Magnetic powder core material, preparation method therefor and use thereof

Abstract

Provided in the present application are a magnetic powder core material, a preparation method therefor and the use thereof. The surface of the magnetic powder core material is coated with a hydrophobic film. The raw materials of the magnetic powder core comprise: a metal magnetic powder core raw material, silica sol, a phosphorus source, adhesive and demolding powder. The preparation method comprises: successively performing annealing, insulation, adhesive coating, demolding forming and sintering on the metal magnetic powder core raw material to obtain the magnetic powder core material. The magnetic powder core prepared by the present application can block water vapor, such that the magnetic powder core does not react with water vapor in the environment, thereby preventing corrosion and rusting of the magnetic powder core, achieving long-time stable storage under temperatures, and improving the inductance characteristic of the magnetic powder core.

Description

A magnetic powder core material and its preparation method and application Technical Field

[0001] The present application relates to the field of magnetic materials, such as a magnetic powder core material, and in particular to a magnetic powder core material and a preparation method and application thereof. Background Art

[0002] Magnetic powder cores, due to their excellent magnetic properties in AC magnetic fields, are widely used in telecommunications, computers, servers, control systems, photovoltaic power generation, automotive, and other fields. The domestic market for magnetic powder cores is rapidly increasing, and the market outlook is promising. The fields in which magnetic powder cores are used place very high demands on product reliability, generally defining this as requiring that the performance variation rate after reliability testing cannot exceed ±10%, and that the product's appearance must be free of rust.

[0003] However, magnetic powder cores themselves consist of a large amount of Fe combined with small amounts of Si, Al, and Ni metal elements, so the environment significantly impacts their stability. It is crucial to ensure that the metal powder cores, after coating, are rust-proof, maintain stable properties in high-temperature and high-humidity environments, and ensure that the products can withstand a service life of more than ten years at the customer's end, while also maintaining the properties and appearance required in harsh environments.

[0004] CN114664509A discloses a double-coated iron-based magnetic powder, its preparation method, and application. The double-coated iron-based magnetic powder comprises an inner core, a phosphate coating, and a bismaleimide resin coating. The magnetic powder core produced from the double-coated iron-based magnetic powder exhibits excellent heat resistance, low loss, and low production cost.

[0005] CN109545537A discloses a magnetic powder and its preparation method. The method involves mixing carbonyl iron powder with a phosphating solution, followed by phosphating to obtain treated iron powder; drying and screening the treated iron powder, and then mixing and coating it with an insulating coating agent to obtain a coated powder; the insulating coating agent comprises an organic resin, an inorganic coating material, a coupling agent, and a curing agent; and granulating the coated powder, pressing and curing it to obtain a magnetic powder core. However, the resulting magnetic powder core exhibits poor water vapor insulation performance.

[0006] However, in the currently disclosed related technologies, the ability of the magnetic powder core to isolate water vapor needs to be further improved. Therefore, how to prepare a magnetic powder core that can prevent rust is an important research direction in this field.

[0007] Summary of the Invention

[0008] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0009] The present application provides a magnetic powder core, a preparation method thereof, and an application thereof. By optimizing the coating process formula of the material, the surface of the prepared magnetic powder core does not rust during reliability testing, and the change rate of the inductance characteristics is controlled within ±2%.

[0010] One of the purposes of the present application is to provide a magnetic powder core material, the surface of which is coated with a hydrophobic film. The raw materials of the magnetic powder core material include: metal magnetic powder core raw material, silica sol, phosphorus source, glue and release powder.

[0011] This application produces a magnetic powder core material coated with a hydrophobic film. This film blocks any contact with external moisture, preventing the core from reacting with it. This prevents corrosion and rust, which could affect the material's inductance. The resulting magnetic powder core can be stably stored over extended periods of time and at varying temperatures.

[0012] In the present application, the magnetic powder core is prepared by using glue, so that the coated powder achieves an ideal granulation effect, making the ultrafine powder easy to shape without cracking, and can be formed into products with complex structures.

[0013] As an optional technical solution of the present application, based on the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the metal magnetic powder core raw material is 96.8-98.5%, wherein the mass fraction can be 96.8%, 96.9%, 97.0%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8%, 97.9%, 98%, 98.1%, 98.2%, 98.3% or 98.4%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0014] In one embodiment, based on the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the silica sol is 0.3-0.9%, wherein the mass fraction can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8% or 0.9%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0015] In one embodiment, based on the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the phosphorus source is 0.3-0.6%, wherein the mass fraction can be 0.3%, 0.4%, 0.5% or 0.6%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0016] In one embodiment, based on the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the glue is 0.8-1.2%, wherein the mass fraction can be 0.8%, 0.9%, 1.0%, 1.1% or 1.2%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0017] In one embodiment, based on the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the demolding powder is 0.1-0.5%, wherein the mass fraction can be 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0018] As an optional technical solution of the present application, the metal magnetic powder core raw material includes any one of iron silicon, sendust or iron nickel, or a combination of at least two of them, wherein typical but non-limiting examples of the combination include: a combination of iron silicon and sendust, a combination of sendust and iron nickel, or a combination of iron silicon and iron nickel, etc.

[0019] In one embodiment, the silica sol includes any one or a combination of at least two of kaolin, SiO2 or dicalcium phosphate, wherein typical but non-limiting examples of the combination include: a combination of kaolin and SiO2, a combination of SiO2 and dicalcium phosphate, or a combination of kaolin and dicalcium phosphate.

[0020] In one embodiment, the phosphorus source comprises phosphoric acid and / or aluminum dihydrogen phosphate.

[0021] In one embodiment, the glue comprises any one or a combination of at least two of silicone epoxy resin, potassium water glass, methylchlorosilane or high-temperature glue, wherein typical but non-limiting examples of the combination include: a combination of silicone epoxy resin and potassium water glass, a combination of potassium water glass and white powdered glue, a combination of potassium water glass and methylchlorosilane, or a combination of white powdered glue and high-temperature glue, etc.

[0022] In one embodiment, the demoulding powder includes any one of MgO, Al2O3 or SKZ100-B or a combination of at least two of them, wherein typical but non-limiting examples of the combination include: a combination of MgO and Al2O3, a combination of Al2O3 and SKZ100-B, or a combination of MgO and SKZ100-B, etc.

[0023] The second object of this application is to provide a method for preparing the magnetic powder core material as described in the first object, the preparation method comprising:

[0024] The raw materials of the metal magnetic powder core material are sequentially subjected to annealing, insulation, glue coating, demoulding and sintering to obtain the magnetic powder core material.

[0025] The present application coats the metal magnetic powder core with glue so that a hydrophobic film is formed on the surface of the coated magnetic powder core, thereby ensuring that after the magnetic powder core is prepared, water vapor can be blocked during the contact between the magnetic powder core and the external water vapor, thereby preventing the magnetic powder core itself from reacting with the water vapor in the environment, preventing the magnetic powder core from corroding and rusting, improving the inductance specificity of the magnetic powder core, and thus improving the stable storage of the magnetic powder core under long-term and high-temperature conditions.

[0026] In one embodiment, the annealing temperature is 900-920°C, wherein the temperature can be 900°C, 902°C, 904°C, 906°C, 908°C, 910°C, 912°C, 914°C, 916°C, 918°C or 920°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In one embodiment, the annealed powder is subjected to a first sieving.

[0028] In one embodiment, the D50 particle size of the first sifted powder is 5 to 35 μm, wherein the D50 particle size can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm or 35 μm, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0029] As an optional technical solution of the present application, the insulation method includes: first mixing the silica sol and the annealed powder.

[0030] In one embodiment, after the first mixing, the powder is subjected to a second sieving and then phosphating.

[0031] In one embodiment, the mesh size of the second sieving is 70 to 90 meshes, wherein the mesh size can be 70 mesh, 72 mesh, 74 mesh, 76 mesh, 78 mesh, 80 mesh, 82 mesh, 84 mesh, 86 mesh, 88 mesh or 90 mesh, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] In one embodiment, the phosphating method includes: performing a second mixing of the phosphorus source, the second sieved powder, and the organic solvent.

[0033] In one embodiment, the organic solvent comprises any one of ethanol, acetone, NN-dimethylformamide or xylene, or a combination of at least two thereof, wherein typical but non-limiting examples of the combination include: a combination of ethanol and acetone, a combination of acetone and NN-dimethylformamide, or a combination of NN-dimethylformamide and xylene, etc.

[0034] In one embodiment, the mass ratio of the phosphorus source and the second sifted powder is (90-99):(10-1), wherein the mass ratio can be 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, 98:2 or 99:1, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0035] In one embodiment, the temperature of the second mixing is 25 to 85°C, wherein the temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C or 85°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] The phosphating temperature in this application is 25-85°C.

[0037] In one embodiment, the solid content of the second mixture is 97-99%, wherein the solid content can be 97%, 98% or 99%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In one embodiment, after the second mixing, the powder is dried and sieved for a third time.

[0039] In one embodiment, the drying temperature is 100-140°C, wherein the temperature can be 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C or 140°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In one embodiment, the mesh size of the third sieving is 60 to 100 meshes, wherein the mesh size can be 60 mesh, 65 mesh, 70 mesh, 75 mesh, 80 mesh, 85 mesh, 90 mesh, 95 mesh or 100 mesh, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] As an optional technical solution of the present application, the glue coating method includes: performing a third mixing of the glue, the insulated powder and the organic solvent.

[0042] In one embodiment, the organic solvent comprises any one of ethanol, acetone, NN-dimethylformamide or xylene, or a combination of at least two thereof, wherein typical but non-limiting examples of the combination include: a combination of ethanol and acetone, a combination of acetone and NN-dimethylformamide, or a combination of NN-dimethylformamide and xylene, etc.

[0043] The present application selects a solvent with an oily group and an organic glue that can be dissolved by the oily solvent to prepare a coated magnetic powder core, and a hydrophobic film can be formed on the surface of the magnetic powder core.

[0044] In one embodiment, the solid content of the third mixture is 91-94%, wherein the solid content can be 91%, 91%, 93% or 94%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In one embodiment, the powder is subjected to a fourth sieving after the third mixing.

[0046] In one embodiment, the mesh size of the fourth sieving is 60 to 100 meshes, wherein the mesh size can be 60 mesh, 65 mesh, 70 mesh, 75 mesh, 80 mesh, 85 mesh, 90 mesh, 95 mesh or 100 mesh, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] As an optional technical solution of the present application, the demoulding molding includes: adding demoulding powder to the powder coated with glue.

[0048] In one embodiment, the fifth sieving is performed after the release powder is added.

[0049] In one embodiment, the mesh size of the fifth sieve is 60 to 100 meshes, wherein the mesh size can be 60 mesh, 65 mesh, 70 mesh, 75 mesh, 80 mesh, 85 mesh, 90 mesh, 95 mesh or 100 mesh, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In one embodiment, the molding density of the demoulding molding is greater than 5.9 g / cm 3 wherein the molding density may be 5.9 g / cm 3 , 6.0g / cm 3 、6.1g / cm 3 、6.2g / cm 3 、6.5g / cm 3 , 7.0g / cm 3 , 7.5g / cm 3 , 8.0g / cm 3 , 8.5g / cm 3 or 9g / cm 3 etc., but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] In one embodiment, the sintering temperature is 650-750°C, wherein the temperature can be 650°C, 660°C, 670°C, 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C or 750°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] As an optional technical solution of this application, the preparation method includes:

[0053] The raw material of the metal magnetic powder core material is sequentially subjected to annealing at 900-920° C., insulation, glue coating, demolding, and sintering at 650-750° C. to obtain the magnetic powder core material;

[0054] The insulation method includes: mixing silica sol and annealed powder, followed by a second screening and phosphating, and the phosphating method includes: mixing a phosphorus source, the second screened powder and an organic solvent, followed by drying at a temperature of 100 to 140° C. and a third screening.

[0055] The method of adding glue and coating comprises: sequentially mixing glue, insulated powder and organic solvent and sieving for the fourth time;

[0056] The demoulding method comprises: adding demoulding powder to the powder after the glue coating, and the molding density of the demoulding is greater than 5.9g / cm 3 .

[0057] The third object of this application is to provide an application of the magnetic powder core material as described in the first object, wherein the magnetic powder core is used in the field of magnetic materials.

[0058] Compared with the related art, this application has the following beneficial effects:

[0059] (1) The magnetic powder core prepared in this application can block water vapor, so that the magnetic powder core itself does not react with water vapor in the environment, preventing the corrosion and rust of the magnetic powder core. It can be stably stored for a long time and temperature. It can be stored for 1000 hours at 85°C, which is equivalent to about 15 years of storage at room temperature.

[0060] (2) The magnetic powder core prepared in this application has very fine powder, is easy to shape, does not crack, and can be molded into products with complex structures;

[0061] (3) This application improves the performance of the inductance characteristics, Q value, 100Oe stacking and 50K / 100mT power consumption of the magnetic powder core, among which the magnetic permeability is 19-90, Q can be as high as 152 or more, the 100Oe stacking ratio can be as high as 72 or more, and the power consumption can be as low as 100mW / cm 3 the following.

[0062] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0064] FIG1 is a cross-sectional electron microscope image of the magnetic powder core prepared in Example 1 of the present application.

[0065] FIG2 is a cross-sectional electron microscope image of the magnetic powder core prepared in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0066] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0067] Example 1

[0068] This embodiment provides a magnetic powder core, the surface of which is coated with a hydrophobic film. The raw materials of the magnetic powder core include 0.6% kaolin, 0.5% phosphoric acid, 1% organic silicon epoxy resin, 0.3% MgO and 97.6% iron silicon.

[0069] This embodiment provides a method for preparing the magnetic powder core, which comprises:

[0070] The iron silicon is subjected to annealing, insulation, glue coating, demoulding and sintering in sequence to obtain the magnetic powder core material;

[0071] The annealing method includes: annealing the ferrosilicon in a nitrogen environment at 910° C. and then performing a first screening, wherein the D50 particle size of the powder after the first screening is 30 μm.

[0072] The insulation method comprises: mixing kaolin and annealed powder, followed by a second sieving and phosphating, wherein the mesh number of the second sieving is 80 mesh; the phosphating method comprises: mixing 50% phosphoric acid, the second sieving powder, and acetone (solid content is 98%), followed by drying at a temperature of 120° C. and a third sieving, wherein the mesh number of the third sieving is 80 mesh;

[0073] The method of adding glue and coating comprises: mixing the organic silicon epoxy resin, the insulated powder and ethanol in sequence (solid content is 92%) and sieving for the fourth time, wherein the mesh number of the fourth sieving is 80 meshes;

[0074] The demoulding method comprises: adding MgO to the powder after the glue coating, and the molding density of the demoulding is greater than 5.9g / cm 3 ;

[0075] Sintering includes: placing the demoulded product into a sintering furnace at a sintering temperature of 700°C.

[0076] The cross-sectional electron microscope image of the magnetic powder core prepared in this embodiment is shown in FIG1 .

[0077] Example 2

[0078] This embodiment provides a magnetic powder core, wherein the surface of the magnetic powder core material is coated with a hydrophobic film, and the raw materials of the magnetic powder core include 0.7% SiO2, 0.5% phosphoric acid, 1% potassium water glass, 0.3% Al2O3 and 97.5% magnetic powder core.

[0079] This embodiment provides a method for preparing the magnetic powder core, which comprises:

[0080] The iron silicon is subjected to annealing, insulation, glue coating, demoulding and sintering in sequence to obtain the magnetic powder core material;

[0081] The annealing method includes: annealing the ferrosilicon in a nitrogen environment at 900° C. and then performing a first screening, wherein the D50 particle size of the powder after the first screening is 30 μm.

[0082] The insulation method comprises: mixing SiO2 and annealed powder, followed by a second screening and phosphating, wherein the mesh number of the second screening is 70 mesh; the phosphating method comprises: mixing 50% phosphoric acid, the second screened powder, and NN-dimethylformamide (solid content is 97%), followed by drying at a temperature of 100° C. and a third screening, wherein the mesh number of the third screening is 70 mesh;

[0083] The method of adding glue and coating comprises: mixing potassium water glass, insulated powder and NN-dimethylformamide in sequence (solid content is 94%) and sieving for the fourth time, wherein the mesh number of the fourth sieving is 70 meshes;

[0084] The demoulding method comprises: adding Al2O3 to the powder after the glue coating, and the molding density of the demoulding is greater than 5.9g / cm 3 ;

[0085] Sintering includes: placing the demoulded product into a sintering furnace at a sintering temperature of 650°C.

[0086] Example 3

[0087] This embodiment provides a magnetic powder core, the surface of which is coated with a hydrophobic film. The raw materials of the magnetic powder core include 0.8% dicalcium phosphate, 0.5% phosphoric acid, 1% high-temperature glue, 0.3% SKZ100-B and 97.4% iron silicon.

[0088] This embodiment provides a method for preparing the magnetic powder core, which comprises:

[0089] The iron silicon is subjected to annealing, insulation, glue coating, demoulding and sintering in sequence to obtain the magnetic powder core material;

[0090] The annealing method includes: annealing the ferrosilicon in a nitrogen environment at 920° C. and then performing a first sieving, wherein the D50 particle size of the powder after the first sieving is 35 μm.

[0091] The insulation method includes: mixing dicalcium phosphate and annealed powder, followed by a second screening and phosphating, wherein the mesh size of the second screening is 90 mesh; the phosphating method includes: mixing 50% phosphoric acid, the second screened powder, and acetone (solid content is 99%), followed by drying at a temperature of 140° C. and a third screening, wherein the mesh size of the third screening is 100 mesh;

[0092] The glue coating method comprises: mixing high temperature glue, insulated powder and ethanol in sequence (solid content is 91%) and sieving for the fourth time, wherein the mesh number of the fourth sieving is 100 meshes;

[0093] The demoulding method comprises: adding SKZ100-B to the powder after the glue coating, and the molding density of the demoulding is greater than 5.9g / cm 3 ;

[0094] Sintering includes: placing the demoulded product into a sintering furnace at a sintering temperature of 700°C.

[0095] Example 4

[0096] In this embodiment, except that 0.6% of the kaolin is replaced by 0.9% and 97.6% of the iron silicon is replaced by 97.3%, other conditions are the same as those in embodiment 1.

[0097] Example 5

[0098] In this embodiment, except that 0.5% of phosphoric acid is replaced by 0.4% and 97.6% of iron silicon is replaced by 97.7%, other conditions are the same as those in embodiment 1.

[0099] Example 6

[0100] In this embodiment, the conditions are the same as those in Example 1 except that 0.6% of the kaolin is replaced by 0.7% and 0.5% of the phosphoric acid is replaced by 0.4%.

[0101] Example 7

[0102] In this embodiment, except that 0.6% of kaolin is replaced by 0.8%, 0.5% of phosphoric acid is replaced by 0.4%, and 97.6% of iron silicon is replaced by 97.5%, other conditions are the same as those in embodiment 1.

[0103] Example 8

[0104] In this embodiment, except that 0.6% of kaolin is replaced by 0.9%, 0.5% of phosphoric acid is replaced by 0.4%, and 97.6% of iron silicon is replaced by 97.4%, other conditions are the same as those in embodiment 1.

[0105] Example 9

[0106] In this comparative example, except that 0.6% of the kaolin was replaced by 0.1% and 97.6% of the iron silicon was replaced by 98.1%, other conditions were the same as those in Example 1.

[0107] Example 10

[0108] In this comparative example, except that 0.6% of the kaolin is replaced by 1.2% and 97.6% of the iron silicon is replaced by 97%, other conditions are the same as those of Example 1.

[0109] Example 11

[0110] In this comparative example, the conditions are the same as those in Example 1 except that 0.5% of phosphoric acid is replaced by 0.1% and 97.6% of iron silicon is replaced by 98%.

[0111] Example 12

[0112] In this comparative example, the conditions are the same as those in Example 1, except that 0.5% of phosphoric acid is replaced by 1.0% and 97.6% of iron silicon is replaced by 97.1%.

[0113] Comparative Example 1

[0114] In this comparative example, except that the step of adding glue and coating is not performed, other conditions are the same as those in Example 1.

[0115] The cross-sectional electron microscope image of the magnetic powder core prepared in this comparative example is shown in FIG2 .

[0116] The magnetic powder cores prepared in Examples 1-12 and Comparative Example 1 were tested for inductance characteristic change rate, Q value, 100 Oe superposition, 50 K / 100 mT power consumption and aging degree. The test results are shown in Table 1.

[0117] The inductance and Q value are tested using the WK3260B inductor meter, and the power consumption is tested using the SY8218 power consumption tester. The specific test methods are as follows:

[0118] 1. Inductance test: L: (46.8±3.8)μH

[0119] Test conditions: CH1061A / 100KHz / 0.25V / 0.4mm / 25TS.

[0120] 2. Q value test: Q2100

[0121] Test conditions: CH1061A / 100KHz / 0.25V / p0.4mm / 25TS.

[0122] 3. Superposition test: L20A / LOA250%

[0123] Test conditions: CH1061A / 100KHz / 1V / 00.4mm / 25TS.

[0124] 4. Loss test: 50k / 100mT<100mw / cm 3

[0125] Test conditions: SY8218 N1=22Ts N2=22TS p=0.4mm 25℃

[0126] 5. Room temperature storage test: Use the life law to design accelerated experiments (for example, if the temperature rises according to the law of 10°C, the life of the electronic product will be shortened according to the law of 2n). This application tests the storage time at 85°C to represent the storage time at room temperature.

[0127] Table 1

[0128] It can be seen from Examples 1-8 that the magnetic powder core material prepared in the present application will not react with water vapor in the environment both inside and outside due to the hydrophobic film coated on the surface, thereby preventing corrosion and rust of the magnetic powder core and improving the inductance characteristics of the magnetic powder core.

[0129] By comparing Example 1 with Examples 9-10, it can be seen that when the content of silica sol is too low, the magnetic permeability of the prepared magnetic powder core material decreases, and regardless of whether the content of silica sol is too low or too high, the anti-rust performance of the prepared magnetic powder core material is slightly reduced; by comparing Example 1 with Examples 11-12, it can be seen that when the content of phosphoric acid is too high or too low, the anti-rust performance and inductance performance of the prepared magnetic powder core material are both reduced.

[0130] By comparing Example 1 with Comparative Example 1, it can be seen that the magnetic powder core prepared without the glue coating step does not have the effect of preventing the magnetic powder core from reacting with water vapor in the environment.

[0131] The applicant declares that the above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Technical personnel in the relevant technical field should understand that any changes or substitutions that can be easily thought of by technical personnel in the relevant technical field within the technical scope disclosed in this application fall within the protection scope and disclosure scope of this application.

Claims

1. A magnetic powder core material, wherein: The surface of the magnetic powder core material is coated with a hydrophobic film, and the raw materials of the magnetic powder core material include: metal magnetic powder core raw material, silica sol, phosphorus source, glue and demoulding powder.

2. The magnetic powder core material according to claim 1, wherein: Taking the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the metal magnetic powder core raw material is 96.8-98.5%.

3. The magnetic powder core material according to claim 1 or 2, wherein: Taking the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the silica sol is 0.3-0.9%.

4. The magnetic powder core material according to any one of claims 1 to 3, wherein: Taking the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the phosphorus source is 0.3-0.6%.

5. The magnetic powder core material according to any one of claims 1 to 4, wherein: Taking the total mass of the raw materials of the magnetic powder core material as 100%, the mass fraction of the glue is 0.8-1.2%; Optionally, based on the total mass of the raw materials of the magnetic powder core material being 100%, the mass fraction of the demoulding powder is 0.1-0.5%.

6. The magnetic powder core material according to any one of claims 1 to 5, wherein: The metal magnetic powder core raw material includes any one of iron silicon, iron silicon aluminum or iron nickel, or a combination of at least two thereof; Optionally, the silica sol includes any one or a combination of at least two of kaolin, SiO2 or dicalcium phosphate; Optionally, the phosphorus source includes phosphoric acid and / or aluminum dihydrogen phosphate; Optionally, the glue includes any one or a combination of at least two of silicone epoxy resin, potassium water glass, methylchlorosilane or high temperature glue; Optionally, the demoulding powder includes any one of MgO, Al2O3 or SKZ100-B or a combination of at least two of them.

7. A method for preparing a magnetic powder core material according to any one of claims 1 to 6, comprising: The raw materials of the metal magnetic powder core are annealed, insulated, coated with glue, demoulded and sintered in sequence. knot to obtain the magnetic powder core material.

8. The preparation method according to claim 7, wherein: The annealing temperature is 900-920°C.

9. The preparation method according to claim 7 or 8, wherein: Performing a first screening on the annealed powder; Optionally, the D50 particle size of the first sieved powder is 5 to 35 μm.

10. The preparation method according to any one of claims 7 to 9, wherein: The insulation method comprises: first mixing silica sol and annealed powder.

11. The preparation method according to any one of claims 7 to 10, wherein: After the first mixing, the powder is subjected to a second screening and then phosphating; Optionally, the mesh size of the second sieving is 70 to 90 meshes; Optionally, the phosphating method comprises: performing a second mixing of the phosphorus source, the second sieved powder and an organic solvent; Optionally, the organic solvent includes any one of ethanol, acetone, NN-dimethylformamide or xylene, or a combination of at least two thereof; Optionally, the mass ratio of the phosphorus source to the second sieved powder is (90-99):(10-1); Optionally, the temperature of the second mixing is 25 to 85°C; Optionally, the second mixture has a solid content of 97-99%; Optionally, after the second mixing, the powder is dried and sieved for a third time; Optionally, the drying temperature is 100-140°C; Optionally, the mesh size of the third screening is 60 to 100 meshes.

12. The preparation method according to any one of claims 7 to 11, wherein: The method of coating with glue comprises: performing a third mixing of glue, the insulated powder and an organic solvent; Optionally, the organic solvent includes ethanol, acetone, NN-dimethylformamide or xylene. Any one or a combination of at least two; Optionally, the solid content of the third mixture is 91-94%; Optionally, after the third mixing, the powder is sieved for the fourth time; Optionally, the mesh size of the fourth screening is 60 to 100 meshes.

13. The preparation method according to any one of claims 7 to 12, wherein: The demoulding molding comprises: adding demoulding powder to the powder material coated with glue; Optionally, a fifth sieving is performed after adding the release powder; Optionally, the mesh number of the fifth sieve is 60 to 100 mesh; Optionally, the molding density of the demoulding molding is greater than 5.9 g / cm 3 ; Optionally, the sintering temperature is 650-750°C.

14. The preparation method according to any one of claims 7 to 13, comprising: The raw material of the metal magnetic powder core material is sequentially subjected to annealing at 900-920° C., insulation, glue coating, demolding and sintering at 650-750° C. to obtain the magnetic powder core material; The insulation method comprises: mixing silica sol and annealed powder, and then performing a second screening and phosphating in sequence; the phosphating method comprises: mixing a phosphorus source, the second screened powder and an organic solvent, and then performing drying at a temperature of 100 to 140° C. and a third screening in sequence; The method of coating with glue comprises: sequentially mixing glue, insulated powder and organic solvent and sieving for the fourth time; The demoulding method comprises: adding demoulding powder to the powder after the glue coating, and the molding density of the demoulding is greater than 5.9g / cm 3 .

15. Use of the magnetic powder core material according to any one of claims 1 to 6, wherein: The magnetic powder core material is applied in the field of magnetic materials.

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