Plasma modified sphere grinding and polishing device, equipment and method

Abstract

The invention discloses a plasma modified sphere grinding and polishing device which comprises an upper grinding suite, a lower grinding suite and a discharging suite. The upper grinding suite comprises an upper grinding disc, a connecting seat and an inverted T-shaped connecting rod; the lower grinding suite comprises a lower grinding disc, an adapter plate, a base plate and a hollow rotating platform; a group of annular grooves are formed in the lower grinding disc; the discharge suite comprises an electrical slip ring, an anode plate, a cathode plate and a conductive slip ring; the rotating end of the electrical slip ring is electrically connected with the anode plate, and a gas port of the rotating end of the electrical slip ring is connected with the gas outlet nozzle through a pipeline; the fixed end of the conductive slip ring is fixedly connected with the substrate, and the rotating end of the conductive slip ring is electrically connected with the cathode plate. The plasma modified sphere grinding and polishing device is of a specific structure, and efficient, high-precision and high-quality polishing machining of spheres made of hard and brittle materials such as carbon and silicon can be achieved. In addition, the invention correspondingly provides plasma modified sphere grinding and polishing equipment and a plasma modified sphere grinding and polishing method.

Description

Technical Field

[0001] The present invention relates to the surface finishing technology of spheres, and particularly to a plasma-modified sphere grinding and polishing device suitable for processing spheres of hard and brittle materials such as carbon and silicon, a device constructed by using this device, and a sphere grinding and polishing method implemented by using this device. Background Art

[0002] Spheres of hard and brittle materials such as carbon and silicon have wide applications in fields such as precision machinery, precision measurement, aerospace, and military defense. For example, diamond-coated spheres are used in precision bearings. Due to the high hardness and low friction coefficient of diamond, the bearings have a long service life. In addition, diamond probe balls have incomparable advantages in the field of probe balls due to their wide application range, low use cost, high measurement accuracy, and good stability. Moreover, spheres of hard and brittle materials such as carbon and silicon are also one of the key parts of the ignition target in laser inertial confinement fusion experiments, and their quality will directly affect the efficiency of the physical process.

[0003] At present, the polishing methods for spheres of hard and brittle materials such as carbon and silicon mainly include mechanical polishing and chemical mechanical polishing. Mechanical polishing removes the protruding parts on the sphere surface through physical friction to achieve a smooth surface, but there are problems of low processing efficiency and poor processing quality. For chemical mechanical polishing, for example, Chinese Patent Document CN 117817489 A discloses a planetary gear type ultra-precision grinding and polishing device and method for precision ball parts, which uses a chemical oxidant to cause an oxidation reaction on the material surface to generate oxides that are easier to remove, realizing high-efficiency polishing. However, the polishing liquid containing chemical reagents will inevitably cause pollution to the environment.

[0004] Therefore, there is still a lack of effective technical means for the high-efficiency and high-quality polishing of spheres of hard and brittle materials such as carbon and silicon. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present application provides a plasma-modified sphere grinding and polishing device. Through a specific design, the plasma-modified sphere grinding and polishing device of the present application can achieve high-efficiency and high-quality polishing of spheres of hard and brittle materials such as carbon and silicon. Correspondingly, the present application also provides a plasma-modified sphere grinding and polishing device constructed by using the plasma-modified sphere grinding and polishing device, and a plasma-modified sphere grinding and polishing method implemented by using the plasma-modified sphere grinding and polishing device.

[0006] For the polishing device, the first technical solution of the present application is as follows:

[0007] Plasma-modified sphere grinding and polishing device, comprising an upper grinding kit, a lower grinding kit and a discharge kit; the upper grinding kit includes an upper grinding disc, a connecting seat and an inverted T-shaped connecting rod arranged in sequence from bottom to top; the upper end of the inverted T-shaped connecting rod is used to connect a driving device; the lower grinding kit includes a lower grinding disc, a transfer plate, a table panel and a hollow rotating platform arranged in sequence from top to bottom; the hollow rotating platform is arranged on a substrate; a set of concentric circular grooves are arranged on the lower grinding disc for placing spheres to be processed; the discharge kit includes an electrical slip ring, an anode plate, a cathode plate and a conductive slip ring; the rotating end of the electrical slip ring is sleeved on the inverted T-shaped connecting rod; an anode plate mounting groove is arranged on the bottom surface of the connecting seat, the anode plate is arranged in the anode plate mounting groove and is pressed by the upper grinding disc; the lead of the rotating end of the electrical slip ring is electrically connected to the anode plate, and the air port of the rotating end of the electrical slip ring is connected to an air outlet nozzle for conveying reaction gas to the grinding area through a pipeline; the cathode plate is arranged between the lower grinding disc and the transfer plate; a conductive slip ring is arranged in the inner cavity of the hollow rotating platform, the fixed end of the conductive slip ring is fixedly connected to the substrate, and the lead of the rotating end of the conductive slip ring is electrically connected to the cathode plate; the anode plate is insulated from the connecting seat and the upper grinding disc; the cathode plate is insulated from the transfer plate and the lower grinding disc.

[0008] Compared with the prior art, the plasma-modified sphere grinding and polishing device of the first solution of the present application has made remarkable progress through a specific design. Among them, the anode plate, the upper grinding disc, the lower grinding disc and the cathode plate form a dielectric barrier discharge structure. During operation, the reaction gas introduced into the grinding area can be ionized into plasma to modify the brittle materials on the surface of the sphere to be processed. Combining with the friction between the upper and lower grinding discs and the sphere to be processed, the sphericity of the brittle material sphere can be quickly converged, realizing efficient and high-quality sphere grinding and polishing processing; and no chemical polishing liquid needs to be added during the grinding process, thus avoiding environmental pollution caused by chemical reagents. In addition, when it is necessary to trim the upper and lower grinding discs, the corresponding reaction gas can be replaced (determine the reaction gas used for disc trimming according to the materials of the upper and lower grinding discs) for rapid disc trimming.

[0009] As an optimization, in the plasma-modified sphere grinding and polishing device of the first technical solution described above, the cross-section of the circular groove is V-shaped. With this structure, the cross-section of the circular groove for placing the sphere to be processed is V-shaped, and the sphere to be processed is in point contact when placed in the circular groove. During polishing, it is beneficial for the sphere to be processed to rotate self, so as to obtain a better polishing effect. Further, an R-angle transition structure is arranged on the circular groove. Performing an R-angle operation on the V-shaped structure of the circular groove can avoid the occurrence of tip discharge.

[0010] For the polishing device, the present application also provides a second technical solution, which is as follows:

[0011] Plasma-modified sphere grinding and polishing device, comprising an upper grinding kit, a lower grinding kit and a discharge kit; the upper grinding kit includes an upper grinding disc, a connecting seat and an inverted T-shaped connecting rod arranged in sequence from bottom to top; the upper end of the inverted T-shaped connecting rod is used to connect a driving device; the lower grinding kit includes a lower grinding disc, a table board and a hollow rotating platform arranged in sequence from top to bottom; the lower grinding disc is connected to the table board, and the table board is connected to the hollow rotating platform; a single annular groove is provided on the lower grinding disc for placing the sphere to be processed; the hollow rotating platform is arranged on a substrate; the discharge kit includes an electrical slip ring, a positive electrode plate, a positive electrode medium, a negative electrode plate, a negative electrode medium and a negative electrode plate fixing frame, and the rotating end of the electrical slip ring is sleeved on the inverted T-shaped connecting rod; the positive electrode plate, the positive electrode medium, the negative electrode plate and the negative electrode medium are all annular structures; the air port at the rotating end of the electrical slip ring is connected through a pipeline to an air outlet nozzle for conveying reaction gas to the grinding area; the negative electrode plate is arranged in the grinding area and located inside the annular groove, and is connected to the negative electrode plate fixing frame; the negative electrode medium is an insulator and is arranged outside the negative electrode plate; the positive electrode plate is arranged outside the annular groove and has circumferential limitation; the positive electrode medium is an insulator and is arranged inside the positive electrode plate; a positive electrode wire is electrically connected to the positive electrode plate, and a negative electrode wire is electrically connected to the negative electrode plate.

[0012] Compared with the prior art, the plasma-modified sphere grinding and polishing device of the second solution of the present application also achieves remarkable progress by adopting a specific design. Among them, the positive electrode plate, the positive electrode medium, the negative electrode medium and the negative electrode plate form a dielectric barrier discharge structure. During operation, the reaction gas introduced into the grinding area can be ionized into plasma to modify the brittle material on the surface of the sphere to be processed. Combining with the friction between the upper and lower grinding discs and the sphere to be processed, the sphericity of the brittle material sphere converges rapidly, realizing high-efficiency and high-quality sphere grinding and polishing processing; and no chemical polishing liquid needs to be added during the grinding process, avoiding environmental pollution caused by chemical reagents. In addition, when it is necessary to trim the upper and lower grinding discs, the corresponding reaction gas can be replaced for rapid disc trimming operation. Compared with the first solution of the present application, the plasma-modified sphere grinding and polishing device of the second solution of the present application can polish and process spheres with a larger diameter (the larger the sphere to be processed, the larger the corresponding annular groove. Also, in the first solution of the present application, the lower grinding disc is used as a blocking medium and its thickness is usually between 1-3 mm. Therefore, a larger annular groove will affect the structural strength of the lower grinding disc; while in the second solution of the present application, the lower grinding disc is not used as a blocking medium and can be designed thicker, thus having higher structural strength).

[0013] As an optimization, in the plasma modified sphere grinding and polishing device of the second technical solution, the negative electrode plate is fixedly mounted inside the hollow rotating platform; a group of limiting posts are provided on the base plate, and a group of positioning holes are correspondingly provided on the positive electrode plate; the limiting posts cooperate with the positioning holes to form circumferential limiting for the positive electrode plate. This structure is easy to implement and has high reliability for circumferential limiting of the positive electrode plate.

[0014] As an optimization, in the plasma-modified sphere grinding and polishing device of the aforementioned second technical solution, the cross-section of the annular groove is V-shaped. With this structure, the cross-section of the annular groove for placing the sphere to be processed is V-shaped, and the sphere to be processed is placed in the annular groove for point contact. During the polishing process, it is convenient for the sphere to be processed to rotate, so as to obtain a better polishing effect. Furthermore, an R angle transition structure is provided on the annular groove. The R angle operation of the V-shaped structure of the annular groove can avoid the occurrence of tip discharge.

[0015] As an optimization, in the plasma modified sphere grinding and polishing device of the second technical solution, a conical airflow guide head is provided on the negative plate fixing frame to guide the reaction gas to between the upper grinding disc and the lower grinding disc. This structure can better guide the reaction gas into the grinding area between the upper grinding disc and the lower grinding disc.

[0016] For the polishing equipment, the technical solution of this application is as follows:

[0017] A plasma modified sphere grinding and polishing device comprises the plasma modified sphere grinding and polishing device of the first technical solution or the second technical solution, a three-axis worktable and a driving motor arranged on the Z axis of the three-axis worktable; the base plate of the lower grinding kit is fixed on the table surface of the three-axis worktable, and the upper end of the inverted T-shaped connecting rod of the upper grinding kit is drivingly connected to the rotating shaft of the driving motor.

[0018] Compared with the prior art, the plasma-modified sphere grinding and polishing equipment of the present application is based on a plasma-modified sphere grinding and polishing device, combined with a three-axis worktable and a drive motor. It can be used for efficient and high-quality polishing processing of spheres made of hard and brittle materials such as carbon and silicon, and avoids chemical reagent pollution, and has the advantage of being easy to implement.

[0019] For the polishing method, the technical solution of this application is as follows:

[0020] Plasma-modified sphere grinding and polishing method, which uses the plasma-modified sphere grinding and polishing device of the aforementioned first technical solution or second technical solution to polish the sphere to be processed; during polishing, the substrate of the lower grinding kit is fixed on the tabletop of the three-axis workbench, the upper end of the inverted T-shaped connecting rod of the upper grinding kit is connected to the driving motor installed on the Z-axis of the three-axis workbench, and the air port on the fixed end of the electrical slip ring is connected to the air outlet device;

[0021] The polishing process includes the following steps:

[0022] ①: Lift the upper grinding kit through the three-axis workbench;

[0023] ②: Place the sphere to be processed in the annular groove of the lower grinding disc;

[0024] ③: Adjust the eccentricity between the upper grinding disc and the lower grinding disc, lower the upper grinding kit, and press the upper grinding disc on the sphere to be processed;

[0025] ④: Turn on the air outlet device, so that the air outlet nozzle connected to the air port on the rotating end of the electrical slip ring sprays the reaction gas;

[0026] ⑤: Turn on the high-voltage power supply to form a dielectric barrier discharge structure, ionize the reaction gas in the grinding area, generate strongly oxidizing plasma, and the surface material of the sphere to be processed is modified under the corrosion of the strongly oxidizing plasma to generate oxides;

[0027] ⑥: At the same time, start the driving motor at the upper end of the inverted T-shaped connecting rod and the hollow rotating platform, drive the upper grinding disc and the lower grinding disc to rotate at a set speed respectively, drive the sphere to be processed to rotate, so that the surface material is uniformly modified, and the modified material is initially removed under the friction;

[0028] ⑦: After reaching the processing time set by the process, disconnect the high-voltage power supply and stop introducing the reaction gas;

[0029] ⑧: Pass deionized water through the air port on the fixed end of the electrical slip ring to remove the residual plasma, stop the modification of the sphere to be processed, and efficiently remove the modified surface material on the sphere to be processed under the friction of the upper grinding disc and the lower grinding disc;

[0030] ⑨: After reaching the processing time set by the process, stop processing.

[0031] Compared with the prior art, the plasma-modified sphere grinding and polishing method of the present application uses a plasma-modified sphere grinding and polishing device, and according to specific steps, can achieve high-efficiency and high-quality grinding and polishing of hard and brittle material spheres, is easy to operate, and is conducive to industrial promotion and use. Brief Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the plasma-modified sphere grinding and polishing device in the first embodiment;

[0033] Figure 2 is Figure 1 a partial enlarged view in;

[0034] Figure 3 is Figure 1 a schematic structural diagram of the connecting seat in;

[0035] Figure 4 It is a schematic structural diagram of the concave adapter plate in the first embodiment;

[0036] Figure 5 It is a schematic structural diagram of the convex adapter plate in the first embodiment;

[0037] Figure 6 is Figure 1 a schematic structural diagram of the cathode plate in;

[0038] Figure 7 It is a schematic structural diagram of the plasma-modified sphere grinding and polishing equipment in the first embodiment;

[0039] Figure 8 is Figure 7 a partial schematic diagram in;

[0040] Figure 9 It is a schematic structural diagram of the plasma-modified sphere grinding and polishing device in the second embodiment;

[0041] Figure 10 is Figure 9 a partial enlarged view in;

[0042] Figure 11 It is a schematic structural diagram of the plasma-modified sphere grinding and polishing equipment in the second embodiment;

[0043] Figure 12 is Figure 11 a partial schematic diagram in.

[0044] The reference signs in the drawings are as follows: 1 - upper grinding kit, 11 - upper grinding disc, 12 - connecting seat, 121 - anode plate mounting groove, 13 - inverted T-shaped connecting rod; 2 - lower grinding kit, 21 - lower grinding disc, 211 - annular groove, 22 - adapter plate, 221 - concave adapter plate, 222 - convex adapter plate, 23 - substrate, 231 - limiting post, 24 - table top plate, 25 - hollow rotating platform; 3 - discharge kit, 31 - electrical slip ring, 32 - anode plate, 33 - cathode plate, 34 - conductive slip ring, 35 - positive plate, 36 - positive medium, 37 - negative plate, 38 - negative medium, 39 - negative plate fixing bracket; 4 - sphere to be processed; 5 - air flow guiding head; 6 - air outlet nozzle; 7 - three-axis workbench, 71 - table top; 8 - drive motor. Detailed implementation manners

[0045] The present application will be further described below in conjunction with the drawings and embodiments, but it shall not be used as a basis for restricting the present application. In the following embodiments, the content that is not described in detail or not shown in detail in the drawings is common technical knowledge in the art.

[0046] Embodiment 1 (see Figures 1 to 8 ):

[0047] In this embodiment, a plasma-modified sphere grinding and polishing device using the first technical solution of the present application is used to construct a plasma-modified sphere grinding and polishing equipment. Specifically, the plasma-modified sphere grinding and polishing equipment includes a plasma-modified sphere grinding and polishing device, a three-axis workbench 7, and a drive motor 8 provided on the Z-axis of the three-axis workbench 7.

[0048] In this embodiment, the plasma-modified sphere grinding and polishing device includes an upper grinding kit 1, a lower grinding kit 2, and a discharge kit 3. The upper grinding kit 1 includes an upper grinding disc 11, a connecting seat 12, and an inverted T-shaped connecting rod 13 arranged in sequence from bottom to top. The upper end of the inverted T-shaped connecting rod 13 is used to connect a driving device. The lower grinding kit 2 includes a lower grinding disc 21, a transfer plate 22, a table panel 24, and a hollow rotating platform 25 arranged in sequence from top to bottom. The hollow rotating platform 25 is arranged on a substrate 23. A set of concentric annular grooves 211 are provided on the lower grinding disc 21 for placing the sphere 4 to be processed. The discharge kit 3 includes an electrical slip ring 31, an anode plate 32, a cathode plate 33, and a conductive slip ring 34. The rotating end of the electrical slip ring 31 is sleeved on the inverted T-shaped connecting rod 13. An anode plate mounting groove 121 is provided on the bottom surface of the connecting seat 12. The anode plate 32 is arranged in the anode plate mounting groove 121 and is pressed by the upper grinding disc 11. The lead of the rotating end of the electrical slip ring 31 is electrically connected to the anode plate 32. The air port of the rotating end of the electrical slip ring 31 is connected to an air outlet nozzle 6 for delivering reaction gas to the grinding area through a pipeline. The cathode plate 33 is arranged between the lower grinding disc 21 and the transfer plate 22. A conductive slip ring 34 is arranged in the inner cavity of the hollow rotating platform 25. The fixed end of the conductive slip ring 34 is fixedly connected to the substrate 23. The lead of the rotating end of the conductive slip ring 34 is electrically connected to the cathode plate 33. The anode plate 32 is insulated from the connecting seat 12 and the upper grinding disc 11. The cathode plate 33 is insulated from the transfer plate 22 and the lower grinding disc 21. The substrate 23 of the lower grinding kit 2 is fixed on the table surface 71 of a three-axis workbench 7. The upper end of the inverted T-shaped connecting rod 13 of the upper grinding kit 1 is in transmission connection with the rotating shaft of a driving motor 8.

[0049] In this embodiment, the upper grinding disc 11 is adhered to the connecting seat 12, and the lower grinding disc 21 is adhered to the concave transfer plate 22. In dielectric barrier discharge, the thickness of the insulating medium needs to be between 1 - 3 mm. Therefore, the upper grinding disc 11 and the lower grinding disc 21 are designed to be relatively thin, and the adhesion method is more reasonable.

[0050] In this embodiment, the cross-section of the annular groove 211 is V-shaped. With this structure, the cross-section of the annular groove 211 for placing the sphere 4 to be processed is V-shaped, and the sphere 4 to be processed is in point contact when placed in the annular groove 211. During polishing, it is beneficial for the sphere 4 to be processed to rotate self - sufficiently to obtain a better polishing effect. Further, an R - corner transition structure is provided on the annular groove 211. Performing an R - chamfer operation on the V - shaped structure of the annular groove 211 can avoid the occurrence of tip discharge.

[0051] In this embodiment, the adapter plate 22 includes a concave adapter plate 221 and a convex adapter plate 222; the concave adapter plate 221 is connected to the lower grinding disc 21; a set of transmission grooves are provided at the bottom of the concave adapter plate 221, and a set of transmission bosses are provided on the convex adapter plate 222; the concave adapter plate 221 is placed on the convex adapter plate 222, and the transmission grooves cooperate with the transmission bosses to transmit torque; the convex adapter plate 222 is connected to the table top plate 24. With this specific structure of the adapter plate 22, it is convenient to load and unload while ensuring the ability to transmit torque.

[0052] In this embodiment, a plasma-modified spherical grinding and polishing device is used to polish the sphere, and the specific steps are as follows:

[0053] ①: Lift the upper grinding kit 1 through the three-axis workbench 7;

[0054] ②: Place the sphere 4 to be processed in the annular groove 211 of the lower grinding disc 21;

[0055] ③: Adjust the eccentricity between the upper grinding disc 11 and the lower grinding disc 21, lower the upper grinding kit 1, and press the upper grinding disc 11 on the sphere 4 to be processed;

[0056] ④: Open the gas outlet device so that the gas outlet nozzle 6 connected to the gas port on the rotating end of the electrical slip ring 31 sprays the reaction gas;

[0057] ⑤: Turn on the high-voltage power supply, an electromotive force is generated between the anode plate 32 and the cathode plate 33, and the anode plate 32, the insulating upper grinding disc 11, the insulating lower grinding disc 21, and the cathode plate 33 arranged in sequence form a dielectric barrier discharge structure, so that the reaction gas in the grinding area is ionized to generate strongly oxidizing plasma, and the surface material of the sphere 4 to be processed is modified under the corrosion of the strongly oxidizing plasma to generate oxides;

[0058] ⑥: At the same time, start the drive motor 8 at the upper end of the inverted T-shaped connecting rod 13 and the hollow rotating platform 25, drive the upper grinding disc 11 and the lower grinding disc 21 to rotate at a set speed respectively, and then drive the sphere 4 to be processed to rotate, so that the surface material thereof is uniformly modified and the modified material is initially removed under the friction action;

[0059] ⑦: After reaching the processing time set by the process, disconnect the high-voltage power supply and stop introducing the reaction gas;

[0060] ⑧: Introduce deionized water through the gas port on the fixed end of the electrical slip ring 31 to remove the residual plasma, stop the modification of the sphere 4 to be processed, and efficiently remove the modified surface material on the sphere 4 to be processed under the action of the upper grinding disc 11 and the lower grinding disc 21 through frictional movement;

[0061] ⑨: After reaching the processing time set by the process, stop processing.

[0062] In this embodiment, a processing experiment is carried out on a single-crystalline silicon sphere: in the first hour, the anode plate 32 and the cathode plate 33 are electrified, reaction gas is introduced, the upper grinding disc 11 and the lower grinding disc 21 rotate, and plasma-assisted processing is carried out (the voltage difference between the upper and lower electrodes ionizes the water vapor between the two grinding discs, generating a large amount of highly reactive oxidation plasma, such as: hydroxyl radicals ∙OH, O - ions, etc. The surface single-crystalline silicon is corroded by the highly reactive and strongly oxidizing plasma to generate SiO2. Under the different rotation speeds of the upper grinding disc 11 and the lower grinding disc 21, the sphere to be processed rotates, and the Si atoms on the convex peaks of its surface are removed by the synergistic action of the corrosion modification of the strongly oxidizing plasma and mechanical friction. After the convex peaks are removed, the voltage and the frequency of the pulse are adjusted to control the material removal rate and the oxide layer generation rate, so that the surface quality at the nanometer level and the roundness requirement at the sub-micron level are achieved after grinding), and in the next 0.5 hour, the anode plate 32 and the cathode plate 33 are powered off, the reaction gas is stopped from being introduced, deionized water is introduced, and the upper grinding disc 11 and the lower grinding disc 21 rotate for polishing; the specific processing parameters are shown in Table 1 below.

[0063] Table 1: Processing parameters

[0064] Parameter Content Sphere material Monocrystalline silicon Sphere diameter 2 mm Number of spheres 100 pieces Electrode material Aluminum alloy Reaction gas Water vapor Rotation speed of upper / lower polishing pads +70 / -50 rpm Eccentricity of upper / lower polishing pads 4 mm Material of upper / lower polishing pads Quartz glass Plasma-assisted machining 1h Deionized water polishing 0.5h Magnitude of voltage 8 KV Magnitude of single-sphere pressure 0.001-0.05N

[0065] Before processing, the initial roughness of the single-crystalline silicon sphere is Sa: 219.5 nm, and the initial roundness is 2.34625 μm; after processing, the roughness of the single-crystalline silicon sphere reaches Sa: 3.2 nm, and the roundness reaches 0.26783 μm. The experimental results show that the technical solution of the present invention can effectively polish the single-crystalline silicon sphere, and the polishing effect is remarkable.

[0066] Example Two (see Figures 9 to 12 ):

[0067] In this embodiment, a plasma-modified sphere grinding and polishing equipment is constructed by using the plasma-modified sphere grinding and polishing device of the second technical solution of the present application.

[0068] In this embodiment, the plasma-modified sphere grinding and polishing equipment includes a plasma-modified sphere grinding and polishing device, as well as a three-axis workbench 7 and a driving motor 8 provided on the Z-axis of the three-axis workbench 7.

[0069] In this embodiment, the plasma-modified spherical grinding and polishing device includes an upper grinding kit 1, a lower grinding kit 2, and a discharge kit 3; the upper grinding kit 1 includes an upper grinding disc 11, a connecting seat 12, and an inverted T-shaped connecting rod 13 arranged in sequence from bottom to top; the upper end of the inverted T-shaped connecting rod 13 is used to connect a driving device; the lower grinding kit 2 includes a lower grinding disc 21, a table panel 24, and a hollow rotating platform 25 arranged in sequence from top to bottom; the lower grinding disc 21 is connected to the table panel 24, and the table panel 24 is connected to the hollow rotating platform 25; a single annular groove 211 is provided on the lower grinding disc 21 for placing the sphere 4 to be processed; the hollow rotating platform 25 is arranged on a substrate 23; the discharge kit 3 includes an electrical slip ring 31, a positive electrode plate 35, a positive electrode medium 36, a negative electrode plate 37, a negative electrode medium 38, and a negative electrode plate fixing frame 39, and the rotating end of the electrical slip ring 31 is sleeved on the inverted T-shaped connecting rod 13; the positive electrode plate 35, the positive electrode medium 36, the negative electrode plate 37, and the negative electrode medium 38 are all annular structures; the air port at the rotating end of the electrical slip ring 31 is connected to an air outlet nozzle 6 for conveying reaction gas to the grinding area through a pipeline; the negative electrode plate 37 is arranged in the grinding area and inside the annular groove 211 and is connected to the negative electrode plate fixing frame 39; the negative electrode medium 38 is an insulator, connected to the negative electrode plate 37, and located outside the negative electrode plate 37; the positive electrode plate 35 is arranged outside the annular groove 211 and has circumferential limitation; the positive electrode medium 36 is an insulator, connected to the positive electrode plate 35, and located inside the positive electrode plate 35; a positive electrode wire is electrically connected to the positive electrode plate 35, and a negative electrode wire is electrically connected to the negative electrode plate 37; the substrate 23 of the lower grinding kit 2 is fixed on the table top 71 of a three-axis workbench 7, and the upper end of the inverted T-shaped connecting rod 13 of the upper grinding kit 1 is in transmission connection with the rotating shaft of a driving motor 8.

[0070] In this embodiment, the negative electrode plate fixing frame 39 is arranged inside the hollow rotating platform 25; a group of limit posts 231 are provided on the substrate 23, and a group of positioning holes are correspondingly provided on the positive electrode plate 35; the limit posts 231 cooperate with the positioning holes to form circumferential limitation on the positive electrode plate 35. Using this structure to perform circumferential limitation on the positive electrode plate 35 is easy to implement and has high reliability.

[0071] In this embodiment, the cross-section of the annular groove 211 is V-shaped. The cross-section of the annular groove 211 for placing the sphere 4 to be processed is V-shaped, and the sphere 4 to be processed is in point contact when placed in the annular groove 211. During polishing, it is convenient for the sphere 4 to be processed to rotate self, so as to obtain a better polishing effect. Further, an R-angle transition structure is provided on the annular groove 211. With this structure, an R-angle operation is performed on the V-shaped structure of the annular groove 211, thereby avoiding the occurrence of tip discharge.

[0072] In this embodiment, a conical gas flow guiding head 5 is provided on the negative plate fixing frame 39 for guiding reaction gas between the upper grinding disc 11 and the lower grinding disc 21. This structure can better guide the reaction gas into the grinding area between the upper grinding disc 11 and the lower grinding disc 21.

[0073] In this embodiment, the constructed plasma modified sphere grinding and polishing equipment is used to polish the sphere, and the specific steps are as follows:

[0074] ①: Lift the upper grinding kit 1 through the three-axis workbench 7;

[0075] ②: Place the sphere 4 to be processed in the annular groove 211 of the lower grinding disc 21;

[0076] ③: Adjust the eccentricity between the upper grinding disc 11 and the lower grinding disc 21, lower the upper grinding kit 1, and press the upper grinding disc 11 on the sphere 4 to be processed;

[0077] ④: Open the gas outlet device to make the gas outlet nozzle 6 connected to the gas port on the rotating end of the electrical slip ring 31 spray reaction gas; guide the reaction gas to the grinding area through the gas flow guiding head 5;

[0078] ⑤: Turn on the high-voltage power supply to generate an electromotive force between the positive plate 35 and the negative plate 37. The sequentially arranged positive plate 35, insulating positive dielectric 36, insulating negative dielectric 38, and negative plate 37 form a dielectric barrier discharge structure, so that the reaction gas in the grinding area is ionized to generate strongly oxidizing plasma. The surface material of the sphere 4 to be processed is modified under the corrosion of the strongly oxidizing plasma to generate oxides;

[0079] ⑥: Simultaneously start the driving device at the upper end of the inverted T-shaped connecting rod 13 and the hollow rotating platform 25 to drive the upper grinding disc 11 and the lower grinding disc 21 to rotate at a set speed respectively, thereby driving the sphere 4 to be processed to rotate, so that the surface material thereof is uniformly modified and the modified material is preliminarily removed under the friction;

[0080] ⑦: After reaching the processing time set by the process, disconnect the high-voltage power supply and stop introducing the reaction gas;

[0081] ⑧: Introduce deionized water through the gas port on the fixed end of the electrical slip ring 31 to remove the residual plasma, stop the modification of the sphere 4 to be processed, and efficiently remove the modified surface material on the sphere 4 to be processed under the action of the upper grinding disc 11 and the lower grinding disc 21 through frictional movement;

[0082] ⑨: After reaching the processing time set by the process, stop the processing.

[0083] In this embodiment, a processing experiment is carried out on a CVD (Chemical Vapor Deposition) polycrystalline diamond sphere: in the first 2.5 hours, the positive electrode plate 35 and the negative electrode plate 37 are energized, reaction gas is introduced, the upper grinding disc 11 and the lower grinding disc 21 rotate, and plasma-assisted processing is carried out (the voltage difference between the upper and lower electrodes ionizes water vapor and oxygen between the two discs, generating a large amount of highly reactive oxidation plasma, such as: hydroxyl radicals ∙OH, O - ions, O 2- ions, etc. The carbon structure on the surface of the polycrystalline diamond and the Si-O-Si bond structure on the surface of the quartz glass grinding disc are modified under the corrosion of the highly reactive oxidation plasma. When the upper grinding disc 11 and the lower grinding disc 21 rotate at different speeds, the sphere to be processed rotates itself. The C atoms on the surface of the polycrystalline diamond are removed in the form of C-O-Si under the synergistic action of the corrosion modification of the strong oxidation plasma and mechanical friction. After the convex peaks are removed, the pressure, voltage, and pulse frequency are adjusted to achieve a nanoscale surface quality and a submicron-level roundness requirement after grinding), in the next 0.5 hours, the positive electrode plate 35 and the negative electrode plate 37 are powered off, the reaction gas is stopped from being introduced, deionized water is introduced, and the upper grinding disc 11 and the lower grinding disc 21 rotate for polishing; the specific processing parameters are shown in Table 2 below.

[0084] Table 2: Processing parameters

[0085] Parameter Content Sphere material CVD polycrystalline diamond Sphere diameter 2.5 mm Number of spheres 10 pieces Electrode material Aluminum alloy Reaction gas Argon containing 0.67% water vapor and 13% oxygen Rotation speed of upper / lower polishing pads +100 / -50 rpm Eccentricity of upper / lower polishing pads 4 mm Material of upper / lower polishing pads Quartz glass Plasma-assisted machining 2.5h Deionized water polishing 0.5h Magnitude of voltage 8 KV Magnitude of single-sphere pressure 0.01-1N

[0086] Before processing, the initial roughness of the CVD polycrystalline diamond sphere is Sa: 356.8 nm, and the initial roundness is 8.63728 μm; after processing, the roughness of the CVD polycrystalline diamond sphere reaches Sa: 5.3 nm, and the roundness reaches 0.75494 μm. The experimental results show that the technical solution of this application can effectively polish a single-crystalline silicon sphere, and the polishing effect is remarkable.

[0087] It should be noted that the plasma-modified sphere grinding and polishing device, polishing equipment, and polishing method of this application are developed for the polishing requirements of spheres made of hard and brittle materials such as carbon and silicon, but they are not only applicable to the polishing of spheres made of hard and brittle materials such as carbon and silicon, but can also polish sphere parts made of other materials (the reaction gas needs to be determined according to the material of the sphere to be processed).

[0088] The above general description of the invention involved in this application and the description of its specific implementation should not be understood as a limitation to the technical solution of this invention. Those skilled in the art can, based on the disclosure of this application, without departing from the constituent elements of the invention involved, add, subtract, or combine the disclosed technical features in the above general description or / and specific implementation (including embodiments) to form other technical solutions within the protection scope of this application.

Claims

1. Plasma-modified spherical grinding and polishing device, characterized in that: It comprises an upper grinding kit (1), a lower grinding kit (2) and a discharge kit (3); The upper grinding kit (1) comprises an upper grinding disc (11), a connecting seat (12) and an inverted T-shaped connecting rod (13) which are arranged in sequence from bottom to top; the upper end of the inverted T-shaped connecting rod (13) is used to connect to a driving device; The lower grinding kit (2) comprises a lower grinding disc (21), an adapter plate (22), a table plate (24) and a hollow rotating platform (25) which are arranged in sequence from top to bottom; the hollow rotating platform (25) is arranged on the base plate (23); the lower grinding disc (21) is provided with a group of concentrically arranged annular grooves (211) for placing the sphere (4) to be processed; The discharge kit (3) comprises an electrical slip ring (31), an anode plate (32), a cathode plate (33) and a conductive slip ring (34); the rotating end of the electrical slip ring (31) is sleeved on an inverted T-shaped connecting rod (13); the bottom surface of the connecting seat (12) is provided with an anode plate mounting groove (121), the anode plate (32) is arranged in the anode plate mounting groove (121) and is pressed by the upper grinding disc (11); the lead wire of the rotating end of the electrical slip ring (31) is connected to the anode plate (32) The gas outlet of the rotating end of the electrical slip ring (31) is connected to a gas outlet nozzle (6) for conveying reaction gas to the grinding area through a pipeline; the cathode plate (33) is arranged between the lower grinding disc (21) and the adapter plate (22); a conductive slip ring (34) is arranged in the inner cavity of the hollow rotating platform (25), the fixed end of the conductive slip ring (34) is fixedly connected to the base plate (23), and the lead wire of the rotating end of the conductive slip ring (34) is electrically connected to the cathode plate (33); The anode plate (32) is insulated from the connection seat (12) and the upper grinding disc (11); and the cathode plate (33) is insulated from the adapter plate (22) and the lower grinding disc (21).

2. The plasma-modified spherical grinding and polishing device according to claim 1, wherein: The cross section of the annular groove (211) is V-shaped.

3. Plasma-modified spherical grinding and polishing equipment, characterized in that: The invention comprises a plasma modified sphere grinding and polishing device as claimed in claim 1 or 2, a three-axis worktable (7) and a drive motor (8) arranged on the Z axis of the three-axis worktable (7); the base plate (23) of the lower grinding kit (2) is fixed on the table surface (71) of the three-axis worktable (7), and the upper end of the inverted T-shaped connecting rod (13) of the upper grinding kit (1) is drivingly connected to the rotating shaft of the drive motor (8).

4. The method for grinding and polishing a plasma-modified sphere, characterized in that: The method uses the plasma-modified sphere grinding and polishing device described in claim 1 or 2 to perform polishing on the sphere (4) to be processed; during polishing, the base plate (23) of the lower grinding kit (2) is fixed on the table surface (71) of the three-axis worktable (7), the upper end of the inverted T-shaped connecting rod (13) of the upper grinding kit (1) is connected to the drive motor (8) installed on the Z axis of the three-axis worktable (7), the air port on the fixed end of the electrical slip ring (31) is connected to the air outlet device, the lead wire of the fixed end of the electrical slip ring (31) is electrically connected to the positive pole of the high-voltage DC power supply, and the lead wire of the fixed end of the conductive slip ring (34) is electrically connected to the negative pole of the high-voltage DC power supply; The polishing process includes the following steps: ①: Lift the upper grinding kit (1); ②: Place the sphere to be processed (4) in the annular groove (211) of the lower grinding plate (21); ③: Adjust the eccentricity between the upper grinding plate (11) and the lower grinding plate (21), and then lower the upper grinding kit (1) so that the upper grinding plate (11) presses on the sphere to be processed (4); ④: Turn on the gas outlet device so that the gas outlet nozzle (6) connected to the gas port on the rotating end of the electrical slip ring (31) sprays the reaction gas; ⑤: Turn on the high-voltage power supply to form a dielectric barrier discharge structure, ionize the reaction gas in the grinding area to generate strongly oxidizing plasma, and the surface material of the sphere to be processed (4) is modified under the corrosion of the strongly oxidizing plasma to form oxides; ⑥: Start the drive motor (8) at the upper end of the inverted T-shaped connecting rod (13) and the hollow rotating platform (25), drive the upper grinding plate (11) and the lower grinding plate (21) to rotate at a set speed respectively, drive the sphere to be processed (4) to rotate, so that the surface material is uniformly modified, and the modified material is initially removed under the friction; ⑦: After reaching the processing time set by the process, disconnect the high-voltage power supply and stop introducing the reaction gas; ⑧: Pass deionized water through the gas port on the fixed end of the electrical slip ring (31) to remove the residual plasma, stop the surface modification of the sphere to be processed (4), and efficiently remove the modified surface material on the sphere to be processed (4) under the friction of the upper grinding plate (11) and the lower grinding plate (21); ⑨: After reaching the processing time set by the process, stop the processing.

5. Plasma-modified sphere grinding and polishing device, characterized in that: It includes an upper grinding kit (1), a lower grinding kit (2) and a discharge kit (3); The upper grinding kit (1) includes an upper grinding plate (11), a connecting seat (12) and an inverted T-shaped connecting rod (13) arranged in sequence from bottom to top; the upper end of the inverted T-shaped connecting rod (13) is used to connect the driving device; The lower grinding kit (2) includes a lower grinding plate (21), a table top plate (24) and a hollow rotating platform (25) arranged in sequence from top to bottom; the lower grinding plate (21) is connected to the table top plate (24), and the table top plate (24) is connected to the hollow rotating platform (25); a single annular groove (211) is provided on the lower grinding plate (21) for placing the sphere to be processed (4); the hollow rotating platform (25) is arranged on the substrate (23); The discharge kit (3) comprises an electrical slip ring (31), a positive electrode plate (35), a positive electrode medium (36), a negative electrode plate (37), a negative electrode medium (38) and a negative electrode plate fixing frame (39); the rotating end of the electrical slip ring (31) is sleeved on an inverted T-shaped connecting rod (13); the positive electrode plate (35), the positive electrode medium (36), the negative electrode plate (37) and the negative electrode medium (38) are all annular structures; the gas outlet of the rotating end of the electrical slip ring (31) is connected to a gas outlet nozzle (13) for conveying reaction gas to the grinding area through a pipeline. 6) connection; the negative electrode plate (37) is arranged in the grinding area and is located on the inner side of the annular groove (211), and is connected to the negative electrode plate fixing frame (39); the negative electrode medium (38) is an insulator, which is arranged on the outer side of the negative electrode plate (37); the positive electrode plate (35) is arranged on the outer side of the annular groove (211) and has a circumferential limit; the positive electrode medium (36) is an insulator, which is arranged on the inner side of the positive electrode plate (35); the positive electrode plate (35) is electrically connected to a positive electrode line, and the negative electrode plate (37) is electrically connected to a negative electrode line.

6. The plasma-modified sphere grinding and polishing device according to claim 5, wherein: The negative electrode plate fixing frame (39) is arranged inside the hollow rotating platform (25); a group of limiting columns (231) are arranged on the base plate (23), and a group of positioning holes are correspondingly arranged on the positive electrode plate (35); the limiting columns (231) cooperate with the positioning holes to form circumferential limiting for the positive electrode plate (35).

7. The plasma-modified sphere grinding and polishing device according to claim 6, wherein: The cross section of the annular groove (211) is V-shaped.

8. The plasma-modified sphere grinding and polishing device according to any one of claims 5-7, characterized in that: The negative plate fixing frame (39) is provided with a conical airflow guide head (5) for guiding the reaction gas to between the upper grinding disc (11) and the lower grinding disc (21).

9. Plasma-modified sphere grinding and polishing equipment, characterized in that: The invention comprises a plasma-modified sphere grinding and polishing device as claimed in any one of claims 5 to 7, a three-axis worktable (7) and a drive motor (8) arranged on the Z axis of the three-axis worktable (7); the base plate (23) of the lower grinding kit (2) is fixed on the table surface (71) of the three-axis worktable (7), and the upper end of the inverted T-shaped connecting rod (13) of the upper grinding kit (1) is drivingly connected to the rotating shaft of the drive motor (8).

10. Method for grinding and polishing a plasma-modified sphere, characterized in that: The method uses the plasma-modified sphere grinding and polishing device described in any one of claims 5 to 8 to perform polishing on the sphere (4) to be processed. During polishing, the base plate (23) of the lower grinding kit (2) is fixed on the table (71) of the three-axis workbench (7), the upper end of the inverted T-shaped connecting rod (13) of the upper grinding kit (1) is connected to the driving motor (8) on the Z axis of the three-axis workbench (7), and the air port on the fixed end of the electrical slip ring (31) is connected to the air outlet device; The polishing process includes the following steps: ①: Lift the upper grinding kit (1) via the three-axis workbench (7); ②: placing the ball (4) to be processed in the annular groove (211) of the lower grinding disc (21); ③: Adjust the eccentricity between the upper grinding disc (11) and the lower grinding disc (21), and lower the upper grinding kit (1) so that the upper grinding disc (11) is pressed against the ball (4) to be processed; ④: Turn on the gas outlet device so that the gas outlet nozzle (6) connected to the gas port on the rotating end of the electrical slip ring (31) sprays the reaction gas; ⑤: Turn on the high-voltage power supply to form a dielectric barrier discharge structure, ionize the reaction gas in the grinding area to generate strongly oxidizing plasma, and the surface material of the sphere to be processed (4) is modified under the corrosion of the strongly oxidizing plasma to form oxides; ⑥: At the same time, start the drive motor (8) at the upper end of the inverted T-shaped connecting rod (13) and the hollow rotating platform (25), drive the upper grinding disc (11) and the lower grinding disc (21) to rotate at a set speed respectively, drive the sphere to be processed (4) to rotate, so that the surface material thereof is uniformly modified, and the modified material is preliminarily removed under the friction; ⑦: After reaching the processing time set by the process, disconnect the high-voltage power supply and stop introducing the reaction gas; ⑧: Introduce deionized water through the gas port on the fixed end of the electrical slip ring (31) to remove the residual plasma, stop the modification of the sphere to be processed (4), and efficiently remove the modified surface material on the sphere to be processed (4) under the friction of the upper grinding disc (11) and the lower grinding disc (21); ⑨: After reaching the processing time set by the process, stop the processing.

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