Liquid metal grinding and polishing disc preparation device and preparation method thereof

Abstract

The invention belongs to the field of polishing, and discloses a liquid metal grinding and polishing disc preparation device and a preparation method thereof.The liquid metal grinding and polishing disc preparation device comprises an electromagnetic stirring unit, a conveying unit and a forming unit, the electromagnetic stirring unit mixes and stirs a liquid metal solution and abrasive particles, and the conveying unit conveys the mixed and stirred liquid metal solution and abrasive particles to the forming unit; the forming unit comprises a mold, an electrode and a first electromagnetic coil are arranged on the mold, the mold provides a cavity for a mixed solution of a liquid metal solution and abrasive particles, the electrode is electrified to improve the current density of the mixed solution, and the first electromagnetic coil is electrified to generate an alternating magnetic field acting on the mixed solution. And the whole mold is filled with the mixed liquid under the common influence of the electric field force and the Lorentz force, and finally the mixed liquid is solidified to form the liquid metal grinding and polishing disc. When the device is used for manufacturing the liquid metal grinding and polishing disc, even if the viscosity of the liquid metal solution is high, contact is not needed in the whole manufacturing process, the purity of the liquid metal and the abrasive particle solution is guaranteed, and adhesion waste is prevented.

Description

Technical Field

[0001] The invention relates to the field of polishing, and in particular to a liquid metal polishing disc preparation device and a preparation method thereof. Background Art

[0002] In the field of polishing, traditional polishing discs are usually made of polymer, rubber or polyurethane materials. Although the performance of these materials can meet certain polishing requirements, their mechanical properties and chemical stability are still limited in the field of ultra-high precision polishing. With the advancement of manufacturing technology, liquid metal has gradually become the focus of researchers due to its unique physical and chemical properties, such as high hardness, high strength, excellent wear resistance and corrosion resistance. Liquid metal generally refers to amorphous alloy materials formed by metal under specific conditions. These materials are in a liquid or near-liquid state at room temperature, with high fluidity and good formability. In addition, the amorphous structure of liquid metal enables it to maintain a uniform structure without grains after cooling, thus exhibiting excellent mechanical properties. Based on these advantages, liquid metal has shown great application potential in the field of precision manufacturing tools including polishing discs.

[0003] However, the steps of making liquid metal into polishing discs are complicated. In the prior art, impurities often exist in the polishing discs due to shaping and stirring steps during the manufacturing process, and the liquid metal and abrasive particles are mixed unevenly. In the preparation process, part of the liquid metal will be adhered to other objects during the stirring or shaping steps, resulting in waste. The present invention can improve this situation to a large extent and greatly improve the efficiency of making liquid metal polishing discs. Summary of the invention

[0004] The object of the present invention is to provide a liquid metal polishing disc preparation device and a preparation method thereof to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A liquid metal polishing plate preparation device, comprising an electromagnetic stirring unit, a conveying unit and a molding unit;

[0007] The electromagnetic stirring unit mixes and stirs the liquid metal solution and the abrasive particles;

[0008] The conveying unit conveys the mixed and stirred liquid metal solution and abrasive particles to the molding unit;

[0009] The molding unit includes a mold, on which electrodes and a first electromagnetic coil are arranged. The mold provides a cavity for a mixture of liquid metal solution and abrasive particles. The electrode is energized to increase the current density of the mixture. The first electromagnetic coil is energized to generate an alternating magnetic field acting on the mixture, so that the mixture fills the entire mold under the combined influence of the electric field force and the Lorentz force, and finally solidifies to form a liquid metal polishing disc.

[0010] Furthermore, the electromagnetic stirring unit comprises a stirring container, and a plurality of second electromagnetic coils in different directions are arranged around the stirring container.

[0011] Furthermore, the conveying unit includes an electromagnetic pump and a guide tube, and the electromagnetic pump accelerates the mixed solution of the liquid metal solution and the abrasive particles to be pumped into the mold through the guide tube.

[0012] Furthermore, there are a plurality of electrodes which are arranged around the inner wall of the mold, and the first electromagnetic coil is sleeved on the outer wall of the mold.

[0013] Furthermore, the molding unit is located at the lower end of the stirring unit and the conveying unit, and the mold is slidably arranged, so that the molding unit can be pulled out from the lower end of the stirring unit and the conveying unit after the preparation work is completed.

[0014] Furthermore, an anti-sticking plate is provided at the bottom of the inner wall of the mold, and the entire formed liquid metal polishing disc is lifted out for use through the anti-sticking plate.

[0015] Furthermore, it also includes a lifting unit, which drives the electromagnetic stirring unit to rotate up and down to tilt the electromagnetic stirring unit.

[0016] Furthermore, the lifting unit is a cylinder.

[0017] The present invention also provides a method for preparing a liquid metal polishing disc, comprising:

[0018] The liquid metal solution and the abrasive particles are mixed and stirred by an electromagnetic stirring unit;

[0019] The mixed liquid of the liquid metal solution and the abrasive particles is transported to the molding unit through the transport unit;

[0020] The electrodes are energized, and the first electromagnetic coil is energized with alternating current. The electrodes are energized to increase the current density of the mixed liquid, and the first electromagnetic coil is energized to generate an alternating magnetic field acting on the mixed liquid, so that the mixed liquid fills the entire mold under the combined influence of the electric field force and the Lorentz force;

[0021] After the mixed liquid solidifies to form a liquid metal polishing disc, the liquid metal polishing disc is taken out from the mold.

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

[0023] 1) When the present invention is used to make a liquid metal polishing disc, even if the viscosity of the liquid metal solution is high, the present invention ensures the purity of the liquid metal and the abrasive solution without contact during the entire production process, thereby preventing adhesion and waste.

[0024] 2) The present invention uses a plurality of second electromagnetic coils in different directions on the stirring container, which can generate alternating electromagnetic fields in multiple directions, thereby making the stirring more uniform.

[0025] 3) The present invention arranges the stirring unit and the molding unit in an upper and lower position, and immediately delivers the mixed liquid to the molding unit through an electromagnetic pump after the mixed liquid is evenly mixed, thereby avoiding the uneven roughness of the liquid metal polishing plate caused by partial solidification of the mixed liquid before preparation.

[0026] 4) When the present invention is used to prepare a liquid metal polishing plate, the production efficiency is greatly improved because the stirring unit and the molding unit are highly integrated.

[0027] 5) The present invention uses the coupling effect of electric field and magnetic field and utilizes self-leveling technology in the preparation process, which is a contactless preparation, so that the density and roughness of the produced liquid metal polishing disc are more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a schematic diagram of the main structure of a liquid metal polishing disc preparation device.

[0029] Figure 2 This is one of the three-dimensional structural schematic diagrams of an invented liquid metal polishing disc preparation device.

[0030] Figure 3 This is the second three-dimensional structural schematic diagram of a liquid metal polishing plate preparation device invented, in which the stirring container is in an inclined state.

[0031] Figure 4 It is a schematic diagram of the top view structure of a molding unit in a liquid metal polishing disc preparation device of the present invention.

[0032] Figure 5 It is a schematic diagram of the main structure of a molding unit in a liquid metal polishing disc preparation device of the present invention.

[0033] Figure 6 It is a schematic diagram of the three-dimensional structure of a molding unit in a liquid metal polishing disc preparation device of the present invention.

[0034] Figure 7 This is one of the schematic diagrams of the connection structure between the stirring container and the second electromagnetic coil in a liquid metal polishing plate preparation device of the present invention.

[0035] Figure 8This is the second schematic diagram of the connection structure between the stirring container and the second electromagnetic coil in a liquid metal polishing plate preparation device of the present invention.

[0036] Fig. 9 The present invention is a flow chart of a method for preparing a liquid metal polishing disc.

[0037] In the figure: guide rail 1, slider 2, first electromagnetic coil 3, bottom plate 4, stirring frame 5, guide tube 6, guide tube fixing ring 7, anti-sticking plate 8, electromagnetic pump 9, cylinder 11, stirring container 12, stirring container cover 13, cantilever main controller 14, second electromagnetic coil 15, electrode 16, mold 17. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1-Figure 8 A liquid metal polishing disc preparation device includes a frame, on which an electromagnetic stirring unit, a conveying unit and a molding unit are arranged. The electromagnetic stirring unit mixes and stirs the liquid metal solution and the abrasive. The conveying unit conveys the mixed and stirred liquid metal solution and the abrasive to the molding unit. The molding unit includes a mold 17, on which an electrode 16 and a first electromagnetic coil 3 are arranged. The mold 17 provides a cavity for the mixed liquid of the liquid metal solution and the abrasive. The electrode 16 is embedded and plugged into the mold 17 for easy disassembly. When it is energized, the current density of the mixed liquid is increased. When the first electromagnetic coil 3 is energized, an alternating magnetic field acting on the mixed liquid is generated, so that the mixed liquid fills the entire mold 17 under the combined influence of the electric field force and the Lorentz force, and finally forms a liquid metal polishing disc with the support of the self-leveling technology.

[0040] Continue reading Figure 1 , Figure 7 and Figure 8 In one embodiment of the present invention, the electromagnetic stirring unit includes a stirring container 12, and second electromagnetic coils 15 are respectively arranged in four directions of the outer wall of the stirring container 12, front, back, left and right. The four electromagnetic coils are used to generate an alternating magnetic field in four directions, and the liquid metal and abrasive particles inside the container are evenly mixed together by electromagnetic stirring technology.

[0041] Continue reading Figure 1In one embodiment of the present invention, the conveying unit includes an electromagnetic pump 9 and a guide tube 6. The electromagnetic pump 9 is arranged at the rear position of the bottom of the stirring container 12. One end of the guide tube 6 is connected to the electromagnetic pump 9, and the other end extends to the mold 17. The electromagnetic pump 9 accelerates the pumping of the mixture of liquid metal solution and abrasive into the mold 17 through the guide tube 6.

[0042] Continue reading Figure 1-Figure 3 In one embodiment of the present invention, the preparation device further comprises a lifting unit arranged on the frame, and the lifting unit drives the electromagnetic stirring unit to rotate up and down, so that the electromagnetic stirring unit is tilted. Specifically, a stirring frame 5 is arranged on the frame, and the upper rear side of the stirring container 12 is rotatably connected to the frame. The lifting unit is preferably a cylinder 11, and the lower end of the cylinder 11 is rotatably connected to the stirring frame 5, and the upper end of the cylinder 11 is rotatably connected to the stirring container 12. The cylinder 11 can drive the stirring container 12 to rotate on the frame. When the mixed liquid in the stirring container 12 is not much, the stirring container 12 can be driven to rotate by the cylinder 11, so that the mixed liquid converges at the bottom rear side of the stirring container 12, that is, converges at the side close to the electromagnetic pump 9, so that the mixed liquid is more easily sucked out by the electromagnetic pump.

[0043] Continue reading Figure 4-Figure 6 In one embodiment of the present invention, there are eight electrodes 16, which are evenly distributed around the inner wall of the mold 17, and the first electromagnetic coil 3 is sleeved on the outer wall of the mold 17. An anti-sticking plate 8 is also provided at the bottom of the inner wall of the mold 17. The upper end of the anti-sticking plate 8 has a handle higher than the mold 17. The entire formed liquid metal polishing plate can be taken out for use through the anti-sticking plate 8. The anti-sticking plate 8 is integrated with the mold 17 in structural design, which is equivalent to a groove reserved on the mold 17 that matches the shape and size of the anti-sticking plate 8. The anti-sticking plate 8 is embedded in the groove, which can ensure that the shape of the liquid metal polishing plate is flat.

[0044] Continue reading Figure 1 and 5 The molding unit is located at the lower end of the stirring unit and the conveying unit, and the mold is slidably arranged. After the preparation work is completed, the molding unit can be pulled out from the lower end of the stirring unit and the conveying unit. Specifically, a guide rail 1 is arranged on the frame, a bottom plate 4 is arranged at the bottom of the mold 17, a slider 2 is arranged at the bottom of the bottom plate 4, and the slider 2 is slidably matched with the guide rail 1, thereby realizing the sliding arrangement of the molding unit.

[0045] The liquid metal polishing plate preparation device of the present invention also includes a guide tube fixing ring 7 and a stirring container cover 13. The guide tube fixing ring 7 is arranged on the mold 17 to allow the guide tube 6 to pass through the ring to play a guiding role. The stirring container cover 13 is arranged on the stirring container 12 to cover the stirring container 12.

[0046] The present invention installs a cantilevered main controller 14 on the right side of the entire device to control the entire preparation process.

[0047] See also Fig. 9 , a method for preparing a liquid metal polishing plate, comprising:

[0048] Step 1: Pour liquid metal solution and abrasive particles into a stirring container 12.

[0049] Step 2: A high-frequency alternating current is passed through the second electromagnetic coil 15, which then generates high-frequency alternating magnetic fields in multiple directions to achieve electromagnetic mixing and stirring of the liquid metal solution and the abrasive particles.

[0050] The magnitude of the alternating magnetic field can be calculated using the following formula.

[0051]

[0052] Where μ0 represents the magnetic permeability in the atmosphere, m is the number of turns of the solenoid coil, L is the length of the solenoid, and I(t) represents the change of the current flowing through the electromagnetic coil over time.

[0053] When the liquid metal solution is exposed to alternating electromagnetic fields in multiple directions, more chaotic eddy currents will be generated inside the liquid metal, and these eddy currents will also heat the liquid metal mixture due to the Joule heating effect. Furthermore, when the more chaotic eddy currents are exposed to the magnetic field, they will be subject to Lorentz forces from all directions, making the liquid metal solution and the abrasive particles mix more evenly.

[0054] The magnitude of the eddy current caused by one of the electromagnetic coils can be calculated using the following formula.

[0055]

[0056] Where r represents the radius of the second electromagnetic coil 15 (since the second electromagnetic coil is installed on the stirring container 12 and is close to the liquid metal, the area through which the magnetic flux lines pass can be regarded as the area of ​​the electromagnetic coil cross section), R represents the resistance of the liquid metal and abrasive mixture, and dΦ represents the change in magnetic flux within the time dt. i It indicates the size of the induced eddy current generated in the liquid metal polishing plate due to the change of magnetic flux.

[0057] Step 3, after stirring evenly, turn on the electromagnetic pump 9.

[0058] Step 4, a mixture of liquid metal solution and abrasive particles is input into the mold through the electromagnetic pump 9 and the guide tube 6. The mixture of liquid metal and abrasive particles is transported to the lower mold 17 through the guide tube 6 under its own gravity and the action of the electromagnetic pump 9 installed at the bottom. The electromagnetic pump 9 can well overcome the problem of excessive viscosity of the liquid metal mixture adhering to the guide tube 6.

[0059] Step 5, when the liquid metal and abrasive mixture evenly mixed above flows into the mold 17, first turn off the electromagnetic pump, and then immediately energize the eight graphene electrodes evenly installed around the mold 17. This will ensure that the temperature of the mixed liquid will not drop too quickly to cause the mixed liquid to form a local solidification phenomenon, and ensure that the produced liquid metal polishing disc has a high degree of flatness. At the same time, a sufficiently large current density J will be provided to the inside of the mixed liquid, providing a basis for the next step of manufacturing the liquid metal polishing disc. At this time, the heat brought to the liquid metal mixture by the power of the graphene electrode can be calculated by the following formula.

[0060] Q1=I 2 Rt (3)

[0061] Where I is the current given by the graphene electrode to the liquid metal mixture, R represents the resistance value of the liquid metal mixture, and t represents time.

[0062] After a certain amount of liquid metal mixture is introduced, the electromagnetic pump 9 located at the bottom of the stirring container 12 will be automatically closed to prevent the liquid metal mixture from continuing to flow into the mold 17 of the preparation device.

[0063] Step 6, an alternating current of a certain frequency is passed through the first electromagnetic coil 3, the electrode 16 is energized to increase the current density of the mixed liquid, and the first electromagnetic coil 3 is energized to generate an alternating magnetic field acting on the mixed liquid, so that the mixed liquid fills the entire mold 17 under the combined influence of the electric field force and the Lorentz force.

[0064] The magnitude of the electromagnetic field generated by the first electromagnetic coil 3 can also be expressed by formula (1). The magnetic field can also cause eddy current effect in the liquid metal in the mold 17, and the magnitude of the eddy current can also be expressed by formula (2). In this process, the total Joule heat generated by the current (the joint heat generated by the graphene electrode and the eddy current) can be expressed by the following formula.

[0065]

[0066] Where r represents the radius of the second electromagnetic coil 3 in the preparation area, I represents the current magnitude of the eight graphene electrodes given to the liquid metal and abrasive mixture in the mold in the preparation area. R represents the resistance value of the liquid metal and abrasive mixture in the mold in the preparation area. B(t) represents the magnitude of the electromagnetic field caused by the second electromagnetic coil 3.

[0067] At this time, the liquid metal and abrasive mixture in the mold 17 will be subjected to the combined action of the electric field force and the Lorentz force. The direction of the Lorentz force can be effectively controlled by passing the second electromagnetic coil 3, so that the liquid metal and abrasive mixture in the mold 17 move in a directional manner until the entire mold is filled. In this process, the electric field force and the Lorentz force on the liquid metal and abrasive in the mold 17 can be obtained by the following formula.

[0068]

[0069] Where F Lorentz represents the Lorentz force, B(t) represents the magnitude of the electromagnetic field caused by the second electromagnetic coil 3, and J represents the current density of the liquid metal and abrasive mixture in the preparation area mold 17. e represents the electric field force, q represents the charge of the liquid metal and abrasive mixture in the mold 17, and E represents the electric field strength given by eight evenly distributed graphene electrodes.

[0070] The liquid metal and abrasive mixture in the mold 17 gradually fills the entire mold 17 and spreads flatly therein under the combined influence of the electric field force and the Lorentz force. The liquid metal polishing disc produced at this time has a high flatness and a relatively uniform surface roughness distribution.

[0071] Step 7, then disconnect the power supply of the electrode 16 and the power supply of the second electromagnetic coil 3. At this time, the liquid metal polishing plate no longer has Joule heat, and will quickly radiate heat to the outside world, and finally solidify gradually with the support of self-leveling technology and the surface becomes smoother.

[0072] Step 8, after the preparation is completed, the bottom plate 4 can be pulled out of the entire molding unit through the slider 2 and the guide rail 1, and then the prepared liquid metal polishing plate can be taken out through the anti-sticking plate 8 to complete the entire preparation process.

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid metal polishing disc preparation device, characterized in that: It includes an electromagnetic stirring unit, a conveying unit and a molding unit; The electromagnetic stirring unit mixes and stirs the liquid metal solution and the abrasive particles; The conveying unit conveys the mixed and stirred liquid metal solution and abrasive particles to the molding unit; The molding unit comprises a mold (17), on which an electrode (16) and a first electromagnetic coil (3) are arranged. The mold (17) provides a cavity for a mixture of a liquid metal solution and abrasive particles. The electrode (16) is energized to increase the current density of the mixture. The first electromagnetic coil (3) is energized to generate an alternating magnetic field acting on the mixture, so that the mixture fills the entire mold (17) under the combined influence of the electric field force and the Lorentz force, and finally solidifies to form a liquid metal polishing disc.

2. A liquid metal polishing disc preparation device according to claim 1, characterized in that: The electromagnetic stirring unit comprises a stirring container (12), and a plurality of second electromagnetic coils (15) in different directions are arranged around the stirring container (12).

3. A liquid metal polishing disc preparation device according to claim 1, characterized in that: The conveying unit comprises an electromagnetic pump (9) and a flow guide tube (6), and the electromagnetic pump (9) accelerates and pumps a mixture of liquid metal solution and abrasive particles into the mold (17) through the flow guide tube (6).

4. A liquid metal polishing disc preparation device according to claim 1, characterized in that: There are a plurality of electrodes (16) which are arranged around the inner wall of the mold (17), and the first electromagnetic coil (3) is sleeved on the outer wall of the mold (17).

5. The liquid metal polishing disc preparation device according to claim 1, characterized in that: The molding unit is located at the lower end of the stirring unit and the conveying unit, and the mold is slidably arranged. After the preparation work is completed, the molding unit can be pulled out from the lower end of the stirring unit and the conveying unit.

6. A liquid metal polishing disc preparation device according to claim 1, characterized in that: An anti-sticking plate (8) is provided at the bottom of the inner wall of the mold (17), and the entire formed liquid metal polishing plate is lifted out for use through the anti-sticking plate (8).

7. The liquid metal polishing disc preparation device according to claim 1, characterized in that: The device also includes a lifting unit, which drives the electromagnetic stirring unit to rotate up and down to tilt the electromagnetic stirring unit.

8. A liquid metal polishing disc preparation device according to claim 7, characterized in that: The lifting unit is a cylinder (11).

9. A method for preparing a liquid metal polishing disc, characterized in that: include: The liquid metal solution and the abrasive particles are mixed and stirred by an electromagnetic stirring unit; The mixed liquid of the liquid metal solution and the abrasive particles is transported to the molding unit through the transport unit; Power is supplied to the electrode, and alternating current is supplied to the first electromagnetic coil (3). The electrode (16) is powered to increase the current density of the mixed liquid. The first electromagnetic coil (3) is powered to generate an alternating magnetic field acting on the mixed liquid, so that the mixed liquid fills the entire mold (17) under the combined influence of the electric field force and the Lorentz force; After the mixed liquid solidifies to form a liquid metal polishing disc, the liquid metal polishing disc is taken out from the mold (17).

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