A high-saturation low-loss soft magnetic composite material, a preparation method and application thereof

Abstract

The application belongs to the technical field of magnetic material preparation, and particularly relates to a high-saturation low-loss soft magnetic composite material and a preparation method and application thereof. The preparation method comprises the following steps: (1) uniformly mixing first powder and second powder to obtain a mixture; wherein the composition of the first powder comprises iron, silicon and chromium, and the composition of the second powder comprises iron and nickel; (2) mixing the mixture with resin, pressing and heat treating; and the temperature of the heat treatment is not higher than 220 DEG C. The application can prepare a soft magnetic material with high saturation characteristics, low loss and high pressing density, and the soft magnetic material has good formability and is not prone to cracking during heat treatment. The application does not need to go through a relatively complex step such as coating when preparing the high-saturation low-loss material, thereby simplifying the process.

Description

Technical Field

[0001] This invention belongs to the field of magnetic material preparation technology, specifically relating to a high-saturation, low-loss soft magnetic composite material, its preparation method, and its application. Background Technology

[0002] As a core component of electronic products, inductors face increasingly stringent performance requirements to meet the demands for thinner and smaller designs. Traditional molded inductors involve integrally molding the coil and powder, followed by low-temperature baking. High-temperature sintering damages the coil's insulation layer, leading to short circuits between layers. Traditional inductor powders are often carbonyl powder, iron-silicon powder, or iron-silicon-chromium powder, and the adhesive used is typically epoxy resin. This results in powders with low permeability, poor saturation characteristics, and high losses. Furthermore, low-temperature baking prevents the powder from achieving its intended magnetic properties; carbonyl powder suffers from thermal aging and cannot withstand long-term temperatures above 130°C. For example, current technologies for preparing low-loss materials use a mixture of iron-silicon-aluminum alloy powder and carbonyl iron for phosphating, followed by coating, granulation, and baking. While this method reduces losses, it still suffers from low Bs (bases), poor saturation characteristics, and low compression density.

[0003] Copper-iron co-fired inductors are made by integrally molding alloy powder and copper sheet and then sintering at high temperature, which greatly reduces losses and improves the magnetic permeability of the powder. However, due to the need to use inorganic glue for high-temperature sintering, the bonding strength of these inductors is poor and they are prone to cracking during molding, especially some thinner inductors. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the inability of the prior art to make soft magnetic composite materials have high saturation characteristics, low loss, easy cracking and good formability, so as to provide a high saturation low loss soft magnetic composite material, its preparation method and application.

[0005] To this end, the present invention provides the following technical solution.

[0006] The first aspect of this invention provides a method for preparing a high-saturation, low-loss soft magnetic composite material, comprising the following steps:

[0007] (1) The first powder and the second powder are mixed to obtain a mixture; wherein the first powder contains iron, silicon and chromium, and the second powder contains iron and nickel.

[0008] (2) The mixture is mixed with resin, pressed and heat-treated; the temperature of the heat treatment is not higher than 220°C.

[0009] The present invention uses first and second powders with specific components to enable soft magnetic materials to have good magnetic permeability without insulation coating treatment, and can reduce losses. It has good DC superposition characteristics, is easy to press and mold, and does not require high-temperature baking. The excellent performance of the composite material can be guaranteed by heat treatment at no higher than 220°C. In particular, the heat treatment process can be carried out at a temperature below 200°C, overcoming the defects of existing technologies that require high-temperature baking.

[0010] The first powder contains iron, silicon, and chromium, making it an amorphous powder without grain boundaries or grains. This contributes to the excellent properties of the soft magnetic material, such as high sphericity, high resistivity, high saturation magnetic induction, corrosion resistance, low coercivity, and low loss. The second powder contains iron and nickel, which helps improve the material's saturation magnetic induction and DC superposition characteristics, reduces eddy current losses, and facilitates pressing and molding. The combined use of the first and second powders allows the soft magnetic composite material to achieve both high saturation and low loss characteristics, and also improves the cracking problem of ultra-thin magnetic cores.

[0011] The first powder has a D50 of 10–20 μm, and the second powder has a D50 of 0.5–2 μm; and / or,

[0012] The mass ratio of the first powder to the second powder is (3-7):(3-7).

[0013] The D50 of the first powder can be any one or any two values ​​of 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm.

[0014] The D50 of the second powder can be any value from 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1.0μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2.0μm, or any value from a range of two values.

[0015] Furthermore, the mass ratio of the first powder and the second powder in this invention can be, but is not limited to, 2:3, 1:1, 4:5, 7:3, etc., and is preferably 2:3.

[0016] This invention, by adjusting the mass ratio and particle size distribution of the first and second powders, can further improve the filling rate and compression density, thereby increasing the magnetic permeability of the composite material. Adjusting the median particle size of the second powder helps reduce eddy current losses.

[0017] The iron content in the first powder is 95-97% by mass percentage; and / or,

[0018] The silicon content in the first powder is 2.0–2.6%; and / or,

[0019] The chromium content in the first powder is 1.0-1.5%.

[0020] Furthermore, by mass percentage, the first powder also includes aluminum and / or manganese;

[0021] Furthermore, the aluminum content in the first powder is 0.02-0.15% by mass percentage;

[0022] Furthermore, the manganese content in the first powder is 0.01 to 0.05% by mass percentage.

[0023] For example, the iron content in the first powder can be any value such as 95%, 95.5%, 96%, 96.5%, 97%; the silicon content can be any value such as 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%; the chromium content can be any value such as 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%; the manganese content can be any value such as 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.15%; and the aluminum content can be any value such as 0.01%, 0.02%, 0.03%, 0.04%, 0.05%. It should be noted that the first powder also contains unavoidable components.

[0024] Furthermore, the iron content in the second powder is 47-52% by mass; and / or,

[0025] The nickel content in the second powder is 47-52%.

[0026] The second powder also includes at least one of manganese, carbon, and oxygen;

[0027] Preferably, the manganese content in the second powder is <0.5% by mass percentage;

[0028] Preferably, the second powder contains C < 800 ppm and O < 8000 ppm.

[0029] The iron content in the second powder can be any value, such as 47%, 48%, 49%, 50%, 51%, or 52%; the nickel content can be any value, such as 47%, 48%, 49%, 50%, 51%, or 52%; and the manganese content only needs to be no less than 0.5%, such as 0.4%, 0.3%, or 0.2%. It should be noted that the second powder also contains unavoidable components.

[0030] The preparation method satisfies at least one of (1) to (2):

[0031] (1) The resin comprises at least two of epoxy resin, polyester resin, polyethylene glycol, polyvinyl butyral resin, micronized wax, and phenolic resin; and / or,

[0032] The resin includes epoxy resin and polyvinyl butyral resin; and / or,

[0033] The amount of resin added is 1.2 to 1.8 wt% of the mixture;

[0034] In this invention, the resin is 1.5% of the mass of the mixture.

[0035] Regarding the resins, it should be noted that they include at least two of the following: epoxy resin, polyester resin, polyethylene glycol, polyvinyl butyral resin, micronized wax, and phenolic resin. The ratio between any of the resins can be determined as needed; for example, the mass ratio of epoxy resin to polyvinyl butyral resin can be (3-5):1, preferably 4:1. Another example is the use of a blend of polyester resin and polyvinyl butyral resin. Epoxy resin, polyester resin, polyvinyl butyral resin, micronized wax, and phenolic resin are all commercially available, and their sources are not specifically limited.

[0036] (2) In step (2), the mixing of the mixture with the resin further includes the step of adding a coupling agent;

[0037] The amount of the coupling agent added is 0.2 to 0.5 wt% of the mixture.

[0038] It should be noted that coupling agents can be added as needed. This invention does not impose specific requirements on the type of coupling agent, such as silane coupling agents, titanate coupling agents, etc., with specific grades such as A171, A151, etc.

[0039] The pressing pressure is 12-15 T / cm. 2 , and / or

[0040] The heat treatment time is 4 to 5 hours and / or

[0041] The heat treatment temperature is 180–220°C.

[0042] This invention allows for heat treatment at temperatures below 220°C during the preparation of soft magnetic composite materials, overcoming the shortcomings of existing technologies that require high-temperature heat treatment. The heat treatment temperature of this invention can be, but is not limited to, 180°C, 183°C, 185°C, 188°C, 190°C, 193°C, 195°C, 198°C, 200°C, 203°C, 205°C, 210°C, 215°C, etc.

[0043] The heat treatment time can be 4h, 4.2h, 4.5h, 4.8h, 5h, etc.

[0044] The pressing pressure is 12T / cm. 2 12.5T / cm 2 13T / cm 2 13.5T / cm 2 14T / cm 2 14.5T / cm 2 15T / cm 2 Any value.

[0045] A second aspect of the present invention provides a high-saturation, low-loss soft magnetic composite material prepared by the above-described preparation method.

[0046] A third aspect of the present invention provides an inductor device comprising a high-saturation, low-loss soft magnetic composite material prepared by the above-described preparation method.

[0047] The soft magnetic composite material is fabricated into an inductor using conventional methods in the art. For example, it is integrally formed with a copper sheet during a pressing process; or, for instance, the soft magnetic composite material is combined with a coil to form an inductor.

[0048] The technical solution of this invention has the following advantages:

[0049] 1. The present invention provides a method for preparing a high-saturation, low-loss soft magnetic composite material, comprising (1) mixing a first powder and a second powder to obtain a mixture; wherein the first powder comprises iron, silicon, and chromium, and the second powder comprises iron and nickel; (2) mixing the mixture with resin, pressing, and heat-treating; wherein the heat-treating temperature is not higher than 220°C. The present invention can prepare a soft magnetic material with high saturation characteristics, low loss, and high pressing density, and has good formability during the preparation of the soft magnetic material, and is not prone to cracking during the heat treatment process. The present invention simplifies the process by eliminating the need for complex steps such as coating when preparing the high-saturation, low-loss material.

[0050] The first powder of this invention comprises iron, silicon, and chromium, and is an amorphous powder without grain boundaries or grains, exhibiting excellent properties such as high sphericity, high resistivity, high saturation magnetic induction, corrosion resistance, low coercivity, and low loss. The second powder comprises iron and nickel, with high saturation magnetic induction (Bs), good DC superposition characteristics, low eddy current loss, and is easy to press and mold. The first and second powders are used together without insulation coating, giving the soft magnetic composite material good permeability. After mixing the first and second powders and adding resin, it has good formability. Heat treatment at a relatively low temperature (not higher than 220°C) can give the soft magnetic material both high saturation and low loss, improving the problem of cracking that easily occurs in ultra-thin magnetic cores.

[0051] The inductor device made of soft magnetic composite material provided by this invention can be applied to autonomous driving and AI servers, and has the advantages of high current resistance and high efficiency.

[0052] 2. The method for preparing high-saturation, low-loss soft magnetic composite material provided by the present invention involves controlling the mass ratio and particle size distribution of the first powder and the second powder, which can improve the filling rate and pressing density, thereby increasing the magnetic permeability of the composite material.

[0053] Furthermore, the present invention controls the particle size of the second powder, which is relatively small, with a median particle size of 0.5 to 2 μm, making it easy to press and mold. Since the eddy current loss in the components is directly proportional to the particle size, the present invention uses a second powder (iron-nickel powder) with a smaller particle size, which can reduce the eddy current loss.

[0054] 3. The method for preparing high-saturation, low-loss soft magnetic composite materials provided by this invention utilizes a mixed resin, which enhances the bonding force and formability between particles, further improving the problem of easy cracking in ultra-thin magnetic cores. The mixed resin of this invention exhibits high bonding strength and toughness, improving the interface between organic and inorganic materials, further increasing the insulation resistance of the powder, and reducing eddy current losses in the magnetic core. The composite resin used in this invention has good toughness, which can suppress cracking caused by resin expansion during heat treatment. Detailed Implementation

[0055] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0056] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0057] Example 1

[0058] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0059] (1) By mass percentage, the first powder comprises 96.13% Fe, 2.42% Si, 1.26% Cr, 0.104% Al, 0.03% Mn, and unavoidable components, with a D50 of 16.51 μm. By mass percentage, the second powder comprises 49.1% Fe, 49.9% Ni, 0.35% Mn, 76 ppm C, 2691 ppm O, and unavoidable components, with a D50 of 0.95 μm.

[0060] The first powder and the second powder are placed in a mixing tank at a mass ratio of 4:6. The mixing speed of the mixing tank is set to 35 r / min and the mixing time is 10 min. The mixture is mixed evenly to obtain a mixture.

[0061] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 12T / cm 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0062] Example 2

[0063] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0064] (1) By mass percentage, the first powder comprises 96.35% Fe, 2.29% Si, 1.24% Cr, 0.047% Al, 0.024% Mn, and unavoidable components, with a D50 of 14.67 μm. By mass percentage, the second powder comprises 48.7% Fe, 49.7% Ni, 0.44% Mn, 42 ppm C, 1895 ppm O, and unavoidable components, with a D50 of 1.02 μm.

[0065] The first powder and the second powder are placed in a mixing tank at a mass ratio of 4:6. The mixing speed of the mixing tank is set to 35 r / min and the mixing time is 10 min. The mixture is mixed evenly to obtain a mixture.

[0066] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 12T / cm 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0067] Example 3

[0068] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0069] (1) By mass percentage, the first powder comprises 96.25% Fe, 2.37% Si, 1.23% Cr, 0.061% Al, 0.023% Mn, and unavoidable components, with a D50 of 16.45 μm. By mass percentage, the second powder comprises 49.2% Fe, 50.1% Ni, 0.38% Mn, 58 ppm C, 2133 ppm O, and unavoidable components, with a D50 of 1.08 μm.

[0070] The first powder and the second powder are placed in a mixing tank at a mass ratio of 4:6. The mixing speed of the mixing tank is set to 35 r / min and the mixing time is 10 min. The mixture is mixed evenly to obtain a mixture.

[0071] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 12T / cm 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0072] Example 4

[0073] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0074] (1) By mass percentage, the first powder comprises 96.29% Fe, 2.34% Si, 1.24% Cr, 0.063% Al, 0.027% Mn, and unavoidable components, with a D50 of 11.5 μm. By mass percentage, the second powder comprises 49.5% Fe, 49.7% Ni, 0.39% Mn, 66 ppm C, 2216 ppm O, and unavoidable components, with a D50 of 1.8 μm.

[0075] The first powder and the second powder are placed in a mixing tank at a mass ratio of 4:6. The mixing speed of the mixing tank is set to 35 r / min and the mixing time is 10 min. The mixture is mixed evenly to obtain a mixture.

[0076] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 15T / cm. 2The rings are formed by pressing and then heat-treated in an oven at 190°C for 3 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0077] Example 5

[0078] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0079] (1) By mass percentage, the first powder comprises 96.13% Fe, 2.42% Si, 1.26% Cr, 0.104% Al, 0.03% Mn, and unavoidable components, with a D50 of 16.51 μm. By mass percentage, the second powder comprises 49.1% Fe, 49.9% Ni, 0.35% Mn, 76 ppm C, 2691 ppm O, and unavoidable components, with a D50 of 0.95 μm.

[0080] The first powder and the second powder were placed in a mixing tank at a mass ratio of 6.5:3.5. The mixing tank was set to a speed of 35 r / min and a mixing time of 10 min. The mixture was mixed evenly to obtain a mixture.

[0081] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 12T / cm 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0082] Example 6

[0083] This embodiment provides a method for preparing a high-saturation, low-loss soft magnetic composite material, including the following steps:

[0084] (1) By mass percentage, the first powder comprises 96.13% Fe, 2.42% Si, 1.26% Cr, 0.104% Al, 0.03% Mn, and unavoidable components, with a D50 of 25.2 μm. By mass percentage, the second powder comprises 49.1% Fe, 49.9% Ni, 0.35% Mn, 76 ppm C, 2691 ppm O, and unavoidable components, with a D50 of 5 μm.

[0085] The first powder and the second powder are placed in a mixing tank at a mass ratio of 4:6. The mixing speed of the mixing tank is set to 35 r / min and the mixing time is 10 min. The mixture is mixed evenly to obtain a mixture.

[0086] (2) Weigh 1.5% of the resin according to the mass of the mixture, dissolve it in acetone solvent to obtain a uniformly mixed solution; add the mixture obtained in step (1) to the above solution, stir, and obtain powder after granulation, drying, and sieving. This powder is subjected to a pressure of 12T / cm 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0087] Comparative Example 1

[0088] This comparative example provides a method for preparing a soft magnetic composite material. The difference from Example 1 is that it uses water vapor-co-atomized iron-silicon-chromium powder (manufactured by Quanzhou Tianzhi) as the raw material instead of the first and second powders. Its D50 is 14.5 μm. The preparation method includes the following steps:

[0089] Weigh 1.5% of the resin according to the mass of the water-vapor co-atomized iron-silicon-chromium powder, dissolve it in acetone to obtain a homogeneous solution; add the water-vapor co-atomized iron-silicon-chromium powder to the above solution, stir, and then granulate, dry, and sieve to obtain the powder. This powder is then subjected to a pressure of 12 T / cm. 2 The rings are formed by pressing and then heat-treated in an oven at 200°C for 4 hours. The resin consists of epoxy resin and polyvinyl butyral in a mass ratio of 4:1.

[0090] Test case

[0091] This experimental example provides the properties of the materials prepared in each embodiment and comparative example, as follows:

[0092] Method for testing magnetic permeability: Take a standard ring (from various embodiments and comparative examples) to measure its size, and then wind it. The test involved 20 turns of copper wire, with test conditions of 100kHz and 1V. The test instrument was an HP4284 inductance tester, and the measured inductance value was converted into permeability.

[0093] Magnetic field strength when the inductance drops by 20%: Test conditions and test instruments are the same as permeability, and the current is gradually applied to test the inductance value after the load is applied until the inductance value is about 80% of the initial inductance value. Record the current value at this time and convert it into magnetic field strength.

[0094] Test method for magnetic loss Pv: Using a standard ring... Two groups of copper wire, N1 and N2, were wound together, with N1 = 20Ts and N2 = 5Ts. The test conditions and results are shown in Table 1. The test equipment was a SY8218 tester. Ts represents the number of turns of copper wire.

[0095] Table 1. Performance test results for each embodiment and comparative example.

[0096]

[0097] The results above show that the soft magnetic composite material prepared by this invention has advantages such as high saturation characteristics and low loss. No cracking or other problems occurred during the experiment, and it has good formability.

[0098] Furthermore, in Example 5, the soft magnetic composite material obtained with a mass ratio of the first powder to the second powder of 6.5:3.5 has a higher loss than the material obtained with a mass ratio of the first powder to the second powder of 4:6 in Example 1. The magnetic permeability and saturation inductance of Example 5 are also slightly worse than those of Example 1. This indicates that using a specific ratio of the two powders helps to further improve the saturation characteristics of the soft magnetic composite material and reduce the loss.

[0099] Furthermore, as seen in Example 6, the particle size of the first and second powders also has a certain impact on the saturation characteristics and losses of the material. Based on the results of Examples 1 and 6, the use of the specific particle size distribution of the first and second powders in Example 1, according to the present invention, can further improve the high saturation characteristics of the soft magnetic composite material and reduce eddy current losses.

[0100] Compared with Comparative Example 1, Example 1 uses iron-silicon-chromium powder co-atomized by water vapor as raw material. The soft magnetic material prepared according to the method of the present invention has a loss of more than 3 times that of Example 1. The saturated magnetic field strength and magnetic permeability are worse than those of the material of the present invention. This shows that the use of powder with specific components in the present invention can make the soft magnetic composite material have both low loss and high saturation characteristics.

[0101] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method of making a high saturation low loss soft magnetic composite material, characterized by, Comprise the following steps: (1) mix the first powder and the second powder to obtain a mixture; wherein the first powder comprises iron, silicon and chromium, and the second powder comprises iron and nickel; the D50 of the first powder is 10-19 μm, and the D50 of the second powder is 0.5-0.9 μm or 1.1-2 μm; (2) mix the mixture with resin, and then press and heat treat; the temperature of the heat treatment is not higher than 220 ℃; The mass ratio of the first powder to the second powder is (3-7):(3-7); The content of iron in the first powder is 95-97% by mass; and / or, the content of silicon in the first powder is 2.0-2.6%; and / or, the content of chromium in the first powder is 1.0-1.5%; The content of iron in the second powder is 47-52% by mass; and / or, the content of nickel in the second powder is 47-52% by mass.

2. The production method according to claim 1, characterized by, The first powder further comprises aluminum and / or manganese by mass; The content of aluminum in the first powder is 0.02-0.15% by mass; The content of manganese in the first powder is 0.01-0.05% by mass.

3. The preparation method according to claim 1, characterized in that, The second powder further comprises at least one of manganese, carbon and oxygen.

4. The preparation method according to claim 3, characterized in that, The content of manganese in the second powder is <0.5% by mass.

5. The preparation method according to claim 3, characterized in that, The content of C in the second powder is <800 ppm, and the content of O in the second powder is <8000 ppm.

6. The method of any one of claims 1 to 5, wherein the method further comprises the step of: At least one of (1)-(2) is satisfied: (1) the resin comprises at least two of epoxy resin, polyester resin, polyethylene glycol, polyvinyl butyral resin, micro-wax and phenolic resin; and / or, The resin comprises epoxy resin and polyvinyl butyral resin; and / or, The resin is added in an amount of 1.2-1.8 wt% of the mixture; (2) in the step (2), the step of mixing the mixture with resin further comprises a step of adding a coupling agent; The coupling agent is added in an amount of 0.2-0.5 wt% of the mixture.

7. The method of any one of claims 1 to 5, wherein the method further comprises the step of: The pressing pressure is 12-15 T / cm 2 and / or, ​ The heat treatment is performed for 4-5 h and / or, The temperature of the heat treatment is 180-220 ℃.

8. A high-saturation low-loss soft magnetic composite material prepared by the preparation method of any one of claims 1-7.

9. An inductive device, characterized by A high-saturation low-loss soft magnetic composite material prepared by the preparation method of any one of claims 1-7.

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