New technology, new process and new formula of surface treatment of neodymium iron boron permanent magnet in 2023

In recent years, with the rapid development of new technology of sintered NdFeB magnetic materials, China’s NdFeB magnetic materials surface treatment technology has made gratifying achievements, many excellent technologies to reach or exceed the level of internationally developed countries. For example, the latest development of the Chinese Academy of Sciences, the international leading formula, can greatly improve the NdFeB coating blackening liquid and organic coating formula, the new formula surface generated oxide film, resistance to neutral salt spray corrosion up to 600h, no electroplating chemical plating pollution.

This album contains selected domestic and foreign surface treatments of NdFeB permanent magnet materials on the latest technology formula technical information. Involving famous companies at home and abroad, scientific research units, well-known enterprises of the latest patented technology full-text information, process formulations detailed, high technology content, environmental protection is engaged in high-performance, high-quality, product processing research and production units to improve product quality, the development of new products is an important information material.

1. Fill in the gaps in the country: for neodymium-iron-boron permanent magnet materials without chrome zinc coating surface treatment method
The surface of NdFeB permanent magnet material is polished by roller grinding and chamfering method; the polished NdFeB permanent magnet material is degreased and de-oiled by using the mixed degreasing solution of sodium phosphate, sodium carbonate, and sodium hydroxide; the NdFeB permanent magnet material is acid-washed and de-rusted by using rust remover and nitric acid solution; and the surface of the NdFeB permanent magnet material is dipped, sprayed or brushed using the chromium-free zinc-aluminum solution; the chromium-free zinc-aluminum coating adopts water-based coating, which does not use organic solvent and does not have any chromium content. The research and application of chromium-free zinc and aluminum coating on NdFeB permanent magnet materials fills a gap in the surface treatment industry of domestic permanent magnet materials and greatly improves the anticorrosion performance of the materials.
2. Decoating solution and decoating method for NdFeB magnet surface coating and its application
The deprocessing solution includes a solvent, selected from water and organic solvents that are miscible with water; a solute, a deprocessing method, by vibration deprocessing, and after adding a small amount of the above deprocessing solution, deprocessing of the surface of the workpiece can be accomplished under the state of low alkaline concentration at room temperature. The annealing solution and the annealing method have a wide range of applicability, good and efficient annealing effect, and the low concentration room temperature annealing has less impact on the magnet, the operator, and the environment. Yantai Zhenghai Magnetic Material Co.
3. Anti-corrosion treatment method for NdFeB permanent magnets
Said anti-corrosion treatment method is using powder hot-dip zincing, comprising the following steps: pre-treatment of the substrate → zincing → post-treatment of zincing, wherein said zincing agent added in said zincing step does not contain any chloride ion. Said zincizing agent comprises a mixture of zinc powder and rare earth powder. As a result of the above technical solution, the sintered neodymium-iron-boron permanent magnet treated by the anti-corrosion treatment method has a uniform and dense zinc-diffusion layer, good anti-corrosion performance, and no loss to the magnet, and can be used continuously. Tianjin Sanhuan Lexi New Material Co., Ltd; Beijing Zhongke Sanhuan High-Tech Co.
4. Coating, NdFeB magnets, and their preparation methods and applications
The surface of the magnet contains a coating, which not only improves the disadvantage of lower corrosion resistance due to its large pores but also improves the overall corrosion resistance of the magnet, insulation, good thickness consistency, good corrosion resistance, and bonding with the magnet and magnet groove. Yantai Zhenghai Magnetic Material Co., Ltd; Nantong Zhenghai Magnetic Material Co.
5. Preparation method of supersonic flame thermal spray coating on the surface of NdFeB magnet
Steps: preparation of spraying material, pretreatment of magnet surface, preparation of thermal spray coating, and heat treatment process of the coated magnet. The adopted supersonic flame thermal spraying technology has the advantages of environmental friendliness and high efficiency. It is one of the most competitive thermal spraying technologies to replace the traditional wet plating process, which has the advantages of fast flame flow rate, long flame flow, small diameter shrinkage, high powder kinetic energy, and energy density, which makes the coating present dense, few oxides and unmelted particles, low porosity, high bonding strength, and good processing performance. Therefore, the protective coating prepared on the surface of NdFeB magnets by supersonic flame thermal spraying technology has excellent comprehensive performance, with lower coating porosity, higher hardness, stronger abrasion resistance, and more durable corrosion resistance, which significantly improves the service life of NdFeB magnets. North Mining Magnetic Materials (Fuyang) Co.
6. Anti-oxidation adhesive for sintered NdFeB coated with hydride and its application
The anti-oxidation type adhesive provided can make the hydride not oxidized, reduce the cost of sintered NdFeB grain boundary diffusion, and improve the stability of sintered NdFeB. In the atmospheric state, the hydride added with the anti-oxidation type adhesive can be stably stored for one year. Its performance will not be reduced when it is used again, and it is more conducive to recycling the heavy rare earth powders left in the production equipment, and the utilization rate can reach 99%. Anhui Hanhai New Material Co.
7. The process of regulating the stability of chemical nickel in NdFeB plating
We can make timely adjustments to the poor stability of the electroless nickel plating solution; if the result of the electroless nickel stability is unqualified, we can add stabilizers to improve the stability of the electroless nickel plating solution, to prolong the service life of the electroless nickel plating solution, and to save the cost. Hangzhou Quadrant Technology Co.
8. Method of chrome-free passivation for galvanized products of NdFeB permanent magnets
Including: electroplating → three countercurrent water washing → out of the light → three countercurrent water washing → passivation solution passivation → hot water washing → drying, passivation using composite chromium-free zinc passivation solution passivation, composite chromium-free zinc passivation solution preparation steps are: weighing the corresponding mass of molybdate, phosphoric acid dissolved in deionized water and stirred well, will be silica-modified acrylic resin solution, OP-10 added to the above Ultrasonic dispersion in the mixture for 10-30min to get composite chromium-free galvanized passivation solution, the method is easy to implement, the effect is good, increased corrosion resistance and to meet the long-term storage of the dyne value is still qualified requirements, the use of composite passivation solution reduces the galvanizing process in the closed treatment link, saving production time, increase efficiency. Tianjin Sanhuan Lexi New Material Co., Ltd; Beijing Zhongke Sanhuan High-Tech Co.
9. Surface passivation treatment method for NdFeB magnets
Semi-finished magnet steel is prepared first, then surface pretreatment, then surface activation treatment, then surface passivation heat treatment, and finally finished product inspection and packaging; the passivation solution used in this invention has good spreading performance on the surface of the magnet body, and the protective film that can be formed on the surface of the magnet steel is uniform and stable, which greatly improves the corrosion resistance to the magnets, making the surface of the magnets uniform in color, the color of the magnets is dark blue, and the passivation solution used does not produce to the passivation solution used does not produce harmful substances to the human body and the environment, is safe and environmentally friendly; simple operation, short time, easy to realize industrialization. Jiangxi Jinli Permanent Magnet Technology Co.
10. Electroless Nickel Plating Solution and Plating Method for NdFeB Magnetic Surfaces
The nickel-containing plating solution can avoid the phenomenon of hydrogen ion precipitation on the surface of NdFeB magnetic material in the electrodeposition process. It will not destroy the magnetic properties of NdFeB magnetic material itself, ensuring the stability of magnetic properties and surface corrosion resistance of NdFeB magnetic material. Also disclosed is a method of plating the surface coating of NdFeB magnetic material. Hefei Huaqing Gamma Technology Co.
11. Preparation method of strong toughness NdFeB magnets
Including: preparing a thin strip of Fe-Co-Ni based high entropy alloy by the melt fast quenching method and mixing it proportionally with nanoscale toughening powder Pr-Ce-Cu alloy and nanoscale nickel-based self-fusing powder of grade Ni45 to make a nanoscale mixed powder alloy, and Add acetone solution mixed with nitrocellulose, and then mixed to make a paste solution; through the nanosecond laser pulse on the surface of the iron boron magnets to make honeycomb grooves, the paste solution is evenly coated in the honeycomb grooves of the NdFeB magnets, and then a strong magnetic field-assisted low-temperature preheating treatment and laser cladding treatment, and finally through the primary and secondary tempering heat treatment, to obtain a strong toughness of the NdFeB magnets. The process is simple and easy to operate, which is conducive to applying NdFeB magnets with strong toughness in more permanent magnetic devices to meet the market demand. Dongyang Top Magnet Co.
12. Fine crystal, high coercivity sintered NdFeB magnets and their preparation methods
The sintered NdFeB magnet has a small grain size, and the content of C, O, and N elements in the magnet is controlled while reducing the size of the grain size, thereby substantially increasing the coercivity of the magnet. The magnets prepared using the described method have lower C, O, and N impurities, and such products are subjected to diffusion treatment to provide better grain boundaries and better diffusion channels. Therefore, fine crystalline products can produce magnets with higher performance after re-diffusion. Yantai Zhenghai Magnetic Material Co.
13. Method to improve the corrosion resistance of sintered NdFeB
To solve the problem of complicated steps of plating anti-corrosion layer under the existing technology, the plating layer affects the magnetic properties, the corrosion channel of the plated single-layer film is relatively shorter, and the corrosion resistance is poorer, the layered sputtering can give better play to the advantages of each layer of the film, and the intermediate layer of the film can strengthen the membrane base bonding force, and the anti-corrosion layer of the film has high hardness, and the anti-abrasion properties, corrosion resistance, and oxidation resistance are good; the double-layer film has longer corrosion channel than the single-layer film and better anti-corrosion effect; the surface protection is better than the single-layer film. This surface protection method has less effect on the magnetic properties of NdFeB; the use of magnetron sputtering coating technology, no pollution, high film purity, denseness, and uniformity. Hangzhou University of Electronic Science and Technology
14. Chromium-free passivation solution and passivation method for NdFeB zinc plating layer
Chromium-free passivation solution for NdFeB zinc plating layer contains soluble silicate and soluble cerium(Ⅳ) salt, in which soluble silicate is a film-forming agent and soluble cerium(Ⅳ) salt is an oxidizing film-forming agent. Solve the existing technology in the silicate zinc coating passivation film is easy to fall off, in the neodymium-iron-boron workpiece dipping and turning process there is broken and fall off; passivation film passivation speed passivation film thinning, thickness is insufficient; passivation process passivation film is not dense enough, resulting in a decline in corrosion resistance problem. Achieved the corrosion protection of NdFeB workpiece zinc coating without chrome passivation. Yongxin Chenyang Magnetoelectric Technology Co.
15. Preparation method of zinc-aluminum organic double-layer composite coating on the surface of bonded NdFeB magnet material
Specifically related to the surface protection technology field of neodymium iron boron magnet material, the preparation method can solve the problem of bonded neodymium iron boron magnet corrosion. The preparation method of zinc-aluminum organic double-layer composite coating on the surface of bonded NdFeB magnet material includes: grinding and chamfering of NdFeB magnet, spraying and curing of zinc-aluminum coating, and electrophoretic coating and curing of organic coating. It is possible to prepare zinc-aluminum and organic coating on the surface of NdFeB magnet material. The double-layer composite coating exerts the synergistic effect of multiple interfacial factors, including electrochemical protection, which can protect the NdFeB magnet substrate for a long period, effectively inhibit the invasion of corrosive medium, and prevent NdFeB magnet substrate from being corroded. Hefei University of Technology
16. Surface corrosion protection method for NdFeB permanent magnets
The surface of the NdFeB permanent magnet is formed with microglia superhydrophobic coating; the superhydrophobic coating can effectively isolate water and oxygen, so the NdFeB permanent magnet has excellent corrosion resistance, and the microglia structure has good toughness, which gives the NdFeB permanent magnet excellent abrasion resistance and mechanical stability for different sizes and shapes of NdFeB magnets, the operation is simple and non-polluting. Hangzhou University of Electronic Science and Technology
17. High coercivity, high magnetic energy product sintered neodymium iron boron permanent magnetic material and preparation method
A kind of high coercivity, high magnetic energy product sintered NdFeB permanent magnet material and preparation method for the mass production of high coercivity, high magnetic energy product “double high” sintered NdFeB permanent magnet material to provide process and technical support. Ganzhou Fuerte Electronics Co.
18. Grain boundary diffusion preparation method of NdFeB permanent magnets for drive motors
Two main-phase alloy compositions are prepared by the dual-alloy method, and then the grain boundary diffusion substrate is prepared by the dual-primary-phase alloy method. This preparation method utilizes both the bi-alloying method and the dual main phase alloying method, which can greatly improve the magnetic properties of the substrate. At the same time, the composition ratio of this method can better regulate the content of heavy rare earths Dy and Tb and optimize the substrate’s microstructure. Finally, the grain boundary diffusion technology can be used to prepare a variety of grades of high-performance NdFeB permanent magnets for drive motors. Hubei Yongmagnet Magnetic Material Technology Co.
19. High-throughput design of grain boundary diffuser compositions in NdFeB magnets
To solve the problem that the existing method is extremely cumbersome and inefficient with high cost when searching for the optimal composition point in diffusion media of different systems, the method includes the following steps: 1) pre-treatment: the magnet is treated to obtain the magnet to be diffused; 2) magnetron sputtering: the magnet to be diffused is subjected to surface treatment and magnetron sputtering, and the diffusion media thin film is made on the surface of the magnet to obtain the coated magnet; 3) compositional detection: Analyze the elemental distribution pattern and atomic ratio of each region of the diffusion medium film by energy spectrum; 4) Heat treatment: Heat treat the coated magnet, and get the sample to be tested after cooling; 5) Magnetic property test: Test the magnetic property of different parts of the surface of the sample to be tested; 6) Analysis: Combine the results of composition test and magnetic property test and come up with the optimal composition ratio. It has the advantage of high efficiency. Hangzhou University of Electronic Science and Technology
20. Organic coating material for NdFeB permanent magnet surface and its preparation method
Neodymium iron boron permanent magnet surface organic coating material raw materials from a wide range of sources, the preparation method is simple, can effectively improve the corrosion resistance of permanent magnets, to avoid the damage of oxygen and water vapor on the permanent magnet, and can to a certain extent to enhance the mechanical properties of the material, high temperature performance, etc., has broad application prospects. Kunming Quodid Human Resource Service Co.
21. The surface strengthening treatment method of NdFeB permanent magnet and its application
Through polishing, roughening, alkaline etching, acetone facelift, ultrasonic cleaning, and vacuum drying technology process sequentially on the magnet surface strengthening treatment, the surface of NdFeB permanent magnets and the coating of the bonding force is significantly enhanced to improve the coating of the temperature and humidity resistance performance, resistance to neutral salt spray performance, at the same time, the surface treatment method process is simple and easy to operate. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences
22. Preparation method of anticorrosion coating on the surface of NdFeB rare earth permanent magnets
Effectively improve the corrosion resistance of NdFeB magnets and increase the service temperature of the organic coating to extend the service life of the magnets. The anticorrosive layer is made of a combination of materials so that the anticorrosive coating has not only excellent corrosion resistance but also has strong water resistance, weather resistance, and wear resistance; before coating the anticorrosive layer of the NdFeB material for electroplating, the main purpose of electroplating is to give the substrate a layer of surface protective coating to ensure that the material continues to be used. Jiangsu Qicheng Magnetic Industry Co.
23. Zn-Al coating on sintered NdFeB substrate and method of preparation thereof
Said Zn-Al coating comprises a component A, a component B, a component C, and a component D, wherein component A comprises Zn powder, Al powder dispersant, γ-(2,3-epoxypropyleneoxy) propyltrimethoxysilane, deionized water, an emulsifier, and isooctanol; the component B comprises γ- (2,3-epoxypropoxy) propyltrimethoxysilane, methanol and deionized water; component C was composed of sodium phosphomolybdate and deionized water; component D was composed of a thickener and deionized water. The obtained Zn-Al coating has strong corrosion resistance and no rust spots on the surface after 1000h of neutral salt spray test; it is characterized by high hardness and strong bonding force; its hardness is 5H, bonding force is grade 1, and the surface has metallic luster. Lower cost, green environmental protection, no three-waste emissions, in line with the development of green environmental protection surface treatment technology. Northwestern Polytechnical University
24. Composite grain boundary diffusers for alloys used in NdFeB magnets and their preparation methods and applications
By coating the composite diffusing agent on the surface of NdFeB magnets and carrying out diffusion heat treatment, the comprehensive magnetic properties of the magnets obtained are better than those of the magnets diffused by a single alloy, especially in the coercivity and squareness. The sintered and nanocrystalline magnets with high coercivity and high magnetic energy products are prepared under low-temperature and short-time diffusion heat treatment. South China University of Technology
25. Surface plating of NdFeB permanent magnets and its preparation method
A plating layer is formed on the surface of the NdFeB permanent magnet by the chemical plating method, which consists of dense alumina film and Ni-Cu-P alloy, and in Ni-Cu-P alloy, the P content is higher, the alloy is an amorphous structure, and has excellent Corrosion resistance, and does not produce magnetic shielding effect, the alloy coating is cellular structure, the particles are more uniform. Kunming quodid human resource service co.
26. NdFeB magnet electroplating copper-nickel process
NdFeB magnet electroplating copper-nickel bonding and corrosion resistance of the process method, which can improve the plating pretreatment process and plating process, increase the area of bonding with the plating layer to increase the bonding strength of the plating layer and the substrate, greatly improve the corrosion resistance of NdFeB magnets, reduce the thermal demagnetization rate of NdFeB magnets. Tianjin Jingmagnet Electronic Components Manufacturing Co.
27. Preparation method of corrosion-resistant protective coating on the surface of sintered NdFeB magnets
The method is as follows: Step 1: The NdFeB magnet is pre-treated by ultrasonic cleaning and acid washing to remove the surface oil stains and oxidized skin, and then the NdFeB magnet is sandblasted; Step 2: The Ni-based composite powder and Cu-based composite powder are sprayed on the surface of the NdFeB magnet by the method of supersonic flame spraying. The Ni-based composite powder and Cu-based composite powder are used as spraying materials, and the combination of multi-layer spraying processes can achieve better corrosion resistance. Tianjin Jingmagnet Electronic Components Manufacturing Co.
28. NdFeB Permanent Magnetic Material Surface Treatment Method and Permanent Magnetic Material Products
The coating of the obtained permanent magnetic material products has significantly improved corrosion resistance, acid and alkali resistance and adhesion, which prolongs the service life of NdFeB permanent magnetic material and meets the requirements of the current harsh environment. Langfang Jingmagnet Precision Material Co.
29. Preparation method of surface protective coating for ultra-thin NdFeB permanent magnets
The surface cleaned NdFeB magnet is subjected to DC magnetron sputtering coating to obtain the NdFeB magnet with surface deposited copper gradient coating; the NdFeB magnet with surface deposited copper layer obtained from the above steps is then subjected to surface pretreatment and then plated with a nickel-based coating to obtain the NdFeB magnet with surface deposited Cu-Ni combination coating; the sputtering process is to turn on Cu -Sn target and Cu target, and sputtering the Cu-Sn target and Cu target at the same time; the initial power of the Cu-Sn target was 120 W, which decreased at a rate of 3-5 W/min during the sputtering process until it was turned off; and the power of the Cu target was 150 W, which was always maintained at the same level, and the time was 1.5-3.0 h. The ultra-thin permanent magnet combines the advantages of magnetron sputtering process without pickling pretreatment, which makes the prepared film layer firmly deposited and dense corrosion-resistant, and solves the problem of magnetic property degradation caused by the erosion of substrate tissues by pickling and plating solutions in the surface treatment process of permanent magnets. Taiyuan University of Technology
30. Plating method of ultra-thin coating for NdFeB
Plating on the surface of a NdFeB substrate, from the inside to the outside are electroplated cyanide-free alkali copper plating and chemical nickel plating, wherein a copper plating solution is used in the process of electroplating cyanide-free alkali copper plating, and the chemical composition of the copper plating solution contains copper carbonate, HEDP, potassium carbonate, potassium hydroxide, bismuth nitrate, and polycationic quaternary ammonium salts. The temperature of the copper plating solution is 40-60°C, and the pH value is 9-12. Using the method of the present invention, A dense cyanide-free alkaline copper plating layer and a dense chemical nickel-plating layer can be coated on the surface of the NdFeB substrate, making it possible to safeguard non-porosity and prevent corrosion of the substrate at a very thin plating thickness. Hangzhou Quadrant Technology Co.
31. Corrosion-resistant and wear-resistant composite plating layer applicable to NdFeB and its preparation method
It includes first plating a metal plating layer on the surface of a metal magnet by electroplating, and then plating a secondary plating layer on the surface of the metal plating layer by vacuum plating; said secondary plating layer being a non-metallic alloy layer and/or a metal layer and/or a metal oxide layer and/or a metal nitride layer; and/or passing oxidizing gases into the secondary plating layer and reacting with the secondary plating layer, to obtain a dense passivation layer. The prepared cladding layer can, on the one hand, improve its surface structure and enhance its wear resistance, and on the other hand, it can prevent the infiltration of corrosive liquid and enhance its corrosion resistance. The preparation method of the present invention is simple and economical, reasonable in design, and has broad application prospects. Fujian Changting Golden Dragon Rare Earth Co., Ltd; Xiamen Tungsten Industry Co.
32. Preparation method of NdFeB magnet with anti-corrosion property
Step 1, surface debris removal: the surface of the NdFeB magnet is cleaned to remove surface impurities, and then dried and processed; Step 2, preparation of an anticorrosive coating; Step 3, coating treatment: the embryo body of the NdFeB magnet is preheated, and then the prepared anticorrosive coating is coated on the surface of said NdFeB magnet while it is still hot; Step 4, curing treatment: the NdFeB magnet coated with the anticorrosive coating is placed in an oven for curing treatment. step 4, curing treatment: placing the coated NdFeB magnet in an oven for curing treatment. The preparation method is simple and easy to operate, and can meet the requirements of various permanent magnet motor fields on the neodymium-iron-boron magnets, the scope of application is more extensive. Ningbo Megulite Magnetic Co.
33. Preparation Method of Functional Film Layer on the Surface of NdFeB Permanent Magnet
The prepared functional film layer on the surface of NdFeB permanent magnets not only has excellent protective properties such as resistance to humidity and heat, corrosion and scratch, but also has excellent mechanical properties such as strong bonding force and toughness, thus extending the service life of sintered NdFeB magnets. Zhejiang Zhonghang New Material Technology Co.
34. Sintered NdFeB magnets with surface functional film layer
Sintered NdFeB magnets with surface functional film layer not only have excellent protective properties such as moisture and heat resistance, corrosion resistance and scratch resistance, but also have excellent mechanical properties such as strong bonding force and toughness, thus prolonging the service life of sintered NdFeB magnets. Zhejiang Zhonghang New Material Technology Co.
35. Bluing anti-corrosion method for sintered NdFeB magnets
The anticorrosion method provided in this application is used when the NdFeB products do not need to pour the C angle and R angle in the pre-treatment, do not need pickling treatment, reduce multiple processes to improve the production efficiency, and provide a method that can improve the anticorrosion stability of the products and at the same time can shorten the production process and improve the production efficiency. Antares Technology Co., Ltd; Antares Technology Co.
36. Method of acid zinc plating of NdFeB magnets
The method is obtained by plating the abrasive material after it is sequentially cleaned by a metal cleaner solution, treated with a mass fraction of 3-10% HNO3 solution and ultrasonically treated to obtain plated parts, and then said plated parts are sequentially treated with a mass fraction of 0.3-2.0% HNO3 solution and trivalent chromium passivation solution and then dried to obtain zinc plated Galvanized parts. Simple operation, high efficiency and good marketability. Tianjin Jingmagnet Electronic Components Manufacturing Co.
37. Method of double-layer zinc plating on the surface of NdFeB permanent magnet material
The surface of NdFeB permanent magnet material is clean, which is conducive to subsequent galvanization; the plating solution formula is non-toxic, and the waste liquid treatment is easy, the process is simple and easy to master, passivation is carried out through passivation solution, forming a certain thickness and dense passivation film, with high corrosion resistance and good resistance to humidity and heat. Jiangsu Lannuo Magnetic Industry Co.
38. Preparation Method of High Corrosion Resistant Coating on the Surface of Flexible Bonded NdFeB-NiZnFeO Composite Magnets
Flexible bonded NdFeB-NiZnFeO composite magnet surface high corrosion-resistant coating is prepared by particle size reorganization, flexible bonded NdFeB-NiZnFeO composite and ZnO nano-coating sprayed on the surface of flexible bonded NdFeB-NiZnFeO composite magnet. The coating has good magnetic and mechanical properties, and is highly resistant to corrosion. The method of preparing a highly corrosion-resistant coating on the surface of a flexible bonded NdFeB-NiZnFeO composite magnet with good magnetic properties, mechanical properties and corrosion resistance, which can provide more long-lasting corrosion protection. Meanwhile, the preparation process of the present invention is simple, easy to operate, low production cost, and suitable for industrial production. Woya Health Technology Co.
39. Surface antioxidant treatment method for low demagnetization rate NdFeB permanent magnet powder
Realizing the internal and external double antioxidant protection of the surface of the magnetic powder, effectively improving the oxidation resistance of the magnetic powder, and at the same time, in the process of antioxidant treatment of the surface of the magnetic powder, the magnetic powder is put into a high-temperature stirrer and spray-coating treatment is adopted, which effectively improves the homogeneity of the film-forming of the surface of the magnetic powder, and thus effectively improves the quality of the film-forming. Jiangsu Juxin Magnetic Industry Co.
40. Method of anti-corrosion coating on the surface of NdFeB magnets
Steps: 1) surface pretreatment: cleaning the surface of the magnet, drying; 2) surface cleaning: vacuum, warming to 100 ℃, pass argon gas, cavity with negative bias pressure, plasma cleaning of the sample; 3) surface vaporization: vacuum, warming to 200-300 ℃, pass auxiliary gases, glow discharge to produce plasma, the bombardment of metal targets, vacuum vaporization, vaporization on the surface of NdFeB magnets on the composite coating; said auxiliary gas includes the first component, the second component, and the third component, said first group is divided into silicon nitrogen, said second group is divided into nitrogen, ammonia in one or two, said the third group is divided into argon, helium; 4) after the end of vaporization, continue to pump the vacuum to the vacuum chamber temperature drops to 100 ℃ or less, turn off the equipment. The use of vacuum thermal vaporization to generate inorganic nanoparticle-metal composite film gives the surface of NdFeB magnet improved corrosion resistance. Ningbo Zhaobao Magnetic Industry Co.
41. NdFeB surface treatment technology
Steps: S01, Primary cleaning: treat the stains on the surface of NdFeB magnet to ensure that the surface of NdFeB magnet is clean; S02, Surface activation: activate the surface of NdFeB by plasma activation technology; S03, Surface film formation: prepare silane conversion film on the surface of NdFeB magnet by immersion method; reduce the oxidation phenomenon of NdFeB magnet. Yuyao Hongwei Magnetic Material Technology Co.
42. Coating materials for permeable magnets and preparation of high coercivity NdFeB magnets
Said low melting point metal powder B is one or two of Zn, Al, Ga. Said preparation method comprises the following steps: making a slurry of said coating material, coating the slurry on the surface of a neodymium-iron-boron substrate, undergoing a two-stage diffusion heat treatment, and then tempering, to obtain a high coercivity neodymium-iron-boron magnet. Ningbo Jinji Strong Magnetic Co.
43. copper plating solution for surface of NdFeB permanent magnet material and its surface treatment method
Including pretreatment and plating metal layer, through a large number of experiments to optimize the treatment method and plating conditions, the plating of the copper layer and the substrate bonding force is good, the metal layer density is good, corrosion-resistant, the magnetic attenuation rate is greatly reduced, improve the product performance, and accordingly extend the life of the product. Baotou Huizhong Magnetic Valley Rare Earth Technology Co.
44. Preparation method of high corrosion-resistant protective coating on the surface of NdFeB magnets
Through the detection and feedback control of plasma characteristic parameters, the Al/Al2O3 multilayer film structure formed by alternating deposition effectively reduces the micro-defects of the coating, and the uniform and dense Al2O3 layer blocks the grain boundaries running through the coating, which realizes a significant improvement in the corrosion resistance of NdFeB magnets; and at the same time, it improves the surface hardness of the Al coating, which effectively prevents the coating failure due to the surface scratches. It solves the problems of low deposition rate, difficult to control the structure and limited coating thickness faced by the existing preparation technology, and guarantees the process stability and reproducibility in the industrialized production process. At the same time, the super corrosion-resistant property can realize long-term use in high salinity climate, which is suitable for NdFeB permanent magnet materials in offshore wind energy motors, and will bring great economic and social benefits. Institute of Mechanics, Chinese Academy of Sciences
45. Preparation method of anticorrosion coating on the surface of NdFeB magnets
Steps: 1) surface pretreatment: cleaning the surface of the magnet, drying; 2) surface cleaning: vacuum, warming to 100 ℃, pass argon, cavity with negative bias pressure, plasma cleaning of the sample; 3) surface vaporization: vacuum, warming to 200-300 ℃, pass auxiliary gases, glow discharge to produce plasma, bombardment of metal targets, vacuum vaporization, vaporization on the surface of NdFeB magnets on the composite The said auxiliary gas includes the first component, the second component and the third component, the said first group is divided into silane, the said second group is divided into oxygen, nitrous oxide, the said third group is divided into argon, helium; 4) after the end of vaporization, continue to pump the vacuum to the vacuum chamber temperature down to 100 ℃ or less, turn off the equipment. The use of vacuum thermal vaporization to generate inorganic nanoparticle-metal composite film makes the surface of NdFeB magnets with improved corrosion resistance. Ningbo Zhaobao Magnetic Industry Co.
46. Method used to solve the problem of NdFeB products’ sand eyes affecting salt spray
Steps: electroplating nickel on a NdFeB product to obtain a nickel-plated NdFeB product, wherein the nickel-plating treatment comprises plating an underlayer nickel layer, plating a copper layer on the underlayer nickel layer, plating a semi-glossy nickel layer on the copper layer, and plating a bright nickel layer on the semi-glossy nickel layer; placing the nickel-plated NdFeB product in an organic sealing solution for sealing treatment, to form an organic film layer having a certain thickness on the surface of the nickel-plated NdFeB product The surface of the nickel-plated NdFeB product with organic film layer is wiped dry and dried. The treated products are significantly more resistant to corrosion, salt spray, and humidity and heat. China Magnetic Technology Co.
47. Galvanized Electroplating Solution for Surface of NdFeB Permanent Magnetic Material and Electroplating Method Thereof
The provided galvanizing plating solution on the surface treatment of NdFeB permanent magnet material yields a plating layer with fine crystallization and good plating bonding force, which greatly improves the corrosion resistance of the sample. On this basis, only one layer of nickel can be plated, and a zinc-nickel two-layer NdFeB material product can be formed to meet the product performance. The price of zinc acetate is low, which reduces the production cost. Baotou Huizhong Magnetic Valley Rare Earth Technology Co.
48. Functional film layer on the surface of sintered NdFeB magnet and its preparation method
The functional film layer is a multi-cycle composite film layer with Al2O3 layer and TiN layer as the cycle, which has the hardness of more than 15GPa, good corrosion protection performance and antioxidant performance at the same time. At the same time through the layer and TiN layer alternating deposition, to avoid the formation of through the single-layer film pinholes, through holes and microcracks and other organizational defects appear, a better solution to the traditional single-layer film thickness is difficult to control the defects, and through the addition of Al2O3 to enhance the magnet’s resistance to high-temperature oxidation. The use of double-layer film alternating deposition, multi-cycle combination of the form, reducing the internal stress of the film layer, and enhance the film base bonding force. By depositing the functional film layer on the surface of NdFeB, it extends the application field of NdFeB in high humidity, heat and acid/alkali environments. Shenyang Zhongbei Tongmagnet Technology Co.
49. Surface protection method for NdFeB permanent magnets
Steps: S1: Depositing a layer of pure nickel protective film on the surface of NdFeB permanent magnets by magnetron sputtering; S2: Shot blasting the pure nickel protective film obtained in step S1, and then impregnating it in titanate solution for compound treatment; S3: adding epoxy organic coating to an electrophoresis tank, adding deionized water, and preparing a tank solution with a mass content of 8-15% of the epoxy organic coating; and then adding the NdFeB permanent magnet treated in step S2 is submerged in said tank solution, and electrophoresis operation is carried out to prepare a NdFeB permanent magnet with a layer of protective function layer on the surface. The damage to the magnetic properties of the magnet is reduced, and on the other hand, the neutral salt spray corrosion resistance time of the NdFeB permanent magnet is increased, and the service life of the NdFeB permanent magnet is extended. Zhejiang Zhonghang New Material Technology Co.
50. Method of reducing the porosity of surface plating of NdFeB permanent magnet material
Steps: 1) de-ash the NdFeB permanent magnet material; 2) soak the NdFeB permanent magnet material in a sealing agent, and then carry out water washing, in which the sealing agent is an alcoholic amine compound; 3) sequentially clean the NdFeB permanent magnet material after the water washing by degreasing agent and acid; 4) activate the NdFeB permanent magnet material, and then carry out electroplating. This method of reducing the porosity of NdFeB permanent magnet material surface plating before plating to seal the pores, is through the capillary action of water into the void, so that the oxide inside the void through hydration to generate hydrated oxide, in order to increase the volume of oxides, thus sealing the pores; and in turn, can reduce the porosity of the plating layer, so that the plating layer is flatter, brighter, and can reduce the loss of flux of the magnets. ACE Technology Co.
51. Dark Nickel Roller Plating Process for Improving the Surface Tension of NdFeB Magnets
NdFeB magnets are first pre-treated, then plated after pre-treatment, and finally post-treated and cleaned and dried after plating. During the plating process, a composite plating layer consisting of a pre-plated nickel layer, an alkaline dark-copper plating layer, a transition dark-nickel layer and a surface dark-nickel layer is formed on the surface of the NdFeB magnet, and the pre-plated nickel layer that is in contact with the surface of NdFeB magnets between the main components of the pre-plated nickel layer is nickel sulfate, Nickel chloride, boric acid and brightener, alkaline dark copper plating layer is mainly composed of copper pyrophosphate and potassium pyrophosphate, and transition dark nickel layer and surface dark nickel layer are adjusted and changed by brightener to meet the requirements of surface tension of NdFeB magnet; the advantage is that the plating layer has high surface tension on the basis of ensuring high corrosion resistance. Ningbo Yunsheng Co., Ltd;Ningbo Yunsheng Magnetic Component Technology Co.
52. Dysprosium penetration process for sintered NdFeB magnets
The process of sintered NdFeB magnets is based on coating the surface of sintered NdFeB magnets with dysprosium-impregnated slurry to form a powder coating of dysprosium-impregnated slurry, and then forming a layer of high endowment coercivity on the surface of sintered NdFeB magnets after dysprosium-impregnated heat treatment and low-temperature tempering to increase the coercivity of sintered NdFeB magnets, which is low in requirements for equipments, easy to operate, and low in cost, and is easy to be popularized as it can be realized for large volume production. Ningbo Hesheng Magnetic Industry Co.
53. Surface treatment method for improving corrosion resistance of NdFeB rare earth permanent magnet material
Steps: step 1) degreasing the NdFeB permanent magnet material; step 2) cleaning the degreased NdFeB permanent magnet material, and then acid washing the NdFeB permanent magnet material; step 3) activating the acid-washed NdFeB permanent magnet material; step 4) sulphate electroplating zinc on the NdFeB permanent magnet material to form a bottom zinc layer; step 5) alkaline plating zinc-nickel alloy on the NdFeB permanent magnet material to form a zinc-nickel alloy plating layer; step 6) passivating the surface of the NdFeB permanent magnet material after zinc-nickel alloy plating. The alloy coating of the surface treatment method for improving the corrosion resistance of NdFeB rare-earth permanent magnet material is an anodic coating, which can provide excellent electrochemical protection. ACE Technology Co.
54. Method of double-layer zinc plating on the surface of NdFeB permanent magnet materials
Step 1) degreasing the NdFeB permanent magnet material; Step 2) cleaning the degreased NdFeB permanent magnet material, and then acid washing the NdFeB permanent magnet material; Step 3) activating the acid-washed NdFeB permanent magnet material; Step 4) zinc plating the NdFeB permanent magnet material with sulphate electroplating, to form a bottom zinc layer; Step 5) zinc plating the NdFeB permanent magnet material with potash, to form a surface zinc layer; Step 6) galvanizing the galvanized step 6) passivating the surface of the galvanized NdFeB permanent magnetic material. The NdFeB permanent magnetic material surface plated with double layer zinc method treated NdFeB, excellent corrosion resistance, passivation after salt spray resistance test can be up to 120 hours or more, not only improve the zinc coating layer and NdFeB permanent magnetic material bonding strength, but also improve the corrosion resistance of the zinc coating layer. ACE Technology Co.
55. Improvement of coercivity and wear and corrosion resistance of NdFeB magnets
An Al-Cr alloy layer was prepared by magnetron sputtering on the surface of NdFeB magnet substrate using Al-Cr alloy as the target material, followed by diffusion heat treatment under atmospheric atmosphere. The obtained Al-Cr layer can effectively improve the magnetic properties, especially the coercivity, of the NdFeB magnet after the diffusion heat treatment process. At the same time, said Al-Cr metal/oxide coating has better metallic luster, higher hardness and wear resistance, better scratch resistance, and good corrosion resistance compared to the pure Al coating. Diffusion heat treatment in air reduces the requirement for heat treatment equipment and has low production cost. South China University of Technology
56. Anti-corrosion treatment method for NdFeB magnet surface
The roughness of NdFeB magnet after pretreatment with the abrasive of the present invention is between 0.2-2.0 μm, and it can be directly phosphated, which can effectively improve the corrosion resistance of the products phosphated after pickling and improve the inconsistency of the appearance of the products directly phosphated without pickling treatment; it can also be directly plated without degreasing and pickling, thus avoiding the effect on the surface hydrogen content and the impact on the product in the pickling process. Surface hydrogen content without degreasing, pickling and plating directly, thus avoiding the influence of pickling process on the surface hydrogen content and the effect of magnetic flux of the product; can also be phosphated directly electrophoresis, spraying or physical vapor deposition and other treatments, thus avoiding the influence of pickling process on the surface hydrogen content and the effect of magnetic flux of the product, to save the steps of phosphatization, to reduce the uncontrollable factors of the phosphatization process, does not produce wastewater, waste, and to improve the environmental protection performance of the production process. Yantai Zhenghai Magnetic Material Co.
57. NdFeB permanent magnet surface protection liquid, surface protection film layer and its preparation method
The surface protection film layer of NdFeB permanent magnet prepared by surface protection liquid has excellent insulating property, corrosion resistance, abrasion resistance, thermal stability, and strong covering ability. Tianjin Sanhuan Lexi New Material Co., Ltd; Beijing Zhongke Sanhuan High-Tech Co.
58. Method of dysprosium penetration on NdFeB surface
Steps: (1) mix dysprosium oxide powder with sodium chloride solution to obtain a suspension, then the suspension is coated on the surface of NdFeB and placed in the environment of 5-10MPa, 170-300 ℃ in the static treatment for 30min, after removing and rinsing off the residue on the surface of NdFeB, drying standby; (2) dysprosium oxide powder is blended into a slurry with an ethanol solution and coated on the surface of NdFeB treated by step (1), quickly blown away, and the surface of NdFeB is then treated by step (1), and the surface of NdFeB is then treated by step (1), and the surface of NdFeB is then treated by step (1). NdFeB surface after the step (1), blow dry quickly to get semi-finished products; (3) the surface of said semi-finished products of NdFeB laser impact treatment, followed by deionized water rinsing, drying can be; through the high temperature and high pressure induction, laser impact treatment with the way to achieve the high efficiency of dysprosium permeation in the surface of the NdFeB magnets, the surface of the dysprosium infiltration of the method is simple and convenient, and has an important prospect of application. Anhui Hanhai New Materials Co.
59. Preparation method of wear-resistant anti-corrosion layer on the surface of NdFeB magnet
Steps: ①, anti-corrosion material preparation; ②, anti-corrosion material coating NdFeB magnet; ③, sintering anti-corrosion material; ④, aluminum powder coating coating. The preparation method is simple, easy to operate and easy to produce, in addition, the resulting NdFeB magnets have excellent wear resistance, corrosion resistance, high bonding firmness and mechanical strength. Ningbo Heli Magnetic Technology Co.
60. Vacuum Coating Equipment and Method for Surface Protection of NdFeB Rare-Earth Permanent Magnet Devices
Rare earth permanent magnet raw materials are firstly carried out as batching, melting, pouring into alloy sheet, hydrogen crushing, mixing and air flow grinding, after air flow grinding, the materials are mixed with mixer under nitrogen protection and then sent to nitrogen-protected magnetic field oriented press for molding, after molding, encapsulated in a protective box for isostatic pressing, and after that, it is sent into a sintering furnace for sintering, and then aging to make a NdFeB rare earth permanent magnet device, and then after that, it is made into the required shape of the machine processing of the rare earth permanent magnet device. Multi-arc and magnetron sputtering hybrid plating solves the defects of pure multi-arc ion plating and magnetron sputtering plating. Based on the defects of magnetron sputtering and multi-arc ion sputtering method, we can finally get the plating layer with flat and smooth surface, dense and delicate, no pockmarks, no porous blistering and skinning, and the plating layer has enhanced bonding force and enhanced salt spray resistance. Tianjin Sanhuan Lexi New Material Co., Ltd; Beijing Zhongke Sanhuan High-Tech Co.
61. NdFeB composite corrosion inhibitor and its application
NdFeB composite corrosion inhibitor, including sodium silicate, ammonium molybdate and sodium hexametaphosphate. The compound corrosion inhibitor has good corrosion inhibition effect, consists of harmless reagents, does not pollute the environment, conforms to the green development of the chemical industry, and is a green corrosion inhibitor with small dosage, low cost, good effect and high application value. Ningde Teachers College
62. Simultaneous improvement of coercivity and corrosion resistance of sintered Nd-Fe-B
. The method uses magnetron sputtering to prepare a new type of multilayer coating on the surface of sintered NdFeB magnets, in which the bottom layer: a heavy rare earth coating is used as a grain boundary diffusion coating; the outermost layer: a high-entropy alloy coating is used as a corrosion-resistant coating; and the middle layer: a high-entropy alloy nitride coating is used as a barrier coating. The multilayer coating composed of the three coatings can solve the problem that the coercivity and corrosion resistance of sintered NdFeB cannot be improved at the same time after vacuum heat treatment. Institute of Mechanics, Chinese Academy of Sciences
63. Preparation method of NdFeB materials with composite coating
The NdFeB material is provided with a composite coating on the surface, which has high coercivity and high temperature stability at a lower Dy(Tb) content, and is suitable for magnet substrates with a thickness of 5 mm or more, with a small decrease in remanent magnetization. Hangzhou Permanent Magnet Group Co.
64. Method of preparing NdFeB magnets using recycled rare earth elements and its coating process
The preparation of finished NdFeB products includes designing the target composition and rare earth element content, melting, hydrogen breaking, air flow milling, diffusion source melt preparation and pressurized impregnation process; the produced NdFeB magnets are characterized by high coercivity and high corrosion resistance, and the processing process can reduce the use of rare earth elements, reduce manufacturing costs, reduce high-temperature roasting, and reduce environmental pollution. Weifang Jiutian Strong Magnet Co.
65. Method of preparing high coercivity NdFeB permanent magnet materials by discharge plasma sintering
Effectively improve the magnet coercivity, but also have good mechanical properties. Xi’an University of Engineering
66. High temperature resistant and high thermal conductivity sintered NdFeB permanent magnet and its preparation method
By adopting the formula of the present invention to produce the main body, utilizing the characteristic that Sm element can improve the temperature resistance of the magnet, and improving the temperature resistance of the sintered permanent magnet, as well as, by setting up a plurality of heat dissipation cores and a heat dissipation coating, and cooperating with the formula to produce the heat dissipation core and the heat dissipation coating, the thermal conductivity of the product is effectively improved, and the self-dissipating heat dissipation performance is very good, which will not make the heat accumulate, and is conducive to the normal operation of the equipment. Ganzhou Jiatong New Material Co.
67. NdFeB permanent magnet with anti-corrosion and wear-resistant coating and its preparation method
The preparation method obtains a NdFeB permanent magnet anticorrosive wear-resistant coating with strong bonding force, good corrosion resistance, and wear resistance on the surface of the permanent magnet without damaging the magnetic properties of the NdFeB permanent magnet. The preparation method includes the following steps: pre-treatment of the NdFeB permanent magnet with coating, so that the permanent magnet is exposed to a fresh surface; then the NdFeB permanent magnet is moved to the vacuum coating chamber of a vacuum coating machine, and a binding layer, an inner protective layer and an outer protective layer are sequentially deposited on the surface of the NdFeB permanent magnet by magnetron sputtering at ≤150°C. The surface of the NdFeB permanent magnet is then deposited by magnetron sputtering, and the outer protective layer is deposited on the surface of the NdFeB permanent magnet by magnetron sputtering. The design of the composite film layer structure realizes the coexistence of corrosion resistance and anti-wear performance, ensuring that the film layer is still effective when the surface film is partially worn out, and ensuring that the magnets can still work normally under extreme working conditions. Shenyang Zhongbei Tongmagnet Technology Co.
68. NdFeB Permanent Magnet Material Surface Treatment Methods and Products
The treatment method specifically includes pre-treatment of the sintered NdFeB substrate first; electroplating of zinc layer after pre-treatment; washing of NdFeB permanent magnet material after zinc plating, and then pre-dipping; then placing it into the electroplating tank for electroplating of copper layer; and washing and activation of NdFeB after copper plating using 2% sulfuric acid, and finally plating of nickel layer using nickel-plating electrolyte. The method of surface treatment of NdFeB permanent magnet material provided by the present invention includes pretreatment and plating metal layer, and the treatment method and plating conditions are optimized through a large number of experiments, and the zinc layer plated by this method has good bonding strength with the substrate, and the rest of the metal layer bonding is also no problem at all. The density of the metal layer is good, while maintaining high corrosion resistance, the magnetic attenuation rate is greatly reduced, which improves the product performance and extends the product life accordingly. Baotou Huizhong Magnetic Valley Rare Earth Technology Co.
69. NdFeB automatic galvanizing process
Adopt 2% HNO3 solution to carry out automatic pickling for 30s; carry out ash removal treatment on the products after automatic pickling, wherein said ash removal treatment is carried out by means of roller ash removal; carry out the first two-stage countercurrent water washing on the products after ash removal treatment; electrolyte zinc plating on the products after the first two-stage countercurrent water washing, wherein said electrolytic zinc plating is carried out by means of potassium chloride electroplating solution, and get the zinc plated NdFeB products; and electrolyte galvanizing on the galvanized NdFeB products. said zinc-plated NdFeB product is subjected to polishing treatment; the NdFeB product subjected to polishing treatment is subjected to automatic passivation treatment; and the product subjected to passivation treatment is subjected to a second second-stage countercurrent water washing. China Magnetic Technology Co.
70. Preparation method of suspension plasma spray coating on surface of NdFeB magnet
Steps: (1) Preparation of rare earth suspension; (2) spraying on both sides of NdFeB magnets by suspension plasma spraying technology to obtain suspension plasma spraying coating; (3) treatment of sprayed magnets by grain boundary thermal diffusion method. The plasma spraying technology combined with the grain boundary thermal diffusion technology has the characteristics of high production efficiency and environmental friendliness, which can effectively enhance the diffusion depth of heavy rare earth elements in magnets and promote the enhancement of magnetic properties, and also help to accelerate the promotion of the industrialization of grain boundary diffusion technology. Inner Mongolia University of Technology;Ruike National Engineering Research Center for Rare Earth Metallurgy and Functional Materials Co.
71. Diffusion source spraying method for NdFeB-based rare earth permanent magnet surface and magnet manufacturing method
A spray gun is used to spray a diffusion source on the surface of a magnet, said magnet is placed on a material disk for movement, and the spray gun reciprocates to spray a diffusion source solution, and the moving speed of the spray gun, the moving speed of the material disk and the number of times the spray gun passes from a single magnet satisfy the following relationship: where l magnet is the length of the magnet, N is the number of times the spray gun passes from a single magnet, V material disk is the speed of movement of the material disk, V spray gun is the speed of movement of the spray gun and is perpendicular to the disk movement direction perpendicular to the disk, said V disk = 2-5 cm/s, a = 0.2-0.9, b = (1.1-3.2)*10^11, c = 450-800. neodymium-iron-boron system magnets manufacturing method, making magnet blanks, the surface of the blanks are sandblasted, acid-washed and grinded, the blanks are heated and treated, and then sprayed as described above, and finally aging treatment is carried out. Advantages are: to ensure the consistency of spraying when spraying, to ensure the lower limit of the product while reducing the amount of spraying, while improving the consistency of the magnet performance and reducing the manufacturing cost. Zhejiang Yingluohua Magnetic Industry Co.
72. NdFeB permanent magnet device surface coating equipment and surface coating method
The apparatus mainly includes an inlet valve, an inlet chamber, an inlet isolation valve, a vacuum coating chamber, an outlet isolation valve, an outlet chamber, an outlet valve, a sputtering device, and a carrier device. The sputtering device includes at least 2 or more combinations of an ion source, a multi-arc target, a magnetron sputtering target, and a radio frequency sputtering target, the sputtering device is 3 or more, and the target material included in the sputtering device is at least one or more selected from Tb, Dy, Nd, Pr, Y, Nb, Al, Ti, Zr, Ni, Cr. When working, the NdFeB permanent magnet device to be coated is placed on the carrier device to move on the conveyor rollers and sequentially passes through the feeding valve, feeding chamber, feeding isolation valve, vacuum coating chamber, discharging isolation valve, discharging chamber, and discharging valve; the NdFeB permanent magnet device placed on the carrier device is coated in the vacuum coating chamber. Shenyang Zhongbei Vacuum Equipment Co.
73. Preparation method of double coating for improving corrosion resistance of sintered NdFeB magnets
Steps: S1, pickling rust and grease removal treatment: the sintered NdFeB magnet is put into a nitric acid solution for pickling to remove rust and grease on the surface of the sintered NdFeB magnet; S2, micro-arc oxidation treatment: the sintered NdFeB magnet after the pickling treatment of step S1 is put into an electrolytic solution prepared from sodium aluminate, sodium hypophosphite, and deionized water to carry out micro-arc oxidation treatment; S3, spraying treatment: the sintered NdFeB magnet is treated with an electrolytic solution consisting of zinc oxide whiskers and polydimethylsiloxane. S3, spraying treatment: using a mixture of zinc oxide whiskers and polydimethylsiloxane to spray the sintered NdFeB magnets after the micro-arc oxidation treatment in step S2; S4, natural drying: placing the sintered NdFeB magnets after the spraying treatment in step S3 in the environment for natural drying to finally form a corrosion-resistant double-coating structure consisting of the ceramic coating of the micro-arc oxidized ceramics and the super-hydrophobic coating of zinc oxide whiskers/polydimethylsiloxane on the surface of the sintered NdFeB magnets. structure. Nanchang University of Aeronautics and Astronautics
74. Composite nickel plating method for NdFeB magnets
The advantages of continuous magnetron sputtering nickel plating are that a dense sputtered nickel layer is formed on the surface of NdFeB magnet itself, and a dense electroless nickel plating layer is formed on the surface of sputtered nickel layer by electroless nickel plating, which ensures that NdFeB magnets have a high level of corrosion resistance and abrasion resistance, and that there is no cusp effect between magnetron sputtering and electroless nickel plating, and that the composite plating layer formed by sputtered nickel layer and electroless nickel plating layer has a good uniformity, and that the product dimensions are easy to control. Moreover, the use of continuous magnetron sputtering nickel plating shortens the plating process and reduces wastewater by 70%. Ningbo Yunsheng Co., Ltd; Ningbo Yunsheng Magnetic Component Technology Co.
75. Method of improving coercivity and thermal stability of sintered NdFeB magnets
Steps: S1, descaling and degreasing the sintered NdFeB magnet; S2, acid washing treatment on the sintered NdFeB magnet treated in step S1 before removing the acid stains; S3, magnetron sputtering for the first time on the sintered NdFeB magnet treated in step S2 to deposit a first layer of a non-rare-earth metal film layer on the surface of the sintered NdFeB magnet; S4, depositing a single layer of a non-rare-earth film layer on the sintered S4, microwave heating grain boundary diffusion and tempering treatment for the sintered NdFeB magnet deposited with a single layer of non-rare earth film layer in step S3; S5, a second magnetron sputtering of the sintered NdFeB magnet treated in step S4, and depositing a second layer of non-rare earth metal film layer on the surface of the sintered NdFeB magnet with a single layer of non-rare earth film layer deposited in step S3; and S6, microwave heating grain boundary diffusion treatment for the sintered NdFeB magnet with a double layer of non-rare earth film layer deposited in step S5. Nanchang University of Aeronautics and Astronautics
76. Composite corrosion-resistant coating on the surface of NdFeB magnet and its preparation method
The composite corrosion-resistant coating includes, in order from the surface of the NdFeB magnet outward, a cold sprayed aluminum coating, an alumina passivation layer obtained by surface passivation treatment, and a hole-sealing ceramic paint layer. The preparation method includes the following steps: (1) surface treatment of the NdFeB substrate; (2) treatment of aluminum powder; (3) cold spraying aluminum coating; (4) passivation treatment to obtain an alumina passivation layer; and (5) sealing treatment to obtain a sealing ceramic paint layer. The produced aluminum-based composite corrosion-resistant coating on the surface of NdFeB magnets has excellent local corrosion resistance, not only combines well with NdFeB magnets to form a corrosion-resistant coating, but also overcomes the defects of the simple aluminum coating itself, which has a low strength and hardness and micropores on the surface, and serves as an anti-corrosion process on the surface of the sintered NdFeB magnetic material to extend its service life. Inner Mongolia University of Technology
77. Rubber-plastic NdFeB magnet surface coating treatment materials and treatment methods
The surface spraying treatment material of the rubber-plastic NdFeB magnet contains acrylic urethane coating, diluent, and curing agent, and the mass ratio of the acrylic urethane coating, diluent, and curing agent is 50-60:40-50:1-1.5. The surface spraying using the novel acrylic urethane coating of the present invention has excellent adhesion to the rubber-like material. At the same time, because the fluidity of the coating can be adjusted, it can be repeatedly sprayed many times to adjust the thickness of the coating, the adhesion is very strong, and compared with the previous waterborne urethane, UV and other coatings have a better thickness control advantage, flexibility and ductility has also been a qualitative leap. And the coating is a kind of elastic coating, which plays a very good role in protecting the surface of rubber NdFeB products, and can be used in the fields of motor motor, magnetic sealing, office electrical appliances and so on. Hengdian Group Dongmagnet Co.
78. Synchronized and efficient extraction of rare earths and iron from high-value reuse of NdFeB waste materials
By reacting the oxidized product obtained after oxidizing and roasting of NdFeB waste with oxalic acid solution, a leaching solution containing iron oxalate and a solid precipitate dominated by oxalic acid rare earths can be obtained, and then only iron reduction and molten salt electrolysis can be carried out on the leaching solution and the precipitate to obtain the rare-earth alloys used for the production of NdFeB materials and the oxalic ferrous iron used for the production of lithium battery materials, respectively. The method only uses oxalic acid solution as leaching agent and precipitant, which can complete the leaching of iron and the transformation of rare earths in one step, so as to achieve the simultaneous realization of efficient extraction and high-value reuse of iron and rare earths. The extraction process is short, environmentally friendly, and can effectively recover and obtain high-value products with high process operability. Jiangxi University of Science and Technology
79. High temperature resistant NdFeB magnets and their preparation methods
With good Curie temperature and coercivity, it effectively improves the maximum working temperature of NdFeB magnets, which is produced through the steps of initial melting, re-melting, hydrogen breaking, air flow grinding, pressing and sintering, and is characterized by simple operation and easy mass production. Ningbo Heli Magnetic Technology