Air pressure imitating mode ultrasonic-assisted core-shell type abrasive magneto-rheological composite polishing machining and manufacturing method and device

Abstract

The invention relates to an air pressure imitating mode ultrasonic-assisted core-shell type abrasive magneto-rheological composite polishing machining and manufacturing method, which comprises the following steps of: 1) selecting a workpiece clamp, and mounting the workpiece clamp on an ultrasonic vibration table; (2) the workpiece is clamped on a workpiece clamp, and the outer surface of the workpiece is wrapped with a flexible polishing sleeve; (3) preparing a polishing solution of a novel composite grinding and polishing abrasive material with core-shell type nano magnetic particles-abrasive particles, and placing the polishing solution in a polishing solution supply device; (4) an airflow auxiliary module is started, the flexible polishing sleeve is made to be highly matched with the shape of the workpiece under the assistance of high-pressure gas, and a'simulation flexible grinding tool 'similar to the shape of the surface of the workpiece is formed; 5) starting a magnetic field control system; and (6) the ultrasonic transducer is started, the ultrasonic vibration table drives the workpiece to vibrate at a high frequency, and fretting friction of relative movement is generated between the workpiece and the imitation flexible grinding tool. Meanwhile, a matched device is provided. The machining efficiency is improved, and the problems of abrasive particle holding force regulation, efficient grinding and polishing of workpieces of different materials and shapes and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-precision rheological polishing, and in particular to a method and a device for manufacturing a core-shell abrasive magnetic rheological composite polishing process assisted by air pressure imitation mode ultrasound. Background Art

[0002] Ultra-precision machining technology is an important part of modern advanced manufacturing science and technology. It is widely used in many fields, such as the processing and manufacturing of parts such as semiconductors, optical components, functional ceramics, hard-to-machine materials and metal plastic materials, and involves ensuring the high precision, low damage and aesthetics of various complex surfaces. Ultra-precision machining technology can reduce the surface roughness and surface damage or sub-surface damage of workpieces. Complex curved surfaces are important working surfaces of many industrial products and parts. They can usually achieve high precision of special mathematical characteristics and pursue functional and aesthetic effects. High-precision aspheric optical parts for aerospace can improve the remote image recognition ability, accuracy and stability of instruments; some complex shapes of flexible mold cavities and automotive parts can achieve both functional requirements and aesthetics. With the further increase in the demand and performance of complex parts, there is an urgent need to improve the ultra-precision machining level of parts. Therefore, achieving efficient and high-quality ultra-precision machining of complex parts has become an important research direction for new methods and process technologies in engineering manufacturing.

[0003] In composite abrasive polishing technology, the composite abrasive used is a new type of particle designed based on nanoparticle technology with specific structure, appearance and physical and chemical properties. Most of these particles are composed of a single hard particle combined with other particles, elements or polymer chains through physical or chemical means. Composite abrasives can be divided into core-shell composite abrasives and doped composite abrasives according to their structure. Compared with the traditional polishing method using single abrasives, polishing with composite abrasives has the advantages of obtaining high surface accuracy, high polishing efficiency, extending the life of the polishing device and reducing polishing surface defects.

[0004] Magnetorheological polishing is a method of surface polishing using the rheological properties of magnetorheological fluid. Magnetorheological fluid is a special material that changes its flow characteristics when affected by a magnetic field, especially under the action of an external magnetic field, it may become more viscous or more fluid. In magnetorheological polishing technology, the magnetorheological fluid needs to be applied to the surface to be polished, and the flow characteristics of the magnetorheological fluid are managed by adjusting the external magnetic field to achieve the effect of polishing the surface. This technology can perform high-precision polishing on complex shapes and tiny parts, so it has broad application prospects in many fields such as aerospace and automobile manufacturing. Magnetorheological polishing technology has many advantages, including high precision of the machined surface, small surface roughness, no new damage during the machining process, easy computer control, stability of the removal function, and controllability of the performance of the magnetorheological micro-grinding head. However, compared with composite abrasive processing, there are still problems such as low material removal efficiency and expensive magnetorheological fluid.

[0005] The invention patent (CN110370093A) has been published, a magnetic composite abrasive flow polishing method with an angle adjustable mechanism. In the polishing method described in the invention, abrasive flow processing is carried out in a low-pressure fluid; the angle adjustable mechanism is placed in a processing device with magnetic field assistance; the magnetic field assistance is an adjustable strength uniform magnetic field perpendicular to the workpiece surface generated by an electromagnet placed directly below the processing device, and under the action of the magnetic field, the magnetic composite abrasive particles in the flow field are moved toward the workpiece surface by the magnetic field force, which can effectively improve the uneven surface roughness. However, this patent still has room for improvement in terms of the expansion of processing material diversity and performance.

[0006] The invention patent (CN115820210A) has been published, a composite abrasive for polishing, a polishing liquid and a preparation method thereof. A magnetic composite abrasive, characterized in that the magnetic composite abrasive includes multiple layers, the inner core of the magnetic composite abrasive is a magnetic nanoparticle, the outer layer of the magnetic nanoparticle is wrapped with a polymer, the outer layer of the polymer is wrapped with a porous hybrid film layer, the porous hybrid film layer is embedded with a first abrasive, and the outer layer of the porous hybrid film layer is wrapped with a second abrasive. This patent can effectively improve the material removal rate and have a better grinding effect, and it is not easy to cause scratches on the workpiece surface. The composite abrasive described in this patent has the problem of being difficult to control the external abrasive, so there is still room for improvement in the workpiece shape accuracy and efficient grinding and polishing.

[0007] The invention patent (CN115946032A) has been disclosed, a small grinding head magnetorheological polishing device and polishing method. The device includes a machine tool body component, a three-dimensional motion component, a spindle drive component, a magnetorheological fluid circulation component, a polishing head component, a magnetic field generating device component, a differential motion component and a workpiece clamping motion component; the small grinding head magnetorheological polishing device of the disclosed invention can realize the movement of the polishing head component in the three-dimensional direction through the three-dimensional motion component; the workpiece is rotated by driving the workpiece transmission shaft through the drive motor of the workpiece clamping motion component; the magnetorheological fluid in the polishing area is updated through the differential motion between the polishing head component and the magnetic field generating device component; the magnetorheological fluid circulation component realizes the transportation and recovery of the magnetorheological fluid. Compared with the traditional magnetorheological polishing device, the small grinding head magnetorheological polishing device provided by the present invention improves the polishing efficiency and quality of the workpiece, and realizes the renewal and circulation of the abrasive in the polishing area. However, this patent does not involve mechanisms such as ultrasound and composite abrasives, and can be further improved and improved in terms of efficient polishing and material expansion. Summary of the invention

[0008] In order to overcome the shortcomings of the existing technology, to further improve processing efficiency, solve the problems of abrasive holding force regulation and efficient polishing of workpieces of different materials and shapes, the present invention provides a method and device for pneumatic simulation mode ultrasonic assisted core-shell abrasive magnetic rheological composite polishing processing.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] A method for manufacturing a core-shell abrasive magnetic rheological composite polishing process assisted by air pressure imitation mode ultrasound comprises the following steps:

[0011] 1) Select a workpiece fixture and install it on the ultrasonic vibration table;

[0012] 2) Clamp the workpiece on the workpiece fixture and wrap the outer surface of the workpiece with a flexible polishing sleeve;

[0013] 3) preparing a polishing liquid having a composite polishing abrasive of core-shell nano magnetic particles-abrasive particles, and then placing the polishing liquid in a polishing liquid replenishing device;

[0014] 4) Start the airflow auxiliary module to allow the high-pressure airflow to quickly fill the airflow conveying device pipeline; then start the polishing liquid circulation supply module to convey the polishing liquid to the polishing workbench until the flexible polishing sleeve is completely immersed;

[0015] 5) Start the magnetic field control system, generate a magnetic field under the action of the magnetic field generating device, and the new composite polishing abrasive of core-shell nano magnetic particles and abrasive grains in the polishing liquid enters into the flexible polishing sleeve, and forms a flexible polishing head on the inner surface of the polishing sleeve. With the assistance of high-pressure gas, the flexible polishing sleeve is highly consistent with the shape of the workpiece, forming a "mold-like flexible abrasive tool" with a similar surface shape to the workpiece.

[0016] 6) Start the ultrasonic transducer, and the ultrasonic vibration table drives the workpiece to vibrate at a high frequency, generating micro-friction of relative motion with the "mold-mimicking flexible abrasive", thereby realizing air pressure-mimicking ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing.

[0017] Furthermore, in step 3), the abrasive is one or a mixture of two or more of boron carbide, silicon carbide, silicon nitride, silicon oxide and aluminum oxide, or a core-shell composite abrasive, such as SiO2 / CeO2 nano-composite abrasive.

[0018] In the step 3), the nano magnetic particles include ferrite (Fe3O4), iron, cobalt, nickel, and alloys having magnetic properties.

[0019] The average diameter of the abrasive particles is 200-1000 nm.

[0020] The average diameter of the nano magnetic particles is 50-100 nm.

[0021] In the step 2), the polishing sleeve is a porous wear-resistant polishing sleeve, and pores are reserved in the polishing sleeve.

[0022] In the step 4), in the airflow assist module, the high-pressure airflow provides dynamic pressure for the polishing liquid, which can not only assist the "mold-copying flexible abrasive tool" to continuously fit the workpiece during the polishing process, but also provide power for the circulation of the polishing liquid, thereby accelerating the removal of material debris attached to the surface of the "mold-copying flexible abrasive tool" and the continuous renewal of abrasive particles in the polishing liquid.

[0023] In the step 5), the flexible polishing head is attached to the surface of the "simulated flexible abrasive tool", and the free nano-magnetic particles in the polishing liquid will form a flexible polishing sleeve along the magnetic field distribution line, and the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles is attached to the gap of the flexible polishing sleeve to form the so-called "flexible polishing head". During the polishing process, the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles constituting the "flexible polishing head" contacts the surface of the workpiece, and the nano-magnetic abrasive particles are squeezed to the middle. At this time, the processing abrasive particles are exposed to the outside and contact the workpiece, accompanied by the ultrasonic vibration table driving the workpiece to vibrate at a high frequency, and produce micro-friction of relative motion with the "simulated flexible abrasive tool", realizing the air pressure simulated mode ultrasonic assisted core-shell abrasive magnetic rheological polishing.

[0024] In the step 2), the workpiece is a regular planar workpiece, a regular circular curved surface or an irregular complex curved surface, and the workpiece material is silicon material, optical crystal and various difficult-to-process materials.

[0025] A pneumatically simulated ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing device comprises an airflow assisting module, a magnetic field generating module, a flexible polishing sleeve, a polishing liquid circulation supply module and an ultrasonic vibration table, wherein the airflow assisting module comprises an airflow emitting device, an airflow conveying device, an airflow hole and a sealing coil, wherein the airflow hole is located on the inner wall of the airflow conveying device, the sealing coil is located on the outer wall of the airflow conveying device, and the airflow assisting module is located above the polishing workbench; the magnetic field generating module comprises a magnetic field control system, a magnetic field generating device and a polishing workbench, wherein the magnetic field generating device is attached to the inner wall of the polishing workbench and arranged in a circular array; the flexible polishing sleeve wraps the workpiece and is fixed on a protective sleeve at the rear end, and the protective sleeve is covered on a workpiece fixture; the polishing liquid circulation supply module reaches the polishing workbench through a polishing liquid conveying pipeline, and the polishing liquid will flow back to the polishing liquid circulation supply module from the polishing liquid pipeline outlet valve; a workpiece fixture is provided on the ultrasonic vibration table.

[0026] Furthermore, the ultrasonic vibration table includes an ultrasonic transducer, which includes a cylindrical pressure head, a variable amplitude rod, a piezoelectric element, an electrode sheet, a screw and a nut, wherein the cylindrical pressure head is connected to one end of the variable amplitude rod, the other end of the variable amplitude rod is connected to the piezoelectric element, the piezoelectric element is provided with an electrode sheet, the piezoelectric element is provided with a screw for pressing the piezoelectric element, the screw is provided with a nut, and a workpiece fixture is provided on the cylindrical pressure head, complex curved surface parts can be installed on the workpiece fixture, and the cylindrical pressure head can drive the workpiece to vibrate at high frequency.

[0027] Furthermore, the polishing liquid circulation supply module includes a polishing liquid supply device, a polishing liquid circulation system starting device, a pH adjustment device, a temperature adjustment device, a polishing liquid delivery pipeline, a polishing liquid pipeline inlet valve, a polishing liquid pipeline outlet valve and a collecting device. During the polishing process, the polishing liquid circulation system starting device is started, and the polishing liquid flows out from the polishing liquid supply device and reaches the polishing workbench through the polishing liquid delivery pipeline. The polishing liquid will flow out from the polishing liquid pipeline outlet valve and flow into the collecting device.

[0028] The protective sleeve is made of wear-resistant material, which not only provides a fixing place for the flexible polishing sleeve, but also prevents the workpiece fixture and the ultrasonic vibration table from being worn during the grinding and polishing process.

[0029] The vibration frequency of the ultrasonic transducer is at least 26Khz, and the power is at least 180 W. A rubber shock-absorbing gasket is arranged between the ultrasonic vibration table and the polishing workbench.

[0030] The prepared polishing liquid is added to the polishing liquid replenishing device, so that the polishing liquid is supplied to the workpiece surface through the polishing liquid delivery pipeline, and the pH value control device and the temperature control device are adjusted through the polishing liquid circulation module according to different workpiece materials or processing requirements, so that the viscosity of the polishing liquid can quickly reach the critical point under the action of the magnetic field, and realize the steady-state discontinuous transition of the viscosity from the critical point directly to the high viscosity point, and can maintain the continuous and stable state of the viscosity at the high point under the action of the magnetic field generating device, become more viscous, and ensure the uniformity of workpiece material removal and controllable surface accuracy.

[0031] During the polishing process, the polishing liquid slowly flows out from the polishing liquid pipeline inlet valve, and under the action of high-pressure airflow, it passes through the workpiece and slowly flows out from the polishing liquid outlet valve.

[0032] The present invention adopts a new type of composite grinding and polishing abrasive of core-shell type nano magnetic particles-abrasive particles. The new type of composite grinding and polishing abrasive of core-shell type nano magnetic particles-abrasive particles is composed of processing abrasive particles and magnetic nano particles. Through polymerization to control the particle structure and chemical environment modification, the magnetic nano particles are aggregated on the surface of the processing abrasive particles to form the new type of composite grinding and polishing abrasive of core-shell type nano magnetic particles-abrasive particles.

[0033] The beneficial effects of the present invention are mainly manifested in:

[0034] 1) Wide range of applications. The present invention provides a new type of composite polishing abrasive of core-shell nano-magnetic particles-abrasives, which is composed of processing abrasives and magnetic nano-particles; the particle structure is regulated by polymerization and the chemical environment is modified to form a new type of composite polishing abrasive of core-shell nano-magnetic particles-abrasives. During the polishing process, the core-shell composite magnetic abrasives contact the surface of the workpiece, and the nano-magnetic abrasives are squeezed to the middle. At this time, the processing abrasives are exposed to the outside and contact the workpiece to achieve polishing. The processing abrasives can be selected according to the processing of different types of materials. For example: aluminum oxide abrasives are suitable for processing steel and ferrous metal materials, silicon carbide is suitable for processing carbides, ceramics, cast iron and tough non-ferrous metals, etc.

[0035] 2) High processing accuracy, strong controllability, and efficient material removal. Since magnetic particles are attached to the outer layer of each abrasive, the processing direction can be accurately controlled by computers and external magnetic fields, so that the polishing liquid of the new composite polishing abrasive of core-shell nano magnetic particles-abrasives is highly consistent with the shape of the workpiece and material removal, thereby achieving precise processing. Compared with traditional abrasive processing, the controllable composite abrasive greatly improves the utilization rate of the abrasive, thereby removing materials more efficiently.

[0036] 3) The composite magnetic abrasive particles have good dispersibility. The composite magnetic abrasive particles are formed by electrostatic self-assembly. The outermost nano-magnetic particles carry the same charge. The composite magnetic abrasive particles repel each other, have good properties, and eliminate the need for dispersants, reducing the difficulty of preparing the polishing liquid.

[0037] 4) Efficient processing of complex curved parts. Under the action of the magnetic field control system, the polishing liquid of the new composite polishing abrasive of core-shell nano-magnetic particles and abrasive grains is highly consistent with the shape of the workpiece. The magnetic field generating device emits a strong magnetic field to change the polishing liquid from a non-Newtonian fluid into a semi-solid with high viscosity, forming a "mold-like flexible mold" with a similar shape to the workpiece surface, and then through friction and vibration, high-precision polishing of complex curved surfaces is achieved.

[0038] 5) High-pressure airflow is used to assist in providing dynamic pressure for the polishing liquid, which can not only assist the "mold-copying flexible abrasive tool" to continuously fit the workpiece during the polishing process, but also provide power for the circulation of the polishing liquid, accelerate the removal of material debris attached to the surface of the "mold-copying flexible abrasive tool" and continuously update the abrasive particles in the polishing liquid.

[0039] 6) The present invention has relatively low requirements on processing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the manufacturing principle of the new composite polishing abrasive of core-shell nanomagnetic particles-abrasive grains.

[0041] Figure 2 This is a schematic diagram of the manufacturing device for air pressure-simulated ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing.

[0042] Figure 3 Schematic diagram of the airflow assist module device.

[0043] Figure 4 This is a cross-sectional view of the airflow assist module.

[0044] Figure 5 Schematic diagram of ultrasonic transducer.

[0045] Among them, 1. abrasive particles; 2. nano magnetic particles; 3. air flow generating device; 4. air flow conveying device; 5. air flow hole; 6. magnetic field control system; 7. magnetic field generating device; 8. polishing workbench; 9. sealing coil; 10. workpiece; 11. workpiece fixture; 12. ultrasonic vibration table; 13. rubber vibration damping gasket; 14. polishing liquid supply device; 15. polishing liquid circulation starting device; 16. pH adjustment device; 17. temperature adjustment device; 18. polishing liquid supply device Delivery pipeline; 19. Polishing liquid pipeline inlet valve; 20. Polishing liquid pipeline outlet valve; 21. Polishing liquid; 22. Collecting device; 23. Flexible polishing sleeve; 24. Protective sleeve; 25. Imitation mold flexible abrasive tool; 121. Cylindrical pressure head; 122. Angular actuator; 123. Piezoelectric element; 124. Electrode sheet; 125. Screw; 126. Nut; 3-1. Magnetic lines of force; 3-2. Extrusion; 3-3. High-frequency vibration; 3-4. Shearing; 3-5. High-pressure airflow. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] Reference Figure 1 to Figure 5 A method for manufacturing a core-shell abrasive magnetic rheological composite polishing process assisted by air pressure-simulated ultrasonic mode includes the following steps:

[0048] 1) Select a workpiece fixture and install it on the ultrasonic vibration table;

[0049] 2) Clamp the workpiece on the workpiece fixture, and wrap the outer surface of the workpiece with a flexible polishing sleeve; the polishing sleeve is a porous wear-resistant polishing sleeve, and pores are reserved in the polishing sleeve; the workpiece is a regular planar workpiece, a regular circular curved surface or an irregular complex curved surface, and the workpiece material is silicon material, optical crystal and various difficult-to-process materials.

[0050] 3) preparing a polishing liquid having a composite polishing abrasive of core-shell nano magnetic particles-abrasive particles, and then placing the polishing liquid in a polishing liquid replenishing device;

[0051] The new composite polishing abrasive of core-shell type nano magnetic particles-abrasive is composed of abrasive 1 and magnetic nano particles 2. Through polymerization to regulate the particle structure and chemical environment modification, the magnetic nano particles 2 are aggregated on the surface of the abrasive 1 to form a new composite polishing abrasive of core-shell type nano magnetic particles-abrasive.

[0052] The abrasive grains 1 are a mixture of one or more of boron carbide, silicon carbide, silicon nitride, silicon oxide and aluminum oxide, or are conventional core-shell composite abrasive grains, such as SiO2 / CeO2 nanocomposite abrasive grains. More specifically, different processing parts need to be selected for different processing materials. Aluminum oxide abrasive grains are suitable for processing steel and ferrous metal materials, and silicon carbide is suitable for processing carbides, ceramics, cast iron and tough non-ferrous metals.

[0053] The nano magnetic particles 2 include ferrite (Fe3O4), iron, cobalt, nickel, and alloys with magnetism. The particle size and concentration of the nano magnetic particles 2 in the polishing liquid 3 should be selected according to the processing quality and efficiency of the polished parts.

[0054] The average diameter of the abrasive grains 1 is 200 to 1000 nm. The average diameter of the nanomagnetic particles 2 is 50 to 100 nm.

[0055] A polishing liquid 21 comprising the core-shell nano magnetic particle-abrasive novel composite polishing abrasive. In ultrapure water, we added the core-shell nano magnetic particle-abrasive novel composite polishing abrasive, pH adjuster, thickener and oxidant to prepare the polishing liquid 21. Among them, the mass fraction of the core-shell nano magnetic particle-abrasive novel composite polishing abrasive is between 20% and 50%, the mass fraction of the pH adjuster is between 0.05% and 1.0%, the mass fraction of the thickener is between 0.05% and 1.0%, and the mass fraction of the oxidant is between 0.05% and 0.1%.

[0056] Optionally, the pH adjuster is aqueous ammonia solution, sodium hydroxide and potassium hydroxide.

[0057] 4) Start the airflow auxiliary module to allow the high-pressure airflow to quickly fill the airflow conveying device pipeline; then start the polishing liquid circulation supply module to convey the polishing liquid to the polishing workbench until the flexible polishing sleeve is completely immersed;

[0058] In the airflow assist module, the high-pressure airflow provides dynamic pressure for the polishing liquid, which can not only assist the "mold-copying flexible abrasive tool" to continuously fit the workpiece during the polishing process, but also provide power for the circulation of the polishing liquid, thereby accelerating the removal of material debris attached to the surface of the "mold-copying flexible abrasive tool" and the continuous renewal of abrasive particles in the polishing liquid.

[0059] 5) Start the magnetic field control system, generate a magnetic field under the action of the magnetic field generating device, and the new composite polishing abrasive of core-shell type nano magnetic particles-abrasive particles in the polishing liquid enters into the flexible polishing sleeve, and forms a flexible polishing head on the inner surface of the polishing sleeve. With the assistance of high-pressure gas, the flexible polishing sleeve is highly consistent with the shape of the workpiece, forming a "mold-like flexible abrasive tool 25" that is similar to the surface shape of the workpiece.

[0060] The flexible polishing head is attached to the surface of the "mold-like flexible abrasive tool". The free nano-magnetic particles in the polishing liquid will form a flexible polishing sleeve along the magnetic field distribution line, and the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles is attached to the gap of the flexible polishing sleeve to form the so-called "flexible polishing head". During the polishing process, the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles constituting the "flexible polishing head" contacts the surface of the workpiece, and the nano-magnetic abrasive particles are squeezed to the middle. At this time, the processing abrasive particles are exposed to the outside and contact the workpiece. Accompanied by the ultrasonic vibration table driving the workpiece to vibrate at a high frequency, the micro-friction of relative motion is generated with the "mold-like flexible abrasive tool", realizing the air pressure imitation mode ultrasonic assisted core-shell abrasive magnetic rheological polishing.

[0061] 6) Start the ultrasonic transducer, and the ultrasonic vibration table drives the workpiece to vibrate at a high frequency, generating micro-friction of relative motion with the "mold-mimicking flexible abrasive", thereby realizing air pressure-mimicking ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing.

[0062] A pneumatically simulated ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing device comprises an airflow assisting module, a magnetic field generating module, a flexible polishing sleeve 23, a polishing liquid circulation supply module and an ultrasonic vibration table 12, wherein the airflow assisting module comprises an airflow emitting device 3, an airflow conveying device 4, an airflow hole 5 and a sealing coil 9; the magnetic field generating module comprises a magnetic field control system 6, a magnetic field generating device 7 and a polishing workbench 8; the polishing liquid circulation supply module comprises a polishing liquid supply device 14, a polishing liquid circulation system starting device 15, a pH adjusting device 16, a temperature adjusting device 17, a polishing liquid conveying pipeline 18, a polishing liquid pipeline inlet valve 19, a polishing liquid pipeline outlet valve 20 and a collecting device 22; the ultrasonic vibration table 12 comprises an ultrasonic transducer, and the ultrasonic transducer comprises a cylindrical pressure head 121, a horn 122, a piezoelectric element 123, an electrode sheet 124, a screw 125 and a nut 126.

[0063] The airflow auxiliary module includes an airflow launching device 3, an airflow conveying device 4, an airflow hole 5 and a sealing coil 9. The lower port of the airflow launching device 3 is in a closed connection with the upper port of the airflow conveying device 4. The airflow hole 5 is located on the inner wall of the airflow conveying device 4. The sealing coil 9 is located on the outer wall of the airflow conveying device 4. The airflow auxiliary module is located above the polishing workbench 8.

[0064] The magnetic field generating module includes a magnetic field control system 6, a magnetic field generating device 7 and a polishing workbench 8. The magnetic field control system 6 is located on the right side of the device and is independent of a control unit outside the device. The magnetic field generating device 7 is attached to the inner wall of the polishing workbench 8 and arranged in a circular array. An ultrasonic vibration table 12 is arranged at the center of the polishing workbench 8, and a rubber shock-absorbing gasket 13 is arranged between the ultrasonic vibration table 12 and the polishing workbench 8.

[0065] The flexible polishing sleeve 23 wraps the workpiece 10 and is fixed on the protective sleeve 24 at the rear end, and the protective sleeve 24 is covered on the workpiece fixture 11;

[0066] The protective cover 24 is made of wear-resistant material, which not only provides a fixing place for the flexible polishing cover 23, but also prevents the workpiece fixture 11 and the ultrasonic vibration table 12 from being worn during the polishing process.

[0067] The polishing liquid circulation supply module includes a polishing liquid supply device 14, a polishing liquid circulation system starting device 15, a pH adjusting device 16, a temperature adjusting device 17, a polishing liquid delivery pipeline 18, a polishing liquid pipeline inlet valve 19, a polishing liquid pipeline outlet valve 20 and a collecting device 22, wherein the temperature adjusting device 17 is embedded in the pH adjusting device 16, and the temperature adjusting device 17 is attached to the polishing liquid delivery pipeline 18. During the polishing process, the polishing liquid circulation system starting device 15 is started, and the polishing liquid 21 flows out from the polishing liquid supply device 14, reaches the polishing workbench 8 through the polishing liquid delivery pipeline 18, and the polishing liquid 21 flows out from the polishing liquid pipeline outlet valve 20 and flows into the collecting device 22;

[0068] The ultrasonic vibration table 12 includes an ultrasonic transducer, which includes a cylindrical pressure head 121, a horn 122, a piezoelectric element 123, an electrode sheet 124, a screw 125 and a nut 126. The cylindrical pressure head 121 is connected to one end of the horn 122, and the other end of the horn 122 is connected to the piezoelectric element 123. The piezoelectric element 123 is provided with an electrode sheet 124, and the piezoelectric element 123 is provided with a screw 125 for pressing the piezoelectric element 123, and the screw 125 is provided with a nut 126. A workpiece fixture 11 is provided on the cylindrical pressure head 121, and a workpiece 10 can be installed on the workpiece fixture 11. The cylindrical pressure head 121 can drive the workpiece 10 to vibrate at a high frequency. The vibration frequency of the ultrasonic transducer is at least 26Khz, and the power is at least 180W.

[0069] The prepared polishing liquid 21 is added to the polishing liquid replenishing device 14, so that the polishing liquid 21 is supplied to the surface of the workpiece 10 through the polishing liquid delivery pipeline 18, and the pH value control device 16 and the temperature control device 17 are adjusted through the polishing liquid circulation module according to different workpiece materials or processing requirements, so that the viscosity of the polishing liquid 21 can quickly reach the critical point under the action of the magnetic field, and realize the steady-state discontinuous transition of the viscosity from the critical point directly to the high viscosity point, and can maintain the continuous and stable state of the high viscosity point under the action of the magnetic field generating device 7, become more viscous, and ensure the uniformity of workpiece material removal and controllable surface shape accuracy.

[0070] During the polishing process, the polishing liquid 21 slowly flows out from the polishing liquid pipeline inlet valve 19, and under the action of the high-pressure airflow, passes through the workpiece and slowly flows out from the polishing liquid outlet valve 20.

[0071] The polishing method of the workpiece 10 in this embodiment includes the following steps:

[0072] 1) Select a workpiece fixture 11 and install it on an ultrasonic vibration table 12;

[0073] 2) Clamping the workpiece 10 on the workpiece fixture 11, and wrapping the outer surface of the workpiece 10 with a flexible polishing sleeve 23;

[0074] 3) preparing a polishing liquid 21 having a novel composite polishing abrasive of core-shell nano magnetic particles-abrasive grains, and then placing it in a polishing liquid replenishing device 14;

[0075] 4) Start the airflow auxiliary module to allow the high-pressure airflow to quickly fill the airflow conveying device pipeline 4; then start the polishing liquid circulation supply module to convey the polishing liquid 21 to the polishing workbench 8 until the flexible polishing sleeve 23 is completely immersed;

[0076] 5) Start the magnetic field control system 6, and generate a magnetic field under the action of the magnetic field generating device 7. The new composite polishing abrasive of core-shell type nano magnetic particles and abrasive grains in the polishing liquid 21 enters into the flexible polishing sleeve 23, and a flexible polishing head is formed on the inner surface of the polishing sleeve 23. With the assistance of high-pressure gas, the flexible polishing sleeve 23 is highly consistent with the shape of the workpiece 10, forming a "mold-like flexible abrasive tool" with a similar shape to the surface of the workpiece.

[0077] 6) Start the ultrasonic transducer, the ultrasonic vibration table 12 drives the workpiece 10 to vibrate at a high frequency, and produces micro-friction of relative motion with the "simulation flexible abrasive tool", thereby realizing the pneumatic simulation mode ultrasonic assisted core-shell abrasive magnetic rheological polishing composite processing and manufacturing.

[0078] The contents described in the embodiments of this specification are merely enumerations of implementation forms of the inventive concept and are for illustrative purposes only. The protection scope of the present invention should not be considered to be limited to the specific forms described in this embodiment, and the protection scope of the present invention also extends to equivalent technical means that can be thought of by ordinary technicians in this field based on the inventive concept.

Claims

1. A method for manufacturing a core-shell abrasive magnetic rheological composite polishing assisted by air pressure-simulated ultrasonic mode. It is characterized in that The method comprises the following steps: 1) Select a workpiece fixture and install it on the ultrasonic vibration table; 2) Clamp the workpiece on the workpiece fixture and wrap the outer surface of the workpiece with a flexible polishing sleeve; 3) preparing a polishing liquid having a novel composite polishing abrasive of core-shell nano magnetic particles-abrasive grains, and then placing the polishing liquid in a polishing liquid replenishing device; 4) Start the airflow auxiliary module to allow the high-pressure airflow to quickly fill the airflow conveying device pipeline; then start the polishing liquid circulation supply module to convey the polishing liquid to the polishing workbench until the flexible polishing sleeve is completely immersed; 5) Start the magnetic field control system, generate a magnetic field under the action of the magnetic field generating device, and the new composite polishing abrasive of core-shell nano magnetic particles and abrasive particles in the polishing liquid enters into the flexible polishing sleeve, and forms a flexible polishing head on the inner surface of the flexible polishing sleeve. With the assistance of high-pressure gas, the flexible polishing sleeve is highly consistent with the shape of the workpiece, forming a "mold-like flexible abrasive tool" with a similar shape to the surface of the workpiece; 6) Start the ultrasonic transducer, and the ultrasonic vibration table drives the workpiece to vibrate at a high frequency, generating micro-friction of relative motion with the "simulation flexible abrasive tool", thereby realizing the pneumatic simulation mode ultrasonic assisted core-shell abrasive magnetic rheological composite polishing.

2. The gas pressure-simulated ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing manufacturing method according to claim 1, It is characterized in that In the step 3), the novel composite polishing abrasive with core-shell nano magnetic particles-abrasive particles comprises abrasive particles and nano magnetic particles, wherein the abrasive particles are one or a mixture of two or more of boron carbide, silicon carbide, silicon nitride, silicon oxide and aluminum oxide, or core-shell composite abrasive particles; the nano magnetic particles include ferrite (Fe 3 O 4 ), iron, cobalt, nickel, and magnetic alloys.

3. The gas pressure-simulated ultrasound-assisted core-shell abrasive magnetic rheological composite polishing manufacturing method according to claim 2, It is characterized in that In the step 3), the average diameter of the abrasive particles is 200-1000 nm, and the average diameter of the nano-magnetic particles is 50-100 nm.

4. The method for manufacturing a core-shell abrasive magnetic rheological composite polishing by air pressure-simulated ultrasound-assisted polishing according to any one of claims 1 to 3, It is characterized in that In the step 2), the flexible polishing sleeve is a porous wear-resistant polishing sleeve, and pores are reserved in the flexible polishing sleeve.

5. The method for manufacturing a core-shell abrasive magnetic rheological composite polishing by air pressure-simulated ultrasound-assisted polishing according to any one of claims 1 to 3, It is characterized in that In the step 4), in the airflow assist module, the high-pressure airflow provides dynamic pressure for the polishing liquid, which can not only assist the "mold-copying flexible abrasive tool" to continuously fit the workpiece during the polishing process, but also provide power for the circulation of the polishing liquid, accelerate the removal of material debris attached to the surface of the "mold-copying flexible abrasive tool" and continuously update the abrasive particles in the polishing liquid.

6. The method for manufacturing a core-shell abrasive magnetic rheological composite polishing assisted by air pressure-simulated ultrasound according to any one of claims 1 to 3, It is characterized in that In the step 5), a flexible polishing head is attached to the surface of the "mold-like flexible abrasive tool", and the free nano-magnetic particles in the polishing liquid will form a flexible polishing sleeve along the magnetic field distribution line, and the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles is attached to the gap of the flexible polishing sleeve to form a so-called "flexible polishing head"; during the polishing process, the new composite polishing abrasive of core-shell nano-magnetic particles-abrasive particles constituting the "flexible polishing head" contacts the surface of the workpiece, and the nano-magnetic abrasive particles are squeezed to move closer to the middle. At this time, the processing abrasive particles are exposed to the outside and contact the workpiece, accompanied by the ultrasonic vibration table driving the workpiece to vibrate at a high frequency, and produce micro-friction of relative motion with the "mold-like flexible abrasive tool", thereby realizing air pressure imitation mode ultrasonic assisted core-shell abrasive magnetic rheological polishing.

7. The method for manufacturing a core-shell abrasive magnetic rheological composite polishing assisted by air pressure-simulated ultrasound according to any one of claims 1 to 3, It is characterized in that In the step 2), the workpiece is a regular planar workpiece, a regular circular curved surface or an irregular complex curved surface, and the workpiece material is silicon material or optical crystal.

8. A device for implementing the gas pressure-simulated ultrasonic-assisted core-shell abrasive magnetic rheological composite polishing manufacturing method as claimed in claim 1, It is characterized in that The device includes an airflow auxiliary module, a magnetic field generating module, a flexible polishing sleeve, a polishing liquid circulation supply module and an ultrasonic vibration table. The airflow auxiliary module includes an airflow emitting device, an airflow conveying device, an airflow hole and a sealing coil. The airflow hole is located on the inner wall of the airflow conveying device, and the sealing coil is located on the outer wall of the airflow conveying device. The airflow auxiliary module is located above the polishing workbench; the magnetic field generating module includes a magnetic field control system, a magnetic field generating device and a polishing workbench. The magnetic field generating device is attached to the inner wall of the polishing workbench and arranged in a circular array; the flexible polishing sleeve wraps the workpiece and is fixed on the protective sleeve at the rear end, and the protective sleeve is covered on the workpiece fixture; the polishing liquid circulation supply module reaches the polishing workbench through a polishing liquid conveying pipeline, and the polishing liquid will flow back to the polishing liquid circulation supply module from the polishing liquid pipeline outlet valve; a workpiece fixture is provided on the ultrasonic vibration table.

9. The device as claimed in claim 8, It is characterized in that The ultrasonic vibration table includes an ultrasonic transducer, which includes a cylindrical pressure head, a variable amplitude rod, a piezoelectric element, an electrode sheet, a screw and a nut, wherein the cylindrical pressure head is connected to one end of the variable amplitude rod, the other end of the variable amplitude rod is connected to the piezoelectric element, the piezoelectric element is provided with an electrode sheet, the piezoelectric element is provided with a screw for pressing the piezoelectric element, the screw is provided with a nut, a workpiece fixture is provided on the cylindrical pressure head, complex curved surface parts can be installed on the workpiece fixture, and the cylindrical pressure head can drive the workpiece to vibrate at high frequency.

10. The device according to claim 8 or 9, It is characterized in that The polishing liquid circulation supply module includes a polishing liquid supply device, a polishing liquid circulation system starting device, a pH adjustment device, a temperature adjustment device, a polishing liquid delivery pipeline, a polishing liquid pipeline inlet valve, a polishing liquid pipeline outlet valve and a collecting device. During the polishing process, the polishing liquid circulation system starting device is started, and the polishing liquid flows out from the polishing liquid supply device and reaches the polishing workbench through the polishing liquid delivery pipeline. The polishing liquid will flow out from the polishing liquid pipeline outlet valve and flow into the collecting device.

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