Graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method and device

Abstract

A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method, comprising the following steps: S1, realize the chemical bonding and graft copolymerization of graphene and nanoparticles by a dynamic high shear field-ultrasonic synergistic induction method first, then let the primary abrasive and secondary graphene be compounded into a graphene composite nanoparticle abrasive with a core-shell structure of a multi-layer structured coating system by a dynamic high shear field-ultrasonic synergistic induction method; S2, adjust the arrangement and movement of particles on the surface by applying an electric field; S3, apply ultrasonic waves in the polishing process to improve the contact between particles and the surface and remove surface defects; S4, track the microstate of abrasive particles and the surface state of the workpiece during polishing. And provide a device to realize the method. The present application improves the polishing precision, surface finish and polishing speed and uniformity, reduces energy consumption; improves the consistency and stability of polishing, reduces the processing cost and reduces the scrap rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ultra-precision polishing, and particularly relates to a graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method and device. BACKGROUND

[0002] Graphene, as a new type of carbon-based material, has shown excellent performance and application potential in many fields, including electronics, optics, materials science, etc. It has excellent electrical conductivity, thermal conductivity and mechanical strength, and is therefore widely studied and applied.

[0003] In the field of polishing, traditional polishing methods usually use abrasives, polishing liquids and mechanical forces to improve the quality of material surfaces. However, these methods may have some drawbacks, such as easy to cause surface damage, high energy consumption, long processing cycle, etc. Therefore, researchers have begun to explore new polishing methods to solve the limitations of traditional methods. External electric field and ultrasonic assistance are two common surface treatment techniques. The external electric field can change the charge distribution and movement of the material surface, thereby affecting the movement and arrangement of particles during polishing, and thus improving the polishing effect. Ultrasonic assistance uses high-frequency vibrations generated by ultrasonic waves in the liquid to improve the polishing effect, such as better contact between particles and the surface and removal of surface defects.

[0004] The prior art Chinese patent CN109848821A provides a green and environmentally friendly chemical mechanical polishing method for nickel alloy. First, the nickel alloy is ground, then rough polishing and fine polishing are performed. During rough polishing, the polishing abrasive is alpha-alumina with an average particle size of 3-5 μm, the polishing liquid is deionized water, and the polishing pad is polyurethane. During fine polishing, the ceramic abrasive is silicon oxide, alpha-alumina, cerium oxide, magnesium oxide, with an average particle size of 20-60 nm and a weight percentage of 0.5%-3%; the complexing agent is imino disuccinic acid sodium salt and sodium citrate, with a weight percentage of 0.5%-2%; the pH adjuster is tartaric acid and acetic acid, with a weight percentage of 0.5%-2%, adjusting the pH of the polishing liquid to 3-5; the polishing pad is sanding leather. After polishing, the measurement range of the nickel alloy is 50x70 μm 2 , the surface roughness Ra reaches 0.4-0.7 nm, achieving ultra-smooth and ultra-low damage chemical mechanical polishing of nickel. The polishing process is easily affected by abrasive particle size, small particle size easily reduces polishing efficiency, and high particle size will cause scratches and pitting defects on the polished surface to some extent.

[0005] The prior art Chinese patent number CN107164764A provides an environmentally friendly chemical mechanical polishing method for copper. The ceramic abrasive particles are silicon dioxide, aluminum oxide, magnesium oxide, and cerium dioxide, with an average particle size of 20-120 nm and a weight percentage of 1-6%. The amino organic matter is proline, glucosamine, chitooligosaccharide, chitin, and cellulose, with a weight percentage of 0.4-2.5%. The pH value of the polishing solution is 3-7. The copper sheet is ground with deionized water as the grinding liquid, and then chemically mechanically polished. The rotation speed of the workpiece and the polishing disc during polishing is 40-80 rpm, the pressure is 20-40 kPa, the polishing liquid flow rate is 60-80 mL / min, and the polishing time is 5-10 min. The polished copper sheet has a measurement range of 50x70 μm 2 , and the surface roughness Ra reaches 0.4-0.7 nm. The invention achieves environmentally friendly chemical mechanical polishing of copper with ultra-smoothness and ultra-low damage. To some extent, the polishing result is easily affected by the abrasive concentration, which can cause removal rate and surface polishing scratches.

[0006] The prior art patent number CN115464472A provides an equipment and process method for shape-adaptive ultrasonic chemical mechanical polishing of hub molds, which includes a bed body and an ultrasonic generator, an upper support, a cable, a fan, a flange plate, a movable support, a transducer, an amplitude rod, a Z-axis lifting table, a translation table, a positioning pin, a working pool, a compressed air pump, a numerical control system, and an air bag installed in the bed body. The invention has shape-adaptive function and can adaptively change and fit with the concave-convex fluctuations of the workpiece surface. The entire process does not require model establishment, scanning, or excessive manual intervention, which can significantly reduce labor. Through dense deployment of ultrasonic enhanced chemical mechanical polishing, the entire surface to be processed is treated simultaneously, with high processing efficiency, good uniformity, good surface consistency after polishing, high precision, and a polished hub mold surface roughness of Ra0.446-1.442 μm. At the same time, it can also be applied to parts other than hub molds, with extremely strong versatility. The polishing process has high energy consumption, which to some extent limits energy-saving and environmentally friendly polishing. SUMMARY

[0007] In order to overcome the shortcomings of the prior art, in order to solve the problems of surface damage, high energy consumption and long processing cycle caused by the traditional polishing method, the present application provides a graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method and device, the present application develops a new type of graphene composite nanoparticle abrasive, which utilizes the high strength and high conductivity characteristics of graphene to significantly improve the grinding efficiency and durability of the abrasive. This abrasive can provide better thermal conductivity and enhanced mechanical properties, and is suitable for high-precision and high-demand polishing processes. The present application uses flexible fluid as a carrier, integrates electric field technology to control the fluid, applies directional force to the abrasive particles through the electric field, realizes the uniform distribution and effective cutting of the abrasive on the surface of the workpiece. And provide ultrasonic technology, use ultrasonic vibration to enhance the dynamic response of abrasive particles, improve the polishing efficiency of abrasive. It can change the charge distribution and movement mode of the material surface, thereby affecting the movement and arrangement of the particles during polishing, and thus improving the polishing effect, while the high-frequency vibration generated by the ultrasonic wave in the liquid can also improve the polishing effect.

[0008] The technical scheme adopted by the present application to solve its technical problems is:

[0009] A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method, comprising the following steps:

[0010] S1, realize the chemical bonding and graft copolymerization of graphene and nanoparticles by a dynamic high shear field-ultrasonic synergistic induction method, and then let the primary abrasive and secondary graphene be compounded into a graphene composite nanoparticle abrasive with a core-shell structure multi-layer structured coating system (incomplete coating, containing cutting exposed area) by a dynamic high shear field-ultrasonic synergistic induction method;

[0011] S2, apply an electric field in the polishing process through the electrodes, power supply and controller in the electric field application assembly, polishing assembly and infusion assembly, adjust the arrangement and movement of the particles on the surface;

[0012] S3, the ultrasonic auxiliary assembly is used to apply ultrasonic waves in the polishing process to improve the contact between the particles and the surface and remove surface defects;

[0013] S4, track the microstate of abrasive particles and the surface state of the workpiece during polishing.

[0014] Further, in the step S1, the nanoparticles are one or a mixture of two or more of metal oxides, carbides or borides, the proportion of graphene is 10% to 50% by weight, the particle size of the nanoparticles is in the range of 10-100 nanometers, the dynamic high shear field-ultrasound synergistic induction method is processing in a high shear homogenizer, using high-speed fluid motion to form strong shear force and vortex effect, making the nanoparticles uniformly embedded in the graphene sheets, turning on the ultrasonic device (preferably frequency 30 kHz), combining with the high shear shear force, prompting the graphene sheets to form a multi-layer coating structure on the abrasive surface, the multi-layer coating structure is an incomplete coating, containing a cutting exposed area; the graphene and nanoparticles are precisely compounded in the process of multi-stage dispersion, dynamic reorganization and multi-layer coating by the dynamic high shear field-ultrasound synergistic induction technology, using the high shear force of fluid and ultrasonic cavitation effect, the new type of composite abrasive is a multifunctional graphene composite nanoparticle abrasive with core-shell structure, the hard core provides high strength and wear resistance, the graphene shell layer endows it with multiple excellent properties such as electrical conductivity, thermal conductivity, self-lubrication and anti-agglomeration, the primary graphene is single-layer graphene, multi-layer graphene or graphene oxide, and the secondary graphene is graphene with different modification methods, including graphene oxide or reduced graphene oxide.

[0015] Further, in the step S2, the electric field application assembly includes electrodes, a power supply electrically connected to the electrodes, and a controller, the controller is used to monitor and adjust the electric field strength, ultrasonic frequency, amplitude and working period, and polishing pressure and time in real time, the electric field and ultrasonic wave are used for microstructure regulation, and the microstructure regulation controls the distribution density, size and morphology of graphene and nanoparticles by adjusting the parameters of electric field and ultrasonic treatment.

[0016] Preferably, the controller automatically adjusts the electric field parameters and ultrasonic wave parameters according to the conductivity, hardness and surface roughness of the workpiece material through sensor input.

[0017] Further, in the step S3, the ultrasonic auxiliary assembly includes an ultrasonic generator, an ultrasonic transducer, an amplitude transformer and a sensor, the ultrasonic generator is used to emit adjustable ultrasonic waves of ultrasonic frequency and amplitude to the polishing liquid.

[0018] In the step S2, the polishing assembly includes a polishing head, a clamp, a workpiece, a polishing pad, a polishing disc and a rack, the rack is used to support and carry the polishing disc, the clamp, the ultrasonic auxiliary assembly, the electric field application assembly and the liquid delivery assembly, the polishing head is used for polishing work on the workpiece, and the polishing disc is used to contain the polishing liquid and the workpiece.

[0019] The step S2, the infusion assembly includes a liquid guide pipe, a hydraulic pump and a box, the box is used for storing the polishing liquid prepared, the liquid guide pipe is used for connecting the liquid guide pipe and the liquid guide pipe, and the hydraulic pump is used for extracting the polishing liquid in the box and conveying to the polishing disc through the liquid guide pipe.

[0020] A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing device, comprising an electric field application assembly, an ultrasonic auxiliary assembly, a polishing assembly and an infusion assembly, the polishing assembly comprises a polishing head, a clamp, a polishing disc and a rack, the rack is used for supporting and carrying the polishing disc, the clamp, the ultrasonic auxiliary assembly, the electric field application assembly and the infusion assembly, the polishing head is used for polishing workpiece, the polishing disc is used for containing polishing liquid and workpiece, the polishing head is located above the polishing disc, the ultrasonic auxiliary assembly is located above the polishing disc, the electric field application assembly is located at the side of the polishing disc, and the liquid guide pipe outlet of the infusion assembly is aligned with the processing station of the polishing head and the workpiece.

[0021] Further, the electric field application assembly comprises an electrode, a power supply and a controller electrically connected to the electrode, the controller is used for real-time monitoring and adjusting the electric field intensity, ultrasonic frequency, amplitude and working period, and polishing pressure and time, the electric field and ultrasonic wave are used for microstructure regulation, and the microstructure regulation controls the distribution density, size and morphology of graphene and nanoparticles by adjusting the parameters of electric field and ultrasonic treatment.

[0022] Further, the ultrasonic auxiliary assembly comprises an ultrasonic generator, an ultrasonic transducer, a variable amplitude rod and a sensor, the ultrasonic generator is used for emitting adjustable ultrasonic frequency and amplitude ultrasonic waves to the polishing liquid, the ultrasonic generator is installed on the top of the polishing disc through a movable arm, the distance can be adjusted to adapt to workpieces of different sizes, the ultrasonic generator is connected with the ultrasonic transducer, the ultrasonic transducer is connected with the variable amplitude rod, the bottom of the variable amplitude rod is installed with the polishing head, and the sensor is installed on the rack.

[0023] The controller automatically adjusts the electric field parameters and ultrasonic wave parameters according to the conductivity, hardness and surface roughness of the workpiece material through the sensor input.

[0024] The infusion assembly comprises a liquid guide pipe, a hydraulic pump and a box, the box is used for storing the polishing liquid prepared, the hydraulic pump is used for extracting the polishing liquid in the box and conveying to the polishing disc through the liquid guide pipe.

[0025] The beneficial effects of the present application mainly include:

[0026] 1、In the present application, the primary graphene is first combined with nanoscale metal oxides, carbides or borides through a dynamic high shear field-ultrasound synergistic induction method, firmly binding with the nanoparticles, and uniformly transmitting the electric field and vibration to the nanoparticle core through its excellent electrical conductivity and mechanical properties. Then the secondary graphene is combined with the basic adsorptive abrasive through this method, providing high hardness and toughness, protecting the inner layer nanoparticles from direct fragmentation or wear, and increasing the service life of the abrasive. This makes the abrasive more effectively remove the micro concave-convex on the material surface during polishing, thereby improving the polishing precision and surface finish. The introduction of ultrasound not only increases the interaction force between the abrasive particles and the workpiece surface, but also helps to release the small particles embedded by the abrasive, further improving the polishing speed and uniformity. At the same time, the application of electric field makes the abrasive particles more uniformly distributed on the workpiece surface, reducing the situation of local over-polishing or unpolished.

[0027] 2、In the present application, compared with traditional polishing methods, the external electric field and ultrasonic assisted polishing method may require less mechanical energy, thereby reducing energy consumption and environmental burden.

[0028] 3、In the present application, the external electric field and ultrasonic assisted technology can effectively remove surface defects, improve surface finish and flatness, thereby improving the surface quality of the material, making it have higher optical and mechanical properties. The external electric field and ultrasonic auxiliary device is usually equipped with a controller, which can accurately adjust the electric field strength, frequency and ultrasonic wave parameters, realize accurate control of the polishing process, and improve the consistency and stability of polishing.

[0029] 4、In the present application, the method is not only suitable for polishing of single workpiece, but also can be applied to surface treatment of other materials such as metal, ceramic, etc., thereby expanding its application range in the field of material processing and manufacturing.

[0030] 5、In the present application, although the introduction of external electric field and ultrasonic auxiliary technology may require certain initial investment, in the long run, due to the improvement of polishing efficiency and quality, it can reduce processing cost and reduce scrap rate, thereby bringing long-term economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of the three-dimensional structure of the polishing device of the present application;

[0032] Figure 2 is a schematic diagram of the front view structure of the polishing device of the present application;

[0033] Figure 3 is a schematic diagram of the composite state of the primary graphene and nanoparticles after the dynamic high shear field-ultrasound synergistic induction method of the present application;

[0034] Figure 4 A schematic diagram of the secondary graphene and the initial abrasive after the dynamic high shear field-ultrasound synergistic induction method of the present application;

[0035] Figure 5 An enlarged schematic diagram of the multifunctional nano-composite abrasive structure with core-shell structure prepared by the present application;

[0036] Figure 6 A schematic diagram of the polishing surface removal mechanism, wherein (a) is the first half of the process, and (b) is the second half of the process;

[0037] Figure 7 A schematic diagram of the effect of the workpiece surface before and after polishing.

[0038] In the figure: 1, ultrasonic generator; 2, ultrasonic transducer; 5, amplitude transformer; 6, polishing head; 7, clamp; 8, workpiece; 10, liquid guide pipe; 11, hydraulic pump; 12, box; 13, polishing disc; 14, machine frame; 15, sensor; 18, electrode; 101, primary graphene; 102, nanoparticles; 103, electric field; 104, debris; 105, strong shear treatment; 106, interfacial bonding layer; 107, cavitation bubble; 108, ultrasonic vibration wave; 109, secondary graphene; 110, primary abrasive; 111, graphene composite nanoparticle abrasive; 112, graphene coating layer; 113, self-lubricating property; 114, anti-agglomeration property; 115, electrical and thermal conductivity. DETAILED DESCRIPTION

[0039] The present application will be further described below with reference to the accompanying drawings.

[0040] Reference Figures 1-7 A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasound assisted polishing method, comprising the following steps:

[0041] S1, by the dynamic high shear field-ultrasound synergistic induction method, first realize the chemical bonding and graft copolymerization of primary graphene and nanoparticles, and then let the primary abrasive and secondary graphene be compounded into a graphene composite nanoparticle abrasive with a core-shell structure of a multi-layer structured coating system (not completely coated, containing a cutting exposed area) by the dynamic high shear field-ultrasound synergistic induction method;

[0042] S2, by the electrode in the electric field application assembly, the power supply and the controller, the polishing assembly and the liquid delivery assembly, an electric field is applied in the polishing process to adjust the arrangement and movement of the particles on the surface;

[0043] S3, by the ultrasonic auxiliary assembly for applying ultrasonic waves in the polishing process to improve the contact between the particles and the surface and remove surface defects;

[0044] S4, tracking the microstate of abrasive particles in the polishing process and the surface state of the workpiece.

[0045] Further, in the step S1, the nanoparticles are one or a mixture of two or more of metal oxides, carbides or borides, the proportion of graphene is 10% to 50% by weight, the particle size of the nanoparticles is in the range of 10-100 nanometers, the dynamic high shear field-ultrasound synergistic induction method is processing in a high shear homogenizer, using high-speed fluid motion to form strong shear force and vortex effect, making the nanoparticles uniformly embedded in the graphene sheet, turning on the ultrasonic device (preferably frequency 30 kHz), combining with the high shear shear force, prompting the graphene sheet to form a multi-layer coating structure on the abrasive surface, the multi-layer coating structure is an incomplete coating, containing a cutting exposed area; the graphene and nanoparticles are induced by dynamic high shear field and ultrasound, using the high shear force of the fluid and the ultrasonic cavitation effect to realize the precise compounding of graphene and nanoparticles in the process of multi-stage dispersion, dynamic reorganization and multi-layer coating. The new type of composite abrasive is a multifunctional graphene composite nanoparticle abrasive with core-shell structure, which provides high strength and wear resistance with hard core, and gives it excellent properties such as electrical conductivity, thermal conductivity, self-lubrication and anti-agglomeration with graphene shell. The primary graphene is single-layer graphene, multi-layer graphene or graphene oxide, and the secondary graphene is graphene with different modification methods, including graphene oxide or reduced graphene oxide.

[0046] A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasound assisted polishing device, comprising an electric field applying assembly, an ultrasonic auxiliary assembly, a polishing assembly and a liquid delivery assembly, the polishing assembly comprises a polishing head 6, a clamp 7, a polishing disc 13 and a rack 14, the rack 14 is used to support and carry the polishing disc 13, the clamp 7, the ultrasonic auxiliary assembly, the electric field applying assembly and the liquid delivery assembly, the polishing head 6 is used for polishing workpiece 8, the polishing disc 13 is used to contain polishing liquid and workpiece 8, the polishing head 6 is located above the polishing disc 13, the ultrasonic auxiliary assembly is located above the polishing disc 13, the electric field applying assembly is located at the side of the polishing disc 13, and the outlet of the liquid guide pipe 10 of the liquid delivery assembly is aligned with the machining station of the polishing head 6 and the workpiece 8.

[0047] The electric field applying assembly comprises an electrode 18, a power supply and a controller electrically connected thereto, the controller is used to monitor and adjust the electric field strength, ultrasonic frequency, amplitude and working period, and polishing pressure and time in real time, the electric field and ultrasonic wave are used for microstructure regulation, and the microstructure regulation controls the distribution density, size and morphology of graphene and nanoparticles by adjusting the parameters of electric field and ultrasonic treatment.

[0048] The ultrasonic auxiliary assembly comprises an ultrasonic generator 1, an ultrasonic transducer 2, an amplitude transformer 5 and a sensor 15, the ultrasonic generator 1 is used for emitting adjustable ultrasonic waves of frequency and amplitude to polishing liquid, the ultrasonic generator 1 is installed on the top of the polishing disc 13 through a movable arm, the distance is adjustable to adapt to workpieces of different sizes, the ultrasonic generator 1 is connected with the ultrasonic transducer 2, the ultrasonic transducer 2 is connected with the amplitude transformer 5, the bottom of the amplitude transformer 5 is installed with the polishing head 6, and the sensor 15 is installed on the rack 14.

[0049] The controller automatically adjusts the electric field parameters and the ultrasonic wave parameters according to the conductivity, hardness and surface roughness of the workpiece material through the sensor 15.

[0050] The liquid delivery assembly comprises a liquid guide pipe 10, a hydraulic pump 11 and a box 12, the box 12 is used for storing prepared polishing liquid, and the hydraulic pump 11 is used for pumping the polishing liquid in the box 12 and delivering the polishing liquid to the polishing disc 13 through the liquid guide pipe 10.

[0051] Embodiment 1

[0052] The application is used for processing flat and thin parts of hard and brittle materials and optical materials, a 304 stainless steel plate is selected as a polishing workpiece, the size is 50mm*50mm*2mm, and the processing steps are as follows:

[0053] 1. The workpiece 8 is fixed on the polishing disc 13 of the experimental equipment by using the clamp 7 or the adhesive resin; the composite polishing liquid is configured, the primary abrasive 110 prepared by the dynamic high shear field-ultrasonic synergistic induction method with a mass ratio of 1:1 of 50nm primary graphene sheet 101 and 100nm aluminum oxide particles is adopted; the graphene-nanoparticle abrasive with basic adsorption is slowly added into the secondary graphene dispersion liquid 109, and stirring is kept uniform. By adjusting the concentration of graphene and the ratio of mixed abrasives to be 1:1, ultrasonic oscillation or a high shear emulsifier is used for treatment, the interfacial force between graphene and mixed abrasives is further improved, and the multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure is obtained. The multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure is added into deionized water, the mass concentration of the abrasive is 2%, 0.5% polyvinylpyrrolidone is added as a dispersant and 0.1% benzotriazole is added as a corrosion inhibitor, the ultrasonic equipment is set to have a frequency of 35kHz and a power of 500W; the electric field 103 strength is set to be 3kV / cm.

[0054] 2. The device comprises a polishing disc 13 containing polishing liquid, the polishing disc 13 is provided with an electrode 18 and an ultrasonic generator 1, two opposite flat plate electrodes 18 are installed on both sides of the polishing disc 13, the material of the electrode 18 is stainless steel, and the size and shape are designed to fit the polishing disc 13, the ultrasonic generator 1 is fixed on the upper part of the polishing disc 13, and the ultrasonic probe on the ultrasonic generator 1 directly contacts the stainless steel plate workpiece 8;

[0055] 3. The workpiece 8 is fixed in the center of the polishing disc 13, the surface of the workpiece 8 is ensured to be in full contact with the polishing liquid, the electric field 103 and the ultrasonic vibration wave 108 are turned on, and the polishing is continued for 30 minutes, after the polishing is completed, the surface of the workpiece 8 is cleaned with deionized water, and the roughness and microtopography of the surface of the workpiece 8 are evaluated by using an atomic force microscope (AFM) and an optical microscope;

[0056] 4. After polishing, the surface roughness of the 304 stainless steel plate is reduced from Ra200nm before polishing to Ra10nm, and there is no obvious scratch and damage on the surface, the above polishing process is repeated for 5 times, and the surface roughness of the workpiece 8 is stable at Ra10nm±0.5nm.

[0057] Example 2

[0058] The present application is used for the processing of flat and thin parts of metal materials, metal alloy materials and the like, a silicon wafer is selected as the polishing workpiece 8, the size is 50mm×50mm×1mm, and the processing steps are as follows:

[0059] 1. The workpiece 8 is fixed on the polishing disc 13 of the experimental equipment by using a clamp 7 or adhesive resin;

[0060] 2. The composite polishing liquid 12 is configured, the primary abrasive 110 prepared by a dynamic high shear field-ultrasonic synergistic induction method with a mass ratio of 2:1 of 30nm primary graphene sheet 101 and 200nm silicon carbide (SiC) particles is selected, the basic adsorbed graphene-nanoparticle abrasive is slowly added into the secondary graphene dispersion liquid 109, and stirring is kept uniform. By adjusting the concentration of graphene and the ratio of mixed abrasive to be 1:1, ultrasonic oscillation or a high shear emulsifier is used for treatment, the interfacial force between graphene and mixed abrasive is further improved, and the multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure is obtained. The multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure is added into ethanol, the mass concentration of the abrasive is 3%, 1% silane coupling agent is added as a surfactant to improve the contact efficiency of the abrasive and the workpiece 8, the ultrasonic vibration wave 108 is set to a frequency of 40kHz and a power of 600W; the strength of the electric field 103 is set to 4kV / cm;

[0061] 3. The device comprises a temperature-adjustable polishing disc 13, in which an electrode 18 made of titanium alloy and shaped as a cylinder is installed on the side wall of the polishing disc 13, and an ultrasonic generator 1 is installed on the top of the polishing disc 13 through a movable arm, and the distance is adjustable to adapt to workpieces 8 of different sizes;

[0062] 4. The workpiece 8 is exposed to the polishing liquid preheated to 35°C, fixed at the center of the polishing disc 13, and the electric field 103 and ultrasonic vibration wave 108 are started, and the position of the ultrasonic generator 1 is adjusted to ensure that the vibration is uniformly distributed on the surface of the workpiece 8, and the polishing is continued for 45 minutes. After polishing, the workpiece is cleaned with ethanol and ultrasonic vibration wave 108, and then the uniformity and microtopography of the surface of the workpiece 8 are checked by using an electron microscope (SEM) and a 3D profiler;

[0063] 5. After polishing, the surface roughness of the silicon wafer is reduced from Ra 10 nm before polishing to Ra 1.0 nm, and the surface quality is significantly improved without surface damage. The results of 10 repeated polishing tests show that the surface roughness of the workpiece is stable at Ra 1.0 nm ± 0.3 nm.

[0064] Example 3

[0065] The present application is used for efficient surface polishing, especially for polishing of curved surfaces. A curved titanium alloy component with complex geometry is selected as the polishing object, and the maximum curvature radius of the component is 10 mm. The processing steps are as follows:

[0066] 1. Configuration, composite polishing liquid, select a primary abrasive 110 prepared by a dynamic high shear field-ultrasonic synergistic induction method with a mass ratio of 3:1 of 50 nm primary graphene sheet 101 and 100 nm aluminum oxide (Al2O3) particles, slowly add the basic adsorbed graphene-nanoparticle abrasive to the secondary graphene dispersion liquid 109, and keep stirring uniform. By adjusting the concentration of graphene and the ratio of mixed abrasive to 1:1, ultrasonic oscillation or high shear emulsifier is used for treatment, and the interfacial force between graphene and mixed abrasive is further improved to obtain multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure. The multifunctional graphene composite nanoparticle abrasive 111 with core-shell structure is suspended in deionized water, and the concentration of the abrasive is set to 4%, and 0.5% polyvinyl alcohol is added as a dispersant to enhance the dispersibility and stability of the abrasive;

[0067] 2. The device comprises a polishing disc 13 equipped with a temperature control system, in which an electrode 18 made of stainless steel and shaped as a ring is installed around the inner wall of the polishing disc, and an ultrasonic generator 1 is installed on the top of the polishing disc 13 by adjusting its position to adapt to workpieces 8 of different curvatures.

[0068] 3. The workpiece 8 is fixed on a specially designed clamp 7, which allows the workpiece 8 to rotate and tilt slightly during polishing to ensure uniformity of polishing. The polishing disc 13 is maintained at a temperature of 40℃, the electric field 103 and ultrasonic vibration wave 108 are started, and the polishing time is 60 minutes. After polishing, the workpiece 8 is cleaned in high-pressure deionized water, and then the surface roughness and topography are evaluated using an atomic force microscope (AFM) and a white light interferometer;

[0069] 4. After polishing, the surface roughness of the titanium alloy part is reduced from Ra 10 nm before polishing to Ra 5 nm, effectively improving the surface finish and reducing micro-damage. Five consecutive polishing tests with the same parameters show that the standard deviation of the surface roughness measurements is not more than 0.2 nm, indicating that the polishing method has good repeatability and stability.

[0070] In the present application, a graphene composite nanoparticle abrasive flexible fluid electric field 103-ultrasonic assisted 108 polishing method and device, in use, the working process is as follows:

[0071] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 And Figure 7As shown, the electrode 18 is installed on the top of the frame 14, ensuring that the electrode 18 maintains a proper distance from the surface of the workpiece 8 to be polished and can cover the entire polishing area, the power supply is electrically connected with the electrode 18 to provide the required electric field 103 intensity and voltage, the power supply voltage and frequency are adjusted according to the needs, the power field 103 intensity, direction and duration of the electric field 103 are adjusted by the controller, the strength and distribution of the electric field 103 are monitored in real time during the application of the electric field 103 using the corresponding monitoring equipment to ensure its stability and accuracy, under the excitation of the ultrasonic vibration wave 108, the nanoparticles 102 and graphene 101 bombard the surface of the workpiece 8, causing the formation of debris 104 on the surface of the workpiece 8, and the electric field 103 is applied during polishing to ensure that the electric field 103 and ultrasonic assisted technology are synchronized with the polishing process to maximize the polishing effect. Under the action of the ultrasonic vibration wave 108, the cavitation bubbles 107 formed in the polishing liquid have a thickening rheological effect on the polishing liquid, and the nano abrasive particles produce a tiny jet shear to remove excess material on the surface of the workpiece 8, thereby achieving the polishing effect. Before the electric field 103 is applied, the abrasive particles in the polishing liquid and the primary graphene 101 and secondary graphene 109 are continuously and uniformly distributed, and when the electric field 103 is applied, the microstructure of the polishing liquid changes. Under the action of the external electric field 103, the solid particles in the polishing liquid are polarized and form particle chains along the direction of the electric field 103, and the abrasive particles required for polishing are combined in the particle chains. Before the electric field 103 is applied, the abrasive particles are free between the polishing head 6 and the workpiece 8, and after the electric field 103 is applied, the polarized particles are concentrated between the dispersed phase particles and the surface of the workpiece 8. When the polishing head 6 moves relatively, the primary graphene 101 and secondary graphene 109 in the polishing liquid carry the abrasive particles to shear and collide with the surface of the workpiece 8, thereby removing excess material on the surface of the workpiece 8. At the same time, the cavitation bubbles 107 carry the nanoparticles 102 and the primary graphene 101 and secondary graphene 109, which release double graphene and nanoparticles 102 with impact force when they collapse, to bombard or scratch the surface of the workpiece 8, thereby removing the surface material.

[0072] The embodiments of the present specification are merely a list of implementation forms of the inventive concept, and are only used for description purposes. The protection scope of the present application should not be regarded as being limited to the specific forms described in the embodiments, and the protection scope of the present application also includes equivalent technical means that can be thought of by those skilled in the art according to the inventive concept.

Claims

1. A graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method, characterized in that, The method comprises the following steps: S1, realize the chemical bonding and graft copolymerization of primary graphene and nanoparticles by a dynamic high shear field-ultrasonic synergistic induction method to obtain a primary abrasive, and then let the primary abrasive and secondary graphene be compounded by a dynamic high shear field-ultrasonic synergistic induction method to obtain a graphene composite nanoparticle abrasive with a core-shell structure of a multi-layer structured coating system; S2, apply an electric field through electrodes, a power supply and a controller in an electric field applying assembly, and adjust the arrangement and movement of the graphene composite nanoparticle abrasive on the surface of the workpiece during polishing through a polishing assembly and a feeding assembly; S3, apply ultrasonic waves during polishing through an ultrasonic auxiliary assembly to improve the contact between the graphene composite nanoparticle abrasive and the surface of the workpiece and remove defects on the surface of the workpiece; S4, track the microstate of the graphene composite nanoparticle abrasive and the state of the surface of the workpiece during polishing.

2. The graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method of claim 1, wherein, In the step S1, the nanoparticles are one or a mixture of two or more of metal oxides, carbides or borides, the proportion of the graphene is 10-50% by weight, the particle size of the nanoparticles is in the range of 10-100 nanometers, and the dynamic high shear field-ultrasonic synergistic induction method is processing in a high shear homogenizer, in which high-speed fluid motion forms strong shear force and vortex action to uniformly embed the nanoparticles in graphene sheets, an ultrasonic device is turned on, and the high shear field shear force is combined to promote the graphene sheets to form a multi-layer coating structure on the surface of the graphene composite nanoparticle abrasive, the multi-layer coating structure is an incomplete coating containing a cutting exposed area, and the graphene and the nanoparticles are precisely compounded in the process of multi-stage dispersion, dynamic recombination and multi-layer coating by the dynamic high shear field-ultrasonic synergistic induction technology using the high shear force of fluid and ultrasonic cavitation effect, the graphene composite nanoparticle abrasive is a multifunctional graphene composite nanoparticle abrasive with a core-shell structure, the hard core provides high strength and wear resistance, and the graphene shell layer endows it with excellent properties of electrical conductivity, thermal conductivity, self-lubrication and anti-agglomeration, the primary graphene is single-layer graphene, multi-layer graphene or graphene oxide, and the secondary graphene is graphene with different modification methods including graphene oxide or reduced graphene oxide.

3. The graphene composite nanoparticle abrasive flexible fluid electric field- ultrasound assisted polishing method according to claim 1 or 2, wherein, In the step S2, the electric field applying assembly comprises electrodes, a power supply and a controller electrically connected to the electrodes, the controller is used for real-time monitoring and adjusting the electric field strength, ultrasonic wave frequency, amplitude and working period, polishing pressure and time, the electric field and ultrasonic waves are used for microstructure regulation, and the microstructure regulation controls the distribution density, size and morphology of the graphene composite nanoparticle abrasive by adjusting the parameters of electric field and ultrasonic treatment.

4. The graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method of claim 3, wherein, The controller automatically adjusts the parameters of electric field and ultrasonic waves according to the electrical conductivity, hardness and surface roughness of the workpiece material through sensor input.

5. The graphene composite nanoparticle abrasive flexible fluid electric field- ultrasound assisted polishing method of claim 1 or 2, wherein, In the step S3, the ultrasonic auxiliary assembly comprises an ultrasonic generator, an ultrasonic transducer, a variable amplitude rod and a sensor, and the ultrasonic generator is used for emitting adjustable ultrasonic waves of frequency and amplitude to the polishing liquid.

6. The graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method of claim 1 or 2, wherein, The polishing assembly in step S2 includes a polishing head, a clamp, a workpiece, a polishing pad, a polishing disc and a rack, the rack is used to support and carry the polishing disc, the clamp, the ultrasonic auxiliary assembly, the electric field application assembly and the liquid delivery assembly, the polishing head is used to polish the workpiece, and the polishing disc is used to contain the polishing liquid and the workpiece.

7. The graphene composite nanoparticle abrasive flexible fluid electric field- ultrasound assisted polishing method of claim 1 or 2, wherein, The liquid delivery assembly in step S2 includes a liquid guide pipe, a hydraulic pump and a box, the box is used to store the prepared polishing liquid, and the hydraulic pump is used to extract the polishing liquid in the box and deliver the polishing liquid to the polishing disc through the liquid guide pipe.

8. An apparatus for implementing the graphene composite nanoparticle abrasive flexible fluid electric field-ultrasonic assisted polishing method as claimed in claim 1, characterized in that, The device includes an electric field application assembly, an ultrasonic auxiliary assembly, a polishing assembly and a liquid delivery assembly, the polishing assembly includes a polishing head, a clamp, a polishing disc and a rack, the rack is used to support and carry the polishing disc, the clamp, the ultrasonic auxiliary assembly, the electric field application assembly and the liquid delivery assembly, the polishing head is used to polish the workpiece, and the polishing disc is used to contain the polishing liquid and the workpiece, the polishing head is located above the polishing disc, the ultrasonic auxiliary assembly is located above the polishing disc, the electric field application assembly is located at the side of the polishing disc, and the liquid guide pipe outlet of the liquid delivery assembly is aligned with the machining station of the polishing head and the workpiece.

9. The apparatus of claim 8, wherein, The electric field application assembly includes an electrode, a power supply and a controller electrically connected to the electrode, the controller is used to monitor and adjust the electric field strength, the ultrasonic frequency, the amplitude and the working period, and the polishing pressure and the time in real time, the electric field and the ultrasonic wave are used for microstructure regulation, and the microstructure regulation controls the distribution density, the size and the morphology of the graphene composite nanoparticle abrasive by adjusting the parameters of the electric field and the ultrasonic treatment.

10. The apparatus of claim 8 or 9, wherein, The ultrasonic auxiliary assembly includes an ultrasonic generator, an ultrasonic transducer, a variable amplitude rod and a sensor, the ultrasonic generator is used to emit adjustable ultrasonic waves with adjustable frequency and amplitude to the polishing liquid, the ultrasonic generator is installed on the top of the polishing disc through a movable arm, the distance can be adjusted to adapt to workpieces of different sizes, the ultrasonic generator is connected to the ultrasonic transducer, the ultrasonic transducer is connected to the variable amplitude rod, the bottom of the variable amplitude rod is installed with the polishing head, and the sensor is installed on the rack. The liquid delivery assembly includes a liquid guide pipe, a hydraulic pump and a box, the box is used to store the prepared polishing liquid, and the hydraulic pump is used to extract the polishing liquid in the box and deliver the polishing liquid to the polishing disc through the liquid guide pipe.

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