Metal soft magnetic powder core, its preparation method and application

Abstract

The application provides a metal soft magnetic powder core and a preparation method and application thereof, and the preparation method comprises the following steps: (1) soaking metal magnetic powder in a composite solution under a protective atmosphere, filtering and cleaning in sequence after stirring to obtain a solid powder; (2) mixing phosphoric acid, water glass and the solid powder obtained in step (1), stirring and drying to obtain an insulating powder; (3) sequentially performing compression molding and sintering on the insulating powder obtained in step (2) to obtain the metal soft magnetic powder core. The preparation method of the metal soft magnetic powder core solves the problem that the utilization rate of the metal magnetic powder core powder is low and the metal magnetic powder core cannot be made finer, thereby reducing the high-frequency loss of the metal soft magnetic powder core. In addition, the metal soft magnetic powder core has a low high-frequency loss, and meets the device application requirements of high-frequency switching power supply.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soft magnetic alloy materials, and relates to a metal soft magnetic powder core, in particular to a metal soft magnetic powder core and a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the gradual increase of GaN switch tube applications, the frequency of switching power supply is constantly increasing, from 100-200 kHz in the SiC switch tube period to 300-500 kHz, and the trend of frequency increase is still deepening. For the transformer, power inductor and other devices in the switching power supply, reducing the high-frequency loss of the devices is a key parameter to improve the overall power supply efficiency. Metal magnetic powder core is one of the main raw materials of transformer and inductor in switching power supply, which has high saturation superposition performance and can have a larger direct current component, and has a very important application on the device.

[0003] The metal magnetic powder core also has obvious disadvantages. Because it is a metal material, it has good electrical conductivity, and the eddy current loss will be larger in the electromagnetic conversion process, especially when the frequency is increased, the proportion of eddy current loss in the overall loss will be larger. After the frequency of the switching power supply is increased, the eddy current loss of the metal magnetic powder core is large, and the heat is serious, and the conversion efficiency of the power supply is low, which is the main reason for the shackles of its development.

[0004] At present, in order to solve the problem of large high-frequency eddy current loss of metal magnetic powder core, the industry often adopts the method of screening finer powder through screening, and then reduces the eddy current loss through the process of insulating coating to realize the purpose of high-frequency application.

[0005] CN 111696746A discloses a method for preparing iron-silicon-aluminum soft magnetic powder core by crushing method, which comprises the following steps: (1) selecting iron-silicon-aluminum magnetic powder: selecting crushed iron-silicon-aluminum magnetic powder with a particle size of less than 200 mesh, and the mass percentage of alloy components is Si 7.0%-11.0%, Al 3.0%-8.0%, and the rest is Fe; (2) preparation of dry insulation coated powder: taking the mass of iron-silicon-aluminum metal magnetic powder in step (1) as the proportioning basis, adding 1%-10% polyvinyl alcohol solution, 0.5%-3.0% SiO2 powder and 0.5%-10% water; stirring uniformly at room temperature to form a uniform mixed slurry; then, heating and continuing to heat and stir; after the heat preservation is completed, the dry insulation powder is sieved to obtain the insulation coated powder; (3) preparation of the magnetic powder to be formed: adding a binder and a release agent to the insulation coated powder of step (2), and after mixing uniformly, the magnetic powder to be formed is obtained; (4) compression molding: using a press to compress the magnetic powder to be formed prepared in step (3) into a powder core blank; (5) heat treatment: under the protection of inert gas, the powder core blank formed in step (4) is heat treated to obtain a semi-finished magnetic powder core; (6) insulation spraying: a layer of insulation and high temperature resistant epoxy resin coating is sprayed on the surface of the semi-finished magnetic powder core of step (5) to obtain a metal soft magnetic powder core product. The volume loss of the iron-silicon-aluminum soft magnetic composite material prepared by this method is 260 mW / cm 3 at 50 mT and 100 kHz, and the loss performance cannot meet the current demand of electronic components.

[0006] CN 111451515A discloses a soft magnetic alloy material, a preparation method thereof and an electronic device. The preparation method of the low-power-consumption soft magnetic alloy material comprises the following steps: (1) obtaining a spherical powder from a metal material, wherein the metal material comprises the following components: 8294wt% Fe, 3-6wt% Si, 1.5-4.5wt% Al, 0.35-2.0wt% Cr, 0.5-2.0wt% P, 0.5-2.0wt% B, 0.05-0.5wt% Co, 0.05-0.5wt% Cu, and 0.05-0.5wt% C; (2) heat treating the spherical powder at 300°C-500°C in a protective atmosphere to form crystallized particles. The material prepared by this method has high magnetic permeability, high saturation magnetic flux and low power consumption. The addition of Cr element forms an oxidation layer of Cr during high temperature treatment, thereby improving the working stability of the material in a high temperature environment. However, the addition of Cr element leads to an increase in power consumption of the material, so although it can provide reliability for the operation of devices at high temperature, the power consumption increases greatly and the comprehensive performance is not good.

[0007] In summary, the prior art still cannot effectively solve the problem of large high-frequency eddy current loss of metal magnetic powder core. By sieving to screen finer powder and by insulation coating process to reduce the eddy current loss, the purpose of high-frequency application can be achieved. However, the qualified rate of the powder with small particle size is only 10%. Therefore, the particle size of the powder still cannot completely meet the requirements of high-frequency application. The low utilization rate and the inability to make the powder finer are the reasons for restricting the application of metal powder core to high-frequency application. SUMMARY

[0008] In view of the deficiencies of the prior art, the purpose of the present application is to provide a metal soft magnetic powder core and a preparation method and application thereof. The preparation method of the metal soft magnetic powder core solves the problems of low utilization rate of metal magnetic powder and inability to make the powder finer. The high-frequency loss of the metal magnetic powder core can be reduced to meet the requirements of high-frequency devices of switching power supply.

[0009] To achieve this purpose, the present application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a preparation method of a metal soft magnetic powder core, which comprises the following steps:

[0011] (1) under a protective atmosphere, metal magnetic powder is soaked in a composite solution, and after stirring, the solid powder is obtained by sequentially filtering and cleaning;

[0012] (2) phosphoric acid, potassium water glass and the solid powder obtained in step (1) are mixed, and after stirring and drying, the insulation powder is obtained;

[0013] (3) the insulation powder obtained in step (2) is sequentially pressed and sintered to obtain the metal soft magnetic powder core.

[0014] The preparation method of the present application reduces the particle size of the metal magnetic powder by soaking the metal magnetic powder in the composite solution and utilizing the reaction between the composite solution and the iron element in the metal magnetic powder, thereby reducing the high-frequency loss of the metal magnetic powder core.

[0015] Preferably, the protective atmosphere in step (1) comprises a nitrogen atmosphere and / or an inert gas atmosphere.

[0016] Preferably, the inert gas atmosphere comprises an argon atmosphere and / or a helium atmosphere.

[0017] Preferably, the composite solution in step (1) comprises an acidic solution.

[0018] Preferably, the acidic solution comprises a hydrochloric acid solution or a phosphoric acid solution, one of which is selected for use according to different production requirements, and the effects produced are also different. Most production uses phosphoric acid solution, and hydrochloric acid solution is used less.

[0019] Preferably, the mass concentration of the composite solution is 0.2-5wt%, for example, it can be 0.2wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt% or 5wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0020] The concentration of the composite solution according to the present application affects the particle size of the metal magnetic powder. If the concentration of the composite solution is too high, the coating layer on the surface of the metal magnetic powder will be thickened, the particle size of the powder will be large, and the subsequent process will be affected. If the concentration is too low, the coating layer on the surface of the powder particle will be thin, the particle size of the powder will be small, and the loss and performance of the product will be affected.

[0021] Preferably, the stirring time in step (1) is 8-15h, for example, it can be 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h or 15h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0022] Preferably, the stirring speed is 50-70r / min, for example, it can be 50r / min, 52r / min, 54r / min, 56r / min, 58r / min, 60r / min, 62r / min, 64r / min, 66r / min, 68r / min or 70r / min, but is not limited to the listed values, and other values not listed in the value range are also applicable, and further preferably 60r / min.

[0023] Preferably, the average particle size of the metal magnetic powder in step (1) is ≤500 mesh, for example, it can be 500 mesh, 480 mesh, 460 mesh, 440 mesh, 420 mesh, 400 mesh or 380 mesh, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0024] The particle size of the metal magnetic powder according to the present application affects the high-frequency eddy current loss of the prepared metal soft magnetic powder core. If the average particle size is too high, the high-frequency eddy current loss will be large, and the high-frequency application of the metal soft magnetic powder core will be affected.

[0025] Preferably, the metal magnetic powder in step (1) includes iron-nickel magnetic powder, iron-silicon-aluminum magnetic powder, iron-silicon magnetic powder or iron-nickel-molybdenum magnetic powder. Typical but non-limiting combinations include combinations of iron-nickel magnetic powder and iron-silicon-aluminum magnetic powder, combinations of iron-nickel magnetic powder and iron-silicon magnetic powder, combinations of iron-nickel magnetic powder, iron-silicon-aluminum magnetic powder and iron-silicon magnetic powder, or combinations of iron-nickel magnetic powder, iron-silicon-aluminum magnetic powder, iron-silicon magnetic powder or iron-nickel-molybdenum magnetic powder.

[0026] Preferably, the filtration in step (1) includes suction filtration.

[0027] Preferably, the number of times of washing in step (1) is 2-5, for example, it can be 2, 3, 4 or 5.

[0028] The purpose of the washing in the present application is to remove the surface impurity layer.

[0029] Preferably, the washing solution used in step (1) comprises deionized water.

[0030] Preferably, the concentration of phosphoric acid in step (2) is 0.2-1wt%, for example, it can be 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1wt%, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0031] Preferably, the mass of potassium water glass in step (2) is 0.1-2wt% of the mass of the solid powder, for example, it can be 0.1wt%, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt%, 1wt%, 1.2wt%, 1.4wt%, 1.6wt%, 1.8wt% or 2wt%, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0032] Preferably, the concentration of potassium water glass in step (2) is 0.5-0.8wt%, for example, it can be 0.5wt%, 0.55wt%, 0.6wt%, 0.65wt%, 0.7wt%, 0.75wt% or 0.8wt%, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0033] Preferably, the mass of potassium water glass in step (2) is 0.1-2wt% of the mass of the solid powder, for example, it can be 0.1wt%, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt%, 1wt%, 1.2wt%, 1.4wt%, 1.6wt%, 1.8wt% or 2wt%, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0034] Preferably, the temperature of the drying in step (2) is 80-120℃, for example, it can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃ or 120℃, but is not limited to the listed values, other values not listed in the range of values are also applicable.

[0035] Preferably, the drying in step (2) is carried out in a protective atmosphere.

[0036] Preferably, the protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere.

[0037] Preferably, the end point of the drying in step (2) is to obtain dried insulation powder.

[0038] Preferably, the pressure for the press forming in step (3) is 1000-2000 MPa, for example, it can be 1000 MPa, 1200 MPa, 1400 MPa, 1600 MPa, 1800 MPa or 2000 MPa, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] Preferably, the shape of the press forming in step (3) comprises a ring-shaped magnetic ring.

[0040] Preferably, the outer diameter of the ring-shaped magnetic ring is 25-30 mm, for example, it can be 25 mm, 26 mm, 27 mm, 28 mm, 29 mm or 30 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0041] Preferably, the inner diameter of the ring-shaped magnetic ring is 15-25 mm, for example, it can be 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm or 25 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0042] The inner diameter of the ring-shaped magnetic ring according to the present application is smaller than the outer diameter.

[0043] Preferably, the sintering in step (3) is carried out in a protective atmosphere or a reducing atmosphere.

[0044] Preferably, the protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere.

[0045] Preferably, the reducing atmosphere comprises a hydrogen atmosphere and / or a carbon monoxide atmosphere.

[0046] Preferably, the temperature for the sintering in step (3) is 720-750℃, for example, it can be 720℃, 725℃, 730℃, 735℃, 740℃, 745℃ or 750℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0047] Preferably, the sintering time of step (3) is 30-90 min, for example, it can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min or 90 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0048] The sintering time and temperature of the present application affect the properties of the prepared metal soft magnetic powder core, wherein too low sintering temperature leads to poor strength and low performance of the metal soft magnetic powder core, and too high sintering temperature leads to sintering and low Q value and large loss; too long sintering time leads to product oxidation, and too short sintering time leads to low performance.

[0049] As a preferred technical solution of the present application, the preparation method of the metal soft magnetic powder core provided in the first aspect of the present application comprises the following steps:

[0050] (1) Under a protective atmosphere, metal magnetic powder with an average particle size of ≤500 μm is soaked in a composite solution with a mass concentration of 0.2-5 wt%, stirred at a speed of 50-70 r / min for 8-15 h, and then sequentially subjected to suction filtration and cleaning 2-5 times to obtain a solid powder; the cleaning liquid used in the cleaning process comprises deionized water;

[0051] (2) Phosphoric acid with a concentration of 0.2-5 wt%, potassium water glass with a concentration of 0.5-0.8 wt% and the solid powder obtained in step (1) are mixed, stirred and dried at a temperature of 80-120°C under a protective atmosphere to obtain a dry insulating powder; the mass of the phosphoric acid is 0.01-2 wt% of the mass of the solid powder; the mass of the potassium water glass is 0.1-2 wt% of the mass of the solid powder;

[0052] (3) The insulating powder obtained in step (2) is subjected to compression molding under a pressure of 1000-2000 MPa to obtain a ring-shaped magnetic ring with an outer diameter of 25-30 mm and an inner diameter of 15-25 mm, and then sintered at a temperature of 720-750°C for 30-90 min under a protective atmosphere or a reducing atmosphere to obtain the metal soft magnetic powder core.

[0053] In the second aspect, the present application provides a metal soft magnetic powder core, which is prepared by the preparation method provided in the first aspect.

[0054] In the third aspect, the present application provides an application of the metal soft magnetic powder core prepared by the preparation method provided in the first aspect, and the metal soft magnetic powder core is used for preparing an electronic device.

[0055] The electronic device of the present application can be a high-frequency electronic device, and the frequency of the high-frequency electronic device is 500 KHz-1 MHz.

[0056] The numerical range described in the present application includes not only the point values exemplified above, but also any point values between the above numerical ranges not exemplified, and the present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0057] Compared with the prior art, the present application has the following beneficial effects:

[0058] (1) The preparation method of the metal soft magnetic powder core provided by the present application solves the problem of low utilization rate of metal magnetic powder and the inability to make it finer, thereby reducing the high-frequency loss of the metal soft magnetic powder core.

[0059] (2) The metal soft magnetic powder core provided by the present application has a lower high-frequency loss, meeting the device application requirements of high-frequency switching power supply. DETAILED DESCRIPTION

[0060] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application and should not be regarded as specific limitations on the present application.

[0061] Example 1

[0062] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, the preparation method comprising the following steps:

[0063] (1) Under an argon atmosphere, metal magnetic powder with an average particle size of 300 mesh is soaked with a composite solution with a mass concentration of 2.3wt%, stirred at a speed of 60r / min for 10h, and then sequentially subjected to suction filtration and cleaning 3 times to obtain a solid powder; deionized water is used as the cleaning liquid in the cleaning; the metal magnetic powder is iron-nickel magnetic powder; and the composite solution is a hydrochloric acid solution;

[0064] (2) Phosphoric acid with a concentration of 2.8wt%, potassium water glass with a concentration of 0.65wt%, and the solid powder obtained in step (1) are mixed, stirred, and dried at a temperature of 100℃ under a nitrogen atmosphere to obtain a dry insulating powder; the mass of the phosphoric acid is 1.35wt% of the mass of the solid powder; and the mass of the potassium water glass is 1.35wt% of the mass of the solid powder;

[0065] (3) The insulating powder obtained in step (2) is pressed at a pressure of 1500MPa to obtain a ring-shaped magnetic ring with an outer diameter of 27mm and an inner diameter of 20mm, and then sintered at a temperature of 740℃ for 60min in a nitrogen atmosphere to obtain the metal soft magnetic powder core.

[0066] Example 2

[0067] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, the preparation method comprising the following steps:

[0068] (1) under argon atmosphere, using a composite solution with a mass concentration of 0.2wt% to soak metal magnetic powder with an average particle size of 200 mesh, stirring at a speed of 50r / min for 8h, then sequentially performing suction filtration and cleaning twice to obtain a solid powder; deionized water is used as the cleaning solution in the cleaning; the metal magnetic powder is iron-nickel magnetic powder;

[0069] (2) mixing phosphoric acid with a concentration of 0.2wt%, potassium water glass with a concentration of 0.8wt% and the solid powder obtained in step (1), stirring and drying at a temperature of 80°C under nitrogen atmosphere to obtain a dry insulation powder; the mass of the phosphoric acid is 2wt% of the mass of the solid powder; the mass of the potassium water glass is 0.1wt% of the mass of the solid powder; the composite solution is a phosphoric acid solution;

[0070] (3) performing press forming on the insulation powder obtained in step (2) under a pressure of 1000MPa to obtain a ring-shaped magnetic ring with an outer diameter of 25mm and an inner diameter of 15mm, and then sintering in a hydrogen atmosphere at a temperature of 720°C for 90min to obtain the metal soft magnetic powder core.

[0071] Example 3

[0072] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, the preparation method comprising the following steps:

[0073] (1) under nitrogen atmosphere, using a composite solution with a mass concentration of 5wt% to soak metal magnetic powder with an average particle size of 500 mesh, stirring at a speed of 70r / min for 15h, then sequentially performing suction filtration and cleaning 5 times to obtain a solid powder; deionized water is used as the cleaning solution in the cleaning; the metal magnetic powder is iron-nickel magnetic powder; the composite solution is a phosphoric acid solution;

[0074] (2) mixing phosphoric acid with a concentration of 5wt%, potassium water glass with a concentration of 0.5wt% and the solid powder obtained in step (1), stirring and drying at a temperature of 120°C under helium atmosphere to obtain a dry insulation powder; the mass of the phosphoric acid is 0.01wt% of the mass of the solid powder; the mass of the potassium water glass is 2wt% of the mass of the solid powder;

[0075] (3) performing press forming on the insulation powder obtained in step (2) under a pressure of 2000MPa to obtain a ring-shaped magnetic ring with an outer diameter of 30mm and an inner diameter of 25mm, and then sintering in a carbon monoxide atmosphere at a temperature of 720°C for 90min to obtain the metal soft magnetic powder core.

[0076] Example 4

[0077] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, the preparation method comprising the following steps:

[0078] (1) The solid powder was obtained by immersing the metal magnetic powder with an average particle size of 500 mesh in a composite solution with a mass concentration of 3.2 wt%, stirring at a speed of 60 r / min for 12 h, and then sequentially performing suction filtration and cleaning 4 times under a helium atmosphere; the cleaning liquid used in the cleaning was deionized water; the metal magnetic powder was iron-nickel magnetic powder; and the composite solution was a hydrochloric acid solution;

[0079] (2) The dry insulation powder was obtained by mixing phosphoric acid with a concentration of 0.46 wt%, potassium water glass with a concentration of 0.39 wt%, and the solid powder obtained in step (1), stirring, and drying at a temperature of 105°C under an argon atmosphere; the mass of the phosphoric acid was 1.2 wt% of the mass of the solid powder; and the mass of the potassium water glass was 1.8 wt% of the mass of the solid powder;

[0080] (3) The insulation powder obtained in step (2) was pressed at a pressure of 1200 MPa to obtain a ring-shaped magnetic ring with an outer diameter of 27 mm and an inner diameter of 17 mm, and then sintered at a temperature of 735°C for 50 min under an argon atmosphere to obtain the metal soft magnetic powder core.

[0081] Example 5

[0082] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, wherein the difference between the preparation method and that of Example 1 is that the concentration of the composite solution in step (1) is changed to 6 wt% in the present embodiment.

[0083] Example 6

[0084] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, wherein the difference between the preparation method and that of Example 1 is that the concentration of the composite solution in step (1) is changed to 0.1 wt% in the present embodiment.

[0085] Example 7

[0086] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, wherein the difference between the preparation method and that of Example 1 is that the mesh number of the metal magnetic powder in step (1) is changed to 600 mesh in the present embodiment.

[0087] Example 8

[0088] The present embodiment provides a metal soft magnetic powder core and a preparation method thereof, wherein the difference between the preparation method and that of Example 1 is that the mesh number of the metal magnetic powder in step (1) is changed to 1000 mesh in the present embodiment.

[0089] Example 9

[0090] The embodiment provides a metal soft magnetic powder core and a preparation method thereof, and the preparation method is different from that of the embodiment 1 only in that the sintering temperature in the step (3) is changed to 700 DEG C.

[0091] Embodiment 10

[0092] The embodiment provides a metal soft magnetic powder core and a preparation method thereof, and the preparation method is different from that of the embodiment 1 only in that the sintering temperature in the step (3) is changed to 780 DEG C.

[0093] Comparative example 1

[0094] The comparative example provides a metal soft magnetic powder core and a preparation method thereof, and the preparation method is different from that of the embodiment 1 only in that the argon atmosphere in the step (1) is changed to an air atmosphere.

[0095] Comparative example 2

[0096] The comparative example provides a metal soft magnetic powder core and a preparation method thereof, and the preparation method is different from that of the embodiment 1 only in that the step (1) is omitted.

[0097] Comparative example 3

[0098] The comparative example provides a metal soft magnetic powder core and a preparation method thereof, and the preparation method is different from that of the embodiment 1 only in that the step (1) is omitted.

[0099] The metal soft magnetic powder cores prepared in the embodiment 1-10 and the comparative examples 1-3 are subjected to performance tests, and the test results are shown in table 1.

[0100] The metal soft magnetic powder cores prepared in the embodiment 1-10 and the comparative examples 1-3 are subjected to permeability tests by using the test conditions shown in table 1, and the permeability is 60H / m after rounding.

[0101] Table 1

[0102]

[0103] As shown in table 1, by analyzing the embodiment 1 and the embodiment 5-10 and the comparative examples 1-3, the metal soft magnetic powder core prepared by using the preparation method provided in the embodiment has low high-frequency loss. In conclusion, the preparation method of the metal soft magnetic powder core provided in the embodiment solves the problem that the metal magnetic powder core powder has low utilization rate and cannot be made finer, thereby reducing the high-frequency loss of the metal soft magnetic powder core. In addition, the metal soft magnetic powder core provided in the embodiment has low high-frequency loss, and meets the device application requirement of high-frequency of a switching power supply.

[0104] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above-described specific embodiments are merely examples of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a metal soft magnetic powder core having a low high-frequency loss, characterized by, The preparation method comprises the following steps: (1) under a protective atmosphere, metal magnetic powder is soaked in a composite solution, and after stirring, the metal magnetic powder is sequentially subjected to filtration and washing to obtain solid powder; the average particle size of the metal magnetic powder in step (1) is ≤500 mesh; the composite solution comprises an acidic solution; the acidic solution comprises a phosphoric acid solution; the mass concentration of the composite solution is 0.2-5 wt%; the number of times of washing is 2-5 times; the washing liquid used in the washing comprises deionized water; (2) phosphoric acid, potassium water glass and the solid powder obtained in step (1) are mixed, and after stirring and drying, insulating powder is obtained; the concentration of the phosphoric acid is 0.2-5 wt%; the mass of the phosphoric acid is 0.01-2 wt% of the mass of the solid powder; the concentration of the potassium water glass is 0.5-0.8 wt%; the mass of the potassium water glass is 0.1-2 wt% of the mass of the solid powder; (3) the insulating powder obtained in step (2) is sequentially subjected to compression molding and sintering to obtain the metal soft magnetic powder core; the sintering temperature in step (3) is 720-750 ℃; the sintering time is 30-90 min.

2. The production method according to claim 1, characterized by, The protective atmosphere in step (1) comprises a nitrogen atmosphere and / or an inert gas atmosphere.

3. The production method according to claim 2, characterized by, The inert gas atmosphere comprises an argon atmosphere and / or a helium atmosphere.

4. The method of claim 1, wherein, The stirring time in step (1) is 8-15 h.

5. The preparation method according to claim 1, characterized in that, The stirring speed is 50-70 r / min.

6. The method of claim 1, wherein, The metal magnetic powder in step (1) comprises any one or a combination of at least two of iron-nickel magnetic powder, iron-silicon-aluminum magnetic powder, iron-silicon magnetic powder or iron-nickel-molybdenum magnetic powder.

7. The preparation method according to claim 1, characterized in that, The filtration in step (1) comprises suction filtration.

8. The method of claim 1, wherein, The drying temperature in step (2) is 80-120 ℃.

9. The method of claim 1, wherein, The drying in step (2) is performed in a protective atmosphere.

10. The method of claim 9, wherein, The protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere.

11. The method of claim 1, wherein, The end point of the drying in step (2) is to obtain dry insulating powder.

12. The method of claim 1, wherein, The compression molding pressure in step (3) is 1000-2000 MPa.

13. The method of claim 1, wherein, The shape of the compression molding in step (3) comprises a ring-shaped magnetic ring.

14. The method of claim 13, wherein, The outer diameter of the ring-shaped magnetic ring is 25-30 mm.

15. The preparation method according to claim 13, characterized in that, The inner diameter of the ring-shaped magnetic ring is 15-25 mm.

16. The method of claim 1, wherein, The sintering in step (3) is performed in a protective atmosphere or a reducing atmosphere.

17. The preparation method according to claim 16, characterized in that, The protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere.

18. The method of claim 16, wherein, The reducing atmosphere comprises a hydrogen atmosphere and / or a carbon monoxide atmosphere.

19. The method of claim 1, wherein, The preparation method comprises the following steps: (1) under a protective atmosphere, metal magnetic powder with an average particle size of ≤500 mesh is soaked in a composite solution with a mass concentration of 0.2-5 wt%, and stirring is performed at a speed of 60 r / min for 8-15 h, and then suction filtration and washing are sequentially performed for 2-5 times to obtain solid powder; the washing liquid used in the washing comprises deionized water; (2) phosphoric acid with a concentration of 0.2-1 wt%, potassium water glass with a concentration of 0.5-0.8 wt% and the solid powder obtained in step (1) are mixed, and after stirring and drying at a temperature of 80-120 ℃ in a protective atmosphere, dry insulating powder is obtained; the mass of the phosphoric acid is 0.01-2 wt% of the mass of the solid powder; the mass of the potassium water glass is 0.1-2 wt% of the mass of the solid powder; (3) The insulating powder obtained in step (2) is subjected to compression molding under a pressure of 1000-2000 MPa to obtain a ring-shaped magnetic ring with an outer diameter of 25-30 mm and an inner diameter of 15-25 mm, and then sintered at a temperature of 720-750 °C for 30-90 min in a protective atmosphere or a reducing atmosphere to obtain the metal soft magnetic powder core.

20. A metal soft magnetic powder core, characterized by The metal soft magnetic powder core is obtained by the preparation method according to any one of claims 1-19.

21. Use of a metal soft magnetic powder core according to claim 20, characterized in that The metal soft magnetic powder core is used for preparing an electronic device.

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