High permeability nanocrystalline magnetic core and method of making same

Abstract

The application discloses a kind of high permeability nanocrystalline magnetic core and preparation method thereof, it is related to magnetic material technical field, the preparation method includes: to nanocrystalline strip material is wound, obtains magnetic core roll;The magnetic core roll is placed in atmosphere furnace, the magnetic core roll is heat treated, obtains first magnetic core;Silicate or epoxy resin is impregnated to the first magnetic core, and the first magnetic core after impregnation is baked to make first magnetic core solidification and shaping by tunnel furnace, obtains second magnetic core;Metal magnetic powder and organic resin are mixed according to preset proportion, and composite magnetic powder material is obtained;The composite magnetic powder material is made into magnetic powder particle, and the magnetic powder particle is combined with the second magnetic core using injection molding, and a high permeability nanocrystalline magnetic core is obtained.The application aims to solve the problem that the existing technology cannot effectively balance the volume of the magnetic core and the strength of the magnetic core, so that the strength of the magnetic core can be effectively improved when the volume of the magnetic core does not change significantly compared to the existing technology.

Description

Technical Field

[0001] This invention relates to the field of magnetic materials technology, specifically to a high-permeability nanocrystalline magnetic core and its preparation method. Background Technology

[0002] Amorphous and nanocrystalline soft magnetic alloys possess high permeability, low coercivity, and excellent high-frequency soft magnetic properties, earning them the title of 21st-century green electronic materials. In recent years, they have received widespread attention and research from academia and industry. With the rapid development of computer network technology, 5G communication, electric vehicles, photovoltaic new energy, and multimedia technology, electronic devices are required to be miniaturized, energy-efficient, and operate at high frequencies. This places newer and higher demands on soft magnetic materials, requiring them to possess higher saturation magnetic induction, higher permeability, lower losses, and good high-frequency performance.

[0003] Due to its advantages of low loss and high Bs compared to traditional magnetic powder core materials, iron-based nanocrystalline alloy soft magnetic materials have a huge market potential in energy storage inductors and common-mode inductors used in power devices such as new energy vehicles and server power supplies, especially in the fields of new energy vehicles and charging piles where they have significant performance advantages. Currently, traditional nanocrystalline alloy magnetic rings mainly use plastic shells or epoxy resin paint to protect the magnetic core. However, both methods have their own drawbacks. Shell protection requires a gap between the magnetic core and the shell, and the shell wall thickness generally needs to reach 1.0mm for easy molding and sufficient strength. This leads to an increase in the size of the magnetic core, resulting in increased copper wire and power supply volume, among other disadvantages. Directly sprayed magnetic cores suffer from limited paint strength, leading to a certain attenuation of magnetic properties after winding. Furthermore, when the winding wire diameter reaches φ1.5 or higher, the magnetic core is very prone to breakage due to the inability to withstand the winding stress.

[0004] Therefore, existing technologies still have the problem of not being able to effectively balance the core volume and core strength. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high permeability nanocrystalline magnetic core and its preparation method, which aims to solve the problem that the prior art cannot effectively balance the magnetic core volume and magnetic core strength, thereby effectively improving the magnetic core strength when the magnetic core volume does not change significantly compared to the prior art.

[0006] A first aspect of the present invention is to provide a method for preparing a high-permeability nanocrystalline magnetic core, the method comprising:

[0007] Nanocrystalline ribbon is wound to obtain a magnetic core roll;

[0008] The magnetic core roll is placed in an atmosphere furnace and heat-treated to obtain a first magnetic core;

[0009] The first magnetic core is impregnated with silicate or epoxy resin, and then baked in a tunnel furnace to solidify and shape the first magnetic core, thus obtaining the second magnetic core.

[0010] Metal magnetic powder and organic resin are mixed in a preset ratio to obtain a composite magnetic powder material;

[0011] The composite magnetic powder material is made into magnetic powder particles, and the magnetic powder particles are combined with the second magnetic core by injection molding to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0012] According to one aspect of the above technical solution, the step of placing the magnetic core roll in an atmosphere furnace and heat-treating the magnetic core roll to obtain a first magnetic core includes:

[0013] The magnetic core roll is placed in a vertical atmosphere furnace, the vertical atmosphere furnace is evacuated, and nitrogen gas is introduced into the vertical atmosphere furnace.

[0014] The magnetic core roll is heat-treated and a transverse magnetic field is applied to the magnetic core roll to obtain the first magnetic core.

[0015] According to one aspect of the above technical solution, the step of heat-treating the magnetic core roll and applying a transverse magnetic field to the magnetic core roll to obtain the first magnetic core includes:

[0016] The vertical atmosphere furnace is heated according to a first heating rate, and after the temperature reaches the first temperature, a transverse magnetic field is applied and the temperature is held for a first time.

[0017] Continue heating at the second heating rate, and hold at the second temperature for a second time after reaching the second temperature.

[0018] Continue heating at the third heating rate, and hold at the third temperature for the third time after reaching the third temperature.

[0019] The magnetic core roll is removed from the vertical atmosphere furnace and cooled according to a preset cooling rate to obtain a first magnetic core that is magnetized.

[0020] According to one aspect of the above technical solution, the first temperature is 360℃-400℃, the second temperature is 440℃-480℃, and the third temperature is 530℃-570℃.

[0021] According to one aspect of the above technical solution, in the step of heating the vertical atmosphere furnace at a first heating rate, applying a transverse magnetic field after the temperature reaches the first temperature and holding it at that temperature for a first time, the transverse magnetic field is applied to act on the magnetic core roll after the temperature reaches the first temperature, and the magnetic induction intensity of the transverse magnetic field is 1000±200Gs.

[0022] According to one aspect of the above technical solution, in the step of taking out the magnetic core roll from the vertical atmosphere furnace and cooling the magnetic core roll at a preset cooling rate to obtain a first magnetic core with magnetization, a blower is used to cool the magnetic core roll to room temperature.

[0023] According to one aspect of the above technical solution, the step of forming the composite magnetic powder material into magnetic powder particles, and then bonding the magnetic powder particles with the second magnetic core using an injection molding method to obtain a nanocrystalline magnetic core with high magnetic permeability includes:

[0024] The composite magnetic powder material was made into magnetic powder particles using a mechanical granulator.

[0025] The magnetic powder particles are poured into the hopper of the injection molding machine;

[0026] The second magnetic core is placed in the preset mold of the injection molding machine, and the magnetic powder particles are controlled to be fed into the mold cavity so that the magnetic powder particles are bonded to the surface of the second magnetic core to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0027] According to one aspect of the above technical solution, the mixing ratio of metal magnetic powder and organic resin in the composite magnetic material is 7:3-8:2, and the magnetic powder particles are 60-80 mesh particles.

[0028] According to one aspect of the above technical solution, the thickness of the magnetic powder particles bonded to the surface of the second magnetic core is 0.4mm-0.6mm.

[0029] A second aspect of the present invention is to provide a high permeability nanocrystalline magnetic core, wherein the high permeability nanocrystalline magnetic core is prepared by the preparation method described in the above technical solution.

[0030] Compared with existing technologies, the advantages of using the high permeability nanocrystalline magnetic core and its preparation method as shown in this invention are as follows:

[0031] This invention obtains a magnetic core roll by pre-winding a magnetic core strip, then heat-treats the magnetic core roll to obtain a first magnetic core, then impregnates and bakes the first magnetic core to shape it, obtaining a second magnetic core, and finally produces magnetic powder particles containing metal magnetic powder and organic resin, and uses injection molding to coat the magnetic powder particles onto the surface of the magnetic core, thereby obtaining a nanocrystalline magnetic core. This invention utilizes the high strength and high stability characteristics of composite powder, as well as its inherent magnetic properties and insulation, to compensate for the defects of directly spraying the magnetic core or using a plastic shell for protection. At the same time, the nanocrystalline magnetic core produced by this invention can be smaller in size than the same type of packaged product, which can save installation space for downstream applications, and its performance is also significantly improved. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1 This is a schematic flowchart of a method for preparing a high-flowability magnetic composite material according to an embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] A first aspect of the present invention is to provide a method for preparing a high-permeability nanocrystalline magnetic core, the method comprising:

[0037] Nanocrystalline ribbon is wound to obtain a magnetic core roll;

[0038] The magnetic core roll is placed in an atmosphere furnace and heat-treated to obtain a first magnetic core;

[0039] The first magnetic core is impregnated with silicate or epoxy resin, and then baked in a tunnel furnace to solidify and shape the first magnetic core, thus obtaining the second magnetic core.

[0040] Metal magnetic powder and organic resin are mixed in a preset ratio to obtain a composite magnetic powder material;

[0041] The composite magnetic powder material is made into magnetic powder particles, and the magnetic powder particles are combined with the second magnetic core by injection molding to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0042] Further, the step of placing the magnetic core roll in an atmosphere furnace and heat-treating the magnetic core roll to obtain the first magnetic core includes:

[0043] The magnetic core roll is placed in a vertical atmosphere furnace, the vertical atmosphere furnace is evacuated, and nitrogen gas is introduced into the vertical atmosphere furnace.

[0044] The magnetic core roll is heat-treated and a transverse magnetic field is applied to the magnetic core roll to obtain the first magnetic core.

[0045] Further, the step of heat-treating the magnetic core roll and applying a transverse magnetic field to the magnetic core roll to obtain the first magnetic core includes:

[0046] The vertical atmosphere furnace is heated according to a first heating rate, and after the temperature reaches the first temperature, a transverse magnetic field is applied and the temperature is held for a first time.

[0047] Continue heating at the second heating rate, and hold at the second temperature for a second time after reaching the second temperature.

[0048] Continue heating at the third heating rate, and hold at the third temperature for the third time after reaching the third temperature.

[0049] The magnetic core roll is removed from the vertical atmosphere furnace and cooled according to a preset cooling rate to obtain a first magnetic core that is magnetized.

[0050] Furthermore, the first temperature is 360℃-400℃, the second temperature is 440℃-480℃, and the third temperature is 530℃-570℃.

[0051] Furthermore, in the step of heating the vertical atmosphere furnace according to the first heating rate, applying a transverse magnetic field after the temperature reaches the first temperature and holding it at that temperature for a first time, the transverse magnetic field is applied to act on the magnetic core roll after the temperature reaches the first temperature, and the magnetic induction intensity of the transverse magnetic field is 1000±200Gs.

[0052] Further, in the step of removing the magnetic core roll from the vertical atmosphere furnace and cooling the magnetic core roll at a preset cooling rate to obtain the first magnetic core with magnetization, a blower is used to cool the magnetic core roll to room temperature.

[0053] Further, the step of forming the composite magnetic powder material into magnetic powder particles and bonding the magnetic powder particles with the second magnetic core using injection molding to obtain a high-permeability nanocrystalline magnetic core includes:

[0054] The composite magnetic powder material is made into magnetic powder particles using a mechanical granulator.

[0055] The magnetic powder particles are poured into the hopper of the injection molding machine;

[0056] The second magnetic core is placed in the preset mold of the injection molding machine, and the magnetic powder particles are controlled to be fed into the mold cavity so that the magnetic powder particles are bonded to the surface of the second magnetic core to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0057] Furthermore, the mixing ratio of metal magnetic powder and organic resin in the composite magnetic material is 7:3-8:2, and the magnetic powder particles are 60-80 mesh particles.

[0058] Furthermore, the thickness of the magnetic powder particles bonded to the surface of the second magnetic core is 0.4mm-0.6mm.

[0059] A second aspect of the present invention is to provide a high permeability nanocrystalline magnetic core, wherein the high permeability nanocrystalline magnetic core is prepared by the preparation method described in the above technical solution.

[0060] Compared with existing technologies, the advantages of using the high permeability nanocrystalline magnetic core and its preparation method as shown in this invention are as follows:

[0061] This invention obtains a magnetic core roll by pre-winding a magnetic core strip, then heat-treats the magnetic core roll to obtain a first magnetic core, then impregnates and bakes the first magnetic core to shape it, obtaining a second magnetic core, and finally produces magnetic powder particles containing metal magnetic powder and organic resin, and uses injection molding to coat the magnetic powder particles onto the surface of the magnetic core, thereby obtaining a nanocrystalline magnetic core. This invention utilizes the high strength and high stability characteristics of composite powder, as well as its inherent magnetic properties and insulation, to compensate for the defects of directly spraying the magnetic core or using a plastic shell for protection. At the same time, the nanocrystalline magnetic core produced by this invention can be smaller in size than the same type of packaged product, which can save installation space for downstream applications, and its performance is also significantly improved.

[0062] Example 1

[0063] Please see Figure 1 The first embodiment of the present invention provides a method for preparing a high-permeability nanocrystalline magnetic core. The preparation method shown in this embodiment includes steps S10-S50:

[0064] Step S10: The nanocrystalline ribbon is wound to obtain a magnetic core roll.

[0065] In this embodiment, the nanocrystalline ribbon is a nanocrystalline magnetic core ribbon with a thickness of 20-22μm. It is rolled into a magnetic core roll, and the magnetic core size of the magnetic core roll is uniformly OD*ID*HT=30*20*10mm.

[0066] Specifically, during the rolling process of nanocrystalline ribbon, a semi-automatic winding machine is used to wind the magnetic core. The optimal winding tightness of the magnetic core is such that it can naturally spring back to a circle after being lightly pinched and released.

[0067] Step S20: Place the magnetic core roll in an atmosphere furnace and perform heat treatment on the magnetic core roll to obtain the first magnetic core.

[0068] In this embodiment, the step of heat-treating the magnetic core roll and applying a transverse magnetic field to the magnetic core roll to obtain the first magnetic core includes:

[0069] The vertical atmosphere furnace is heated according to a first heating rate, and after the temperature reaches the first temperature, a transverse magnetic field is applied and the temperature is held for a first time.

[0070] Continue heating at the second heating rate, and hold at the second temperature for a second time after reaching the second temperature.

[0071] Continue heating at the third heating rate, and hold at the third temperature for the third time after reaching the third temperature.

[0072] The magnetic core roll is removed from the vertical atmosphere furnace and cooled according to a preset cooling rate to obtain a first magnetic core that is magnetized.

[0073] Furthermore, the first temperature is 380°C, the second temperature is 460°C, and the third temperature is 550°C.

[0074] Furthermore, in the step of heating the vertical atmosphere furnace according to the first heating rate, applying a transverse magnetic field after the temperature reaches the first temperature and holding it at that temperature for a first time, the transverse magnetic field is applied to act on the magnetic core roll after the temperature reaches the first temperature, and the magnetic induction intensity of the transverse magnetic field is 1000±200Gs.

[0075] Further, in the step of removing the magnetic core roll from the vertical atmosphere furnace and cooling the magnetic core roll at a preset cooling rate to obtain the first magnetic core with magnetization, a blower is used to cool the magnetic core roll to room temperature.

[0076] Specifically, in this embodiment, after the magnetic core roll is placed in the atmosphere furnace, a vacuum is first drawn, and then nitrogen is introduced for protection. The heating power of the atmosphere furnace is set, and the furnace temperature is raised to 380°C at the first heating rate and held for 30 minutes. Then, the furnace temperature is raised to 460°C at the second heating rate and held for 40 minutes. Finally, the furnace temperature is raised to 550°C at the third heating rate and held for 30 minutes. After that, a blower is used to quickly cool the magnetic core roll, and a constant magnetic field is maintained during the cooling process, thereby obtaining the first magnetic core with magnetization.

[0077] Specifically, when heating at the first heating rate, the heating time from room temperature to 380°C is 30 minutes. If the room temperature is 30°C, then the first heating rate is approximately 11.6°C / min. When heating at the second heating rate, the heating time from 380°C to 460°C is 40 minutes, so the second heating rate is 2°C / min. When heating at the third heating rate, the heating time from 460°C to 550°C is 60 minutes, so the third heating rate is 1.5°C / min.

[0078] As can be seen, in this embodiment, a three-stage heating process is used to heat treat the magnetic core roll. As the temperature rises, the heating rate slows down and the holding time is longer.

[0079] Step S30: Impregnate the first magnetic core with silicate or epoxy resin, and bake the impregnated first magnetic core in a tunnel furnace to solidify and shape the first magnetic core, thereby obtaining the second magnetic core.

[0080] In this embodiment, the first magnetic core is impregnated with silicate. After heat treatment, the first magnetic core is impregnated with silicate and then baked in a tunnel furnace to solidify and shape the first magnetic core, thereby reducing the influence of external stress on the first magnetic core.

[0081] Step S40: Mix the metal magnetic powder and organic resin in a preset ratio to obtain a composite magnetic powder material.

[0082] In this embodiment, the mixing ratio of metal magnetic powder and organic resin is 7:3. By fully mixing 70% metal magnetic powder and 30% organic resin, a composite magnetic powder material is obtained.

[0083] Step S50: The composite magnetic powder material is made into magnetic powder particles, and the magnetic powder particles are combined with the second magnetic core by injection molding to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0084] In this embodiment, the step of forming the composite magnetic powder material into magnetic powder particles and then bonding the magnetic powder particles with the second magnetic core using injection molding to obtain a high-permeability nanocrystalline magnetic core includes:

[0085] The composite magnetic powder material was made into magnetic powder particles using a mechanical granulator.

[0086] The magnetic powder particles are poured into the hopper of the injection molding machine;

[0087] The second magnetic core is placed in the preset mold of the injection molding machine, and the magnetic powder particles are controlled to be fed into the mold cavity so that the magnetic powder particles are bonded to the surface of the second magnetic core to obtain a nanocrystalline magnetic core with high magnetic permeability.

[0088] Specifically, after mixing metal magnetic powder and organic resin in a 7:3 ratio and stirring thoroughly, the composite magnetic powder material is granulated into small particles that pass through a 65-mesh sieve using a mechanical granulator, resulting in magnetic powder particles. These particles are then poured into an injection molding machine, with a corresponding second magnetic core pre-embedded in the mold. After reaching a suitable temperature, injection molding is performed, and the mixture is held under pressure for a period of time to cure. Essentially, the second magnetic core is encapsulated by the magnetic powder particles. Upon opening the mold, the nanocrystalline magnetic core, specifically a magnetic ring structure, can be removed. In this embodiment, by mixing in different ratios, magnetic powder particles with different properties can be obtained, thereby adjusting the product's magnetism and strength. Furthermore, the wall thickness of the nanocrystalline magnetic core can be adjusted through mold design.

[0089] In some preferred embodiments, the magnetic powder particles are small particles that have passed through a 65-mesh sieve, and the thickness of the magnetic powder particles bonded to the surface of the second magnetic core is 0.5 mm through injection molding. Optionally, the mesh size of the magnetic powder particles can also be 60-80 mesh, and the thickness of the magnetic powder particles covering the second magnetic core can also be 0.5 mm-0.6 mm.

[0090] The nanocrystalline magnetic core prepared in this embodiment is compared in size with the directly sprayed magnetic core and the encapsulated magnetic core in the prior art. The size comparison results are shown in Table 1.

[0091] Table 1

[0092]

[0093] As shown in Table 1, using the same size magnetic core winding, the nanocrystalline magnetic core shown in this embodiment can reduce the volume by about 27.4% compared to the directly sprayed magnetic core and the shelled magnetic core in the prior art.

[0094] The compressive strength of the nanocrystalline magnetic core prepared in this embodiment was compared with that of the directly sprayed magnetic core and the magnetic core with a casing in the prior art. The results of the compressive strength comparison are shown in Table 2.

[0095] Table 2

[0096]

[0097] As shown in Table 2, the nanocrystalline magnetic core shown in this embodiment has a similar resistance to external pressure as the shelled magnetic core, and is significantly better than the directly sprayed magnetic core. This indicates that the nanocrystalline magnetic core prepared by the method shown in this embodiment has a strong resistance to external pressure.

[0098] After winding 20TS of φ1.5 copper wire, the nanocrystalline magnetic core prepared in this embodiment was compared with the winding performance attenuation of directly sprayed magnetic cores and shelled magnetic cores in the prior art. The results of the winding performance attenuation comparison are shown in Table 3:

[0099] Table 3

[0100]

[0101] As shown in Table 3, the performance of the nanocrystalline magnetic core shown in this embodiment is basically not degraded after winding, and is similar to that of the shelled magnetic core. It is significantly better than the directly sprayed magnetic core.

[0102] In Table 3, negative numbers represent an increase, indicating better performance after winding. The winding wire diameter and number of turns are the same for all three types of magnetic cores.

[0103] The inductance (permeability) of the nanocrystalline magnetic core prepared in this embodiment was compared with that of the directly sprayed magnetic core and the shelled magnetic core in the prior art. The comparison results are shown in Table 4.

[0104] Table 4

[0105]

[0106] As shown in Table 4, when using the nanocrystalline magnetic core shown in this embodiment, since the metal magnetic powder in the magnetic powder particles formed on the surface of the second magnetic core by injection molding has certain magnetic properties, after combining it with the second magnetic core to form a nanocrystalline magnetic core, the inductance (permeability) is increased by 6%-10% compared with the shelled magnetic core in the prior art, and the inductance (permeability) is increased by more than 30% compared with the directly sprayed magnetic core.

[0107] Therefore, compared with the prior art, the advantages of using the preparation method shown in this embodiment to prepare nanocrystalline magnetic cores are as follows:

[0108] Example 2

[0109] The second embodiment of the present invention also provides a method for preparing a high-permeability nanocrystalline magnetic core. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except that:

[0110] In this embodiment, the mixing ratio of metal magnetic powder to organic resin is 8:2. By fully mixing 80% metal magnetic powder with 20% organic resin, a composite magnetic powder material is obtained. Furthermore, nanocrystalline magnetic cores are fabricated using the same process.

[0111] The nanocrystalline magnetic core shown in this embodiment was compared with the directly sprayed magnetic core and the encased magnetic core in the prior art. The comparison results are shown in Table 5.

[0112] Table 5

[0113]

[0114] As shown in Table 5, in this embodiment, by adjusting the ratio of metal magnetic powder to organic resin in the composite magnetic powder material, and then using an injection molding machine to wrap the second magnetic core, a nanocrystalline magnetic core is obtained. The magnetic permeability advantage is still very obvious, and the magnetic core strength is high, with the lowest winding attenuation compared to the same period last year.

[0115] Example 3

[0116] The third embodiment of the present invention also provides a method for preparing a high-permeability nanocrystalline magnetic core. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except that:

[0117] In this embodiment, after mixing the metal magnetic powder and organic resin in a ratio of 8:2 and stirring evenly, a composite magnetic powder material is obtained. The composite magnetic powder material is then processed into small particles that pass through a 75-mesh sieve using a mechanical granulator to obtain magnetic powder particles.

[0118] The nanocrystalline magnetic core shown in this embodiment was compared with the directly sprayed magnetic core and the encased magnetic core in the prior art. The comparison results are shown in Table 6.

[0119] Table 6

[0120]

[0121]

[0122] As shown in Table 6, in this embodiment, by adjusting the mesh size of the magnetic powder particles made from the composite magnetic powder material and then using an injection molding machine to wrap the second magnetic core, the magnetic permeability advantage is still very obvious, and the magnetic core strength is high, with the lowest winding attenuation compared to the same period last year.

[0123] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for preparing a high-permeability nanocrystalline magnetic core, characterized in that, The preparation method includes: Nanocrystalline ribbon is wound to obtain a magnetic core roll; The magnetic core roll is placed in a vertical atmosphere furnace, the vertical atmosphere furnace is evacuated and nitrogen is introduced, the magnetic core roll is heat-treated and a transverse magnetic field is applied to the magnetic core roll to obtain the first magnetic core. The first magnetic core is impregnated with silicate or epoxy resin, and then baked in a tunnel furnace to solidify and shape the first magnetic core, thus obtaining the second magnetic core. Metal magnetic powder and organic resin are mixed in a ratio of 7:3 to 8:2 to obtain a composite magnetic powder material; The composite magnetic powder material is made into 60-80 mesh magnetic powder particles using a mechanical granulator. The magnetic powder particles are poured into the hopper of an injection molding machine. The second magnetic core is placed in the preset mold of the injection molding machine. The magnetic powder particles are controlled to be fed into the mold cavity so that the magnetic powder particles are bonded to the surface of the second magnetic core, thereby obtaining a nanocrystalline magnetic core with high magnetic permeability.

2. The method for preparing a high-permeability nanocrystalline magnetic core according to claim 1, characterized in that, The step of heat-treating the magnetic core roll and applying a transverse magnetic field to the magnetic core roll to obtain the first magnetic core includes: The vertical atmosphere furnace is heated according to a first heating rate, and after the temperature reaches the first temperature, a transverse magnetic field is applied and the temperature is held for a first time. Continue heating at the second heating rate, and hold at the second temperature for a second time after reaching the second temperature. Continue heating at the third heating rate, and hold at the third temperature for the third time after reaching the third temperature. The magnetic core roll is removed from the vertical atmosphere furnace and cooled according to a preset cooling rate to obtain a first magnetic core that is magnetized.

3. The method for preparing a high-permeability nanocrystalline magnetic core according to claim 2, characterized in that, The first temperature is 360℃-400℃, the second temperature is 440℃-480℃, and the third temperature is 530℃-570℃.

4. The method for preparing a high-permeability nanocrystalline magnetic core according to claim 2, characterized in that, In the step of heating the vertical atmosphere furnace according to the first heating rate, applying a transverse magnetic field after the temperature reaches the first temperature and holding it at the temperature for a first time, the transverse magnetic field is applied to act on the magnetic core roll after the temperature reaches the first temperature, and the magnetic induction intensity of the transverse magnetic field is 1000±200Gs.

5. The method for preparing a high-permeability nanocrystalline magnetic core according to claim 2, characterized in that, In the step of removing the magnetic core roll from the vertical atmosphere furnace and cooling the magnetic core roll at a preset cooling rate to obtain the first magnetic core with magnetization, a blower is used to cool the magnetic core roll to room temperature.

6. The method for preparing a high-permeability nanocrystalline magnetic core according to claim 1, characterized in that, The thickness of the magnetic powder particles bonded to the surface of the second magnetic core is 0.4mm-0.6mm.

7. A high-permeability nanocrystalline magnetic core, characterized in that, The high permeability nanocrystalline magnetic core is prepared by the preparation method according to any one of claims 1-6.

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