Magnetic steel nickel coating cleaning and drying process

Abstract

The invention relates to the technical field of permanent magnet materials, and discloses a magnetic steel nickel coating cleaning and drying process which comprises the following steps: S1, ultrasonic cleaning: taking ultrapure water as a medium, and putting a magnetic steel material plated with a nickel coating into an ultrasonic cleaning machine for cleaning; s2, bubble cleaning: taking ultrapure water as a medium, and putting the magnetic steel material cleaned in the step S1 into a bubble cleaning machine for cleaning; s3, heating and cleaning: taking a coating self-repairing cleaning solution as a medium, putting the magnetic steel material cleaned in the step S2 into a heating and cleaning tank, and heating and cleaning; s4, dehydration: loading the magnetic steel material cleaned in the step S3 into a dehydrator for dehydration; and S5, drying is conducted, specifically, the magnetic steel material dehydrated in the step S4 is put into a drying box to be heated and dried, active ingredients of the coating self-repairing type cleaning solution comprise perfluoropolyether, nano silane and CeO2 nano particles, and a solvent is ultrapure water. The process can realize batch operation, and is short in time consumption and high in safety.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnetic materials, in particular to a cleaning and drying process for a nickel-plated layer of magnetic steel. Background Art

[0002] Neodymium iron boron (NdFeB), a third-generation rare earth permanent magnet material, has been developed since 1983. Due to its one-step molding, high magnetic energy product, excellent dynamic recovery characteristics and high cost-effectiveness, it is an ideal material for manufacturing high-efficiency, small-sized and light-weight industrial magnetic devices. It has been widely used in information technology, high-end CNC machine tools, robots, new energy vehicles, high-end medical equipment, urban rail transit, energy-saving home appliances and other fields.

[0003] Ultra-thin NdFeB magnets generally refer to products with a thickness of less than 0.4mm. These magnets are primarily used for wireless charging of mobile phones, with high daily shipment demand and extremely high requirements for appearance. After electroplating, the NdFeB magnets undergo multiple water washes. However, during the electroplating and cleaning process, the thin NdFeB magnets are prone to lamination, resulting in water stains and lowering yield. Furthermore, the surface tension of the electroplated product decreases rapidly during inspection due to environmental issues, resulting in dyne levels not meeting standards upon shipment. After rework and electroplating to increase dyne levels, the magnets must be re-inspected due to the poor environment of the electroplating plant. However, the dyne levels decrease again during the inspection process, creating a vicious cycle that severely impacts shipping efficiency and prevents guaranteed results.

[0004] Prior art solutions to the problem of contamination after electroplating cleaning involve soaking the nickel-plated layer in alcohol. For example, patent application number CN114318479B discloses a cleaning process for ultra-thin nickel-plated magnets. The process includes the following steps: S1. Ethanol soaking: soaking the magnet in an ethanol solution; S2. Cleaning: cleaning the soaked magnet with clean water; S3. Centrifuge drying: drying the cleaned magnet in a centrifuge; S4. Ethanol dehydration: soaking the centrifugally dried magnet again in an ethanol solution; and S5. Drying: drying the magnet with hot air. This process removes contamination, water stains, and increases dyne content.

[0005] However, this process involves two alcohol soaks: placing the product on a dust-free cloth, dipping both the product and the cloth into a barrel of alcohol, manually pulling the cloth to clean the product, and then drying it with hot air from a fan after removing it. This solution has the following issues: 1. Due to the limited use of alcohol, only a small number of products can be cleaned at a time, making batch processing impossible. If a product is dirty, it must be returned to the electroplating plant for cleaning, which is time-consuming and impacts production schedules. 2. Manual cleaning is not thorough enough and can only clean slightly soiled products. 3. The alcohol and air drying process poses safety risks. SUMMARY

[0006] The technical problem solved by the present application is that alcohol is used in the existing magnetic steel nickel plating layer cleaning and drying process, which cannot be batched, takes a long time, and has safety hazards.

[0007] The technical solution of the present application is a magnetic steel nickel plating layer cleaning and drying process, comprising the following steps: S1, ultrasonic cleaning: using ultrapure water as a medium, the magnetic steel material plated with a nickel plating layer is placed in an ultrasonic cleaning machine for cleaning; S2, bubble cleaning: using ultrapure water as a medium, the magnetic steel material cleaned in step S1 is placed in a bubble cleaning machine for cleaning; S3, heating cleaning: using a plating self-repairing cleaning solution as a medium, the magnetic steel material cleaned in step S2 is placed in a heating cleaning tank for cleaning; S4, dehydration: the magnetic steel material cleaned in step S3 is loaded into a dehydration machine for dehydration; S5, drying: the magnetic steel material dehydrated in step S4 is placed in a drying oven for heating and drying, The active ingredients of the plating self-repairing cleaning solution include perfluoropolyether, nanosilane and CeO2 nanoparticles, and the solvent is ultrapure water.

[0008] In the above solution, ultrapure water medium is used, ultrasonic cleaning and bubble cleaning are used cooperatively to reduce the adhesion of surface pollutants on the magnetic steel material and its substrate, and heating treatment is used to facilitate the complete shedding of pollutants; then the material is transferred to a dehydration machine to quickly remove free water, and is directly heated and dried to ensure rapid drying of the surface without water stains. This pretreatment process is efficient, safe and can be continuously batched. After the basic cleaning is completed, the material is placed in a plating self-repairing cleaning solution for heating treatment, so that the cleaning solution is left on the surface in a controlled manner; in the subsequent drying stage, the residual liquid undergoes a silane condensation reaction to generate a SiO2-CeO2 composite film in situ at the nickel plating layer defects, and the rare earth elements in the magnetic steel substrate adsorb the oxygen elements in the composite film to form trace rare earth oxides, which together seal the plating pinholes and enhance the density of the plating, thereby effectively reducing pinhole corrosion and ultimately reducing the loss of magnetic flux of the magnetic steel caused by corrosion.

[0009] In one possible implementation, the volume concentration of perfluoropolyether in the plating self-repairing cleaning solution is 3-5 vol%, the mass concentration of nanosilane is 0.5-1.5 wt%, and the mass concentration of CeO2 nanoparticles is 30-100 ppm.

[0010] In a possible embodiment, the preparation method of the coating self-repairing cleaning solution is: directly adding perfluoropolyether, nanosilane, and CeO2 nanoparticles into ultrapure water, and uniformly dispersing them by ultrasonication.

[0011] In the above scheme, perfluoropolyether and ultrapure water can form an aqueous emulsion base liquid, which can well dissolve nanosilane and CeO2 nanoparticles.

[0012] In one possible embodiment, the ultrasonic cleaning in step S1 is performed at a temperature of 40-60° C. and for a time of 2-10 minutes. And / or, the bubbling cleaning temperature in step S2 is 40-60°C and the time is 2-5 minutes, And / or, in step S3, the heating temperature is 75-80° C. and the heating time is 2-5 min.

[0013] In the above scheme, the ultrasonic cleaning temperature is set at 40-60°C and the duration is 2-10 minutes to achieve the best cleaning effect without damaging the magnetic material. If the temperature is too high, the ultrasonic vibration will easily damage the material surface; if the temperature is too low, the ultrasonic wave will not have enough power to destroy the surface dirt and the tightness of the magnetic material. Therefore, determining the appropriate cleaning temperature range and ultrasonic action time are key process parameters.

[0014] The bubbling cleaning temperature is set at 40-60°C and the duration is 2-5 minutes. This is also a comprehensive consideration for cleaning efficiency and preventing damage to the magnetic material. Bubbling cleaning does not vibrate and is gentler than ultrasonic cleaning. It can meet the requirements of reducing the adhesion of dirt while not damaging the nickel plating. After the adhesion of dirt on the nickel plating surface is reduced by ultrasonic vibration, the gentle bubbling method is used to further reduce the adhesion, facilitating the subsequent heating cleaning to remove the dirt.

[0015] A heating temperature of 75-80°C and a time of 2-5 minutes are crucial for the cleaning process of magnetic materials. A heating temperature that is too high will cause the internal temperature of the magnetic material to be too high during the subsequent drying process, affecting product performance and forming water stains. A heating temperature that is too low will cause the internal temperature of the magnetic material to be too low during the subsequent drying process, making it difficult to dry and prone to water stains. This process parameter is the best result obtained from practical experiments.

[0016] In a possible implementation, in step S1, when the maximum single-side dimension of the magnetic steel material is ≤5.0 mm, the ultrasonic cleaning time is 2-5 minutes; when the maximum single-side dimension of the magnetic steel material is >5.0 mm, the ultrasonic cleaning time is 4-10 minutes.

[0017] In the above scheme, for NdFeB or other magnetic steel materials with nickel coating, the operating rules of ultrasonic cleaning can be obtained after many experimental experiences. At a temperature of 40-60℃, the ultrasonic time is longer for large-size products and shorter for small-size products, which can reduce the time consumption while meeting the cleaning effect to be achieved by ultrasound.

[0018] In one possible embodiment, the dehydration in step S4 is specifically as follows: the magnetic steel material cleaned in step S3 is placed in a storage bag, the bag opening is tied so that there is no extra space for the magnetic steel material to move, and then the storage bag containing the magnetic steel material is placed in the dehydration barrel of the dehydrator, and the gap between the storage bag and the dehydration barrel is plugged with a dust-free cloth, and then dehydration is performed.

[0019] In a possible implementation, the storage bag in step S4 is a cotton gauze bag, a polyester mesh bag, or a mesh nylon bag.

[0020] In a possible implementation, the dehydration frequency in step S4 is 30-50 Hz, and the time is 1-3 minutes.

[0021] In the above scheme, this process uses cotton gauze bags, polyester mesh bags or mesh nylon bags to hold magnetic steel materials. The bags made of the above materials are soft, have good water absorption and are easy to tighten and seal. The wrinkles of the fabric can effectively limit the movement space of the magnetic steel materials, ensuring that during the operation of the dehydrator, the materials can not only effectively remove moisture, but also avoid damage to the nickel plating caused by violent collision or rotation. On this basis, the present invention combines the storage bag with the above-mentioned dehydration frequency and dehydration time, which can not only prevent the magnetic steel materials from dispersing and causing collision damage during the dehydration process, but also avoid the magnetic steel materials from being damaged by excessive vibration in the dehydration barrel, and prevent the generation of weak magnetism. After many experiments, the inventors have shown that no weak magnetism is generated at 30-50Hz and a time of 1-3min.

[0022] In a possible implementation, step S5 specifically involves laying the dehydrated magnetic steel material flat into a drying box, controlling the temperature of the drying box at 50-70° C., and drying for 10-20 minutes.

[0023] In the above scheme, the drying temperature is controlled at 50-70°C and the drying time is 10-20 minutes. These are important parameters for rapid drying without leaving water stains. Excessively high drying temperatures affect the product performance of the magnetic material and may result in water stains. Excessively low drying temperatures slow drying, reduce efficiency, and easily result in water stains. Furthermore, flat drying prevents water stains from forming on the laminated magnetic material. Based on this, the present invention utilizes a drying box for drying instead of a fan or hair dryer, resulting in a safer, enclosed drying mode.

[0024] In one possible embodiment, in step S5, when the length×width of the magnetic steel material is less than 18 mm,2 The drying time is 10-15min; when the length × width of the magnetic steel material is ≥18mm 2 The drying time is 15-20min.

[0025] The current ultra-thin NdFeB magnet material size is mostly 18mm 2 According to the commonly used magnetic steel material sizes in the prior art, the present invention provides different drying times, which can be applicable to different magnetic steel material sizes.

[0026] The present invention has the following beneficial effects compared to the prior art: 1. The present invention systematically optimizes the cleaning process of magnetic steel materials: traditional manual cleaning is upgraded to ultrasonic cleaning, which significantly improves cleaning efficiency; ultrapure water is used instead of alcohol as the cleaning medium, which not only eliminates the safety hazards of organic solvents but also meets green environmental protection requirements; at the same time, a drying box is used instead of a hair dryer, further improving process safety.

[0027] 2. The cleaning process of the present invention achieves efficient cleaning through multiple synergistic effects: ultrasonic cleaning uses the cavitation effect to destroy the adsorption of dirt and the magnetic steel surface; bubbling cleaning prevents the re-deposition of pollutants through fluid disturbance; heating cleaning not only removes surface dirt, but also increases the internal temperature of the magnetic steel through heat conduction, thereby accelerating the evaporation of water in the subsequent drying process.

[0028] 3. The cleaning process of the present invention innovatively adopts a composite coating self-repairing cleaning solution, which is composed of perfluoropolyether, nanosilane, CeO2 nanoparticles and ultrapure water. During the cleaning process, the cleaning solution can form a residual liquid containing active ingredients on the surface of the nickel coating of the magnetic steel material, and undergo a phase change during the drying stage: the perfluoropolyether promotes the rapid evaporation of ultrapure water, while the nanosilane and CeO2 nanoparticles form a SiO2-CeO2 composite ceramic film in situ. At the same time, the rare earth elements in the magnetic steel matrix will selectively adsorb the oxygen elements in the composite film to generate trace rare earth oxides, thereby effectively sealing the pinhole defects in the nickel coating, improving the density of the coating, inhibiting the pinhole corrosion phenomenon, and ultimately reducing the magnetic flux loss of the magnetic steel material.

[0029] 4. In the dehydration process, the present invention uses a special tightened gauze bag for physical dehydration. This design has dual advantages: it can ensure that there is no obvious water stain residue on the surface of the magnetic steel, and it can avoid the risk of mechanical damage or breakage of the coating caused by traditional dehydration methods.

[0030] 5. The drying process of the present invention adopts an intelligent control strategy to dynamically adjust the drying time according to the surface area of ​​the magnetic steel material, significantly shortening the operation time while ensuring the dehydration effect, thereby improving the overall production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a cross-sectional SEM image of the magnetic steel material after cleaning in Example 1; Figure 2 for Figure 1 Line scan element distribution in the direction of the arrow in the SEM image; Figure 3 This is the XRD image of the magnetic steel material in Example 1; Figure 4 This is the surface water stain morphology of the magnetic steel material obtained in Comparative Example 1. DETAILED DESCRIPTION

[0032] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only intended to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter ranges described in the present invention. Reasonable variations derived therefrom are still within the scope of protection of the claims of the present invention.

[0033] It should be noted that the endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0034] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventional meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents and instruments was carried out in accordance with the protocols and parameters given by the manufacturers.

[0035] The present invention provides a cleaning and drying process for a nickel-plated layer on magnetic steel, comprising the following steps: S1. Ultrasonic cleaning: Use ultrapure water as the ultrasonic medium and place the nickel-plated magnetic steel material into the ultrasonic cleaning machine for cleaning. The specific operation is: first turn on the main switch of the ultrasonic cleaning machine and the ultrapure water machine, press the power switch button, turn on the heating button, wait for the water temperature to heat to the predetermined temperature between 40-60°C, and then place the magnetic steel material into the slot in the ultrasonic cleaning machine for cleaning. The ultrasonic cleaning machine and ultrapure water machine here do not need to be customized, and machines purchased on the market can be used, such as the Jiemei brand automated ultrasonic cleaning machine. The temperature for ultrasonic cleaning can be 40°C, 45°C, 50°C, 55°C, and 60°C. The time does not need to be too long, and it can be controlled within 2-10 minutes. Generally, when the physical maximum single-side size of the magnetic steel material is ≤5.0mm, the ultrasonic cleaning time is 2-5 minutes; when the physical maximum single-side size of the magnetic steel material is >5.0mm, the ultrasonic cleaning time is 4-10 minutes. Of course, you can also use multiple ultrasonic cleaning machines, adjust the temperature and time parameters, and let the magnetic steel material pass through multiple ultrasonic cleaning machines in turn for cleaning to ensure sufficient ultrasonic degreasing requirements.

[0036] S2, bubbling cleaning: using ultrapure water as the bubbling medium, the magnetic steel material cleaned in step S1 is placed in a bubbling cleaning machine for cleaning. During the entire cleaning process, for the convenience of control, the magnetic steel material can be placed in a mesh basket, and the mesh basket can be pulled up and placed in different cleaning tanks for cleaning. At the same time, the cleaning force can be increased by pulling the mesh basket up and down during the cleaning process. Specifically, the temperature of the bubbling cleaning machine is set to 40-60°C, and the mesh basket taken out of the ultrasonic cleaning machine is placed in the cleaning tank in the bubbling cleaning machine for 2-5 minutes. Similarly, this step can also be refined into the operation of using multiple bubbling cleaning machines for short-term multiple bubbling cleaning, that is, multiple bubbling cleaning machines are set as needed, the temperature and duration are uniformly set, and the magnetic steel material after ultrasonic cleaning is placed in multiple bubbling cleaning machines in turn by pulling the mesh basket for cleaning. In this way, different magnetic steel materials can be cleaned in batches without frequently adjusting the parameters of the bubbling cleaning machine, which is suitable for batch operations. The bubbling cleaning machine here can be any bubbling cleaning machine available on the market, such as the Tianjin Zhongchen brand bubbling cleaning machine.

[0037] S3, heating cleaning: The heating cleaning machine uses a coating self-repairing cleaning liquid as the cleaning medium, and the active ingredients of the coating self-repairing cleaning liquid include perfluoropolyether, nanosilane and CeO2 nanoparticles, and the solvent is ultrapure water. Preferably, the volume concentration of perfluoropolyether in the coating self-repairing cleaning liquid is 3-5vol%, the mass concentration of nanosilane is 0.5-1.5wt%, and the mass concentration of CeO2 nanoparticles is 30-100ppm. Put the magnetic steel material cleaned in step S2 into the heating cleaning machine, pour in the coating self-repairing cleaning liquid, and directly heat it for cleaning. The heating cleaning machine here can be a water tank machine with a heating function on the market, or multiple water tanks can be set in the heating cleaning machine for multiple cleanings. The heating temperature of the heating cleaning machine is 75-80℃, and the cleaning time is 2-5min.

[0038] S4. Dehydration: Place the magnetic steel material cleaned in step S3 into a storage bag and place it in a dehydrator for dehydration. The specific steps are as follows: Place the magnetic steel material cleaned in step S3 into the storage bag, tighten the bag opening to ensure that there is no excess space for the magnetic steel material to move, place it into the dehydration barrel of the dehydrator, and then stuff a dust-free cloth around it. Then, turn on the dehydrator and set the dehydrator frequency to 30-50Hz for 1-3 minutes. The dehydrator here is preferably a small centrifugal dehydrator. The storage bag can be a cotton gauze bag, a polyester mesh bag, or a mesh nylon bag.

[0039] S5, drying: spread the magnetic steel material after dehydration in step S4 flat and put it into the drying box, heat and dry it. The specific steps are: after the oven temperature reaches the preset temperature, pour the magnetic steel material dehydrated in step S4 into the baking tray, spread it flat and quickly move it into the drying box, and heat and dry it until the surface is dry and no water stains remain. The temperature of the drying box is controlled at 50-70℃, the drying time is 10-20min, and when the length × width of the magnetic steel material is less than 18mm 2 The drying time is 10-15min; when the length × width of the magnetic steel material is ≥18mm 2 The drying time is 15-20min.

[0040] S6. Inspection: Place the dried magnetic steel material under light to visually inspect whether there is water stain. If there is water stain, return to steps S1-S5.

[0041] The present invention discloses a cleaning and drying process for the nickel-plated magnetic steel layer. Through a triple cleaning process of ultrasonic cleaning, bubbling cleaning, and heating cleaning, dirt on the surface of the magnetic steel material can be effectively removed by appropriately controlling temperature and time. A dehydration process is added after cleaning and before drying to promptly remove the contaminated medium water. Subsequently, the temperature and time of the drying box are controlled to quickly remove water stains, ensuring the cleanliness of the nickel-plated layer. This process does not require alcohol, a blower, or a fan, and is safe to operate. It is applicable to all nickel-plated magnetic steel materials, can be operated in batches, and is time-efficient.

[0042] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] Clean and dry the nickel coating on the NdFeB magnet material. The maximum physical single-side dimension of the NdFeB magnet material is 4.5mm, with a length × width of 4.5mm × 2.85mm.

[0045] S1. Ultrasonic cleaning: Place the entire package of NdFeB magnets into a mesh basket, place it in the first tank of an ultrasonic cleaning machine with ultrapure water as the medium, control the temperature at 50°C, and clean it for 3 minutes; then lift the mesh basket and place it in the second tank of an ultrasonic cleaning machine, control the temperature at 50°C, and clean it for 3 minutes.

[0046] S2. Bubble cleaning: Three cleaning tanks are set up in the bubble cleaning machine in sequence, namely tank three, tank four, and tank five. Ultrapure water is added to each tank as the cleaning medium. The temperature is set to 50°C. The net basket cleaned in step S1 is lifted and cleaned in tank three, tank four, and tank five in sequence for 3 minutes each.

[0047] S3. Heating and cleaning: A water tank 6 is set in the heating cleaning machine, and the temperature is set to 80°C. The cleaning medium in the water tank 6 is a coating self-repairing cleaning liquid, whose composition is a volume concentration of 3 vol% of perfluoropolyether, a mass concentration of 0.5 wt% of nanosilane, and a mass concentration of 30 ppm of CeO2 nanoparticles. The solvent is ultrapure water. Lift the net basket cleaned in step S2 and put it into the water tank 6 for cleaning for 3 minutes.

[0048] S4. Dehydration: After heating and cleaning, remove the mesh basket and pour the NdFeB magnet material into a cotton gauze bag. Tighten the bag opening to leave no excess space for the NdFeB magnet material to move. Place the bag in the dehydration bucket of the dehydrator and plug the gap with a dust-free cloth. Dehydrate the material until no obvious water droplets remain on the surface of the magnet material. The dehydration frequency is 30Hz and the time is 2 minutes.

[0049] S5. Drying: Preheat the drying box and set the temperature to 70℃. Then pour the dehydrated magnetic steel material into the baking tray of the drying box, spread it out flat and quickly move it into the drying box. Set the timer to 10 minutes.

[0050] S6. Inspection: Place the dried magnetic steel material under the exterior light for visual inspection. If there is no water stain, place the dried product in the designated area.

[0051] The phase and cross-sectional morphology of the dried product obtained in Example 1 were analyzed. Figure 1-3 As shown, from Figure 1 SEM image of the cross section of the magnetic steel and Figure 2It can be seen from the composition analysis that a ceramic phase is formed on the nickel plating layer of the NdFeB magnet material of this application. Figure 3 The XRD pattern of the ceramic phase confirms that it is a SiO2-CeO2 composite ceramic phase. Figure 1 It can also be seen from the SEM image that the nickel plating of the NdFeB magnet material after the cleaning process of this application has better density and no pinholes. Combined with XRD, it can be seen that the rare earth element Nd adsorbs O in the composite ceramic phase to form an Nd2O3 phase that fills the pinholes in the nickel plating, reducing the pinhole corrosion of the nickel plating, thereby reducing the magnetic flux loss of the magnet material.

[0052] Example 2

[0053] Clean and dry the nickel plating of the samarium cobalt magnet material. The maximum physical single-side dimension of the samarium cobalt magnet material is 10.1mm, and the length × width is 10.1mm × 3mm.

[0054] S1. Ultrasonic cleaning: put half a pack of samarium cobalt magnet material into a mesh basket, and place it in the first tank of an ultrasonic cleaning machine with ultrapure water as the medium at a temperature of 50°C for 3 minutes; then lift the mesh basket and place it in the second tank of an ultrasonic cleaning machine at a temperature of 50°C for 3 minutes.

[0055] S2. Bubble cleaning: Three cleaning tanks are set up in the bubble cleaning machine in sequence, namely tank three, tank four, and tank five. Ultrapure water is added to each tank as the cleaning medium. The temperature is set to 50°C. The net basket cleaned in step S1 is lifted and cleaned in tank three, tank four, and tank five in sequence for 3 minutes each.

[0056] S3. Heating and cleaning: A water tank 6 is set in the heating cleaning machine, and the temperature is set to 80°C. The cleaning medium in the water tank 6 is a coating self-repairing cleaning liquid, whose composition is a volume concentration of 5 vol% of perfluoropolyether, a mass concentration of 1.5 wt% of nanosilane, and a mass concentration of 100 ppm of CeO2 nanoparticles. The solvent is ultrapure water. Lift the net basket cleaned in step S2 and put it into the water tank 6 for cleaning for 3 minutes.

[0057] S4. Dehydration: After heating and cleaning, remove the mesh basket and pour the samarium-cobalt magnet material into a cotton gauze bag. Tighten the bag opening to leave no excess space for the samarium-cobalt magnet material to move. Place the bag in the dehydrator's dehydration bucket and seal the gaps with a dust-free cloth. Dehydrate the magnet material until no visible water droplets remain on the surface. The dehydration frequency is 50 Hz and the time is 2 minutes.

[0058] S5. Drying: Preheat the drying box and set the temperature to 70℃. Then pour the dehydrated samarium cobalt magnet material into the baking tray of the drying box, spread it out flat and quickly move it into the drying box. Set the timer to 20 minutes.

[0059] S6. Check the dried samarium-cobalt magnet material under the exterior light for visual inspection. If there is no water stain, place the dried product in the designated area.

[0060] Example 3

[0061] Clean and dry the nickel plating of AlNiCo magnets. The maximum physical single-side dimension of AlNiCo magnets is 6.5mm, with a length × width of 6.5mm × 3.93mm.

[0062] S1. Ultrasonic cleaning: Place half a package of Alnico magnet material into a mesh basket, and place it in the first tank of an ultrasonic cleaning machine with ultrapure water as the medium at a temperature of 50°C for 3 minutes; then lift the mesh basket and place it in the second tank of an ultrasonic cleaning machine at a temperature of 50°C for 3 minutes.

[0063] S2. Bubble cleaning: Three cleaning tanks are set up in the bubble cleaning machine in sequence, namely tank three, tank four, and tank five. Ultrapure water is added to each tank as the cleaning medium. The temperature is set to 50°C. The net basket cleaned in step S1 is lifted and cleaned in tank three, tank four, and tank five in sequence for 3 minutes each.

[0064] S3. Heating and cleaning: A water tank 6 is set in the heating cleaning machine, and the temperature is set to 80°C. The cleaning medium in the water tank 6 is a coating self-repairing cleaning liquid, whose composition is a volume concentration of perfluoropolyether of 4 vol%, a mass concentration of nanosilane of 1 wt%, and a mass concentration of CeO2 nanoparticles of 65 ppm. Lift the net basket cleaned in step S2 and place it in the water tank 6 for cleaning for 3 minutes.

[0065] S4. Dehydration: After heating and cleaning, remove the mesh basket and pour the Alnico magnet material into a cotton gauze bag. Tighten the bag opening to ensure that the Alnico magnet material has no excess space to move. Then, place the cotton gauze bag containing the magnet material into the dehydration bucket of the dehydrator. Use a dust-free cloth to plug the gaps and dehydrate until no obvious water droplets remain on the surface of the magnet material. The dehydration frequency is 40Hz and the time is 2 minutes.

[0066] S5. Drying: Preheat the drying box and set the temperature to 70℃. Then pour the dehydrated magnetic steel material into the baking tray of the drying box, spread it out flat and quickly move it into the drying box. Set the timer for 15 minutes.

[0067] S6. Inspection: Place the dried magnetic steel material under the exterior light for visual inspection. If there is no water stain, place the dried product in the designated area.

[0068] Comparative Example 1 The difference between this comparative example and Example 1 is that the temperature of the drying box is set to 100°C. The magnetic steel material after drying is photographed under the light as shown below. Figure 4As shown in the figure, it can be seen that there are obvious water stains on the surface of the magnetic steel material dried at this temperature.

[0069] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A cleaning and drying process for a magnetic steel nickel coating, characterized in that: The steps include: S1. Ultrasonic cleaning: Use ultrapure water as the medium and put the nickel-plated magnetic steel material into an ultrasonic cleaning machine for cleaning; S2, bubbling cleaning: using ultrapure water as the medium, the magnetic steel material cleaned in step S1 is placed in a bubbling cleaning machine for cleaning; S3, heating and cleaning: using the coating self-repairing cleaning liquid as the medium, the magnetic steel material cleaned in step S2 is placed in a heating and cleaning tank for cleaning; S4, dehydration: the magnetic steel material after cleaning in step S3 is placed in a dehydrator for dehydration; S5, drying: placing the magnetic steel material dehydrated in step S4 into a drying oven for heating and drying; The active ingredients of the coating self-repairing cleaning solution include perfluoropolyether, nanosilane and CeO2 nanoparticles, and the solvent is ultrapure water.

2. The cleaning and drying process for the magnetic steel nickel plating according to claim 1, characterized in that: The volume concentration of perfluoropolyether in the coating self-repairing cleaning solution is 3-5 vol%, the mass concentration of nanosilane is 0.5-1.5 wt%, and the mass concentration of CeO2 nanoparticles is 30-100 ppm.

3. The cleaning and drying process for the magnetic steel nickel plating according to claim 1 or 2, characterized in that: The preparation method of the coating self-repairing cleaning liquid is as follows: perfluoropolyether, nanosilane, and CeO2 nanoparticles are directly added into ultrapure water and uniformly dispersed by ultrasonication.

4. The cleaning and drying process for the magnetic steel nickel plating according to claim 1, characterized in that: The ultrasonic cleaning temperature in step S1 is 40-60°C and the time is 2-10 minutes. And / or, the bubbling cleaning temperature in step S2 is 40-60°C and the time is 2-5 minutes, And / or, in step S3, the heating temperature is 75-80° C. and the heating time is 2-5 min.

5. The cleaning and drying process for the magnetic steel nickel plating according to claim 4, characterized in that: In step S1, when the maximum single side size of the magnetic steel material is ≤5.0 mm, the ultrasonic cleaning time is 2-5 minutes; when the maximum single side size of the magnetic steel material is >5.0 mm, the ultrasonic cleaning time is 4-10 minutes.

6. The cleaning and drying process for the magnetic steel nickel plating according to claim 1, characterized in that: The dehydration in step S4 is specifically as follows: the magnetic steel material cleaned in step S3 is placed in a storage bag, the bag opening is fastened so that there is no extra space for the magnetic steel material to move, and then the storage bag containing the magnetic steel material is placed in the dehydration barrel of the dehydrator, and the gap between the storage bag and the dehydration barrel is plugged with a dust-free cloth, and then dehydration is carried out.

7. The cleaning and drying process for the magnetic steel nickel plating according to claim 6, characterized in that: The storage bag in step S4 is a cotton gauze bag, a polyester mesh bag or a mesh nylon bag.

8. The cleaning and drying process for the magnetic steel nickel plating according to claim 7, characterized in that: The dehydration frequency in step S4 is 30-50 Hz, and the time is 1-3 minutes.

9. The cleaning and drying process for the magnetic steel nickel plating according to claim 1, characterized in that: Step S5 specifically involves laying the magnetic steel material flat into a drying oven, controlling the temperature of the drying oven at 50-70° C., and drying for 10-20 minutes.

10. The cleaning and drying process for the magnetic steel nickel plating according to claim 9, characterized in that: In step S5, when the length x width of the magnetic steel material is less than 18 mm 2 The drying time is 10-15min; when the length × width of the magnetic steel material is ≥18mm 2 The drying time is 15-20min.

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