A photoelectric Fenton composite magnetorheological polishing device and its use method

Abstract

The present invention relates to the technical field of ultra-precision machining equipment, and more specifically, to a photoelectric Fenton composite magnetorheological polishing device and a method for using the same. The photoelectric Fenton composite magnetorheological polishing device comprises a fixture, a polishing pool, a cantilever, a driving mechanism, a dispersing mechanism, a magnetic field generating mechanism, an electric field generating mechanism, and a power supply. A polishing tank for containing polishing liquid is provided on the top of the polishing pool. A light-emitting mechanism for emitting light toward the fixture is provided on the cantilever. The magnetic field generating mechanism is provided so that the polishing liquid performs physical and mechanical polishing on a workpiece, and the electric field generating mechanism generates an electro-Fenton reaction between the polishing liquid and the workpiece, thereby oxidizing the surface of the workpiece to form an oxide layer. At this time, a flexible polishing pad formed by the polishing liquid under the action of the magnetic field will mechanically remove the oxide layer formed on the surface of the workpiece, thereby achieving the polishing of a workpiece with high hardness and high chemical stability.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machining equipment, and more specifically, to a photoelectric Fenton composite magnetorheological polishing device and a method for using the same. Background Art

[0002] With the development of information technology and electronic technology, the performance of optoelectronic devices is becoming increasingly excellent, while the working environment is also becoming increasingly extreme. This places higher physical and chemical performance requirements on the various components used to prepare optoelectronic devices. In order to keep up with the development speed of optoelectronic devices, optoelectronic chip substrate materials have evolved to third-generation wide-bandgap optoelectronic chips such as SiC and GaN, which have physical and chemical properties such as high hardness, high brittleness, high temperature resistance, and high chemical stability. The improvement in the physical and chemical properties of optoelectronic chip substrate materials enables their application in optoelectronic devices operating under more extreme conditions, making them a key core material for chips in fields such as artificial intelligence, 5G communication base stations, new energy vehicles, and photovoltaic power generation. However, this also brings new challenges to the ultra-precision processing of optoelectronic chip substrate materials.

[0003] Magnetorheological polishing is an ultra-precision polishing method that uses magnetic particles to form magnetic chains under the influence of a magnetic field, clamping non-magnetic abrasives to process workpieces. This method can achieve a polished surface with little or no subsurface damage, but the processing efficiency is relatively low. An electro-Fenton cluster magnetorheological composite grinding and polishing device currently available includes a base, a cluster magnet, a self-rotating transmission assembly, a revolving transmission assembly, a first drive assembly, a polishing plate containing magnetorheological fluid, a second drive assembly, and an electro-Fenton assembly. The cluster magnet is mounted on the self-rotating transmission assembly, which is connected between the cluster magnet and the first drive assembly, and the revolving transmission assembly is connected between the first drive assembly and the self-rotating transmission assembly. The polishing plate is connected to the second drive assembly and positioned above the cluster magnet. This magnetorheological polishing device improves the uniformity of polishing force distribution, but the removal method is still purely mechanical, resulting in low processing efficiency for high-hardness optoelectronic wafers. Furthermore, the dynamic magnetic field makes it difficult to effectively re-clamp the dense and easily agglomerated abrasives within the flexible polishing pad.

[0004] There is also a chemical cluster magnetorheological processing method for single-crystal silicon carbide wafers, in which the single-crystal silicon carbide wafer is bonded to an anti-magnetic tool head with an adhesive, and the anti-magnetic tool head is installed on the motor spindle. While the anti-magnetic tool head and the polishing disk rotate around their respective axes, the anti-magnetic tool head swings relative to the polishing disk to a certain extent. The method of the present invention is based on the magnetorheological effect, and abrasives and acid-base chemical reagents are mixed into the magnetorheological fluid as a polishing working fluid. A magnetic body is used as a matrix to form a magnetorheological effect small grinding head to constrain and aggregate free abrasives. The cluster action principle is used to form a flexible polishing film by an array combination of multi-point magnetorheological effect small grinding heads, and the distance between the workpiece and the anti-magnetic polishing disk and the relative rotation speed between the workpiece and the polishing disk are controlled to reduce the surface defects and damage layer of the single-crystal silicon carbide wafer, thereby obtaining an ultra-smooth and high-quality surface.

[0005] The above method introduces a chemical reaction into magnetorheological polishing, using it to generate a strong oxidizing substance that then mechanically removes the low-hardness oxide layer on the workpiece. However, the chemical reaction is not significant, and the efficiency of chemical oxidation is lower than that of mechanical removal, resulting in ineffective improvement in processing efficiency. Summary of the Invention

[0006] In order to overcome the problems of low polishing efficiency and poor polishing effect of the magnetorheological polishing device in the above-mentioned prior art, the present invention provides a photoelectric Fenton composite magnetorheological polishing device and a method for using it.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a photoelectric Fenton composite magnetorheological polishing device, including a clamp, a polishing pool, a cantilever, a driving mechanism, a dispersion mechanism, a magnetic field generating mechanism, an electric field generating mechanism, a power supply and a control device; a polishing tank for containing polishing liquid is provided on the top of the polishing pool; the cantilever is arranged above the polishing tank, the clamp is arranged at the bottom of the cantilever, and the cantilever is provided with a light-emitting mechanism for emitting light to the clamp; the dispersion mechanism is arranged at the bottom of the cantilever; the magnetic field generating mechanism is arranged in the polishing pool, and the magnetic field generating mechanism applies a magnetic field to the polishing tank; the electric field generating mechanism is arranged on the polishing pool, and the electric field generating mechanism applies an electric field to the polishing tank; the driving mechanism is connected to the cantilever power, and the driving mechanism drives the cantilever to rise and fall above the polishing pool and drives the cantilever to rotate axially; the power supply, magnetic field generating mechanism, electric field generating mechanism, control device, driving mechanism, and light-emitting mechanism are all electrically connected.

[0008] The fixture holds the workpiece to be polished; the polishing tank holds the polishing fluid, while the workpiece is polished within the tank. The magnetic field generating mechanism generates a magnetic field within the tank, causing the polishing fluid to form a flexible polishing pad under the action of the magnetic field, thereby mechanically polishing the workpiece surface. The electric field generating mechanism generates an electric field within the tank, causing an electro-Fenton reaction between the polishing fluid and the workpiece, thereby corroding and oxidizing the workpiece. The light emitting mechanism illuminates the workpiece to photocatalyze the oxidation reaction between the workpiece and the polishing fluid. The drive mechanism drives the cantilever to rotate, ensuring that the workpiece on the cantilever is in full contact with the polishing fluid in the tank. The control device controls the operation of the magnetic field generating mechanism, electric field generating mechanism, drive mechanism, and light emitting mechanism.

[0009] Furthermore, the light-emitting mechanism includes a light source and a light channel; the clamp is a transparent clamp; the light channel is arranged through the cantilever, the light source is arranged at the top of the light channel, and the clamp is arranged at the bottom of the light channel, and the light emitted by the light source is irradiated on the clamp through the light channel.

[0010] Furthermore, the dispersion mechanism includes a dispersion drive member and a paddle; the paddle is arranged on the output end of the dispersion drive member; and the dispersion drive member is arranged on the cantilever.

[0011] Furthermore, a convex column is provided in the polishing groove, and there is a gap between the outer wall of the convex column and the inner wall of the polishing groove; the electric field generating mechanism includes multiple anodes and cathodes, and the multiple anodes are circumferentially arranged on the inner wall of the polishing groove, and there is a gap between adjacent anodes; the cathode is circumferentially arranged on the outer wall of the convex column; the anode and cathode are both electrically connected to the power supply.

[0012] Furthermore, the magnetic field generating mechanism includes a magnetic field controller and multiple electromagnets; the electromagnets are arranged in the polishing pool and located below the gap between the polishing groove and the boss; the electromagnets are electrically connected to the magnetic field controller and the power supply; the controller is electrically connected to the power supply; the electric field generating mechanism also includes an electric field controller, and the electric field controller, power supply, anode and cathode are all electrically connected.

[0013] Furthermore, there are multiple dispersion mechanisms, fixtures and light-emitting mechanisms; multiple dispersion mechanisms and fixtures are alternately arranged on the cantilever; when the cantilever descends, the fixtures and dispersion mechanisms enter between the polishing groove and the protruding column.

[0014] Furthermore, the polishing pool is provided with a detection mechanism for detecting the position of the fixture; the detection mechanism is electrically connected to the magnetic field controller and the electric field controller; the magnetic field controller controls the electromagnet under the fixture to be connected to the power supply, and the magnetic field controller controls the other electromagnets to be disconnected from the power supply; the electric field controller controls the anode close to the fixture to be connected to the power supply, and the controller controls the other anodes to be disconnected from the power supply.

[0015] Furthermore, it also includes a clamp driving assembly, which is arranged on the cantilever and drives the clamp to rotate axially.

[0016] Furthermore, the driving mechanism includes a lifting assembly, a suspension beam and a rotating assembly; the lifting assembly is arranged at the top of the polishing pool, the suspension beam is dynamically connected to the lifting assembly, the rotating assembly is arranged on the suspension beam, and the cantilever is dynamically connected to the rotating assembly; the lifting assembly drives the suspension beam to move up and down; the rotating assembly drives the cantilever to rotate axially.

[0017] The present invention also provides a method for polishing using a photoelectric Fenton composite magnetorheological polishing device, comprising the following steps:

[0018] S1. Place the workpiece to be polished on the fixture, lower the cantilever through the drive mechanism, so that the workpiece moves into the polishing tank;

[0019] S2. Adjust the magnetic field strength generated by the magnetic field generating mechanism, adjust the wavelength and intensity of the light emitted by the light emitting mechanism; according to the material of the workpiece to be polished, inject the appropriate polishing fluid into the polishing tank;

[0020] S3. The cantilever is rotated by the drive mechanism, the magnetic field generating mechanism, the electric field generating mechanism and the light emitting mechanism are started, and the polishing operation begins;

[0021] S4. The polishing operation is completed and an ultra-smooth workpiece is obtained.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. A magnetic field generating mechanism is provided to enable the polishing liquid to perform physical mechanical polishing on the workpiece. An electric field generating mechanism causes an electro-Fenton reaction between the polishing liquid and the workpiece, thereby oxidizing the workpiece surface to form an oxide layer. At this time, the flexible polishing pad formed by the polishing liquid under the action of the magnetic field will mechanically remove the oxide layer formed on the workpiece surface, thereby achieving the polishing of high-hardness and high-chemical-stability workpieces;

[0024] 2. By setting up a light-emitting mechanism, light is used to catalyze the oxidation reaction between the polishing liquid and the workpiece. The photocatalytic chemical reaction and the electro-Fenton chemical reaction produce a chemical synergistic effect to bidirectionally enhance the chemical oxidation effect, efficiently generate strong oxidizing groups and oxidize the workpiece material, thereby improving the oxidation corrosion efficiency of the workpiece;

[0025] 3. By setting up a dispersion mechanism, the dispersion mechanism disperses the polishing liquid that has not come into contact with the workpiece, avoiding the deposition of abrasives with high density and easy to agglomerate in the polishing liquid, and ensuring that the abrasives in the polishing liquid are always in a highly dispersed state during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1Schematic diagram of the internal structure of an embodiment of the photoelectric Fenton composite magnetorheological polishing device of the present invention;

[0027] Figure 2 2. It is a schematic structural diagram of a cantilever in an embodiment of a photoelectric Fenton composite magnetorheological polishing device of the present invention;

[0028] Figure 3 It is a structural schematic diagram of a polishing pool in an embodiment of a photoelectric Fenton composite magnetorheological polishing device of the present invention.

[0029] In the accompanying drawings: 1. fixture; 2. polishing pool; 21. polishing groove; 22. boss; 3. cantilever; 4. driving mechanism; 41. lifting assembly; 411. screw assembly; 412. lifting motor; 42. cantilever; 43. rotating assembly; 431. rotating shaft; 432. rotating motor; 5. dispersion mechanism; 51. dispersion drive member; 52. blade; 6. magnetic field generating mechanism; 61. magnetic field controller; 62. electromagnet; 7. electric field generating mechanism; 71. anode; 72. cathode; 73. electric field controller; 8. power supply; 9. light-emitting mechanism; 91. light source; 92. light channel; 10. detection mechanism; 101. sensor; 102. receiver; 11. fixture driving assembly; 111. fixture driving member; 112. gear set. DETAILED DESCRIPTION

[0030] The drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate the embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent actual product dimensions. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted from the drawings. The positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0031] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "long", "short", etc. indicating the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0033] Example 1

[0034] Reference Figure 1 , an embodiment 1 of a photoelectric Fenton composite magnetorheological polishing device, comprising a fixture 1, a polishing pool 2, a cantilever 3, a driving mechanism 4, a dispersing mechanism 5, a magnetic field generating mechanism 6, an electric field generating mechanism 7 and a power supply 8; a polishing tank 21 for holding polishing liquid is provided at the top of the polishing pool 2; the cantilever 3 is arranged above the polishing tank 21, the fixture 1 is arranged at the bottom of the cantilever 3, and the cantilever 3 is provided with a light-emitting mechanism 9 for emitting light to the fixture 1; the dispersing mechanism 5 is arranged at the bottom of the cantilever 3; the magnetic field generating mechanism 6 is arranged in the polishing pool 2, and the magnetic field generating mechanism 6 applies a magnetic field to the polishing tank 21; the electric field generating mechanism 7 is arranged on the polishing pool 2, and the electric field generating mechanism 7 applies an electric field to the polishing tank 21; the driving mechanism 4 is power-connected to the cantilever 3, and the driving mechanism 4 drives the cantilever 3 to rise and fall above the polishing pool 2 and drives the cantilever 3 to rotate axially; the power supply 8 is electrically connected to the magnetic field generating mechanism 6 and the electric field generating mechanism 7.

[0035] Specifically, fixture 1 is made of a transparent, chemically resistant material, allowing light emitted by light-emitting mechanism 9 to pass through fixture 1 and illuminate the workpiece. Fixture 1 is used to hold the workpiece to be polished; polishing tank 21 is used to hold polishing liquid, while the workpiece is polished within polishing tank 21. A magnetic field generating mechanism 6 is used to generate a magnetic field within polishing tank 21, causing the polishing liquid to form a flexible polishing pad under the action of the magnetic field, thereby mechanically polishing the workpiece surface. An electric field generating mechanism 7 is used to generate an electric field within polishing tank 21, causing an electro-Fenton reaction between the polishing liquid and the workpiece, thereby corroding and oxidizing the workpiece. Light-emitting mechanism 9 is used to illuminate the workpiece to photocatalyze the oxidation reaction between the workpiece and the polishing liquid. The photocatalytic chemical reaction and the electro-Fenton chemical reaction produce a chemical synergistic effect, bidirectionally enhancing the chemical oxidation reaction, efficiently generating strong oxidizing radicals and oxidizing the workpiece material, thereby improving the efficiency of oxidative corrosion of the workpiece. The flexible polishing pad formed by the polishing liquid under the action of the magnetic field mechanically removes the oxide layer formed on the workpiece surface, thereby achieving the polishing of high-hardness, high-chemical stability workpieces. The driving mechanism 4 drives the cantilever 3 to rotate so that the workpiece on the cantilever 3 can fully contact the polishing liquid in the polishing tank 21.

[0036] In this embodiment, the light-emitting mechanism 9 includes a light source 91 and a light channel 92; the clamp 1 is a transparent clamp; the light channel 92 is passed through the cantilever 3, the light source 91 is arranged at the top of the light channel 92, and the clamp 1 is arranged at the bottom of the light channel 92, and the light emitted by the light source 91 is irradiated on the clamp 1 through the light channel 92.

[0037] The light channel 92 is a hollow tube that passes through the cantilever 3. The fixture 1 is ultrasonically welded to the bottom end of the light channel 92. The light source 91 is installed at the top of the light channel 92. The light emitted by the light source 91 can pass through the light channel 92 and the fixture 1 and irradiate the workpiece.

[0038] In this embodiment, the dispersion mechanism 5 includes a dispersion driving component 51 and a paddle 52 ; the paddle 52 is disposed on the output end of the dispersion driving component 51 ; and the dispersion driving component 51 is disposed on the cantilever 3 .

[0039] Specifically, the dispersion drive 51 is a motor mounted inside the cantilever 3. Multiple paddles 52 are mounted on the output end of the dispersion drive 51. The output end of the dispersion drive 51 extends through the bottom wall of the cantilever 3 toward the polishing tank 21. Activating the dispersion drive 51 rotates the paddles 52, thereby stirring and dispersing the polishing liquid within the polishing tank 21.

[0040] In this embodiment, a boss 22 is provided in the polishing groove 21, and there is a gap between the outer wall of the boss 22 and the inner wall of the polishing groove 21; the electric field generating mechanism 7 includes multiple anodes 71 and cathodes 72, and the multiple anodes 71 are circumferentially arranged on the inner wall of the polishing groove 21, and there is a gap between adjacent anodes 71; the cathode 72 is circumferentially arranged on the outer wall of the boss 22; the anodes 71 and the cathode 72 are both electrically connected to the power supply 8.

[0041] Specifically, the polishing groove 21 is circular, the boss 22 is cylindrical, and the boss 22 is formed by the upward protrusion of the middle part of the bottom wall of the polishing groove 21. The boss 22 is coaxially arranged with the polishing groove 21. A plurality of anodes 71 are embedded in the inner wall of the polishing groove 21. The cathode 72 is annular and is sleeved on the bottom end of the outer wall of the boss 22. The anode 71 and the cathode 72 are in the same horizontal plane. When the cathode 72 and the anode 71 are energized, an electric field is generated between the anode 71 and the cathode 72. The material of the anode 71 can be titanium or platinum, and the material of the cathode 72 can be graphite felt or nickel foam.

[0042] In this embodiment, the dispersion mechanism 5, the fixture 1 and the light-emitting mechanism 9 are all multiple; the multiple dispersion mechanisms 5 and the fixture 1 are alternately arranged on the cantilever 3; when the cantilever 3 descends, the fixture 1 and the dispersion mechanism 5 enter between the polishing groove 21 and the boss 22.

[0043] Specifically, the cantilever 3 is cross-shaped, and includes two each of the dispersion mechanism 5, fixture 1, and light-emitting mechanism 9. The dispersion mechanism 5 and fixture 1 are arranged alternately around the cantilever 3. The axis of the cantilever 3 faces the protrusion 22, allowing both the dispersion mechanism 5 and fixture 1 to extend into the polishing tank 21.

[0044] In this embodiment, the magnetic field generating mechanism 6 includes a magnetic field controller 61 and multiple electromagnets 62; the electromagnets 62 are disposed within the polishing tank 2 and below the gap between the polishing groove 21 and the protrusion 22; the electromagnets 62 are electrically connected to the magnetic field controller 61 and the power supply 8; the magnetic field controller 61 is electrically connected to the power supply 8; the electric field generating mechanism 7 also includes an electric field controller 73, which is electrically connected to the power supply 8, the anode 71, and the cathode 72. Multiple electromagnets 62 are installed within the polishing tank 2 and arranged circumferentially below the polishing groove 21, forming a circular shape.

[0045] The polishing pool 2 is provided with a detection mechanism 10 for detecting the position of the fixture 1; the detection mechanism 10 is electrically connected to the magnetic field controller 61 and the electric field controller 73; the magnetic field controller 61 controls the electromagnet 62 below the fixture 1 to be connected to the power supply 8, and the magnetic field controller 61 controls the other electromagnets 62 to be disconnected from the power supply 8; the electric field controller 73 controls the anode 71 close to the fixture 1 to be connected to the power supply 8, and the controller controls the other anodes 71 to be disconnected from the power supply 8.

[0046] The detection mechanism 10 is a position sensing detector currently available on the market, including a sensor 101 and a receiver 102. The receiver 102 is installed in the polishing pool 2, near the polishing tank 21. The sensor 101 is installed on the cantilever 3 near the light channel 92. The power supply 8 is a DC power supply 8. The magnetic field controller 61 is installed in the polishing pool 2 at a position away from the boss 22, and the electric field controller 73 is installed in the boss 22. The power supply 8 is electrically connected to the anode 71 and the cathode 72 through the electric field controller 73, and the power supply 8 is electrically connected to the electromagnet 62 through the magnetic field controller 61. The electric field controller 73 and the magnetic field controller 61 can be a PLC or a single-chip microcomputer.

[0047] When the receiver 102 senses the receptor, the electric field controller 73 controls the anode 71 near the fixture 1 to connect to the power source 8, and the magnetic field controller 61 controls the electromagnet 62 below the fixture 1 to connect to the power source 8. At this time, the workpiece is simultaneously subjected to chemical oxidation etching and mechanical physical polishing. The anode 71 and electromagnet 62 far from the workpiece and fixture 1 are not energized, which not only saves power from the power source 8 but also facilitates the dispersion mechanism 5 to disperse the polishing liquid. When the cantilever 3 rotates, the fixture 1 and the dispersion mechanism 5 sequentially pass through the polishing liquid in the polishing tank 21, so that the polishing liquid is in a state of alternating reaction with the workpiece and dispersion by the dispersion mechanism 5.

[0048] This embodiment also includes a fixture 1 drive assembly, which is arranged on the cantilever 3 and drives the fixture 1 to rotate axially. The fixture 1 drive assembly includes a fixture 1 drive member and a gear set 112. The fixture 1 drive member is installed in the cantilever 3. The output end of the fixture 1 drive member passes through the top wall of the cantilever 3. The output end of the fixture 1 drive member is power-connected to the light channel 92 via the gear set 112. After the fixture 1 drive member is started, it drives the light channel 92 to rotate axially through the gear set 112, thereby driving the fixture 1 and the workpiece to rotate axially, so that the workpiece can fully contact with the polishing liquid.

[0049] In this embodiment, the driving mechanism 4 includes a lifting assembly 41, a suspension beam 42 and a rotating assembly 43; the lifting assembly 41 is arranged at the top of the polishing pool 2, the suspension beam 42 is dynamically connected to the lifting assembly 41, the rotating assembly 43 is arranged on the suspension beam 42, and the cantilever 3 is dynamically connected to the rotating assembly 43; the lifting assembly 41 drives the suspension beam 42 to move up and down; the rotating assembly 43 drives the cantilever 3 to rotate axially.

[0050] The lifting assembly 41 includes a lifting motor 412 and a screw assembly 411. The lifting motor 412 is installed above the polishing tank 2. The travel direction of the screw assembly 411 is perpendicular to the top surface of the polishing tank 2. The suspension beam 42 is fixedly connected to the nut of the screw assembly 411. The rotating assembly 43 includes a rotating shaft 431 and a rotating motor 432. The rotating shaft 431 passes through the suspension beam 42 and is fixedly connected to the axis of the cantilever 3. The output end of the rotating motor 432 is connected to the rotating shaft 431. The rotating motor 432 drives the rotating shaft 431 to rotate axially, thereby driving the cantilever 3 to rotate axially.

[0051] Example 2

[0052] This embodiment is a method for polishing a SiC workpiece using the photoelectric Fenton composite magnetorheological polishing device in Example 1, comprising the following steps:

[0053] S1. The workpiece to be polished is placed on the fixture 1, and the cantilever 3 is lowered by the lifting assembly 41, so that the workpiece is moved into the polishing tank 21;

[0054] S2. Adjust the magnetic field strength generated by the magnetic field generating mechanism 6 so that the electromagnet can generate a magnetic field strength of 3000 Gs. Adjust the wavelength and intensity of the light emitted by the light emitting mechanism 9 so that the light source 91 can emit ultraviolet light with a wavelength of 365 nm and an intensity of 150 mW / cm2. Inject a polishing solution containing diamond abrasive, titanium dioxide, and hydrogen peroxide into the polishing tank 21.

[0055] S3 starts the dispersion mechanism 5, starts the light emitting mechanism 9 and the fixture drive assembly 1, rotates the fixture 1, starts the rotating assembly 43, rotates the cantilever 3, starts the magnetic field generating mechanism 6 and the electric field generating mechanism 7, and starts the polishing operation;

[0056] The light emitted by the light source 91 can induce titanium dioxide to undergo a photocatalytic reaction as shown in formula (1-1) and generate photogenerated electron-hole pairs:

[0057] (1-1)

[0058] The generated free electrons e- or holes h+ can induce the polishing liquid to produce reactions as shown in formula (1-2) and formula (1-3):

[0059] (1-2)

[0060] (1-3)

[0061] The strong oxidizing radicals generated by the polishing fluid oxidize the workpiece surface;

[0062] The anode 71 can induce the polishing liquid to produce a reaction as shown in formula (1-4):

[0063] (1-4)

[0064] The generated Fe2+ and Fe3+ react with H2O2 as shown in formula (1-5) and formula (1-6):

[0065] (1-5)

[0066] (1-6)

[0067] The cathode 72 can induce the polishing liquid to produce a chemical reaction as shown in formula (1-7):

[0068] (1-7);

[0069] The cathode 72 and the anode 71 cause the polishing liquid to produce an electro-Fenton reaction. The generated strong oxidizing radicals oxidize and corrode the surface of the workpiece. The oxide layer formed on the surface of the workpiece is then mechanically polished away by the abrasive in the polishing liquid, thus achieving a polishing effect.

[0070] S4. The polishing operation is completed and an ultra-smooth workpiece is obtained.

[0071] Example 3

[0072] This embodiment is a method for polishing a Si workpiece using a photoelectric Fenton composite magnetorheological polishing device in Example 1. The difference between this embodiment and Example 2 is that step S2 is:

[0073] S2. Adjust the magnetic field strength generated by the magnetic field generating mechanism 6 so that the electromagnet can generate a magnetic field strength of 2000Gs, adjust the wavelength and light intensity of the light emitted by the light emitting mechanism 9 so that the light source 91 can emit ultraviolet light with a wavelength of 365nm and a light intensity of 25 mW / cm2; inject the polishing liquid containing cerium oxide abrasive, titanium dioxide and hydrogen peroxide into the polishing tank 21.

[0074] Example 4

[0075] This embodiment is a method for polishing a SiC workpiece using a photoelectric Fenton composite magnetorheological polishing device in Example 1. The difference between this embodiment and Example 2 is that step S2 is:

[0076] S2. Adjust the magnetic field strength generated by the magnetic field generating mechanism 6 so that the electromagnet can generate a magnetic field strength of 3000Gs, adjust the wavelength and light intensity of the light emitted by the light emitting mechanism 9 so that the light source 91 can emit ultraviolet light with a wavelength of 365nm and a light intensity of 150mW / cm2; inject the polishing liquid containing magnetic abrasive, magnetic catalyst and hydrogen peroxide into the polishing tank 21.

[0077] Magnetic abrasives and magnetic catalysts are added to the polishing liquid. The magnetic abrasives can enhance the mechanical grinding and removal ability of the magnetorheological flexible polishing pad. The magnetic catalyst can control the position where the polishing liquid and the workpiece produce oxidation reactions, thereby bidirectionally promoting the oxidation rate and mechanical removal ability of the polishing slurry on SiC.

[0078] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A photoelectric Fenton composite magnetorheological polishing device, characterized in that: The invention comprises a fixture (1), a polishing pool (2), a cantilever (3), a driving mechanism (4), a dispersing mechanism (5), a magnetic field generating mechanism (6), an electric field generating mechanism (7), a power supply (8) and a control device; the polishing pool (2) is provided with a polishing tank (21) for containing polishing liquid on the top; the cantilever (3) is provided above the polishing tank (21); the fixture (1) is provided at the bottom of the cantilever (3); the cantilever (3) is provided with a light emitting mechanism (9) for emitting light toward the fixture (1); the dispersing mechanism (5) is provided at the bottom of the cantilever (3); the magnetic field generating mechanism (6) is provided in the polishing pool (2), and the magnetic field generating mechanism (6) applies a magnetic field to the polishing tank (21); the electric field generating mechanism (7) The electric field generating mechanism (7) is arranged on the polishing pool (2), and applies an electric field to the polishing tank (21); the driving mechanism (4) is connected to the cantilever (3) in a power connection, and the driving mechanism (4) drives the cantilever (3) to rise and fall above the polishing pool (2) and drives the cantilever (3) to rotate axially; the power supply (8), the magnetic field generating mechanism (6), the electric field generating mechanism (7), the driving mechanism (4), the light emitting mechanism (9) and the control device are all electrically connected, and the light emitting mechanism (9) includes a light source (91) and a light channel (92); the clamp (1) is a transparent clamp; the light channel (92) is provided through the cantilever (3), the light source (91) is provided at the top of the light channel (92), and the clamp (1) is provided at the light channel (92). At the bottom of the line channel (92), the light emitted by the light source (91) is irradiated onto the fixture (1) through the light channel (92), and the dispersion mechanism (5) includes a dispersion drive member (51) and a paddle (52); the paddle (52) is arranged on the output end of the dispersion drive member (51); the dispersion drive member (51) is arranged on the cantilever (3), and a convex column (22) is provided in the polishing groove (21), and there is a gap between the outer wall of the convex column (22) and the inner wall of the polishing groove (21); the electric field generating mechanism (7) includes a plurality of anodes (71) and cathodes (72), and the plurality of anodes (71) are circumferentially arranged on the inner wall of the polishing groove (21), and there is a gap between two adjacent anodes (71); the The cathode (72) is circumferentially arranged on the outer wall of the convex column (22); the anode (71) and the cathode (72) are both electrically connected to the power supply (8); the magnetic field generating mechanism (6) includes a magnetic field controller (61) and a plurality of electromagnets (62); the electromagnets (62) are arranged in the polishing pool (2) and are located below the gap between the polishing groove (21) and the convex column (22); the electromagnets (62) are electrically connected to the magnetic field controller (61) and the power supply (8); the magnetic field controller (61) is electrically connected to the power supply (8); the electric field generating mechanism (7) further includes an electric field controller (73); the electric field controller (73), the power supply (8), the anode (71) and the cathode (72) are all electrically connected.

2. The photoelectric Fenton composite magnetorheological polishing device according to claim 1, characterized in that: The dispersion mechanism (5), the fixture (1) and the light-emitting mechanism (9) are all multiple; the multiple dispersion mechanisms (5) and the fixture (1) are alternately arranged on the cantilever (3); when the cantilever (3) descends, the fixture (1) and the dispersion mechanism (5) enter between the polishing groove (21) and the protruding column (22).

3. The photoelectric Fenton composite magnetorheological polishing device according to claim 2, characterized in that: The polishing pool (2) is provided with a detection mechanism (10) for detecting the position of the fixture (1); the detection mechanism (10) is electrically connected to the magnetic field controller (61) and the electric field controller (73); the magnetic field controller (61) controls the electromagnet (62) below the fixture (1) to be connected to the power supply (8), and the magnetic field controller (61) controls the other electromagnets (62) to be disconnected from the power supply (8); the electric field controller (73) controls the anode (71) close to the fixture (1) to be connected to the power supply (8), and the electric field controller (73) controls the other anodes (71) to be disconnected from the power supply (8).

4. The photoelectric Fenton composite magnetorheological polishing device according to claim 1, characterized in that: It also includes a clamp (1) drive component, wherein the clamp (1) drive component is arranged on the cantilever (3), and the clamp (1) drive component drives the clamp (1) to rotate axially.

5. The photoelectric Fenton composite magnetorheological polishing device according to claim 1, characterized in that: The driving mechanism (4) comprises a lifting assembly (41), a suspension beam (42) and a rotating assembly (43); the lifting assembly (41) is arranged on the top of the polishing pool (2); the suspension beam (42) is connected to the lifting assembly (41) by power; the rotating assembly (43) is arranged on the suspension beam (42); the cantilever (3) is connected to the rotating assembly (43) by power; the lifting assembly (41) drives the suspension beam (42) to move up and down; the rotating assembly (43) drives the cantilever (3) to rotate axially.

6. A method for polishing using the photoelectric Fenton composite magnetorheological polishing device according to any one of claims 1 to 5, characterized in that: The steps include: S1. Place the workpiece to be polished on the fixture (1), lower the cantilever (3) through the drive mechanism (4), and move the workpiece into the polishing tank (21); S2. Adjusting the magnetic field strength generated by the magnetic field generating mechanism (6), adjusting the wavelength and intensity of the light emitted by the light emitting mechanism (9); injecting a suitable polishing fluid into the polishing tank (21) according to the material of the workpiece to be polished; S3. The cantilever (3) is rotated by the driving mechanism (4), the magnetic field generating mechanism (6), the electric field generating mechanism (7) and the light emitting mechanism (9) are started to start the polishing operation; S4. The polishing operation is completed and an ultra-smooth workpiece is obtained.

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