly adopt an open tank design. The tank is made of PP plates welded into a square structure, with air pipes installed at the bottom to stir the solution. Stainless steel cathode plates are built into both sides of the tank and connected to a micro-arc oxidation power supply, a refrigeration unit, etc., to form a complete micro-arc oxidation system. When this traditional device is used in production, the following problems exist: First, the entire tank relies on compressed air for stirring, which cannot guarantee the uniformity of the solution at all locations; second, multiple parts in the same tank are powered by a single power input, which cannot guarantee the uniformity of the current density on the surface of each part; third, the tank solution is indirectly controlled by the refrigeration unit, resulting in large temperature fluctuations and making it impossible to guarantee the temperature uniformity of the tank solution in different areas; in addition, when the parts to be micro-arc oxidized have irregular and complex structures, the parallel anode and cathode installed in the traditional device can easily affect the electric field distribution. The cathode cannot effectively absorb negative ions from the anode, disrupting the electrical balance of the entire system, thus affecting the uniformity and density of the film layer, and even affecting film formation in local areas, resulting in uneven film formation or no film formation. Therefore, when the application scenario has high requirements for the performance of the micro-arc oxidation film, the traditional micro-arc oxidation device is affected by the above four problems, resulting in poor film performance consistency and making it difficult to control the quality. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a closed-loop uniform circulation control micro-arc oxidation device that can accurately control the micro-arc oxidation solution and ensure uniform solution, temperature, current density and electric field distribution.

[0005] The objective of this invention is achieved as follows: A closed-loop, uniformly circulated micro-arc oxidation device includes an anode device, a cathode device, a liquid supply device, and an electrical system device. The cathode device includes a cathode cylinder 5, a cathode protection conductive fixture 6, and a cathode conductive interface 9. The bottom of the cathode cylinder 5 is a sealed structure, and the top of the cathode cylinder 5 is an open structure. The bottom of the cathode cylinder 5 is placed inside the cathode protection conductive fixture 6 to achieve insulation protection for the bottom of the cathode cylinder 5. The cathode conductive interface 9 is provided at the bottom of the cathode cylinder 5 and is located inside the cathode protection conductive fixture 6. The anode device is installed on the top of the cathode cylinder 5. The anode device includes a clamping conductive fixture 1, a cathode cylinder sealing fixture 2, and a conductive anode rod 7. The cathode cylinder sealing fixture 2 seals the top of the cathode cylinder 5. The conductive anode rod 7 is erected in the middle of the cathode cylinder sealing fixture 2. The lower end of the conductive anode rod 7 extends into the cathode cylinder 5. The upper end of the conductive anode rod 7 is provided with an anode conductive interface 7-1. The lower end of the conductive anode rod 7 is used to connect the sample 8. The clamping conductive fixture 1 is located above the conductive anode rod 7. The clamping conductive fixture 1 is installed on the cathode cylinder sealing fixture 2 and is used to clamp the upper end of the conductive anode rod 7. The conductive clamping fixture 1 is installed on the cathode cylinder sealing fixture 2, and moves up and down together with the cathode cylinder sealing fixture 2 and the lifting mechanism 3.

[0006] The electrical system is electrically connected to the cathode conductive interface 9 of the cathode cylinder 5 and the anode conductive interface 7-1 of the conductive anode rod 7, so that the cathode cylinder 5 acts as the cathode and the conductive anode rod 7 acts as the anode to perform micro-arc oxidation processing on the sample 8. The cathode cylinder 5 is provided with a liquid inlet and a liquid outlet, and the liquid supply device is connected to the liquid inlet and the liquid outlet respectively to provide micro-arc oxidation solution 15 to the cathode cylinder 5.

[0007] Preferably, the cathode cylinder 5 has an inlet at the bottom and an outlet at the top. The liquid supply device includes a closed tank 14, a mechanical pump 12, an electromagnetic ball valve 11, and a flow meter 10 connected in sequence via a liquid delivery pipe. The closed tank 14 is used to hold the micro-arc oxidation solution 15. The top of the closed tank 14 is connected to the outlet of the cathode cylinder 5 via a liquid delivery pipe 13. The mechanical pump 12 is connected to the bottom of the closed tank 14 via a liquid delivery pipe. The flow meter 10 is connected to the inlet of the cathode cylinder 5 via a liquid delivery pipe. The micro-arc oxidation solution 15 is delivered to the inlet of the cathode cylinder 5 under the power of the mechanical pump 12, then flows from bottom to top in the inner cavity of the cathode cylinder 5, and then flows back to the closed tank 14 from the outlet of the cathode cylinder 5, realizing the recycling of the micro-arc oxidation solution 15 during the processing. The bottom-up flow effect: Within the stainless steel cathode cylinder, external force generates pressure to ensure the solution flows upwards, serving a circulating and stirring function. This ensures both solution homogeneity and the removal of gases generated during the reaction process. The solution flows back into the closed tank from the outlet, returning from a higher position to re-dissolve the consumed solution back into the tank, maintaining uniform solution composition. The solution is then transported from the bottom of the tank.

[0008] The enclosed tank 14 is equipped with a cooling device 16 and a heating device 17, which are used to control the temperature of the micro-arc oxidation solution 15. The heating device 17 is located at the bottom of the enclosed tank 14, and the cooling device 16 is located in the middle of the enclosed tank 14. The micro-arc oxidation process is an exothermic reaction, and heat is released throughout the process. The cooling device 16 is mainly used to cool down the solution and maintain the temperature of the tank solution. The heating device is only used when the temperature of the tank solution is lower than the process temperature. It is a function that is used infrequently but is necessary.

[0009] Preferably, the electrical system includes a micro-arc oxidation power supply and final control system 18 and multiple wires. The micro-arc oxidation power supply and final control system has a positive terminal, a negative terminal, and a power supply interface. The positive terminal is connected to the anode conductive interface 7-1 of the conductive anode rod 7 via a wire to realize the output of positive current for micro-arc oxidation. The negative terminal is connected to the cathode conductive interface 9 of the cathode cylinder 5 via a wire to realize the output of negative current for micro-arc oxidation. The power supply interface is connected to a flow meter 10, an electromagnetic ball valve 11, a mechanical pump 12, a cooling device 16, and a heating device 17 via wires. The flow meter 10, the electromagnetic ball valve 11, and the mechanical pump 12 realize precise flow rate circulation control of the micro-arc oxidation solution 15, and the cooling device 16 and the heating device 17 realize constant temperature control of the micro-arc oxidation solution 15.

[0010] Preferably, the anode device further includes a moving chuck 1-1, a self-centering sealing clamp 1-2, and a clamp sealing sleeve 1-3. The moving chuck 1-1 is installed below the conductive clamping fixture 1. The conductive clamping fixture 1 controls the moving chuck 1-1, which locks and releases the upper end of the conductive anode rod 7, realizing the clamping and disassembly function of the conductive anode rod 7. The self-centering sealing clamp 1-2 is installed inside the cathode cylinder sealing fixture 2, and the clamp sealing sleeve 1-3 is installed on the self-centering sealing clamp 1-2 to achieve a sealing effect on the micro-arc oxidation solution 15 along the vertical direction of the conductive anode rod 7. The conductive clamping fixture 1 is held by a cylinder.

[0011] Preferably, the main function of the self-centering sealing fixture 1-2 is to ensure that the anode rod 7 is held in a 90° vertical position after clamping, thereby ensuring that the sample 8 is in a vertical mounting state, rather than at an angle. This fixture is mainly made of steel and has a small groove on its conical surface. It has a certain closing effect when used in conjunction with the conductive tooling 1 and the moving chuck 1-1. However, there is a certain gap between the outer surface and the cathode cylinder sealing tooling 2, which cannot guarantee that the solution will not overflow due to pressure during the upward flow of the solution. Therefore, a sealing sleeve 2-1 is designed with grooves on its outer circumference. This sealing sleeve is mainly made of rubber.

[0012] Preferably, the anode device further includes a tooling sealing sleeve 2-1, which is disposed at the vertical contact part between the cathode cylinder sealing tooling 2 and the cathode cylinder 5 to further seal the micro-arc oxidation solution 15.

[0013] Preferably, the conductive anode rod is made of aluminum alloy, and the cathode cylinder is made of stainless steel.

[0014] Preferably, it also includes a lifting device, which includes a fixed bracket 4 and a lifting motion mechanism 3. The lifting motion mechanism 3 is mounted on the fixed bracket 4, and the cathode cylinder sealing fixture 2 is mounted on the lifting motion mechanism 3 to install and disassemble the conductive anode rod and the sample.

[0015] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: This invention employs a closed-loop structure design, with the solution forced to circulate by external mechanical force, effectively ensuring uniform control of the solution between the anode and cathode. Temperature is controlled by an independent tank to guarantee uniform temperature across all areas of the solution. Current density is ensured by a small, modular power supply for each individual component. The electric field utilizes a ring cathode design to address the issue of uniform distribution between the anode and cathode. This device effectively solves the problems of poor stability, poor uniformity, and poor consistency in traditional micro-arc oxidation devices regarding solution, temperature, current density, and electric field control. It can precisely control the process parameters of each stage of micro-arc oxidation, improving product quality consistency and overall performance stability. It possesses advantages such as small size, modularity, integrated automation, high efficiency, and precision, and plays a positive role in promoting the development of high-end intelligent micro-arc oxidation surface treatment equipment. It has particularly significant engineering application value in fields requiring high uniformity and overall performance of micro-arc oxidation films. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a partially enlarged structural schematic diagram of the anode device of the present invention.

[0018] Figure Labels In the attached diagram, 1 is a clamping conductive fixture, 1-1 is a moving chuck, 1-2 is a self-centering sealing fixture, 1-3 is a fixture sealing sleeve, 2 is a cathode cylinder sealing fixture, 2-1 is a fixture sealing sleeve, 3 is a lifting motion mechanism, 4 is a fixed bracket, 5 is a stainless steel cathode cylinder, 6 is a cathodic protection conductive fixture, 7 is a conductive anode rod, 7-1 is an anode conductive interface, 8 is a sample, 9 is a cathode conductive interface, 10 is a flow meter, 11 is a solenoid ball valve, 12 is a mechanical pump, 13 is a liquid delivery pipeline, 14 is a closed tank, 15 is a micro-arc oxidation solution, 16 is a cooling device, 17 is a heating device, 18 is a micro-arc oxidation power supply and final control system, and 18-1, 18-2, 18-3, and 18-4 are all electrical system device wires. Detailed Implementation

[0019] Example

[0020] Please see Figure 1 This invention provides a closed-loop uniform circulation control micro-arc oxidation device, including a clamping conductive fixture 1, a cathode cylinder sealing fixture 2, a lifting motion mechanism 3, a fixed support 4, a stainless steel cathode cylinder 5, a cathode protection conductive fixture 6, a conductive anode rod 7, a sample 8, a cathode conductive interface 9, a flow meter 10, an electromagnetic ball valve 11, a mechanical pump 12, a liquid delivery pipeline 13, a closed tank 14, a micro-arc oxidation solution 15, a cooling device 16, a heating device 17, a micro-arc oxidation power supply and final control system 18, and electrical system device wires 18-1, 18-2, 18-3, 18-4, etc.

[0021] This device integrates a control system for multiple process parameters, enabling stable, uniform, and consistent control of parameters such as solution, temperature, current density, and electric field, thereby improving product quality consistency and stability. It mainly consists of five parts: an anode device, a lifting device, a cathode device, a liquid supply device, and an electrical system device.

[0022] The anode device comprises a conductive clamping fixture 1, a moving chuck 1-1, a conductive anode rod 7, a self-centering sealing fixture 1-2, a fixture sealing sleeve 1-3, a cathode cylinder sealing fixture 2, and a fixture sealing sleeve 2-1. The conductive clamping fixture 1 of the anode device clamps the conductive anode rod 7 and connects it to the sample 8 being processed, thus connecting the sample 8 to the positive terminal of the micro-arc oxidation power supply 18. Simultaneously, the cathode cylinder sealing fixture 2 seals the stainless steel cathode cylinder 5 and fixes the entire anode device as a whole onto the lifting and moving mechanism 3.

[0023] Its main functions are: first, to vertically clamp the conductive anode rod and the sample, ensuring that the anode rod and the sample to be treated are both parallel to the stainless steel cathode cylinder; second, to seal the opening of the stainless steel cathode cylinder, ensuring that the micro-arc oxidation solution can only flow through the infusion pipeline; and third, to connect the positive terminal of the power supply, ensuring that the current acts on the surface of the sample to be treated for micro-arc oxidation processing.

[0024] The lifting device consists of a fixed support 4 and a lifting mechanism 3. The lifting mechanism 3 enables the longitudinal up-and-down movement of the anode device on the fixed support 4, so that the conductive anode rod 7 and the sample 8 can be disassembled and mounted during production and processing.

[0025] The cathode device consists of a stainless steel cathode cylinder 5, a cathode protection conductive fixture 6, and a cathode conductive interface 9. The stainless steel cathode cylinder 5 adopts a cylindrical design with an open top, which, together with the cathode cylinder sealing fixture 2, achieves the sealing of the micro-arc oxidation solution 15. The bottom of the stainless steel cathode cylinder 5 has only one solution notch and is built into the cathode protection conductive fixture 6. The cathode conductive interface 9 is designed at the bottom of the stainless steel cathode cylinder 5 to connect to the negative terminal of the micro-arc oxidation power supply 18, so as to achieve conductivity of the stainless steel cathode cylinder 5.

[0026] The liquid supply device consists of a flow meter 10, an electromagnetic ball valve 11, a mechanical pump 12, a liquid delivery pipeline 13, a closed tank 14, and a micro-arc oxidation solution 15. The closed tank 14 has an outlet at its bottom, connected to the mechanical pump 12 via the liquid delivery pipeline 13. The mechanical pump 12 is connected in sequence to the electromagnetic ball valve 11 and the flow meter 10, and then the liquid delivery pipeline 13 is connected to the stainless steel cathode cylinder 5 to complete the delivery of the micro-arc oxidation solution 15. Under the power of the mechanical pump 12, the micro-arc oxidation solution 15 is delivered by the liquid delivery pipeline 13 to the bottom of the stainless steel cathode cylinder 5, then flows upwards, and flows back into the closed tank 14 through the liquid delivery pipeline 13 from the outlet of the upper cathode cylinder sealing fixture 2, thus realizing the recycling of the micro-arc oxidation solution 15 during processing. Simultaneously, a cooling device 16 and a heating device 17 are configured in the closed tank 14 to achieve constant temperature control of the micro-arc oxidation solution 15.

[0027] The liquid inlet and outlet are connected to the cathode cylinder sealing fixture 2 and the cathode protection conductive fixture 6, which have a special function of preventing electric shock. During the micro-arc oxidation process, the entire cathode cylinder 5, solution 15, and anode rod 7 are charged after being energized. The liquid inlet and outlet are protected by the cathode cylinder sealing fixture 2 and the cathode protection conductive fixture 6.

[0028] The electrical system consists of a micro-arc oxidation power supply and final control system 18, and wires 18-1, 18-2, 18-3, and 18-4. Wire 18-1 connects the positive terminal of the micro-arc oxidation power supply and final control system 18 to the anode conductive interface 7-1, realizing the output of positive current for micro-arc oxidation. Wire 18-2 connects the cathode conductive interface 9 to the negative terminal of the micro-arc oxidation power supply and final control system 18, realizing the output of negative current for micro-arc oxidation. Wire 18-3 connects the flow meter 10, the solenoid ball valve 11, and the... The mechanical pump 12 is connected to achieve precise flow rate circulation control of the micro-arc oxidation solution 15; the wire 18-4 connects the cooling device 16 and the heating device 17 in the micro-arc oxidation closed tank 14 to achieve constant temperature control of the micro-arc oxidation solution 15, ensuring that the temperature of the micro-arc oxidation solution 15 in the entire infusion pipeline 13, the micro-arc oxidation tank 14 and the stainless steel cathode cylinder 5 is uniform, and the integrated control of process parameters such as "electricity, liquid and temperature" of micro-arc oxidation is achieved through the micro-arc oxidation power supply and final control system 18. Example

[0029] Please see Figure 2 The diagram shows a partially enlarged structural schematic of the anode device of the present invention. The clamping conductive fixture 1 of the anode device is located at the top of the entire device, and a moving chuck 1-1 is installed directly below it. This moving chuck can lock and release the conductive anode rod 7, realizing the clamping and disassembly functions of the conductive anode rod 7. The cathode cylinder sealing fixture 2 is located below the moving chuck 1-1. A self-centering sealing fixture 1-2 is designed inside the fixture, and a fixture sealing sleeve 1-3 is designed on the self-centering sealing fixture 1-2 to achieve a sealing effect on the micro-arc oxidation solution 15 along the vertical direction of the conductive anode rod 7. A fixture sealing sleeve 2-1 is designed at the longitudinal vertical contact point between the cathode cylinder sealing fixture 2 and the stainless steel cathode cylinder 5 to further seal the micro-arc oxidation solution 15, ensuring that the micro-arc oxidation solution can only flow back to the micro-arc oxidation sealing tank 14 from the right side of the stainless steel cathode cylinder 5 along the infusion pipe 13.

[0030] Using the device of this invention for micro-arc oxidation processing can effectively ensure and accurately control the uniformity of solution composition, solution temperature, current density, and electric field distribution. At the same time, it can achieve synergistic integrated control of process parameters such as "electricity, liquid, and temperature", which has important guiding significance for improving the consistency and stability of product quality.

[0031] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A closed-loop, uniformly circulated micro-arc oxidation device, characterized in that: Includes anode devices, cathode devices, liquid supply devices, and electrical system devices; The cathode device includes a cathode cylinder, a cathode protection conductive fixture, and a cathode conductive interface. The bottom of the cathode cylinder is sealed, and the top of the cathode cylinder is open. The bottom of the cathode cylinder is placed inside the cathode protection conductive fixture to achieve insulation protection for the bottom of the cathode cylinder. The cathode conductive interface is provided at the bottom of the cathode cylinder and is located inside the cathode protection conductive fixture. The anode device is installed on the top of the cathode cylinder. The anode device includes a clamping conductive fixture, a cathode cylinder sealing fixture, and a conductive anode rod. The cathode cylinder sealing fixture seals the top of the cathode cylinder. The conductive anode rod is erected in the middle of the cathode cylinder sealing fixture. The lower end of the conductive anode rod extends into the cathode cylinder. The upper end of the conductive anode rod is provided with an anode conductive interface. The lower end of the conductive anode rod is used to connect the sample. The clamping conductive fixture is installed on the cathode cylinder sealing fixture and is used to clamp the upper end of the conductive anode rod. The electrical system is electrically connected to the cathode conductive interface of the cathode cylinder and the anode conductive interface of the conductive anode rod, respectively, so that the cathode cylinder acts as the cathode and the conductive anode rod acts as the anode to perform micro-arc oxidation processing on the sample. The cathode cylinder is provided with a liquid inlet and a liquid outlet, and the liquid supply device is connected to the liquid inlet and the liquid outlet respectively to provide micro-arc oxidation solution to the cathode cylinder.

2. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 1, characterized in that: The cathode cylinder has an inlet at its lower part and an outlet at its upper part. The liquid supply device includes a closed tank, a mechanical pump, a solenoid ball valve, and a flow meter connected in sequence via a liquid delivery pipe. The closed tank is used to hold the micro-arc oxidation solution. The top of the closed tank is connected to the outlet of the cathode cylinder via a liquid delivery pipe. The mechanical pump is connected to the bottom of the closed tank via a liquid delivery pipe. The flow meter is connected to the inlet of the cathode cylinder via a liquid delivery pipe. The micro-arc oxidation solution is delivered to the inlet of the cathode cylinder by the power of the mechanical pump, then flows from bottom to top in the inner cavity of the cathode cylinder, and then flows back to the closed tank from the outlet of the cathode cylinder, realizing the recycling of the micro-arc oxidation solution during the processing. The enclosed tank is equipped with a cooling device and a heating device, which are used to control the temperature of the micro-arc oxidation solution.

3. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 2, characterized in that: The electrical system includes a micro-arc oxidation power supply and final control system, and multiple wires. The micro-arc oxidation power supply and final control system has a positive terminal, a negative terminal, and a power supply interface. The positive terminal is connected to the anode conductive interface of the conductive anode rod through a wire to realize the output of positive current for micro-arc oxidation. The negative terminal is connected to the cathode conductive interface of the cathode cylinder through a wire to realize the output of negative current for micro-arc oxidation. The power supply interface is connected to a flow meter, an electromagnetic ball valve, a mechanical pump, a cooling device, and a heating device through wires. The flow meter, electromagnetic ball valve, and mechanical pump realize precise flow rate circulation control of the micro-arc oxidation solution, and the cooling device and heating device realize constant temperature control of the micro-arc oxidation solution.

4. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 1, characterized in that: The anode device also includes a moving chuck, a self-centering sealing clamp, and a clamp sealing sleeve. The moving chuck is installed below the conductive fixture. The conductive fixture controls the moving chuck, which locks and releases the upper end of the conductive anode rod, thus realizing the clamping and disassembly function of the conductive anode rod. The self-centering sealing clamp is installed inside the cathode cylinder sealing fixture, and the clamp sealing sleeve is installed on the self-centering sealing clamp to achieve a sealing effect on the micro-arc oxidation solution along the vertical direction of the conductive anode rod.

5. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 4, characterized in that: The anode device also includes a tooling enclosure, which is installed at the vertical contact point between the cathode cylinder sealing tooling and the cathode cylinder to further seal the micro-arc oxidation solution.

6. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 1, characterized in that: The conductive anode rod is made of aluminum alloy, and the cathode cylinder is made of stainless steel.

7. The micro-arc oxidation device with closed-loop uniform circulation control according to claim 1, characterized in that: It also includes a lifting device, which includes a fixed bracket and a lifting motion mechanism. The lifting motion mechanism is mounted on the fixed bracket, and the cathode cylinder sealing fixture is mounted on the lifting motion mechanism to install and disassemble the conductive anode rod and the sample.

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