A mask electrolytic processing device and method based on alternating magnetic field

Abstract

The present invention discloses a mask electrolytic machining device and method based on an alternating magnetic field, comprising: an annular cathode, an anode workpiece, a magnetic mask, a magnetic field generating device, a transmission device, a pulse power supply, an upper end cover, a lower end cover, a sealing ring, a fastening bolt, a liquid inlet, an exhaust valve, and a lead-in bolt; the annular cathode is fixedly connected to the upper end cover and the lower end cover via fastening bolts and a sealing ring, respectively; the anode workpiece is fixed between the upper end cover and the lower end cover; the magnetic mask is pressed against the surface of the anode workpiece; and the magnetic field generating device includes a permanent magnet bracket and a sector-shaped magnetic pole. The present invention utilizes the adsorption of the magnetic mask by the magnetic field generating device to achieve a tight fit between the magnetic mask and the workpiece surface. Furthermore, the alternating magnetic field in the micro-textured machining area helps to confine the motion radius of charged ions and optimize the electric field distribution at the bottom of the micro-pits. Simultaneously, under the alternating magnetic field, the charged ions are acted upon by the Lorentz force and are rapidly ejected from the machining area, thereby increasing the amount of electrolyte.

Description

Technical Field

[0001] The present invention belongs to the field of micro electrolytic machining, and in particular relates to a mask electrolytic machining device and method based on an alternating magnetic field. Background Art

[0002] Metal micro-nano features refer to microstructures with specific functional shapes, structures, and distributions on the metal surface. Metal micro-nano features possess excellent heat dissipation, friction reduction, wettability, and biocompatibility, and are widely used in key fields such as aerospace, biomedicine, and 5G communications. Existing micro-nano feature manufacturing technologies primarily include laser processing, electrical discharge machining (EDM), and masked electrochemical machining (MEM). Among these, MEM has been widely used in metal micro-nano feature processing due to its advantages, including being unrestricted by the hardness of the processed material, lacking residual processing stress, lacking a recast layer, and achieving high processing efficiency.

[0003] Existing mask electrochemical machining (MEM) technologies can be categorized based on the properties of the mask attachment: fixed anode and cathode masks, and removable masks. Anode / cathode fixed masks are fixed to the anode / cathode surfaces, enabling the fabrication of high-quality micro-nano features on regular surfaces. However, due to limitations in existing photolithography techniques, removable masks are difficult to produce with high consistency on curved surfaces, and suffer from disadvantages such as high processing costs and low efficiency. Removable masks often achieve relative fixation between the workpiece and the mask through various pressing methods, offering advantages such as reusability and improved processing efficiency. To improve the machining accuracy of large-area micro-nano arrays using removable mask electrochemical machining, Chen Xiaolei and Qu Ningsong proposed a method for mask electrochemical machining under high-pressure hydrostatic pressure (System and Method for Pressure-Assisted Electrochemical Machining of Micropit Arrays, Patent Application No. 201610640144.2). This method utilizes high-pressure hydrostatic pressure to mitigate the poor machining uniformity and stray corrosion caused by uneven flow field distribution and mask erosion. However, this method achieves localized processing, and after processing, there are serious lateral corrosion of micro-pits and poor quality of the bottom surface of the micro-pits. Therefore, it is urgent to explore new electrolytic processing devices and methods to solve the above technical problems. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above problems existing in the existing mask electrochemical processing technology, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to provide a mask electrolytic processing device and method based on an alternating magnetic field, which utilizes the adsorption of the magnetic mask by the magnetic field generating device to achieve close fitting between the magnetic mask and the workpiece surface, and the alternating magnetic field in the micro-texture processing area is conducive to confining the movement radius of charged ions and optimizing the electric field distribution at the bottom of the micro-pits. At the same time, the charged ions are affected by the Lorentz force under the alternating magnetic field and are quickly thrown away from the processing area, thereby improving the processing efficiency. The electric field of the micro-pit sidewalls is shielded by the air film generated on the sidewalls of the micro-pits, thereby obtaining a large-area micro-nano array with high processing accuracy and surface quality.

[0007] To solve the above technical problems, the present invention provides the following technical solution: a mask electrochemical processing device based on an alternating magnetic field, comprising:

[0008] Annular cathode, anode workpiece, magnetic mask, magnetic field generating device, transmission device, pulse power supply, upper end cover, lower end cover, sealing ring, fastening bolts, liquid inlet, exhaust valve and lead bolts;

[0009] The annular cathode is fixedly connected to the upper end cover and the lower end cover respectively by fastening bolts and sealing rings, the anode workpiece is fixed between the upper end cover and the lower end cover, the magnetic mask is pressed against the surface of the anode workpiece, the magnetic field generating device includes a permanent magnet bracket and a fan-shaped magnetic pole, the fan-shaped magnetic pole is installed on the permanent magnet bracket through a fixing groove, the transmission device includes a servo motor, a synchronous belt, a pulley and a bearing, the servo motor is connected to the pulley through a synchronous belt, the magnetic field generating device is connected to the pulley, the lower end cover is connected to the permanent magnet support frame through a bearing, the pulse power supply anode is connected to the anode workpiece through a lead-in bolt, and the pulse power supply cathode is connected to the annular cathode.

[0010] As a preferred solution of the mask electrochemical processing device based on alternating magnetic field described in the present invention, wherein: by adjusting the output pulse of the servo motor, the rotation speed of the magnetic field generating device driven by the pulley is changed, thereby adjusting the changing frequency of the alternating magnetic field generated in the processing area, and improving the electrochemical processing quality of micro-nano features.

[0011] As a preferred solution of the mask electrolytic processing device based on an alternating magnetic field described in the present invention, the fan-shaped magnetic pole arrangement includes N-N-S-S and N-S-N-S. When the arrangement is N-N-S-S, the N poles and N poles or the S poles and S poles adjacent to each other produce a mutual repulsion phenomenon, forming a near-zero magnetic field area, while the N poles and S poles adjacent to each other produce an attraction phenomenon, forming a high magnetic field area.

[0012] As a preferred solution of the mask electrolytic processing device based on the alternating magnetic field described in the present invention, when the fan-shaped magnetic poles are arranged as N-S-N-S, an attraction phenomenon occurs at adjacent N poles and S poles, forming a high magnetic field area, thereby generating an alternating magnetic field with a weak gradient in the processing area.

[0013] As a preferred solution of the mask electrolytic processing device based on alternating magnetic field described in the present invention, the magnetic field generating device rotates continuously, and the fan-shaped magnetic poles arranged with N-N-S-S polarity generate a strong gradient magnetic field in the processing area, while the fan-shaped magnetic poles arranged with N-S-N-S polarity generate a weak gradient magnetic field in the processing area.

[0014] As a preferred solution of the mask electrolytic processing device based on an alternating magnetic field described in the present invention, the upper end cover and the lower end cover are both made of epoxy resin, an electrically insulating material; the sector-shaped magnetic pole is made of neodymium iron boron N; the permanent magnet support frame is made of titanium alloy, a magnetic shielding material; the annular cathode is made of stainless steel; and the sealing ring is made of rubber.

[0015] As a preferred embodiment of the mask electrochemical processing device based on an alternating magnetic field of the present invention, a method for using the mask electrochemical processing device based on an alternating magnetic field comprises the following steps:

[0016] Step 1: Arrange the polarity of the sector-shaped magnetic poles of the magnetic field generating device as N-N-S-S, fix the anode workpiece between the upper end cover and the lower end cover, and attach the magnetic mask to the surface of the anode workpiece. The magnetic mask is tightly attached to the surface of the workpiece under the action of the magnetic field force of the magnetic field generating device;

[0017] Step 2: Open the exhaust valve, slowly fill the entire chamber with electrolyte through the liquid inlet, close the exhaust valve, and adjust the electrolyte pressure at the liquid inlet to 0.5MPa. The magnetic mask is further closely attached to the surface of the anode workpiece under the action of high-pressure static force;

[0018] Step 3: Turn on the servo motor and adjust the speed of the magnetic field generator to 30 r / min to generate the required alternating magnetic field in the processing area;

[0019] Step 4: Turn on the pulse power supply to achieve electrolytic machining of micro-nano features on the surface of the anode workpiece.

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention utilizes the alternating magnetic field generated by the magnetic field generating device in the processing area and the high-voltage electrolyte, so that the magnetic mask is tightly attached to the surface of the workpiece under the action of the magnetic field force and the high-voltage static force of the electrolyte, effectively avoiding stray corrosion;

[0022] 2. The rotational motion of the magnetic field generating device in the present invention generates an alternating magnetic field on the workpiece surface. The alternating magnetic field is beneficial for confining the movement radius of charged ions and optimizing the electric field distribution at the bottom of the micro-pits. At the same time, the metal ions dissolved in the workpiece in the processing area are ejected from the processing area under the action of the Lorentz force, thereby realizing the circulation and renewal of the electrolyte solute, improving the processing efficiency, and promoting the speed of microbubble generation at the bottom of the micro-nano feature. The microbubbles merge with each other and form an air film along the sidewalls of the micro-nano feature, thereby shielding the electric field of the sidewalls of the micro-nano feature, avoiding further electrolytic processing of the sidewalls, and improving the processing accuracy.

[0023] 3. The alternating magnetic field in the present invention adsorbs the magnetic insoluble products generated by electrochemical processing to the bottom surface of the micro-nano feature, thereby improving the problem of uneven current density distribution in the micro-nano feature processing area existing in active mask electrochemical processing, achieving a more uniform distribution of the micro-nano feature processing current density, and improving the flatness of the bottom of the micro-nano feature;

[0024] 4. In the present invention, the charged ions in the processing area are affected by the combined action of the electric field and the magnetic field. Under the action of the electric field force and the direction-changing Lorentz force, the charged ions perform irregular spiral motion, which increases the probability of the charged ions colliding with the micro-peaks on the surface of the micro-nano features, causing the dissolution rate of the micro-peaks on the surface to be higher than that of the concave parts, thereby improving the surface quality of the micro-nano features. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0026] Figure 1 It is a schematic diagram of a mask electrochemical processing device based on an alternating magnetic field.

[0027] Figure 2 It is a three-dimensional schematic diagram of a mask electrochemical processing device based on an alternating magnetic field.

[0028] Figure 3 It is a three-dimensional schematic diagram of the magnetic field generating device and the transmission device.

[0029] Figure 4 This is a schematic diagram of the polarity arrangement of sector-shaped magnetic poles. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0033] Furthermore, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, when describing the embodiments of the present invention, cross-sectional views illustrating device structures may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0034] Reference Figure 1 - Figure 4 , provides a mask electrochemical processing device based on an alternating magnetic field, comprising:

[0035] annular cathode 1, anode workpiece 2, magnetic mask 3, magnetic field generating device 4, transmission device 5, pulse power supply 6, upper end cover 7-1, lower end cover 7-4, sealing ring 7-2, fastening bolt 7-7, liquid inlet 7-5, exhaust valve 7-4 and lead bolt 7-6;

[0036] The annular cathode 1 is fixedly connected to the upper end cover 7-1 and the lower end cover 7-4 by fastening bolts 7-7 and sealing rings 7-2 respectively. The anode workpiece 1 is fixed between the upper end cover 7-1 and the lower end cover 7-1. The magnetic mask 3 is pressed against the surface of the anode workpiece 2. The magnetic field generating device 4 includes a permanent magnet bracket 4-1 and a sector magnetic pole 4-2. The sector magnetic pole 4-2 is installed on the permanent magnet bracket 4-1 through a fixing groove. The transmission device 5 includes a servo motor 5-1, a synchronous belt 5-2, a pulley 5-3 and a bearing 5-4. The servo motor 5-1 is connected to the pulley 5-3 through the synchronous belt 5-2. The magnetic field generating device 4 is connected to the pulley 5-3. The lower end cover 7-3 is connected to the permanent magnet support frame 4-1 through the bearing 5-4. The anode of the pulse power supply 6 is connected to the anode workpiece 2 through the lead-in bolt 7-6, and the cathode of the pulse power supply 6 is connected to the annular cathode 1.

[0037] Among them, by adjusting the output pulse of the servo motor 5-1, the rotation speed of the pulley 5-3 driving the magnetic field generating device 4 is changed, thereby adjusting the frequency of the alternating magnetic field generated in the processing area and improving the electrolytic processing quality of micro-nano features.

[0038] Furthermore, the arrangement of the sector magnetic poles 4-2 includes N-N-S-S8-1 and N-S-N-S8-2. When the arrangement is N-N-S-S8-1, the N poles and N poles or the S poles and S poles produce mutual repulsion at their adjacent locations, forming a near-zero magnetic field region, while the N poles and S poles produce attraction at their adjacent locations, forming a high magnetic field region. Specifically, when the sector magnetic poles 4-2 are arranged as N-S-N-S8-2, the N poles and S poles produce attraction at their adjacent locations, forming a high magnetic field region, thereby generating an alternating magnetic field with a weak gradient in the processing area; the magnetic field generating device 4 continues to rotate, and the sector magnetic poles with the N-N-S-S8-1 polarity arrangement produce a strong gradient magnetic field in the processing area, while the sector magnetic poles with the N-S-N-S8-2 polarity arrangement produce a weak gradient magnetic field in the processing area.

[0039] Among them, the upper end cover 7-1 and the lower end cover 7-4 are both made of epoxy resin, an electrically insulating material, the sector pole 4-2 is made of neodymium iron boron N52, the permanent magnet support frame 4-1 is made of titanium alloy, a magnetic shielding material, the annular cathode 1 is made of stainless steel, and the sealing ring 7-2 is made of rubber.

[0040] The method for using the mask electrochemical processing device based on the alternating magnetic field comprises the following steps:

[0041] Step 1: Arrange the polarity of the sector-shaped magnetic poles 4-2 of the magnetic field generating device 4 as N-N-S-S8-1, fix the anode workpiece 2 between the upper end cover 7-1 and the lower end cover 7-4, and attach the magnetic mask 3 to the surface of the anode workpiece 2. The magnetic mask 3 is tightly attached to the surface of the workpiece under the action of the magnetic field force of the magnetic field generating device 4;

[0042] Step 2: Open the exhaust valve 7-4, slowly fill the entire chamber with electrolyte through the liquid inlet, close the exhaust valve 7-4, and adjust the electrolyte pressure at the liquid inlet to 0.5 MPa. The magnetic mask 3 is further tightly attached to the surface of the anode workpiece 2 under the action of high-pressure static force;

[0043] Step 3: Turn on the servo motor 5 - 1 and adjust the speed of the magnetic field generating device 4 to 30 r / min, thereby generating the required alternating magnetic field in the processing area;

[0044] Step 4: Turn on the pulse power supply 6 to achieve electrolytic machining of micro-nano features on the surface of the anode workpiece 2.

[0045] The rotational motion of the magnetic field generating device in the invention generates an alternating magnetic field on the surface of the workpiece. The alternating magnetic field is beneficial to confining the movement radius of charged ions and optimizing the electric field distribution at the bottom of the micro-pits. At the same time, the metal ions dissolved in the workpiece in the processing area are thrown away from the processing area under the action of the Lorentz force, thereby realizing the circulation and renewal of the electrolyte solute, improving the processing efficiency, and promoting the speed of microbubble generation at the bottom of the micro-nano feature. The microbubbles merge with each other and form an air film along the side wall of the micro-nano feature, thereby shielding the electric field of the side wall of the micro-nano feature, avoiding further electrolytic processing of the side wall, and improving the processing accuracy.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A mask electrochemical processing device based on an alternating magnetic field, characterized in that: include: An annular cathode (1), an anode workpiece (2), a magnetic mask (3), a magnetic field generating device (4), a transmission device (5), a pulse power supply (6), an upper end cover (7-1), a lower end cover (7-3), a sealing ring (7-2), a fastening bolt (7-7), a liquid inlet (7-5), an exhaust valve (7-4) and a lead bolt (7-6); The annular cathode (1) is fixedly connected to the upper end cover (7-1) and the lower end cover (7-3) respectively through a fastening bolt (7-7) and a sealing ring (7-2); the anode workpiece (2) is fixed between the upper end cover (7-1) and the lower end cover (7-3); the magnetic mask (3) is pressed against the surface of the anode workpiece (2); the magnetic field generating device (4) includes a permanent magnet bracket (4-1) and a sector-shaped magnetic pole (4-2); the sector-shaped magnetic pole (4-2) is installed on the permanent magnet bracket (4-1) through a fixing groove; the transmission device (5) The invention comprises a servo motor (5-1), a synchronous belt (5-2), a pulley (5-3) and a bearing (5-4); the servo motor (5-1) is connected to the pulley (5-3) via the synchronous belt (5-2); the magnetic field generating device (4) is connected to the pulley (5-3); the lower end cover (7-3) is connected to the permanent magnet bracket (4-1) via the bearing (5-4); the anode of the pulse power supply (6) is connected to the anode workpiece (2) via the lead-in bolt (7-6); and the cathode of the pulse power supply (6) is connected to the annular cathode (1).

2. The mask electrochemical processing device based on an alternating magnetic field according to claim 1, characterized in that: By adjusting the output pulse of the servo motor (5-1), the rotation speed of the magnetic field generating device (4) driven by the pulley (5-3) is changed, thereby adjusting the frequency of the alternating magnetic field generated in the processing area and improving the electrolytic processing quality of micro-nano features.

3. The mask electrochemical processing device based on an alternating magnetic field according to claim 2, characterized in that: The sector-shaped magnetic pole (4-2) arrangement includes NNSS (8-1) and NSNS (8-2). When the arrangement is NNSS (8-1), a mutual repulsion phenomenon occurs between adjacent N poles or adjacent S poles, forming a near-zero magnetic field region, while an attraction phenomenon occurs between adjacent N poles and S poles, forming a high magnetic field region.

4. The mask electrochemical processing device based on an alternating magnetic field according to claim 3, characterized in that: When the sector-shaped magnetic poles (4-2) are arranged as NSNS (8-2), an attraction phenomenon occurs between adjacent N poles and S poles, forming a high magnetic field area, thereby generating an alternating magnetic field with a weak gradient in the processing area.

5. The mask electrochemical processing device based on an alternating magnetic field according to claim 4, characterized in that: The magnetic field generating device (4) rotates continuously, and the sector-shaped magnetic poles arranged with the polarity of NNSS (8-1) generate a strong gradient magnetic field in the processing area, while the sector-shaped magnetic poles arranged with the polarity of NSNS (8-2) generate a weak gradient magnetic field in the processing area.

6. The mask electrochemical processing device based on an alternating magnetic field according to claim 5, characterized in that: The upper end cover (7-1) and the lower end cover (7-3) are both made of epoxy resin, an electrically insulating material; the sector-shaped magnetic pole (4-2) is made of neodymium iron boron N52; the permanent magnet bracket (4-1) is made of titanium alloy, a magnetic shielding material; the annular cathode (1) is made of stainless steel; and the sealing ring (7-2) is made of rubber.

7. The mask electrochemical processing device based on an alternating magnetic field according to claim 6, characterized in that: The method for using the mask electrochemical processing device based on the alternating magnetic field comprises the following steps: Step 1: Arrange the polarity of the sector-shaped magnetic poles (4-2) of the magnetic field generating device (4) into NNSS (8-1), fix the anode workpiece (2) between the upper end cover (7-1) and the lower end cover (7-3), and attach the magnetic mask (3) to the surface of the anode workpiece (2). The magnetic mask (3) is tightly attached to the surface of the workpiece under the action of the magnetic field force of the magnetic field generating device (4); Step 2: Open the exhaust valve (7-4), slowly fill the entire chamber with electrolyte through the liquid inlet, close the exhaust valve (7-4), and adjust the electrolyte pressure at the liquid inlet to 0.5 MPa. The magnetic mask (3) is further tightly attached to the surface of the anode workpiece (2) under the action of high-pressure static force; Step 3: Turn on the servo motor (5-1) and adjust the speed of the magnetic field generating device (4) to 30 r / min, thereby generating the required alternating magnetic field in the processing area; Step 4: Turn on the pulse power supply (6) to achieve electrolytic machining of micro-nano features on the surface of the anode workpiece (2).

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