A method for preparing composite coating on the surface of sintered NdFeB permanent magnet material

Abstract

The invention belongs to the technical field of permanent magnet materials, and specifically is a method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material. The method comprises the following steps: arranging an equipment box, a column, a turntable, a No. 1 motor, a hydraulic cylinder and an immersion tube. The polished permanent magnet is adsorbed on the bottom surface of a cross magnet, the No. 1 motor drives the turntable to rotate, and drives the permanent magnet to rotate to the top of the immersion tube. The hydraulic cylinder pushes the permanent magnet into the interior of the immersion tube, and molten paraffin is poured into the interior of the immersion tube so that the molten paraffin wraps the outer wall of the permanent magnet. After the molten paraffin is cooled and solidified, the hydraulic cylinder drives the permanent magnet to move out of the immersion tube, and the solidified paraffin is peeled off, so that the debris solidified in the paraffin is taken away, thereby realizing the cleaning of the debris, improving the cleanliness of the surface of the permanent magnet, and then improving the subsequent processing quality of the permanent magnet.

Description

Technical Field

[0001] The invention belongs to the technical field of permanent magnetic materials, in particular to a method for preparing a composite coating on the surface of a sintered NdFeB permanent magnetic material. Background Art

[0002] The main components of sintered NdFeB permanent magnet materials are rare earth elements neodymium, iron and boron. Due to its excellent magnetic properties and good performance-price ratio, it is widely used in microwave communications, audio and video, instrumentation, electrical engineering, computers, magnetic separation, magnetic therapy and other fields; there are two main types of protective coatings for permanent magnet materials: one is to add alloy elements to improve the corrosion resistance of the material matrix, and the other is to use effective protective coatings such as metal coatings, organic coatings, and composite coatings.

[0003] A Chinese patent with publication number CN103993302A discloses a method for preparing a sintered NdFeB permanent magnet material with high corrosion resistance. The method adopts the method of placing the sintered NdFeB blank after mechanical processing in a degreasing liquid for surface degreasing; then placing the degreasing product in a sandblasting machine for sandblasting process, then placing the above-mentioned sandblasted product in pure water for ultrasonic cleaning, then subjecting the ultrasonically cleaned product to a phosphating process, then drying and curing the above-mentioned phosphated product after ultrasonic cleaning, placing the magnet on a hanger for coating with a Teflon coating, and finally drying and curing the product coated with the Teflon coating. The sintered NdFeB magnetic material with a phosphating / Teflon composite coating on the surface prepared by the treatment method of the present invention has high corrosion resistance, and its salt spray resistance is particularly outstanding, and compared with other organic coatings, its heat resistance and wear resistance are also partially improved.

[0004] When coating the surface of sintered NdFeB permanent magnets, the surface of the sintered NdFeB permanent magnets needs to be polished. Since sintered NdFeB permanent magnets have strong magnetism and the debris generated by polishing is also magnetic, the debris is adsorbed on the surface of the sintered NdFeB permanent magnets and is difficult to clean, affecting subsequent processing steps.

[0005] To this end, the present invention provides a method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to the present invention, the preparation method comprises the following steps:

[0008] A1: Use a grinder to grind the surface of the sintered NdFeB permanent magnet, and use a chip cleaning device to clean the debris on the surface of the sintered NdFeB permanent magnet to make the surface of the sintered NdFeB permanent magnet smooth and flat;

[0009] A2: Soak the polished sintered NdFeB permanent magnet in a sodium silicate aqueous solution and start ultrasonic cleaning. Then rinse it with deionized water for multiple times to remove the oil stains on the surface of the sintered NdFeB permanent magnet. Then, pickle it with nitric acid solution and activate it with acetic acid solution.

[0010] A3: Mix and stir the cobalt-based alloy powder and the fiber-reinforced material to obtain a metal-based cladding material;

[0011] A4: Mix and stir the silicon carbide powder and the fiber reinforcement material to obtain a ceramic-based cladding material;

[0012] A5: Through the plasma cladding process, a metal-based cladding layer and a ceramic-based cladding layer are sequentially prepared on the surface of the pretreated sintered NdFeB permanent magnet;

[0013] A6: Heat treat the sintered NdFeB permanent magnet after treatment.

[0014] Preferably, the method for using the chip cleaning device in A1 comprises the following steps:

[0015] B1: Adsorb the polished permanent magnet to the bottom surface of the cross magnet;

[0016] B2: Start the No. 1 motor to drive the permanent magnet to rotate to the top of the immersion cylinder, and the hydraulic cylinder pushes the permanent magnet into the interior of the immersion cylinder;

[0017] B3: Pour molten paraffin into the interior of the immersion tube so that the molten paraffin wraps the outer wall of the permanent magnet;

[0018] B4: After the molten paraffin is cooled and solidified, the permanent magnet is removed from the immersion tube, and the solidified paraffin is peeled off, so that the debris solidified inside the paraffin is taken away.

[0019] Preferably, the chip cleaning device comprises an equipment box, a column, a turntable, a No. 1 motor, a hydraulic cylinder and an immersion cylinder; a column is fixedly connected to the middle part of the top surface of the equipment box, a No. 1 motor is fixedly connected to the top of the column, a turntable is rotatably installed on the top of the column, the top end of the rotating shaft of the No. 1 motor is fixedly connected to the middle bottom surface of the turntable, a plurality of hydraulic cylinders are fixedly connected to the outer ring of the top surface of the turntable, the piston rod of the hydraulic cylinder slides through the turntable, the bottom end of the piston rod of the hydraulic cylinder is fixedly connected to a cross magnet, a permanent magnet is adsorbed on the bottom surface of the cross magnet, an immersion cylinder is fixedly connected to one side of the outer ring of the top surface of the equipment box, and molten paraffin is filled inside the immersion cylinder; the top view of the cross magnet is cross-shaped, and when the cross magnet adsorbs the permanent magnet, it not only reduces the contact between the cross magnet and the permanent magnet The contact area reduces the probability of debris being clamped by the cross magnet and the permanent magnet and causing debris residue, and the cross shape of the cross magnet improves the strength of adsorption to the permanent magnet; when working, the permanent magnet after grinding is adsorbed to the bottom surface of the cross magnet, and the No. 1 motor drives the turntable to rotate, driving the hydraulic cylinder to rotate, so that the permanent magnet rotates to the top of the immersion cylinder, and the hydraulic cylinder pushes the permanent magnet into the interior of the immersion cylinder, and pours molten paraffin into the interior of the immersion cylinder, so that the molten paraffin wraps the outer wall of the permanent magnet. After the molten paraffin is cooled and solidified, the hydraulic cylinder drives the permanent magnet to move out of the immersion cylinder, peels off the solidified paraffin, and takes away the debris solidified in the paraffin, thereby realizing the cleaning of the debris, improving the cleanliness of the permanent magnet surface, and then improving the subsequent processing quality of the permanent magnet.

[0020] Preferably, a storage box is fixedly connected to the inner bottom surface of the equipment box, and the interior of the storage box is filled with molten paraffin. A heating pipe is arranged inside the side wall of the storage box, and a hot melt adhesive pump is bolted to the side of the inner bottom surface of the equipment box close to the immersion cylinder. The inlet end pipe of the hot melt adhesive pump is connected to the bottom of the storage box, and the outlet end pipe of the hot melt adhesive pump is connected to the bottom of the immersion cylinder. When working, the heating pipe keeps the internal temperature of the storage box in a constant temperature state, so that the paraffin inside the storage box always remains in a molten state. After the hydraulic cylinder pushes the permanent magnet into the interior of the immersion cylinder, the hot melt adhesive pump pumps the molten paraffin inside the storage box into the interior of the immersion cylinder, thereby reducing the workload of the staff to manually add paraffin and improving the work efficiency of the staff.

[0021] Preferably, a chip removal cylinder is fixedly connected to the other side of the outer ring of the top surface of the equipment box, and a rotating drum is rotatably installed inside the chip removal cylinder. The rotating drum rotates and penetrates the top wall of the equipment box, and the bottom end of the rotating drum rotates with the top surface of the storage box, and the inner ring of the rotating drum is connected to the interior of the storage box. A plurality of wire brushes are fixedly connected to the top inner wall of the rotating drum, and a gear ring is fixedly connected to the bottom outer ring of the rotating drum. A No. 2 motor is fixedly connected to the internal top side of the equipment box, and a gear is fixedly connected to the rotating shaft of the No. 2 motor, and the gear is meshed with the gear ring. A partition is fixedly connected to the side of the top of the storage box close to the rotating drum, and a through groove is opened in the middle of the side wall of the partition; the wire brush is made of stainless steel wire and is not magnetic; when working, the molten paraffin After cooling and solidification, the hydraulic cylinder drives the permanent magnet to move out of the immersion cylinder, and the No. 1 motor drives the turntable to rotate, so that the permanent magnet wrapped in paraffin moves to the top of the drum, and the hydraulic cylinder pushes the permanent magnet wrapped in paraffin into the interior of the drum. The No. 2 motor drives the gear to rotate, driving the gear ring to rotate, so that the drum rotates, driving the wire brush to scrape the outer wall of the permanent magnet, and clean the paraffin on the outer wall of the permanent magnet. The cleaned paraffin falls into the inner top surface of the partition, and the paraffin is heated and melted again to release the debris wrapped in the paraffin. The debris is precipitated on the inner bottom surface of the partition, and the clean molten paraffin on the top of the partition flows back to the bottom of the storage box through the groove; the workload of the staff to peel off the solidified paraffin is reduced, and the recycling rate of the paraffin is improved.

[0022] Preferably, spiral water holes are opened around the inside of the immersion cylinder, and both ends of the spiral water holes are connected to a cooling water tank by pipes, and the cooling water tank is provided with a water pump; when working, the hot melt adhesive pump pumps the molten paraffin inside the storage tank into the inside of the immersion cylinder, and after the molten paraffin wraps the permanent magnet, the cooling water inside the cooling water tank is pumped into the inside of the spiral water holes under the action of the water pump, thereby improving the cooling rate of the immersion cylinder and then improving the efficiency of cleaning debris.

[0023] Preferably, an elastic rod is fixedly connected around the inner wall of the top of the rotating drum, the elastic rod and the wire brush are staggered, and a rubber ball is fixedly connected to the end of the elastic rod, and the outer wall of the rubber ball is slidably matched with the outer wall of the permanent magnet; when working, the rotation of the rotating drum drives the wire brush to scrape the outer wall of the permanent magnet, and at the same time drives the rubber ball to hit the outer wall of the permanent magnet, so that the elastic rod bends, and the solidified paraffin on the outer wall of the permanent magnet is broken, so that the broken paraffin falls off from the surface of the permanent magnet, thereby improving the shedding efficiency of the solidified paraffin.

[0024] Preferably, a steel ball is fixedly connected to the inside of the rubber ball, and a plurality of thorns are fixedly connected to the outer wall of the steel ball, and the thorns slide through the outer wall of the rubber ball; during operation, when the rubber ball hits the outer wall of the permanent magnet, the thorns slide out from the inside of the rubber ball, thereby increasing the impact force on the solidified paraffin and improving the crushing rate of the solidified paraffin.

[0025] Preferably, a plurality of horizontal knives are fixedly connected around the inner wall of the bottom of the rotating drum, and the plurality of horizontal knives are distributed in a staggered manner; during operation, when the paraffin fragments falling along the rotating drum pass through the horizontal knives, the rotating horizontal knives cut the large pieces of paraffin into pieces, thereby improving the degree of crushing of the paraffin fragments entering the storage box, thereby improving the melting rate of the paraffin fragments.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. A method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to the present invention comprises the following steps: arranging an equipment box, a column, a turntable, a No. 1 motor, a hydraulic cylinder and an immersion cylinder; the polished permanent magnet is adsorbed to the bottom surface of a cross magnet, the No. 1 motor drives the turntable to rotate, and drives the permanent magnet to rotate to the top of the immersion cylinder, the hydraulic cylinder pushes the permanent magnet into the interior of the immersion cylinder, and molten paraffin is poured into the interior of the immersion cylinder so that the molten paraffin wraps the outer wall of the permanent magnet, and after the molten paraffin is cooled and solidified, the hydraulic cylinder drives the permanent magnet to move out of the immersion cylinder, peels off the solidified paraffin, and takes away the debris solidified in the paraffin, thereby realizing the cleaning of the debris, improving the cleanliness of the surface of the permanent magnet, and then improving the subsequent processing quality of the permanent magnet.

[0028] 2. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material described in the present invention comprises the following steps: a rotating drum, a wire brush, a gear ring, a second motor, a gear, an elastic rod and a rubber ball are arranged; after the molten paraffin is cooled and solidified, the hydraulic cylinder drives the permanent magnet to move out of the immersion cylinder, the turntable rotates, so that the permanent magnet wrapped in paraffin moves to the top of the rotating drum, the hydraulic cylinder pushes the permanent magnet wrapped in paraffin into the interior of the rotating drum, the second motor drives the rotating drum through the gear and the gear ring, drives the rubber ball to hit the outer wall of the permanent magnet, causes the elastic rod to bend, breaks the solidified paraffin on the outer wall of the permanent magnet, causes the broken paraffin to fall off from the surface of the permanent magnet, and the paraffin falls into the inner top surface of the partition, the paraffin is heated and melted again, and the debris wrapped in the paraffin is released, and the debris is precipitated on the inner bottom surface of the partition, and the clean molten paraffin on the top of the partition flows back to the bottom of the storage box through the groove; the workload of the staff in peeling off the solidified paraffin is reduced, and the recycling rate of the paraffin is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 is a three-dimensional diagram of the first embodiment of the present invention;

[0031] Figure 2 is a cross-sectional view of the first embodiment of the present invention;

[0032] Figure 3 yes Figure 2 A partial enlarged view of the middle part;

[0033] Figure 4 yes Figure 3 A partial enlarged view of point B in the middle;

[0034] Figure 5 is a partial cross-sectional view of a partition plate according to a second embodiment of the present invention;

[0035] Figure 6 is a flow chart of the preparation method of the present invention;

[0036] Figure 7 It is a flow chart of the method for using the chip cleaning device of the present invention;

[0037] In the figure: 1. Equipment box; 2. Column; 3. Turntable; 4. Motor No. 1; 5. Hydraulic cylinder; 6. Immersion cylinder; 7. Permanent magnet; 8. Storage box; 9. Heating tube; 10. Hot melt adhesive pump; 11. Chip removal cylinder; 12. Rotating cylinder; 13. Wire brush; 14. Gear ring; 15. Motor No. 2; 16. Gear; 17. Partition; 18. Spiral water hole; 19. Elastic rod; 20. Rubber ball; 21. Steel ball; 22. Spike; 23. Horizontal knife; 24. Support plate; 25. Magnetic rod; 26. Rubber sleeve; 27. Cross magnet. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0039] Embodiment 1

[0040] like Figure 6 As shown, a method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to an embodiment of the present invention comprises the following steps:

[0041] A1: Use a grinder to grind the surface of the sintered NdFeB permanent magnet, and use a chip cleaning device to clean the debris on the surface of the sintered NdFeB permanent magnet to make the surface of the sintered NdFeB permanent magnet smooth and flat;

[0042] A2: Soak the polished sintered NdFeB permanent magnet in a sodium silicate aqueous solution and start ultrasonic cleaning. Then rinse it with deionized water for multiple times to remove the oil stains on the surface of the sintered NdFeB permanent magnet. Then, pickle it with nitric acid solution and activate it with acetic acid solution.

[0043] A3: Mix and stir the cobalt-based alloy powder and the fiber-reinforced material to obtain a metal-based cladding material;

[0044] A4: Mix and stir the silicon carbide powder and the fiber reinforcement material to obtain a ceramic-based cladding material;

[0045] A5: Through the plasma cladding process, a metal-based cladding layer and a ceramic-based cladding layer are sequentially prepared on the surface of the pretreated sintered NdFeB permanent magnet;

[0046] A6: Heat treat the sintered NdFeB permanent magnet after treatment.

[0047] like Figure 7 As shown, the method for using the chip cleaning device described in A1 includes the following steps:

[0048] B1: Adsorbing the polished permanent magnet 7 to the bottom surface of the cross magnet 27;

[0049] B2: Start the No. 1 motor 4 to drive the permanent magnet 7 to rotate to the top of the immersion tube 6, and the hydraulic cylinder 5 pushes the permanent magnet 7 into the interior of the immersion tube 6;

[0050] B3: Pour molten paraffin into the interior of the immersion tube 6 so that the molten paraffin wraps the outer wall of the permanent magnet 7;

[0051] B4: After the molten paraffin is cooled and solidified, the permanent magnet 7 is removed from the immersion tube 6, and the solidified paraffin is peeled off, so that the debris solidified inside the paraffin is taken away.

[0052] like Figure 1 to Figure 2As shown, the chip cleaning device includes an equipment box 1, a column 2, a turntable 3, a No. 1 motor 4, a hydraulic cylinder 5 and an immersion cylinder 6; a column 2 is fixedly connected to the middle part of the top surface of the equipment box 1, a No. 1 motor 4 is fixedly connected to the top of the column 2, a turntable 3 is rotatably installed on the top of the column 2, the top end of the rotating shaft of the No. 1 motor 4 is fixedly connected to the middle bottom surface of the turntable 3, a plurality of hydraulic cylinders 5 are fixedly connected to the outer ring of the top surface of the turntable 3, the piston rod of the hydraulic cylinder 5 slides through the turntable 3, the bottom end of the piston rod of the hydraulic cylinder 5 is fixedly connected to a cross magnet 27, the bottom surface of the cross magnet 27 is adsorbed with a permanent magnet 7, an immersion cylinder 6 is fixedly connected to one side of the outer ring of the top surface of the equipment box 1, and the interior of the immersion cylinder 6 is filled with molten paraffin; the top view of the cross magnet 27 is cross-shaped, and when the cross magnet 27 adsorbs the permanent magnet 7, it not only reduces the cross magnet 27 and the permanent magnet The contact area between 7 reduces the probability of debris being clamped by the cross magnet 27 and the permanent magnet 7 and causing debris residue, and the cross shape of the cross magnet 27 increases the strength of the adsorption of the permanent magnet 7; during operation, the permanent magnet 7 after grinding is adsorbed to the bottom surface of the cross magnet 27, and the No. 1 motor 4 drives the turntable 3 to rotate, driving the hydraulic cylinder 5 to rotate, so that the permanent magnet 7 rotates to the top of the immersion tube 6, and the hydraulic cylinder 5 pushes the permanent magnet 7 into the interior of the immersion tube 6, and pours molten paraffin into the interior of the immersion tube 6, so that the molten paraffin wraps the outer wall of the permanent magnet 7. After the molten paraffin is cooled and solidified, the hydraulic cylinder 5 drives the permanent magnet 7 to move out of the immersion tube 6, peels off the solidified paraffin, and takes away the debris solidified in the paraffin, thereby realizing the cleaning of the debris, improving the cleanliness of the surface of the permanent magnet 7, and then improving the subsequent processing quality of the permanent magnet 7.

[0053] like Figure 2 As shown, a storage box 8 is fixedly connected to the inner bottom surface of the equipment box 1, and the interior of the storage box 8 is filled with molten paraffin. A heating pipe 9 is arranged inside the side wall of the storage box 8. A hot melt adhesive pump 10 is bolted to the side of the inner bottom surface of the equipment box 1 close to the immersion cylinder 6. The inlet end pipe of the hot melt adhesive pump 10 is connected to the bottom of the storage box 8, and the outlet end pipe of the hot melt adhesive pump 10 is connected to the bottom of the immersion cylinder 6. When working, the heating pipe 9 keeps the internal temperature of the storage box 8 in a constant temperature state, so that the paraffin inside the storage box 8 always remains in a molten state. After the hydraulic cylinder 5 pushes the permanent magnet 7 into the interior of the immersion cylinder 6, the hot melt adhesive pump 10 pumps the molten paraffin inside the storage box 8 into the interior of the immersion cylinder 6, thereby reducing the workload of the staff to manually add paraffin and improving the work efficiency of the staff.

[0054] like Figures 2 to 3As shown, a chip removal cylinder 11 is fixedly connected to the other side of the outer ring of the top surface of the equipment box 1, and a rotating drum 12 is rotatably installed inside the chip removal cylinder 11. The rotating drum 12 rotates and penetrates the top wall of the equipment box 1, and the bottom end of the rotating drum 12 rotates with the top surface of the storage box 8, and the inner ring of the rotating drum 12 is connected to the interior of the storage box 8. A plurality of wire brushes 13 are fixedly connected to the top inner wall of the rotating drum 12, and a gear ring 14 is fixedly connected to the bottom outer ring of the rotating drum 12. A No. 2 motor 15 is fixedly connected to the internal top side of the equipment box 1, and a gear 16 is fixedly connected to the rotating shaft of the No. 2 motor 15, and the gear 16 is meshed with the gear ring 14. A partition 17 is fixedly connected to the side of the top of the storage box 8 close to the rotating drum 12, and a through groove is opened in the middle of the side wall of the partition 17; the wire brush 13 is made of stainless steel wire and is not magnetic; working When the molten paraffin is cooled and solidified, the hydraulic cylinder 5 drives the permanent magnet 7 to move out of the immersion cylinder 6, and the No. 1 motor 4 drives the turntable 3 to rotate, so that the permanent magnet 7 wrapped in paraffin moves to the top of the rotating drum 12, and the hydraulic cylinder 5 pushes the permanent magnet 7 wrapped in paraffin into the interior of the rotating drum 12, and the No. 2 motor 15 drives the gear 16 to rotate, driving the gear ring 14 to rotate, so that the rotating drum 12 rotates, driving the wire brush 13 to scrape the outer wall of the permanent magnet 7, and clean the paraffin on the outer wall of the permanent magnet 7, and the cleaned and fallen paraffin falls into the inner top surface of the partition 17, and the paraffin is heated and melted again, releasing the debris wrapped in the paraffin, and the debris is precipitated on the inner bottom surface of the partition 17, and the clean molten paraffin on the top of the partition 17 flows back to the bottom of the storage box 8 through the groove; the workload of the staff to peel off the solidified paraffin is reduced, and the recycling rate of the paraffin is improved.

[0055] like Figure 2 As shown, a spiral water hole 18 is opened around the inside of the immersion cylinder 6, and both ends of the spiral water hole 18 are connected to a cooling water tank by pipes. The cooling water tank is provided with a water pump. When working, the hot melt adhesive pump 10 pumps the molten paraffin in the storage box 8 into the inside of the immersion cylinder 6. After the molten paraffin wraps the permanent magnet 7, the cooling water in the cooling water tank is pumped into the inside of the spiral water hole 18 under the action of the water pump, thereby improving the cooling rate of the immersion cylinder 6 and then improving the efficiency of cleaning debris.

[0056] like Figures 2 to 3 As shown, an elastic rod 19 is fixedly connected around the inner wall of the top of the rotating drum 12, and the elastic rod 19 and the wire brush 13 are staggered. A rubber ball 20 is fixedly connected to the end of the elastic rod 19, and the outer wall of the rubber ball 20 is slidably matched with the outer wall of the permanent magnet 7; when working, the rotating drum 12 rotates to drive the wire brush 13 to scrape the outer wall of the permanent magnet 7, and at the same time drives the rubber ball 20 to hit the outer wall of the permanent magnet 7, so that the elastic rod 19 bends, and the solidified paraffin on the outer wall of the permanent magnet 7 is broken, so that the broken paraffin falls off from the surface of the permanent magnet 7, thereby improving the efficiency of the solidified paraffin falling off.

[0057] like Figure 4As shown, a steel ball 21 is fixedly connected to the inside of the rubber ball 20, and a plurality of thorns 22 are fixedly connected to the outer wall of the steel ball 21. The thorns 22 slide through the outer wall of the rubber ball 20. When the rubber ball 20 hits the outer wall of the permanent magnet 7 during operation, the thorns 22 slide out from the inside of the rubber ball 20, thereby increasing the impact force on the solidified paraffin and improving the crushing rate of the solidified paraffin.

[0058] like Figure 2 As shown, a plurality of transverse knives 23 are fixedly connected around the inner wall of the bottom of the rotating drum 12, and the plurality of transverse knives 23 are staggeredly distributed around; during operation, when the paraffin fragments falling along the rotating drum 12 pass through the transverse knives 23, the rotating transverse knives 23 cut the large pieces of paraffin into pieces, thereby improving the degree of crushing of the paraffin fragments entering the storage box 8, thereby improving the melting rate of the paraffin fragments.

[0059] Embodiment 2

[0060] like Figure 5 As shown, compared with Example 1, another implementation of the present invention is: the inner bottom surface of the partition 17 is bolted with a support plate 24, the top surface of the support plate 24 is fixedly connected with a plurality of magnetic rods 25, and the outer wall of the magnetic rods 25 is bonded with a rubber sleeve 26; when working, the solidified paraffin is heated and melted again inside the partition 17, and the debris wrapped inside the paraffin is released. The debris is attracted by the magnetic rods 25 and adsorbed to the surface of the rubber sleeve 26, thereby improving the cleanliness of the molten paraffin inside the storage box 8. At the same time, it is convenient for the staff to clean out the debris later, thereby improving the work efficiency of the staff.

[0061] During operation: the surface of the sintered NdFeB permanent magnet is polished by a polishing machine, and the polished permanent magnet 7 is adsorbed to the bottom surface of the cross magnet 27. The No. 1 motor 4 drives the turntable 3 to rotate, driving the hydraulic cylinder 5 to rotate, so that the permanent magnet 7 rotates to the top of the immersion tube 6, and the hydraulic cylinder 5 pushes the permanent magnet 7 into the interior of the immersion tube 6; the heating tube 9 keeps the internal temperature of the storage box 8 at a constant temperature, so that the paraffin inside the storage box 8 always remains in a molten state. After the hydraulic cylinder 5 pushes the permanent magnet 7 into the interior of the immersion tube 6, the hot melt adhesive pump 10 pumps the molten paraffin inside the storage box 8 into the interior of the immersion tube 6, so that the molten paraffin wraps the outer wall of the permanent magnet 7; the cooling water inside the cooling water tank is pumped into the interior of the spiral water hole 18 under the action of the water pump, thereby increasing the cooling rate of the immersion tube 6;

[0062] After the molten paraffin is cooled and solidified, the hydraulic cylinder 5 drives the permanent magnet 7 to move out of the immersion cylinder 6, and the No. 1 motor 4 drives the turntable 3 to rotate, so that the permanent magnet 7 wrapped in paraffin moves to the top of the rotating drum 12, and the hydraulic cylinder 5 pushes the permanent magnet 7 wrapped in paraffin into the interior of the rotating drum 12. The No. 2 motor 15 drives the gear 16 to rotate, driving the gear ring 14 to rotate, so that the rotating drum 12 rotates, driving the rubber ball 20 to hit the outer wall of the permanent magnet 7, so that the elastic rod 19 bends, and the solidified paraffin on the outer wall of the permanent magnet 7 is broken, so that the broken paraffin is removed from the permanent magnet 7. The surface of the magnet 7 falls off, and at the same time, the wire brush 13 is driven to scrape the outer wall of the permanent magnet 7, and the paraffin on the outer wall of the permanent magnet 7 is cleaned, and the cleaned paraffin falls into the inner top surface of the partition 17, and the paraffin is heated and melted again, and the debris wrapped inside the paraffin is released, and the debris is precipitated on the inner bottom surface of the partition 17, and the clean molten paraffin on the top of the partition 17 flows back to the bottom of the storage box 8 through the groove; thereby, the debris cleaning work is achieved, the cleanliness of the surface of the permanent magnet 7 is improved, and then the subsequent processing quality of the permanent magnet 7 is improved;

[0063] The polished sintered NdFeB permanent magnet is immersed in a sodium silicate aqueous solution, and ultrasonic cleaning is started, and then it is rinsed with deionized water for multiple times to remove oil stains on the surface of the sintered NdFeB permanent magnet, and then the sintered NdFeB permanent magnet is pickled with a nitric acid solution and activated with an acetic acid solution; the cobalt-based alloy powder and the fiber-reinforced material are mixed and stirred evenly to obtain a metal-based cladding material; the silicon carbide powder and the fiber-reinforced material are mixed and stirred evenly to obtain a ceramic-based cladding material; through a plasma cladding process, a metal-based cladding layer and a ceramic-based cladding layer are sequentially prepared on the surface of the pretreated sintered NdFeB permanent magnet; the treated sintered NdFeB permanent magnet is heat treated; and the composite coating preparation of the sintered NdFeB permanent magnet is completed.

[0064] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0065] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material, characterized in that: The preparation method comprises the following steps: A1: Use a grinder to grind the surface of the sintered NdFeB permanent magnet, and use a chip cleaning device to clean the debris on the surface of the sintered NdFeB permanent magnet to make the surface of the sintered NdFeB permanent magnet smooth and flat; A2: Soak the polished sintered NdFeB permanent magnet in a sodium silicate aqueous solution and start ultrasonic cleaning. Then rinse it with deionized water for multiple times to remove the oil stains on the surface of the sintered NdFeB permanent magnet. Then, pickle it with nitric acid solution and activate it with acetic acid solution. A3: Mix and stir the cobalt-based alloy powder and the fiber-reinforced material to obtain a metal-based cladding material; A4: Mix and stir the silicon carbide powder and the fiber reinforcement material to obtain a ceramic-based cladding material; A5: Through the plasma cladding process, a metal-based cladding layer and a ceramic-based cladding layer are sequentially prepared on the surface of the pretreated sintered NdFeB permanent magnet; A6: Heat treatment is performed on the sintered NdFeB permanent magnet after treatment; The method for using the chip cleaning device described in A1 comprises the following steps: B1: Adsorbing the polished permanent magnet (7) to the bottom surface of the cross magnet (27); B2: Start the No. 1 motor (4), drive the permanent magnet (7) to rotate to the top of the immersion cylinder (6), and the hydraulic cylinder (5) pushes the permanent magnet (7) into the interior of the immersion cylinder (6); B3: pouring molten paraffin into the interior of the immersion tube (6) so that the molten paraffin wraps around the outer wall of the permanent magnet (7); B4: After the molten paraffin is cooled and solidified, the permanent magnet (7) is removed from the immersion tube (6), and the solidified paraffin is peeled off, so that the debris solidified inside the paraffin is taken away; The chip cleaning device comprises an equipment box (1), a column (2), a turntable (3), a No. 1 motor (4), a hydraulic cylinder (5) and an immersion cylinder (6); the column (2) is fixedly connected to the middle of the top surface of the equipment box (1), the No. 1 motor (4) is fixedly connected to the top of the column (2), the turntable (3) is rotatably mounted on the top of the column (2), the top of the rotating shaft of the No. 1 motor (4) is fixedly connected to the middle bottom surface of the turntable (3), a plurality of hydraulic cylinders (5) are fixedly connected to the outer ring of the top surface of the turntable (3), the piston rods of the hydraulic cylinders (5) slide through the turntable (3), the bottom ends of the piston rods of the hydraulic cylinders (5) are fixedly connected to a cross magnet (27), the bottom surface of the cross magnet (27) is adsorbed with a permanent magnet (7), the immersion cylinder (6) is fixedly connected to one side of the outer ring of the top surface of the equipment box (1), and the interior of the immersion cylinder (6) is filled with molten paraffin.

2. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 1, characterized in that: The internal bottom surface of the equipment box (1) is fixedly connected to a storage box (8), the interior of the storage box (8) is filled with molten paraffin, a heating pipe (9) is arranged inside the side wall of the storage box (8), and a hot melt adhesive pump (10) is bolted to the side of the internal bottom surface of the equipment box (1) close to the immersion cylinder (6), the inlet end pipeline of the hot melt adhesive pump (10) is connected to the bottom of the storage box (8), and the outlet end pipeline of the hot melt adhesive pump (10) is connected to the bottom of the immersion cylinder (6).

3. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 2, characterized in that: A chip removal cylinder (11) is fixedly connected to the other side of the outer ring of the top surface of the equipment box (1), and a rotating cylinder (12) is rotatably installed inside the chip removal cylinder (11). The rotating cylinder (12) rotates and penetrates the top wall of the equipment box (1). The bottom end of the rotating cylinder (12) is rotatably matched with the top surface of the storage box (8), and the inner ring of the rotating cylinder (12) is connected to the inside of the storage box (8). A plurality of steel brushes (13) are fixedly connected to the top inner wall of the rotating cylinder (12). A gear ring (14) is fixedly connected to the bottom outer ring of the rotating cylinder (12). A No. 2 motor (15) is fixedly connected to the top side of the interior of the equipment box (1), and a gear (16) is fixedly connected to the rotating shaft of the No. 2 motor (15). The gear (16) meshes with the gear ring (14). A partition (17) is fixedly connected to the top of the storage box (8) on one side close to the rotating cylinder (12), and a through groove is opened in the middle of the side wall of the partition (17).

4. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 1, characterized in that: The interior of the immersion cylinder (6) is provided with a spiral water hole (18) around it, and both ends of the spiral water hole (18) are connected to a cooling water tank through pipes, and the cooling water tank is provided with a water pump.

5. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 3, characterized in that: An elastic rod (19) is fixedly connected around the inner wall of the top of the rotating drum (12), the elastic rod (19) and the wire brush (13) are arranged in an alternating manner, a rubber ball (20) is fixedly connected to the end of the elastic rod (19), and the outer wall of the rubber ball (20) is slidably matched with the outer wall of the permanent magnet (7).

6. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 5, characterized in that: A steel ball (21) is fixedly connected to the interior of the rubber ball (20), and a plurality of thorns (22) are fixedly connected to the outer wall of the steel ball (21), wherein the thorns (22) slide through the outer wall of the rubber ball (20).

7. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 3, characterized in that: A plurality of transverse knives (23) are fixedly connected around the inner wall of the bottom of the rotating drum (12), and the plurality of transverse knives (23) are distributed in a staggered manner around the rotating drum.

8. The method for preparing a composite coating on the surface of a sintered NdFeB permanent magnet material according to claim 3, characterized in that: A support plate (24) is bolted to the inner bottom surface of the partition (17), a plurality of magnetic rods (25) are fixed to the top surface of the support plate (24), and a rubber sleeve (26) is bonded to the outer wall of the magnetic rod (25).

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