Method for improving surface tension of sintered neodymium-iron-boron magnet coating

Abstract

The invention provides an application of a surface conditioning agent in an aluminized neodymium-iron-boron magnet. The surface conditioning agent is prepared from the following components in parts by mass: 1 to 10 parts by weight of tetramethyl divinyl disilazane, 40 to 60 parts by weight of acrylic resin, 1 to 10 parts by weight of anionic surfactant, 1 to 20 parts by weight of dispersing agent and 1 to 20 parts by weight of stabilizing agent. The surface conditioning agent for the aluminized neodymium-iron-boron magnet, which is designed by the invention and has specific composition and proportion, can improve the performance of a neodymium-iron-boron magnet coating, especially the surface tension. According to the invention, a solution soaking process is adopted, and a soaking process of a surface conditioning agent is added on an aluminum alloy coating on the surface of a neodymium iron boron matrix, so that the surface tension of the coating can be remarkably improved, meanwhile, a certain effect on improving the corrosion resistance of the coating can be achieved, and the technical problems existing in vacuum aluminum plating can be effectively solved. The method does not need post-treatment, is simple in process and low in cost, does not generate waste gas / slag, and has good environmental protection property.

Description

Technical Field

[0001] The invention belongs to the field of sintered NdFeB magnet preparation, relates to the application of a surface conditioner in aluminum-plated NdFeB magnets and a method for treating a NdFeB magnet coating, and in particular to a method for improving the surface tension of a sintered NdFeB magnet coating. Background Art

[0002] NdFeB permanent magnets are very susceptible to corrosion due to their porous surface. To prevent NdFeB from being corroded, a common practice is to coat the surface of NdFeB with a layer of corrosion-resistant metal by chemical or physical methods to achieve an anti-corrosion effect. Vacuum aluminum plating is one of the coatings. Vacuum aluminum plating is a protective technology that uses evaporation vapor deposition to form a layer of aluminum coating on the surface of the NdFeB substrate under vacuum conditions. The coating surface not only has a high surface hardness, but also has good corrosion resistance. However, the coating has the following disadvantages: the surface tension (dyne value) of the coating is not high, generally only 35mN / m. The lower surface tension value will affect the bonding strength between the coating and the glue, resulting in the risk of the magnet falling off after assembly.

[0003] In order to improve the surface tension of the aluminum coating, the current common practice is generally to strictly control the flow process of the NdFeB magnet after aluminum plating to prevent the surface of the coating from being contaminated, but this method is relatively cumbersome, and the surface tension of the aluminum coating is also unstable. For example, in patent application CN201010606023.9, vacuum aluminum plating and cathode electrophoresis are used to obtain a composite coating, and its process steps are: 1. Degreasing and rust removal of the NdFeB magnet; 2. Vacuum aluminum plating of the NdFeB magnet; 3. Surface finishing and passivation treatment of the NdFeB magnet after vacuum aluminum plating; 4. Cathode electrophoresis of the NdFeB magnet after the above treatment; 5. Drying and curing the NdFeB magnet after cathode electrophoresis. This method is to strictly control the process after NdFeB aluminum plating to prevent the surface of the coating from being contaminated, but it requires a large number of personnel to implement process supervision, which has high labor costs, is relatively cumbersome, and the surface tension value of the coating is unstable. Although the prior art also discloses that the surface tension of the coating can be improved by re-plating another coating on the surface of the NdFeB magnet after vacuum aluminum plating, this method is more complicated to operate and has a higher cost.

[0004] Therefore, how to find a more suitable treatment method to solve the above-mentioned problems existing in the aluminum plating layer on the surface of the existing NdFeB magnets has become one of the urgent problems to be solved by many manufacturers and front-line researchers in the industry. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide the application of a surface conditioner in aluminum-plated NdFeB magnets and a method for treating NdFeB magnet coatings, in particular, a method for improving the surface tension of sintered NdFeB magnet coatings. The present invention adopts a solution immersion process, and adds a surface conditioner immersion process after an aluminum alloy coating is formed on the surface of the NdFeB substrate. The process is not only simple to operate, but can also significantly improve the surface tension of the coating. At the same time, it can also have a certain effect on improving the corrosion resistance of the coating, and can effectively solve the technical problems existing in vacuum aluminum plating. At the same time, the process is simple, the conditions are mild, and the controllability is good, which is more suitable for the promotion and application of industrial production.

[0006] The present invention provides the application of a surface conditioning agent in an aluminum-plated NdFeB magnet;

[0007] The surface conditioning agent, by weight, includes:

[0008]

[0009] Preferably, the application is specifically the application of the surface conditioning agent in the aluminum coating layer of the aluminum-coated NdFeB magnet;

[0010] The surface conditioner includes a surface conditioner aqueous solution;

[0011] The mass concentration of the surface conditioner aqueous solution is 20% to 100%.

[0012] Preferably, the application includes improving the surface tension of the aluminum coating layer on the surface of the aluminum-coated NdFeB magnet;

[0013] The anionic surfactant includes sodium lauryl sulfate;

[0014] The dispersant includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol;

[0015] The stabilizer is sodium diacetate.

[0016] Preferably, the aluminum-plated NdFeB magnet comprises an aluminum-plated NdFeB magnet obtained by passivation treatment of an aluminum-plated sintered NdFeB magnet;

[0017] The application method comprises immersing the aluminum-plated NdFeB magnet in a surface conditioner solution.

[0018] The present invention provides a method for treating a NdFeB magnet coating, comprising the following steps:

[0019] 1) Aluminum-plating the NdFeB magnet to obtain a NdFeB magnet with an aluminum alloy coating on the surface;

[0020] 2) subjecting the NdFeB magnet obtained in the above step and having the aluminum alloy coating on the surface thereof to passivation treatment to obtain a passivated NdFeB magnet;

[0021] 3) soaking the passivated NdFeB magnet obtained in the above step in a surface conditioner solution to obtain a treated NdFeB magnet;

[0022] The surface conditioning agent, by weight, includes:

[0023]

[0024] Preferably, the aluminum plating method includes vacuum aluminum plating;

[0025] The vacuum aluminum plating process comprises the following steps:

[0026] Under vacuum conditions and argon atmosphere, a multi-arc power supply is heated and turned on to plasmatize the argon gas and bombard the aluminum alloy target, so that the aluminum alloy is sputtered onto the surface of the NdFeB magnet in the form of ions or atoms to obtain a NdFeB magnet with an aluminum alloy coating on the surface.

[0027] Preferably, the vacuum pressure of the vacuum aluminum plating is 1.0×10 -3 ~9.0×10 -3 Pa;

[0028] The temperature of the vacuum aluminum plating is 100-300°C;

[0029] The NdFeB magnet includes a NdFeB magnet that has been subjected to one or more steps of degreasing, ultrasonic pickling and drying.

[0030] Preferably, the passivation treatment further includes a sandblasting step;

[0031] The sandblasting treatment is specifically performed by sandblasting with 180-240 mesh glass sand;

[0032] The pressure of the sandblasting treatment is 0.04-0.1 MPa.

[0033] Preferably, the passivation treatment comprises immersing in a passivation solution for passivation treatment;

[0034] The passivation treatment time is 20 to 50 seconds;

[0035] The passivation solution comprises, by mass content, 1% to 4% of basic chromium sulfate, 5% to 10% of fluorozirconic acid, 1% to 4% of citric acid and the balance of water;

[0036] The mass concentration of the passivation solution is 20% to 100%.

[0037] Preferably, the soaking time is 60 to 180 seconds.

[0038] The dispersant includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol;

[0039] The stabilizer is sodium diacetate;

[0040] After the soaking, the method further comprises the steps of cleaning and / or drying.

[0041] The present invention provides the application of a surface conditioner in an aluminum-plated NdFeB magnet; the surface conditioner, by weight, comprises: 1 to 10 parts by weight of tetramethyldivinyldisilazane, 40 to 60 parts by weight of acrylic resin, 1 to 10 parts by weight of anionic surfactant, 1 to 20 parts by weight of dispersant, and 1 to 20 parts by weight of stabilizer. Compared with the prior art, the present invention particularly designs a surface conditioner for aluminum-plated NdFeB magnets with a specific composition and ratio, which can improve the performance of the NdFeB magnet coating, especially the surface tension, including but not limited to vacuum aluminum plating, electroplating zinc, electroplating nickel, electroplating nickel copper nickel and other coatings. The present invention adopts a solution immersion process, and adds a surface conditioner immersion process after forming an aluminum alloy coating on the surface of the NdFeB substrate. The process is not only simple to operate, but can significantly improve the surface tension of the coating, and can also have a certain effect on improving the corrosion resistance of the coating, and can effectively solve the technical problems existing in vacuum aluminum plating.

[0042] The present invention also provides a method for treating NdFeB magnet coatings, which is a method for improving the surface tension of sintered NdFeB magnet coatings, and the treatment process is surface finishing treatment (sandblasting) → degreasing → cleaning → passivation → cleaning → soaking in surface conditioner solution → cleaning → drying. The present invention adopts a method for soaking NdFeB magnet solution after vacuum aluminum plating, and the steps are vacuum aluminum plating on the NdFeB magnet after degreasing and rust removal, surface finishing treatment and passivation treatment on the NdFeB magnet after vacuum aluminum plating, and surface conditioner solution soaking on the NdFeB magnet after the above treatment, and the surface tension of the NdFeB magnet after soaking is significantly improved, and the corrosion resistance is improved at the same time. After the NdFeB magnet is vacuum aluminum-plated, the present invention can significantly improve the coating performance and enhance the surface tension of the coating by soaking in a surface conditioner solution.

[0043] The present invention can significantly improve the surface tension of the NdFeB magnet coating by using a solution immersion process, does not require post-processing, has a simple process, is low in cost, does not generate waste gas and waste residue, has good environmental performance, and is more suitable for promotion and application in industrial production. DETAILED DESCRIPTION

[0044] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0045] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0046] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses industrial purity or conventional purity used in the field of NdFeB magnets.

[0047] Surface tension: refers to the tension acting on any interface along the surface of the liquid due to the uneven molecular attraction.

[0048] Dyne value: A value used to characterize the magnitude of surface tension, generally tested using a dyne pen.

[0049] The present invention provides the application of a surface conditioning agent in an aluminum-plated NdFeB magnet;

[0050] The surface conditioning agent, by weight, includes:

[0051]

[0052] In the present invention, the content of tetramethyldivinyldisilazane is 1 to 10 parts by weight, can be 3 to 8 parts by weight, and can be 5 to 6 parts by weight.

[0053] In the present invention, the content of the acrylic resin is 40 to 60 parts by weight, can be 44 to 56 parts by weight, and can be 48 to 52 parts by weight.

[0054] In the present invention, the content of the anionic surfactant is 1 to 10 parts by weight, can be 3 to 8 parts by weight, and can be 5 to 6 parts by weight.

[0055] In the present invention, the content of the dispersant is 1 to 20 parts by weight, can be 5 to 16 parts by weight, and can be 9 to 12 parts by weight.

[0056] In the present invention, the content of the stabilizer is 1 to 20 parts by weight, can be 5 to 16 parts by weight, and can be 9 to 12 parts by weight.

[0057] In the present invention, the application is preferably the application of the surface conditioning agent in the aluminum coating layer of the aluminum-coated NdFeB magnet.

[0058] In the present invention, the surface conditioner preferably comprises an aqueous surface conditioner solution.

[0059] In the present invention, the mass concentration of the surface conditioner aqueous solution is preferably 20% to 100%, more preferably 35% to 85%, and more preferably 50% to 70%.

[0060] In the present invention, the application preferably includes the application in improving the surface tension of the aluminum coating layer on the surface of the aluminum-coated NdFeB magnet.

[0061] In the present invention, the anionic surfactant includes sodium lauryl sulfate;

[0062] In the present invention, the dispersant preferably includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol, and more preferably an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant or polyvinyl alcohol.

[0063] In the present invention, the stabilizer is preferably sodium diacetate.

[0064] In the present invention, the aluminum-plated NdFeB magnet preferably includes an aluminum-plated NdFeB magnet obtained by passivation treatment of an aluminum-plated sintered NdFeB magnet.

[0065] In the present invention, the application method preferably includes immersing the aluminum-plated NdFeB magnet in a surface conditioner solution.

[0066] The present invention provides a method for treating a NdFeB magnet coating, comprising the following steps:

[0067] 1) Aluminum-plating the NdFeB magnet to obtain a NdFeB magnet with an aluminum alloy coating on the surface;

[0068] 2) subjecting the NdFeB magnet obtained in the above step and having the aluminum alloy coating on the surface thereof to passivation treatment to obtain a passivated NdFeB magnet;

[0069] 3) soaking the passivated NdFeB magnet obtained in the above step in a surface conditioner solution to obtain a treated NdFeB magnet;

[0070] The surface conditioning agent, by weight, includes:

[0071]

[0072] The invention firstly subjects the NdFeB magnet to aluminum plating to obtain the NdFeB magnet with an aluminum alloy coating on the surface.

[0073] In the present invention, the aluminum plating method preferably includes vacuum aluminum plating.

[0074] In the present invention, the vacuum aluminum plating process preferably includes the following steps:

[0075] Under vacuum conditions and argon atmosphere, a multi-arc power supply is heated and turned on to plasmatize the argon gas and bombard the aluminum alloy target, so that the aluminum alloy is sputtered onto the surface of the NdFeB magnet in the form of ions or atoms to obtain a NdFeB magnet with an aluminum alloy coating on the surface.

[0076] In the present invention, the vacuum pressure of the vacuum aluminum plating is preferably 1.0×10 -3 ~9.0×10 -3 Pa, more preferably 3.0×10 -3 ~8.0×10 -3 Pa, more preferably 4.0×10 -3 ~7.0×10 -3 Pa, more preferably 5.0×10 -3 ~6.0×10 -3 Pa.

[0077] In the present invention, the temperature of the vacuum aluminum plating is preferably 100-300°C, more preferably 140-260°C, and more preferably 180-220°C.

[0078] In the present invention, the NdFeB magnet preferably includes a NdFeB magnet that has undergone one or more steps of degreasing, ultrasonic pickling and drying, and more preferably a NdFeB magnet that has undergone degreasing, ultrasonic pickling or drying.

[0079] In the present invention, the NdFeB magnet with the aluminum alloy coating on the surface obtained in the above steps is subjected to passivation treatment to obtain a passivated NdFeB magnet.

[0080] In the present invention, the passivation treatment preferably further includes a sandblasting step.

[0081] In the present invention, the sandblasting is preferably performed with glass sand of 180-240 mesh, more preferably 190-230 mesh, and even more preferably 200-220 mesh.

[0082] In the present invention, the pressure of the sandblasting treatment is preferably 0.04 to 0.1 MPa, more preferably 0.05 to 0.09 MPa, and even more preferably 0.06 to 0.08 MPa.

[0083] In the present invention, the passivation treatment method preferably includes immersing in a passivation solution for passivation treatment.

[0084] In the present invention, the passivation treatment time is preferably 20 to 50 seconds, more preferably 25 to 45 seconds, and more preferably 30 to 40 seconds.

[0085] Finally, the present invention soaks the passivated NdFeB magnet obtained in the above steps in a surface conditioner solution to obtain a treated NdFeB magnet;

[0086] The surface conditioning agent, by weight, includes:

[0087]

[0088] In the present invention, the content of tetramethyldivinyldisilazane is 1 to 10 parts by weight, can be 3 to 8 parts by weight, and can be 5 to 6 parts by weight.

[0089] In the present invention, the content of the acrylic resin is 40 to 60 parts by weight, can be 44 to 56 parts by weight, and can be 48 to 52 parts by weight.

[0090] In the present invention, the content of the anionic surfactant is 1 to 10 parts by weight, can be 3 to 8 parts by weight, and can be 5 to 6 parts by weight.

[0091] In the present invention, the content of the dispersant is 1 to 20 parts by weight, can be 5 to 16 parts by weight, and can be 9 to 12 parts by weight.

[0092] In the present invention, the content of the stabilizer is 1 to 20 parts by weight, can be 5 to 16 parts by weight, and can be 9 to 12 parts by weight.

[0093] In the present invention, the surface conditioner preferably comprises, by mass content, 1% to 4% basic chromium sulfate, 5% to 10% fluorozirconic acid, 1% to 4% citric acid and the balance water, more preferably 1.5% to 3.5% basic chromium sulfate, 6% to 9% fluorozirconic acid, 1.5% to 3.5% citric acid and the balance water, more preferably 2% to 3% basic chromium sulfate, 7% to 8% fluorozirconic acid, 2% to 3% citric acid and the balance water.

[0094] In the present invention, the mass concentration of the surface conditioner solution is preferably 20% to 100%, more preferably 35% to 85%, and more preferably 50% to 70%.

[0095] In the present invention, the soaking time is 60 to 180 seconds, more preferably 80 to 160 seconds, and more preferably 100 to 140 seconds.

[0096] In the present invention, the dispersant preferably includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol, and more preferably an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant or polyvinyl alcohol.

[0097] In the present invention, the stabilizer is preferably sodium diacetate.

[0098] In the present invention, after the soaking, preferably, a cleaning and / or drying step is further included, and more preferably a cleaning and drying step.

[0099] The present invention is to complete and refine the overall technical solution, better ensure the composition and ratio of the surface conditioner, further improve the surface tension and corrosion resistance of the aluminum coating on the surface of the sintered NdFeB magnet, and the application of the surface conditioner in the aluminum-plated NdFeB magnet and a method for improving the surface tension of the sintered NdFeB magnet coating can specifically include the following contents:

[0100] After the NdFeB magnets are vacuum-plated with aluminum, they are surface-finished and passivated, and then immersed in a surface conditioner solution to further improve the properties of the coating. The specific implementation steps are as follows:

[0101] 1. Degrease the NdFeB magnets, clean them by ultrasonic pickling and dry them.

[0102] 2. Place the magnet in a vacuum aluminum plating furnace, heat it to 100-300°C, and evacuate the vacuum (1.0-9.0)*10 -3 At the same time, argon gas is introduced into the furnace, and the multi-arc power supply is turned on to plasmatize the argon gas and bombard the aluminum alloy target in the furnace, so that the aluminum alloy is sputtered to the surface of the magnet in the form of ions or atoms to form an aluminum alloy coating.

[0103] 3. The vacuum aluminum-plated NdFeB magnets are sandblasted with 180-240 mesh glass sand (pressure 0.04-0.1MPa) and passivated for 20-50s. (Passivation solution: 1%-4% basic chromium sulfate, 5%-10% fluorozirconic acid, 1%-4% citric acid and the balance water)

[0104] 4. Soak the NdFeB magnets treated as above in a surface conditioner solution with a concentration of 20% to 100% for 60 to 180 seconds to improve the properties of the coating.

[0105] 5. The surface conditioner is a mixture containing 1% to 10% of tetramethyldivinyldisilazane, 40% to 60% of acrylic resin, 1% to 10% of anionic surfactant, 1% to 20% of dispersant, 1% to 20% of stabilizer, and water.

[0106] 6. Clean and dry the NdFeB magnets after soaking.

[0107] The above content of the present invention provides the application of a surface conditioner in aluminum-plated NdFeB magnets and a method for improving the surface tension of a sintered NdFeB magnet coating. The surface conditioner specially designed by the present invention for aluminum-plated NdFeB magnets with a specific composition and ratio can improve the performance of the NdFeB magnet coating, especially the surface tension, including but not limited to vacuum aluminum plating, electroplated aluminum, aluminum alloy plating and other coatings. The present invention adopts a solution immersion process, and adds a surface conditioner immersion process after the aluminum alloy coating is formed on the surface of the NdFeB substrate. This process is not only simple to operate, but can also significantly improve the surface tension of the coating. At the same time, it can also have a certain effect on improving the corrosion resistance of the coating, and can effectively solve the technical problems existing in vacuum aluminum plating.

[0108] The present invention also provides a method for treating NdFeB magnet coatings, which is a method for improving the surface tension of sintered NdFeB magnet coatings, and the treatment process is surface finishing treatment (sandblasting) → degreasing → cleaning → passivation → cleaning → soaking in surface conditioner solution → cleaning → drying. The present invention adopts a method for soaking NdFeB magnet solution after vacuum aluminum plating, and the steps are vacuum aluminum plating on the NdFeB magnet after degreasing and rust removal, surface finishing treatment and passivation treatment on the NdFeB magnet after vacuum aluminum plating, and surface conditioner solution soaking on the NdFeB magnet after the above treatment, and the surface tension of the NdFeB magnet after soaking is significantly improved, and the corrosion resistance is improved at the same time. After the NdFeB magnet is vacuum aluminum-plated, the present invention can significantly improve the coating performance and enhance the surface tension of the coating by soaking in a surface conditioner solution.

[0109] The present invention can significantly improve the surface tension of the NdFeB magnet coating by using a solution immersion process, does not require post-processing, has a simple process, is low in cost, does not generate waste gas and waste residue, has good environmental performance, and is more suitable for promotion and application in industrial production.

[0110] In order to further illustrate the present invention, the application of the surface conditioning agent provided by the present invention in aluminum-plated NdFeB magnets and a method for treating NdFeB magnet coatings are described in detail below in combination with the embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following embodiments.

[0111] Comparative Example 1

[0112] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0113] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3When Pa, the multi-arc power supply is turned on to coat the surface of the magnet with an aluminum alloy coating.

[0114] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The passivation solution composition is the same as in Example 1)

[0115] 4. The NdFeB magnets after the above treatment are cleaned and dried, and the surface dyne value (arcotest dyne pen test) and salt spray test results of the magnets are summarized in Table 1. Table 1 summarizes the process, dyne value and salt spray test results of the embodiments of the present invention and the comparative examples.

[0116] Example 1

[0117] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0118] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When Pa, the multi-arc power supply is turned on to coat the surface of the magnet with an aluminum alloy coating.

[0119] 3. The vacuum aluminum-plated NdFeB magnets are sandblasted with 220-mesh glass sand (pressure 0.05Mpa) and passivated for 30 seconds. (Passivation solution: 2% basic chromium sulfate, 7% fluorozirconic acid, 3% citric acid, and the rest water)

[0120] 4. Soak the treated NdFeB magnet in a 20% surface conditioner solution for 60 seconds. The surface conditioner is a mixture containing 2% tetramethyldivinyldisilazane, 50% acrylic resin, 5% sodium dodecyl sulfate, 10% fatty alcohol polyoxyethylene ether, 8% sodium diacetate, and the balance deionized water.

[0121] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0122] Example 2

[0123] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0124] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When Pa, the multi-arc power supply is turned on to coat the surface of the magnet with an aluminum alloy coating.

[0125] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The composition of the passivation solution is the same as in Example 1)

[0126] 4. Soak the treated NdFeB magnet in a 20% surface conditioning agent solution for 180 seconds. The surface conditioning agent composition is the same as that in Example 1.

[0127] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0128] Example 3

[0129] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0130] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When the multi-arc power supply is turned on, the surface of the magnet is plated with an aluminum alloy coating.

[0131] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The composition of the passivation solution is the same as in Example 1)

[0132] 4. Soak the treated NdFeB magnet in a 50% surface conditioning agent solution for 60 seconds. The surface conditioning agent composition is the same as that in Example 1.

[0133] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0134] Example 4

[0135] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0136] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When the multi-arc power supply is turned on, the surface of the magnet is plated with an aluminum alloy coating.

[0137] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The composition of the passivation solution is the same as in Example 1)

[0138] 4. Soak the treated NdFeB magnet in a 50% surface conditioning agent solution for 180 seconds. The surface conditioning agent composition is the same as that in Example 1.

[0139] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0140] Example 5

[0141] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0142] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When the multi-arc power supply is turned on, the surface of the magnet is plated with an aluminum alloy coating.

[0143] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The composition of the passivation solution is the same as in Example 1)

[0144] 4. Soak the treated NdFeB magnet in a 100% surface conditioning agent solution for 60 seconds. The surface conditioning agent composition is the same as that in Example 1.

[0145] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0146] Example 6

[0147] 1. After the NdFeB magnet is soaked in degreasing liquid for 10 minutes, it is ultrasonically pickled for 20 seconds to clean the surface dust. After drying, it is placed in a vacuum aluminum plating furnace.

[0148] 2. Turn on the furnace and heat it to about 200℃, and turn on the vacuum pump to a vacuum degree of 5.0*10 -3 When the multi-arc power supply is turned on, the surface of the magnet is plated with an aluminum alloy coating.

[0149] 3. The vacuum aluminum-plated NdFeB magnets were sandblasted with 220-mesh glass sand (pressure 0.05 MPa) and passivated for 30 seconds. (The composition of the passivation solution is the same as in Example 1)

[0150] 4. Soak the treated NdFeB magnet in a 100% surface conditioning agent solution for 180 seconds. The surface conditioning agent composition is the same as that in Example 1.

[0151] 5. Clean and dry the NdFeB magnets after immersion. The surface dyne value (arcotest dyne pen test) and salt spray test of the magnets are summarized in Table 1 below.

[0152] Table 1 Summary of the process, dyne value and salt spray test results of the embodiments of the present invention and the comparative examples

[0153]

[0154] The above is a detailed introduction to the application of the surface conditioner provided by the present invention in the aluminum-plated NdFeB magnet and a method for improving the surface tension of the sintered NdFeB magnet coating. The principle and implementation method of the present invention are described in detail using specific examples. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. Application of surface conditioner in aluminum-plated NdFeB magnets; The surface conditioning agent, by weight, includes:

2. The use according to claim 1, characterized in that: The application is specifically the application of the surface conditioning agent in the aluminum coating of the aluminum-coated NdFeB magnet; The surface conditioner includes a surface conditioner aqueous solution; The mass concentration of the surface conditioner aqueous solution is 20% to 100%.

3. The use according to claim 1, characterized in that: The application includes improving the surface tension of the aluminum coating layer on the surface of the aluminum-coated NdFeB magnet; The anionic surfactant includes sodium lauryl sulfate; The dispersant includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol; The stabilizer is sodium diacetate.

4. The use according to claim 1, characterized in that: The aluminum-plated NdFeB magnet comprises an aluminum-plated NdFeB magnet obtained by passivation treatment of an aluminum-plated sintered NdFeB magnet; The application method comprises immersing the aluminum-plated NdFeB magnet in a surface conditioner solution.

5. A method for treating a coating of a neodymium iron boron magnet, characterized in that: The following steps are involved: 1) Aluminum-plating the NdFeB magnet to obtain a NdFeB magnet with an aluminum alloy coating on the surface; 2) subjecting the NdFeB magnet obtained in the above step and having the aluminum alloy coating on the surface thereof to passivation treatment to obtain a passivated NdFeB magnet; 3) soaking the passivated NdFeB magnet obtained in the above step in a surface conditioner solution to obtain a treated NdFeB magnet; The surface conditioning agent, by weight, includes:

6. The preparation method according to claim 5, characterized in that: The aluminum plating method includes vacuum aluminum plating; The vacuum aluminum plating process comprises the following steps: Under vacuum conditions and argon atmosphere, a multi-arc power supply is heated and turned on to plasmatize the argon gas and bombard the aluminum alloy target, so that the aluminum alloy is sputtered onto the surface of the NdFeB magnet in the form of ions or atoms to obtain a NdFeB magnet with an aluminum alloy coating on the surface.

7. The preparation method according to claim 6, characterized in that: The vacuum pressure of the vacuum aluminum plating is 1.0×10 -3 ~9.0×10 -3 Pa; The temperature of the vacuum aluminum plating is 100-300°C; The NdFeB magnet includes a NdFeB magnet that has been subjected to one or more steps of degreasing, ultrasonic pickling and drying.

8. The preparation method according to claim 5, characterized in that: The passivation treatment also includes a sandblasting step; The sandblasting treatment is specifically performed by sandblasting with 180-240 mesh glass sand; The pressure of the sandblasting treatment is 0.04-0.1 MPa.

9. The preparation method according to claim 5, characterized in that: The passivation treatment method includes immersing in a passivation solution for passivation treatment; The passivation treatment time is 20 to 50 seconds; The passivation solution comprises, by mass content, 1% to 4% of basic chromium sulfate, 5% to 10% of fluorozirconic acid, 1% to 4% of citric acid and the balance of water; The mass concentration of the passivation solution is 20% to 100%.

10. The preparation method according to claim 5, characterized in that: The soaking time is 60 to 180 seconds. The dispersant includes one or more of an alkali metal phosphate dispersant, a silicate dispersant, an alkylbenzene sulfonate dispersant, a trimethyl stearamide chloride dispersant, a fatty alcohol polyoxyethylene ether dispersant and polyvinyl alcohol; The stabilizer is sodium diacetate; After the soaking, the method further comprises the steps of cleaning and / or drying.

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