Electrochemical machining device with thick mask and low frequency reciprocating vibration and machining method thereof

Abstract

The present application relates to a kind of thick mask low-frequency reciprocating vibration electrolytic processing device and method thereof.The device includes cathode, mask, square clamp body and electrolytic power supply;Small holes are provided on the mask, and through the cooperation of low-frequency reciprocating vibration and intermittent power supply, pulse type electrolyte flow is formed during electrolytic processing, liquid inlet channel and mud flushing channel are alternately opened, and effective discharge of electrolytic mud is realized.The method of the present application solves the problem of inconsistent pit size and poor surface quality caused by electrolytic mud accumulation in thick mask electrolytic processing, significantly improves the consistency, precision and surface quality of group pit processing, and is suitable for electrolytic processing of high-precision micro-pit structure, with the advantages of good processing stability, high efficiency and wide application range.

Description

Technical Field

[0001] This invention relates to the field of electrolytic machining technology, specifically to an electrolytic machining apparatus and method for a thick mask with low-frequency reciprocating vibration. Background Technology

[0002] Surface texture refers to the formation of patterns such as pits, grooves, or protrusions of a specific size and distribution on the surface of a friction pair using certain processing techniques. Surface pit textures can accommodate particles during frictional motion, reducing wear on the friction pair surface, and their structural quality can improve the service life of the friction pair. In terms of heat dissipation, micro-pit structures can increase the heat exchange area and improve heat exchange efficiency. These applications place extremely high demands on processing accuracy and surface quality. Therefore, achieving high-quality, high-precision surface texture processing has become a key issue in current manufacturing technology.

[0003] Currently, methods for creating micro-pits on metal surfaces mainly include micro-machining, ultrasonic machining, micro-electrical discharge machining (EDM), LIGA technology, photolithography, surface shot peening, laser surface micro-modeling, and electrolytic machining. Among these, micro-machining, due to the cutting force, easily deforms the workpiece during processing, and the resulting micro-pits often have burrs and other defects, requiring secondary processing; EDM and laser machining create heat-affected zones on the material surface, making the workpiece prone to deformation; surface shot peening involves forces during processing, resulting in residual stress around the micro-pits and causing material deformation; LIGA and photolithography are complex processes requiring specialized photomasks, have long processing cycles, and high equipment investment. Electrolytic machining removes material in the form of ions, with no mechanical force during processing, and produces a smooth surface without heat-affected zones, thus it is widely used in micro-pit machining.

[0004] Currently, the main method for electrolytic machining of micro-pit arrays, both domestically and internationally, is mask electrolytic machining. This involves using an insulating or composite material with a through-hole structure as a mask, which is tightly fitted to the workpiece and forms a flow channel between itself and the plate. Electrolytic machining is then performed after the cathode and anode are connected to an electrolytic power source, resulting in a pit structure on the workpiece surface. This method offers advantages such as high processing efficiency and low cost. However, during mask electrolytic machining, the micro-holes on the mask serve as both inflow and outflow channels for the electrolyte and sites for the generation and accumulation of electrolytic sludge. Furthermore, the extremely small diameter of these micro-holes prevents the timely and effective removal of electrolytic sludge from the micro-holes and within the pits on the workpiece. These problems are particularly pronounced in mask electrolytic machining processes with thick insulating layers.

[0005] Compared to traditional mask electrochemical machining, thick mask electrochemical machining theoretically avoids the inconsistency in micro-pit size at the workpiece edge compared to the central area, as well as poor machining accuracy, when machining large-area micro-pits. It also avoids irregular micro-pit morphology and the formation of "islands" with protruding structures at the center of individual micro-pits. However, the thick mask further exacerbates the difficulty of mud removal, leading to more severe inconsistencies in corrosion rates among the micro-pits, greater differences in micro-pit size, and ultimately, unsatisfactory machining quality and accuracy.

[0006] Therefore, it is necessary to explore a new processing method to improve the dimensional accuracy of micro-pits while ensuring the consistency of pit dimensions in thick mask electrolytic processing. Summary of the Invention

[0007] This invention aims to provide an electrochemical machining apparatus and method using low-frequency reciprocating vibration of a thick mask, to solve the technical problems of poor consistency in pit size and poor surface quality caused by low electrolyte renewal efficiency and difficulty in removing processed products during thick mask electrochemical machining in the prior art. By employing a thick mask capable of reciprocating low-frequency vibration and intermittent power supply, the reciprocating vibration of the thick mask causes the electrolyte flow in the machining area to form a pulsed flow. Combined with the corresponding intermittent power supply, this disturbs the flow field in the machining area, enhances the mass transfer process, and thus achieves high-precision machining of group pits with consistent dimensions.

[0008] This invention discloses an electrolytic machining apparatus for low-frequency reciprocating vibration of a thick mask, comprising: A cathode, made of conductive material, is a sheet-like structure or a sheet-like structure with through holes, and is used as a tool electrode in electrolytic machining. A mask, made of an electrical insulator, has multiple through-holes on it. These through-holes are used to selectively restrict the area to be etched off from the workpiece surface during the processing. The square clamp body is milled from an insulator. The square clamp body is provided with a processing platform for placing the cathode, mask and workpiece. The square clamp body is provided with a liquid inlet hole. One side of the processing platform is provided with two deep grooves. The depth of the deep grooves reaches the liquid inlet hole. An electrolytic power supply, wherein the negative and positive terminals of the electrolytic power supply are respectively used for electrical connection with the cathode and the workpiece; The workpiece is placed on the processing platform, the mask is in close contact with the processing surface of the workpiece, and the cathode is located on the side of the mask away from the workpiece. The cathode, the mask, and the two deep trenches cooperate to form a liquid inlet channel above the mask and a mud flushing channel below the mask, respectively. The mask can reciprocate at low frequency in a direction perpendicular to the processing surface of the workpiece. When the mask descends and is in close contact with the workpiece, the mud flushing channel is blocked and the liquid inlet channel is opened. Electrolyte flows into the processing area through the liquid inlet hole, the liquid inlet channel, and the micro-holes on the mask for electrolytic processing. When the mask vibrates and rises and is in close contact with the cathode, the liquid inlet channel is blocked and the mud flushing channel is opened. Electrolyte flushes the micro-holes on the mask and the electrolytic mud in the processing area of ​​the workpiece through the mud flushing channel.

[0009] Selective etching of the workpiece surface is achieved through tiny holes in an electrically insulating mask, which can simultaneously form multiple micro-pits in a single processing step, resulting in high processing efficiency. Meanwhile, the liquid inlet channel and the mud flushing channel are alternately opened and closed by the low-frequency reciprocating vibration of the mask, eliminating the need for additional valves or independent switching mechanisms, making the structure simple and reliable. The electrolyte forms a pulse switching between the liquid inlet and mud flushing channels, effectively solving the problems of poor product discharge and low electrolyte renewal efficiency in thick mask electrolytic machining, thus improving the consistency and processing accuracy of multi-pit machining.

[0010] Furthermore, the cathode is a thin sheet structure with through holes, and the cathode and the mask are stacked and bonded to form a template; the template is in close contact with the workpiece and can reciprocate at low frequency in a direction perpendicular to the workpiece's processing surface; the device also includes a flow guide plate, which is located on the side of the template away from the workpiece; when the template vibrates and rises, the template is in close contact with the flow guide plate to block the liquid inlet channel.

[0011] The advantages of the above technical solution are as follows: the low-frequency reciprocating vibration of the mask is achieved by an external vibration device, which can be an electromagnetic vibrator or a servo motor drive mechanism. The vibration frequency range is set to 0.1Hz~10Hz, and the amplitude is controlled to 0.5mm~5mm. The specific parameters can be adjusted according to the mask thickness and electrolyte flow rate.

[0012] Furthermore, the insulating material used in the square clamp is fiberglass, polytetrafluoroethylene (PTFE), or Teflon. The advantages of the above technical solution are: fiberglass, PTFE, and Teflon all possess excellent electrical insulation properties, resistance to electrolyte corrosion, and machinability. They can withstand long-term immersion in electrolyte without swelling, deformation, or electrical leakage, ensuring the dimensional stability and insulation reliability of the square clamp during electrolytic processing, thereby guaranteeing processing accuracy and extending the service life of the device.

[0013] Furthermore, the thickness of the mask is from 0.4 mm to 10 mm.

[0014] The advantages of the above technical solution are as follows: the thickness range not only meets the requirements of thick mask electrolytic machining for mask stiffness and insulation shielding capability, but also effectively avoids problems such as the size of micro-dimples at the edge of the workpiece being larger than that in the central area and the appearance of "islands" in the center of a single micro-dimple in traditional thin mask electrolytic machining; at the same time, the thickness range matches the low-frequency reciprocating vibration scheme of the present invention, which can achieve stable pulsed electrolyte flushing while ensuring the flexibility of mask vibration response, thus taking into account both the processing range and processing accuracy.

[0015] Furthermore, the machined surface of the workpiece is flush with the lower surface of the mud flushing channel, and the lower surface of the mask is flush with the lower surface of the liquid inlet.

[0016] The advantages of the above technical solution are as follows: the flush relationship ensures that there are no steps or dead zones between the workpiece processing surface and the mud flushing channel, and the electrolyte can flow smoothly along the workpiece surface during the mud flushing stage, avoiding the formation of eddies and accumulation of electrolytic mud at the steps; at the same time, the lower surface of the mask is flush with the lower surface of the inlet hole, so that the electrolyte can directly and uniformly enter the processing area through the tiny holes on the mask during the inlet stage, reducing flow resistance, improving the electrolyte renewal rate, and further ensuring the uniformity of micro-dimple processing.

[0017] Furthermore, the liquid inlet channel and the sludge flushing channel are at the same height.

[0018] The advantages of the above technical solution are as follows: the two flow channels are at the same height, so that the mask only needs to move between two extreme positions with the same amplitude during the low-frequency reciprocating vibration process to seal the mud flushing flow channel and the liquid inlet flow channel respectively, which simplifies the design and control logic of the vibration control mechanism; at the same time, the two flow channels have the same flow cross section, which can ensure that the flow field parameters of the liquid inlet and mud flushing stages are symmetrical and stable, which is conducive to forming a uniform pulsed electrolyte flow and improving the stability of the processing.

[0019] Furthermore, the device also includes a power switch connected in series with the electrolytic power supply. The switching of the power switch is coordinated with the low-frequency reciprocating vibration of the mask: when the mask is in close contact with the workpiece, the power switch is closed, and the electrolytic power supply is turned on for electrolytic processing; when the mask vibrates and rises, the power switch is turned off, and the electrolytic processing is stopped, so that the electric field in the processing area exhibits intermittent alternating changes.

[0020] The advantages of the above technical solution are as follows: the power switch and the mask vibration are synchronized, completely separating the electrolytic machining and the mud rinsing process in time, avoiding non-selective erosion in the rinsing stage under energized conditions, and ensuring the regularity of the micro-pit morphology; at the same time, the intermittent power supply makes the workpiece material exhibit discrete dissolution and the processing products discretely distributed, which is conducive to the timely removal of electrolytic mud from the processing area during the mud rinsing stage, further alleviating the problem of electrolytic mud accumulation in the micro-holes of the thick mask, and broadening the applicable scope of electrolytic machining.

[0021] Furthermore, the cathode is made of a thin copper plate.

[0022] The advantages of the above technical solution are: the thin copper plate has excellent electrical conductivity and good mechanical strength, and can withstand the load generated by the electrolyte scouring and vibration during the processing without significant deformation while ensuring uniform current density in electrolytic processing; the thin copper plate has good processing performance, and it is easy to process through micro-holes as needed to overlap with the mask to form a template, thereby facilitating the implementation of the two typical embodiments of the present invention.

[0023] This invention also discloses an electrolytic machining method for low-frequency reciprocating vibration of a thick mask, comprising the following steps: Step 1: Mill a machining platform on an insulator and use drilling technology to machine an inlet hole in the insulator; mill two deep grooves on one side of the machining platform so that the depth of the deep grooves reaches the inlet hole, and cooperate to form an inlet flow channel and a mud flushing flow channel. Step 2: Place the workpiece on the processing platform and make the processed surface of the workpiece flush with the lower surface of the mud flushing channel; Step 3: Place the mask or template tightly against the workpiece so that the mask or template blocks the mud flushing channel, and the upper surface of the mask or template is flush with the lower surface of the liquid inlet channel; Step four: Electrically connect the workpiece and the cathode to the positive and negative terminals of the electrolysis power supply, respectively. Step 5: Inject the electrolyte into the processing area sequentially through the inlet hole, the inlet channel, and the micro-holes on the mask or template; Step 6: Turn on the power switch to connect the electrolytic power supply for electrolytic processing. After the electrolytic processing is completed, turn off the power switch. Step 7: The mask or template is vibrated at a low frequency to lift it and contact the cathode or guide plate to block the liquid inlet channel. At the same time, the mud flushing channel is opened, and the electrolyte flushes the electrolytic mud in the micro-holes of the mask or template and the workpiece processing area. Step 8: Reduce the low-frequency vibration of the mask or template, re-block the mud flushing channel, open the liquid inlet channel, and re-close the power switch to connect the electrolysis power supply for electrolytic processing; Step nine: Repeat steps six through eight until a group of micro-pit structures are machined on the workpiece surface.

[0024] Furthermore, the electrolytic machining method employs an intermittent power supply, where the switching on and off of the electrolytic power supply is synchronized with the low-frequency reciprocating vibration of the mask or template, causing the electric field in the machining area to exhibit intermittent alternating changes, thus forming intermittent electrolytic machining, and driving the workpiece material to dissolve discretely and the machining products to be distributed discretely.

[0025] By synchronously coupling intermittent power supply and mechanical vibration, the two originally interfering processes of "electrolytic machining" and "flow field flushing and mud removal" are decoupled in the time dimension. This ensures that each machining operation is carried out in a fresh electrolyte environment and each mud removal is completed under power-off conditions, avoiding stray erosion caused by charged flushing. The workpiece material exhibits discrete dissolution and the processed products exhibit discrete distribution, which is more conducive to the pulse flushing and removal of electrolytic mud in the micro-holes on the thick mask. This further improves the dimensional consistency and machining accuracy of the pits and broadens the applicability of electrolytic machining to parameters such as mask thickness and micro-hole diameter.

[0026] In summary, this invention, by introducing a reciprocating oscillating mask or template structure and combining it with the function of selectively limiting the workpiece etching area through micro-holes on the mask or template, achieves effective control of the flow field and electric field during micro-pit electrolytic machining. The reciprocating oscillating mask or template actively disturbs the electrolyte during operation, causing the electrolyte to flush away the electrolytic sludge in a pulsed manner, significantly improving mass transfer conditions within the narrow machining area and solving the problem of poor sludge removal in traditional mask electrolytic machining. This method improves the machining consistency of pit dimensions and surface quality.

[0027] Compared with the prior art, the beneficial effects of the present invention are: (1) In electrolytic machining apparatus with low-frequency reciprocating vibration of thick mask, the small aperture of the micro-holes on the thick mask and the thickness of the mask make it difficult for the electrolytic machining products in the machining area to be discharged smoothly. The mask in this method reciprocates and vibrates, and the electrolytic products between the anode and cathode are directly agitated by mechanical movement, thereby enhancing the mass transfer efficiency of the electrolytic products in the electrolyte flow field, improving machining stability, and increasing the machining consistency and accuracy of the pit size.

[0028] (2) In the electrolytic machining method of low-frequency reciprocating vibration of thick mask, the power supply is switched on and off intermittently, and the electric field in the machining area also changes intermittently, forming an intermittent electrolytic machining method. This drives the workpiece material to dissolve discretely and the machining products to be distributed discretely, which is more conducive to flushing out the electrolytic mud generated during the machining process. It is especially suitable for thick mask electrolytic machining technology and broadens the machining range.

[0029] In summary, the present invention features good processing stability, good consistency of pit dimensions, high processing accuracy, and a wide processing range. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the principle of thick mask low-frequency reciprocating vibration electrolytic machining according to the present invention.

[0032] Figure 2 This is a schematic diagram illustrating the electrolytic machining principle during low-frequency lifting of the thick mask according to the present invention.

[0033] Figure 3 This is a schematic diagram of the square clamp of the present invention.

[0034] Figure 4 This is a cross-sectional view of the square clamp of the present invention.

[0035] Figure 5 This is a diagram of the cathode structure without micropores according to the present invention.

[0036] Figure 6 This is a schematic diagram of the template electrolytic processing principle of the cathode with micropores according to the present invention.

[0037] Figure 7 This is a schematic diagram illustrating the electrolytic machining principle during low-frequency lifting of the template according to the present invention.

[0038] The attached diagram lists the components represented by each number as follows: 1. Cathode plate; 2. Mask; 3. Workpiece; 4. Micro-hole; 5. Liquid inlet; 6. Liquid inlet channel; 7. Sludge flushing channel; 8. Square clamping body; 9. Power switch; 10. Electrolysis power supply; 11. Drain plate; 12. Template; 13. Machining platform; a Electrolyte; b Reciprocating vibration. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please refer to Figures 1-7. This embodiment provides an electrolytic machining apparatus for low-frequency reciprocating vibration of a thick mask, including a cathode 1 made of conductive material, the cathode 1 being a thin sheet structure; a mask 2 made of an electrically insulating material, the mask 2 having multiple through-holes, which are used to selectively restrict the area to be etched from the workpiece 3 during machining; a template 12 composed of the cathode 1 with multiple micro-holes and the mask 2 with multiple micro-holes; and a square clamping body 8, which is milled from an insulator, with a machining platform 13 milled on the insulator for placing the cathode 1. The mask 2, the guide plate 11, and the workpiece 3 are connected to an insulator with a drilled inlet hole 5. The processing platform 13 has two deep grooves milled on one side, reaching the inlet hole 5, forming part of two flow channels. The two flow channels are an inlet flow channel 6 and a sludge flushing flow channel 7. The inlet flow channel 6 is composed of the cathode 1 or the guide plate 11, the upper surface of the template 12, the micro-holes on the template 12, the workpiece 3, and the inlet hole 5. The sludge flushing flow channel 7 is composed of the cathode 1 or the guide plate 11, the lower surface of the template 12, the micro-holes on the template 12, the workpiece 3, and the inlet hole 5. The negative and positive terminals of the electrolysis power supply 10 are connected to the cathode 1 and the workpiece 3, respectively. During processing, the electrolyte a flows through the inlet channel 6, the workpiece 3 is etched away, and electrolytic products are generated; the power supply 10 is disconnected, the electrolytic processing stops, the mask 2 or template 12 vibrates at low frequency b and rises to press against the cathode 1 or the guide plate 11, the inlet channel 6 is closed, and the electrolyte a flows through the sludge inlet channel 7 to further flush away the electrolytic sludge generated during the electrolytic processing and promote its discharge.

[0041] The insulator is made of fiberglass, polytetrafluoroethylene, or Teflon. The thickness of the mask 2 or template 12 is between 0.4 mm and 10 mm; The machined surface of workpiece 3 is flush with the lower surface of the mud flushing channel 7, and the lower surface of mask 2 or template 12 is flush with the lower surface of the liquid inlet hole 5. The liquid inlet channel 6 and the mud flushing channel 7 have the same height.

[0042] An electrolytic machining method using a thick mask with reciprocating vibration, comprising the following specific steps: Step 1: Mill a processing platform 13 on an insulator and use drilling to process an inlet hole 5. Then, mill two deep grooves on one side of the processing platform 13, reaching the depth of the inlet hole 5, to form two flow channels: one is the inlet flow channel 6, and the other is the mud flushing flow channel 7. Step 2: Place workpiece 3 on processing platform 13 and make the upper surface of processing platform 13 flush with the lower surface of mud flushing channel 7; Step 3: The mask 2 or template 12 is pressed tightly against the workpiece 3, and the mask 2 or template 12 blocks the mud flushing channel 7. In this way, the upper surface of the mask 2 or template 12 is flush with the lower surface of the liquid inlet channel 6. Step 4: Connect workpiece 3 and cathode 1 electrically to the positive and negative terminals of electrolysis power supply 10, respectively; Step 5: Electrolyte a is injected into the processing area through the inlet hole 5, the inlet channel 6, and the micro-holes 4 on the mask 2 or template 12; Step 6: Turn on the power switch 9 and connect the electrolytic power supply 10 to perform electrolytic processing. After the processing is completed, turn off the power switch 9. Step 7: The mask 2 or template 12 vibrates and lifts, and contacts the cathode 1 or the guide plate 11, blocking the liquid inlet channel 6 and opening the mud flushing channel 7 to flush the electrolytic mud in the micro-holes 4 on the mask 2 or template 12 and the pits on the workpiece 3. Step 8: Next, the mask 2 or template 12 vibrates and descends, re-blocking the mud flushing channel 7 and opening the liquid inlet channel 6 to perform electrolytic machining. This cycle is repeated until a group of micro-pit structures are machined on the surface of the workpiece 3.

[0043] One specific application of this embodiment is: Example 1 refer to Figures 1-5 As shown, workpiece 3 is mounted on machining platform 11, and mask 2 is tightly attached to workpiece 3. This blocks the sludge flushing channel 7. Electrolyte a flows into the machining area through inlet hole 5, inlet channel 6, and the group of small holes 4 on mask 2. During machining, power switch 9 is turned on, connecting electrolytic power supply 10. As electrolyte a flushes away the electrolytic sludge generated during machining, micro-pit structures appear on workpiece 3. With the upward low-frequency vibration b of mask 2, power switch 9 is turned off, electrolytic machining is interrupted, mask 2 vibrates upward, contacting cathode 1, blocking inlet channel 6, and opening sludge flushing channel 7 to flush away the electrolytic sludge in the pits on workpiece 3 and the small holes 4 on mask 2. Then, mask 2 vibrates downward until it contacts the surface of workpiece 3, blocking sludge flushing channel 7 again, opening inlet channel 6, turning on power switch 9, connecting electrolytic power supply 10, and performing electrolytic machining. This cycle repeats continuously.

[0044] Example 2 refer to Figures 6-7As shown, workpiece 3 is mounted on processing platform 11. A mask 2 on template 12 is placed in close contact with workpiece 3, thus blocking the mud flushing channel 7. Electrolyte a flows into the processing area through inlet hole 5, inlet channel 6, and small holes 4 on template 12. During processing, power switch 9 is turned on, connecting electrolytic power supply 10. As electrolyte a flushes away the electrolytic mud generated during processing, micro-pit structures appear on workpiece 3. With the upward low-frequency vibration b of template 12, power switch 9 is turned off, and electrolytic processing is interrupted. As template 12 rises with low-frequency vibration b, and as template 12 contacts the guide plate 11, blocking inlet channel 6, mud flushing channel 7 opens, flushing away the electrolytic mud in the pits of workpiece 3 and the small holes 4 on the mask. Then the template 12 vibrates at a low frequency and descends until it contacts the surface of the workpiece 3. The mud flushing channel 7 is blocked again, the liquid inlet channel 6 is opened, the power switch 9 is turned on, the electrolytic power supply 10 is connected, and electrolytic processing is carried out. This cycle is repeated.

[0045] In the above embodiments of the present invention: The vibration mode of the mask 2 or template 12 is a low-frequency reciprocating motion along the direction perpendicular to the processing surface of the workpiece 3. The vibration frequency is synchronized with the on and off frequency of the power switch 9 to ensure that the electrolytic processing and the mud flushing process are carried out alternately without interfering with each other. The "on-off" cycle of the power switch 9 corresponds to the "down-up" cycle of the mask 2 or template 12, thus forming a coupled control of intermittent power supply and pulsed flow field. The duration of a single work cycle can be adjusted according to parameters such as the material of the workpiece 3, the thickness of the mask 2, the diameter of the micro-hole 4, and the type and concentration of the electrolyte a.

[0046] Any equivalent structural changes, material substitutions, and parameter adjustments made by those skilled in the art to the above embodiments without departing from the spirit of the technical solution of the present invention shall fall within the protection scope of the present invention.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrolytic machining apparatus for low-frequency reciprocating vibration of a thick mask, characterized in that, include: A cathode, made of conductive material, is a sheet-like structure or a sheet-like structure with through holes, and is used as a tool electrode in electrolytic machining. A mask, made of an electrical insulator, has multiple through-holes on it. These through-holes are used to selectively restrict the area to be etched off from the workpiece surface during the processing. The square clamp body is made of an insulator. The square clamp body is provided with a processing platform for placing the cathode, mask and workpiece. The square clamp body is provided with a liquid inlet hole. One side of the processing platform is provided with two deep grooves. The depth of the deep grooves reaches the liquid inlet hole. An electrolytic power supply, wherein the negative and positive terminals of the electrolytic power supply are respectively used for electrical connection with the cathode and the workpiece; The workpiece is placed on the processing platform, the mask is in close contact with the processing surface of the workpiece, and the cathode is located on the side of the mask away from the workpiece. The cathode, the mask, and the two deep trenches cooperate with each other to form a liquid inlet channel above the mask and a mud flushing channel below the mask, respectively. The mask is capable of low-frequency reciprocating vibration in a direction perpendicular to the processing surface of the workpiece. When the mask descends and presses against the workpiece, the mud flushing channel is blocked and the liquid inlet channel is opened. Electrolyte flows into the processing area sequentially through the liquid inlet hole, the liquid inlet channel, and the micro-holes on the mask for electrolytic processing. When the mask vibrates and rises and presses against the cathode, the liquid inlet channel is blocked and the mud flushing channel is opened. Electrolyte flushes the micro-holes on the mask and the electrolytic mud in the processing area of ​​the workpiece through the mud flushing channel.

2. The electrolytic machining apparatus for low-frequency reciprocating vibration of a thick mask according to claim 1, characterized in that, The cathode is a thin sheet structure with through holes, and the cathode and the mask are stacked and bonded to form a template; the template is in close contact with the workpiece and can reciprocate at low frequency in a direction perpendicular to the workpiece's processing surface; the device also includes a flow guide plate, which is located on the side of the template away from the workpiece; when the template vibrates and rises, the template is in close contact with the flow guide plate to block the liquid inlet channel.

3. The thick-mask low-frequency reciprocating vibration electrochemical machining device according to claim 1, characterized in that, The insulating material used in the square clamp is fiberglass, polytetrafluoroethylene, or Teflon.

4. The thick-mask low-frequency reciprocating vibration electrochemical machining device according to claim 1, characterized in that, The thickness of the mask is 0.4 mm to 10 mm.

5. The thick-mask low-frequency reciprocating vibration electrochemical machining device according to claim 1, wherein The machined surface of the workpiece is flush with the lower surface of the mud flushing channel, and the lower surface of the mask is flush with the lower surface of the liquid inlet.

6. The thick-mask low-frequency reciprocating vibration electrochemical machining device according to claim 1, wherein The liquid inlet channel and the sludge flushing channel are at the same height.

7. The thick-mask low-frequency reciprocating vibration electrochemical machining device according to claim 1, wherein The device also includes a power switch connected in series with the electrolytic power supply. The switching of the power switch is coordinated with the low-frequency reciprocating vibration of the mask: when the mask is in close contact with the workpiece, the power switch is closed, and the electrolytic power supply is turned on for electrolytic processing; when the mask vibrates and rises, the power switch is turned off, and the electrolytic processing is stopped, so that the electric field in the processing area exhibits intermittent alternating changes.

8. The electrolytic machining apparatus for low-frequency reciprocating vibration of a thick mask according to claim 1, characterized in that, The cathode is made of a thin copper plate.

9. A thick mask low frequency reciprocating vibration electrochemical machining method using the thick mask low frequency reciprocating vibration electrochemical machining apparatus according to any one of claims 1 to 8, characterized by, Includes the following steps: Step 1: Mill a machining platform on an insulator and use drilling technology to machine an inlet hole in the insulator; mill two deep grooves on one side of the machining platform so that the depth of the deep grooves reaches the inlet hole, and cooperate to form an inlet flow channel and a mud flushing flow channel. Step 2: Place the workpiece on the processing platform and make the processed surface of the workpiece flush with the lower surface of the mud flushing channel; Step 3: Place the mask or template tightly against the workpiece so that the mask or template blocks the mud flushing channel, and the upper surface of the mask or template is flush with the lower surface of the liquid inlet channel; Step four: Electrically connect the workpiece and the cathode to the positive and negative terminals of the electrolysis power supply, respectively. Step 5: Inject the electrolyte into the processing area sequentially through the inlet hole, the inlet channel, and the micro-holes on the mask or template; Step 6: Turn on the power switch to connect the electrolytic power supply for electrolytic processing. After the electrolytic processing is completed, turn off the power switch. Step 7: The mask or template is vibrated at a low frequency to lift it and contact the cathode or guide plate to block the liquid inlet channel. At the same time, the mud flushing channel is opened, and the electrolyte flushes the electrolytic mud in the micro-holes of the mask or template and the workpiece processing area. Step 8: Reduce the low-frequency vibration of the mask or template, re-block the mud flushing channel, open the liquid inlet channel, and re-close the power switch to connect the electrolysis power supply for electrolytic processing; Step nine: Repeat steps six through eight until a group of micro-pit structures are machined on the workpiece surface.

10. The electrochemical material-removing process with a thick mask and low frequency reciprocating vibrations according to claim 9, characterized in that The electrolytic machining method employs an intermittent power supply. The switching on and off of the electrolytic power supply is synchronized with the low-frequency reciprocating vibration of the mask or template, causing the electric field in the machining area to exhibit intermittent alternating changes, thus forming intermittent electrolytic machining. This process drives the workpiece material to dissolve discretely and the machining products to be distributed discretely.

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