Mask electrolytic machining device and method based on alternating magnetic field

Abstract

The invention discloses a mask electrolytic machining device and method based on an alternating magnetic field. The mask electrolytic machining device comprises an annular cathode, an anode workpiece, a magnetic mask, a magnetic field generating device, a transmission device, a pulse power source, an upper end cover, a lower end cover, a sealing ring, a fastening bolt, a liquid inlet, an exhaust valve and an electricity leading bolt. The annular cathode is fixedly connected with the upper end cover and the lower end cover through a fastening bolt 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 and attached to the surface of the anode workpiece, and the magnetic field generating device comprises a permanent magnet support and a fan-shaped magnetic pole. The magnetic mask is tightly attached to the surface of the workpiece by means of the adsorbability of the magnetic field generating device to the magnetic mask, the alternating magnetic field of the micro-texture machining area is beneficial for constraining the movement radius of charged ions and optimizing electric field distribution at the bottom of the micro-pit, meanwhile, the charged ions are subjected to the effect of Lorentz force under the alternating magnetic field, and the magnetic mask and the surface of the workpiece are tightly attached to each other. Therefore, the electrolysis quality is improved.

Description

Technical Field

[0001] The 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 have good heat dissipation, friction reduction, wettability, biocompatibility and other characteristics, and are widely used in important fields such as aerospace, biomedicine, and 5G communications. The existing micro-nano feature manufacturing technologies mainly include laser processing, electrospark processing, and masked electrolytic processing technology. Among them, masked electrolytic processing technology has been widely used in metal micro-nano feature processing because it is not limited by the hardness of the processing material, has no residual processing stress, has no recast layer, and has high processing efficiency.

[0003] Existing mask electrolytic processing technology can be divided into anode and cathode fixed type mask and movable type mask according to the properties of the mask attachment body. Among them, the anode / cathode fixed type mask is fixed on the anode / cathode surface, and high-quality micro-nano features can be manufactured on a regular plane. However, due to the limitations of existing photolithography technology, it is difficult to prepare a highly consistent fixed type mask on a curved surface, and there are disadvantages such as high processing cost and low efficiency. The movable mask often achieves relative fixation of the workpiece and the mask through different pressing methods, which has the advantages of reusability and improved processing efficiency. In order to improve the processing accuracy of large-area micro-nano arrays processed by movable mask electrolytic processing, Chen Xiaolei and Qu Ningsong proposed a method for mask electrolysis under high-pressure static liquid (system and method for pressure-assisted electrolytic processing of micro-pit arrays, patent application number: 201610640144.2). The proposed method uses high-pressure static liquid to improve the poor processing uniformity and stray corrosion caused by uneven flow field distribution and mask scouring. However, this method realizes localized processing, and after processing, there are serious lateral corrosion of micro-pits and poor quality of the bottom surface of 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 embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems existing in the existing mask electrolytic 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 a close fit between the magnetic mask and the surface of the workpiece, and the alternating magnetic field in the micro-texture processing area is beneficial to constraining 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 side walls of the micro-pits, thereby obtaining a large-area micro-nano array with high processing accuracy and surface quality.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a mask electrolytic 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-in 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 electrolytic 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, thereby improving the electrolytic processing quality of micro-nano features.

[0011] As a preferred solution of the mask electrolytic processing device based on 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 the N poles or the S poles and the S poles produce mutual repulsion at their adjacent locations, forming a near-zero magnetic field region, while the N poles and the S poles produce mutual attraction at their adjacent locations, forming a high magnetic field region.

[0012] As a preferred solution of the mask electrolytic processing device based on alternating magnetic field described in the present invention, when the fan-shaped magnetic poles are arranged as N-S-N-S, attraction occurs between adjacent N poles and S poles to form 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, wherein: the magnetic field generating device rotates continuously, the fan-shaped magnetic poles arranged with N-N-S-S polarity generate a strong gradient magnetic field in the processing area, and 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 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 solution of the mask electrolytic processing device based on an alternating magnetic field of the present invention, the method for using the mask electrolytic 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 generating device to 30r / min, so as 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 and high-voltage electrolyte generated by the magnetic field generating device in the processing area, so that the magnetic mask is closely 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 rotating motion of the magnetic field generating device in the present invention generates an alternating magnetic field on the surface of the workpiece. The alternating magnetic field is beneficial to the movement radius of the bound charged ions and optimizes 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, so as to realize the circulation and renewal of the electrolyte solute, improve the processing efficiency, and promote the speed of generating microbubbles at the bottom of the micro-nano features. The microbubbles merge with each other and generate an air film along the side wall of the micro-nano features, thereby shielding the electric field of the side wall of the micro-nano features, avoiding further electrolytic processing of the side wall, and improving the processing accuracy;

[0023] 3. The alternating magnetic field in the present invention adsorbs the magnetic insoluble products produced by electrolytic 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 in active mask electrolytic processing, realizing 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 effects 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 make irregular spiral motion, which increases the probability of the charged ions colliding with the micro-convex peaks on the surface of the micro-nano features, causing the dissolution rate of the micro-convex 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. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. 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 implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and 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" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0034] Reference Figure 1 - Figure 4 , provides a mask electrolytic 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-in 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 through the fastening bolts 7-7 and the sealing ring 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 pole 4-2. The sector 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 change 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-shaped 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 the N poles or the S poles and the S poles repel each other, forming a near-zero magnetic field area, while the N poles and the S poles attract each other, forming a high magnetic field area. Specifically, when the sector-shaped magnetic poles 4-2 are arranged as N-S-N-S8-2, the N poles and the S poles attract each other, forming a high magnetic field area, 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-shaped magnetic poles with the N-N-S-S8-1 polarity arrangement generate a strong gradient magnetic field in the processing area, while the sector-shaped magnetic poles with the N-S-N-S8-2 polarity arrangement generate 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 electrical insulating material epoxy resin, the sector pole 4-2 is made of neodymium iron boron N52, the permanent magnet support frame 4-1 is made of magnetic shielding material titanium alloy, 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 pole 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 0.5MPa, so that the magnetic mask 3 is further closely 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 rotation speed of the magnetic field generating device 4 to 30r / min, so as to generate 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 rotating 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 the movement radius of bound charged ions and optimizes 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, so as to realize the circulation and renewal of the electrolyte solute, improve the processing efficiency, and promote the speed of generating microbubbles at the bottom of the micro-nano features. The microbubbles merge with each other and generate an air film along the side wall of the micro-nano features, thereby shielding the electric field of the side wall of the micro-nano features, 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 rather than to limit it. 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 electrolytic 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 (7-4), a sealing ring (7-2), a fastening bolt (7-7), a liquid inlet (7-5), an exhaust valve (7-4) and a lead-in bolt (7-6); The annular cathode (1) is fixedly connected to the upper end cover (7-1) and the lower end cover (7-4) respectively through fastening bolts (7-7) and sealing rings (7-2); 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) comprises 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 support frame (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 pulley (5-3) driving the magnetic field generating device (4) is changed, thereby adjusting the change 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 fan-shaped magnetic pole (4-2) arrangement includes N-N-S-S (8-1) and N-S-N-S (8-2). When the arrangement is N-N-S-S (8-1), adjacent N poles or adjacent S poles produce a mutual repulsion phenomenon to form a near-zero magnetic field area, while adjacent N poles produce an attraction phenomenon to form a high magnetic field area.

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 N-S-N-S (8-2), an attraction phenomenon occurs between adjacent N poles and S poles to form 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 fan-shaped magnetic poles arranged in N-N-S-S (8-1) polarity generate a strong gradient magnetic field in the processing area, while the fan-shaped magnetic poles arranged in N-S-N-S (8-2) polarity generate a weak gradient magnetic field in the processing area.

6. The mask electrochemical processing device based on alternating magnetic field according to claim 5, characterized in that: 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-shaped magnetic 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.

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) as N-N-S-S (8-1), 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); 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, so that the magnetic mask (3) is further closely 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 rotation speed of the magnetic field generating device (4) to 30r / min, so as to generate the required alternating magnetic field in the processing area; Step 4: Turn on the pulse power supply (6) to achieve electrolytic processing of micro-nano features on the surface of the anode workpiece (2).

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