A soft magnetic composite material and a method for producing the same

Abstract

The application discloses a soft magnetic composite material and a preparation method thereof, and belongs to the technical field of soft magnetic materials. The preparation method of the soft magnetic composite material comprises the following steps: preparing ultrafine alloy powder with a D50 particle size of 100-3000 nm from iron, nickel, manganese, aluminum, silicon and chromium; and then reacting the ultrafine alloy powder with 3-aminopropyl triethoxysilane and tetraethyl orthosilicate, and then reacting the mixture with cyclobutane tetracarboxylic dianhydride and 3-aminobenzophenone to obtain the soft magnetic composite material. The application discloses a soft magnetic composite material with excellent direct current bias performance and excellent quality factor and a preparation method thereof.

Description

Technical Field

[0001] This invention relates to the field of soft magnetic materials technology, specifically to a soft magnetic composite material and its preparation method. Background Technology

[0002] Soft magnetic composite materials are made by mixing and pressing a metal magnetic powder matrix and an insulating coating layer. The magnetic properties of soft magnetic composite materials mainly depend on the properties of the magnetic powder itself, while the insulation and mechanical properties mainly depend on the insulating coating layer. Soft magnetic composite materials are isotropic in magnetic, mechanical, and thermal properties, thus possessing excellent soft magnetic properties and frequency characteristics. At the same time, the composite coating structure also brings great convenience to the application design of soft magnetic composite materials.

[0003] Insulating coating refers to the preparation of an insulating coating layer on the surface of magnetic powder using physical or chemical methods. This insulating layer effectively isolates the current conduction between magnetic particles, improves the resistivity of soft magnetic composite materials, and thus reduces eddy current losses. The insulating coating process can be summarized as a transformation from single-layer organic coating to inorganic-organic composite coating and double-layer inorganic coating. Initially, to ensure the mechanical strength of soft magnetic composite materials, organic coating materials such as thermosetting resins like epoxy resin, silicone resin, and phenolic resin were mainly used as coating agents. Thermosetting resins themselves have excellent insulating properties, and the process is simple and easy to operate, thus they are widely used in industrial production. However, organic coating materials have poor thermal stability; excessively high temperatures accelerate resin aging and even cause decomposition. Inorganic coating materials have excellent thermal stability, but the wettability between inorganic coating agents and metal matrices is poor. Therefore, a new soft magnetic composite material and its preparation method are needed to prepare soft magnetic composite materials with excellent comprehensive performance. Summary of the Invention

[0004] The purpose of this invention is to provide a soft magnetic composite material and its preparation method, thereby improving the DC bias performance and quality factor of the soft magnetic composite material.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] A method for preparing a soft magnetic composite material, comprising,

[0007] S1. Iron, nickel, manganese, aluminum, silicon and chromium are smelted into an alloy at high temperature. The alloy is heated to the boiling point by evaporation and condensation method, and then cooled by steam to obtain ultrafine alloy powder with a D50 particle size of 100-3000nm.

[0008] S2. The ultrafine alloy powder is first reacted with 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and then reacted with a surface modifier to obtain a soft magnetic composite material.

[0009] The surface modifiers include cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone. The mass ratio of ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride is 1:2-4, and the mass ratio of ultrafine alloy powder to 3-aminobenzophenone is 1:2-4.

[0010] This invention prepares ultrafine alloy powders from iron, nickel, manganese, aluminum, silicon, and chromium, then reacts the ultrafine alloy powders with 3-aminopropyltriethoxysilane and tetraethyl orthosilicate to coat the surface of the ultrafine alloy powders with a silica coating layer. The silica coating layer is then modified using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to prepare a soft magnetic composite material with excellent DC bias performance and a good quality factor.

[0011] Preferably, the mass ratio of iron to nickel is 1:1-2.

[0012] Preferably, the mass ratio of iron to manganese is 1:0.001-0.02.

[0013] Preferably, the mass ratio of iron to aluminum is 1:0.001-0.02.

[0014] Preferably, the mass ratio of iron to silicon is 1:0.001-0.02.

[0015] Preferably, the mass ratio of iron to chromium is 0.001-0.02.

[0016] Preferably, the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1g:2-4mL.

[0017] Preferably, the ratio of ultrafine alloy powder to tetraethyl orthosilicate is 1g:1-2mL.

[0018] Preferably, the preparation of the soft magnetic composite material specifically involves,

[0019] S1. Iron, nickel, manganese, aluminum, silicon and chromium are smelted into an alloy at high temperature. The alloy is heated to the boiling point by evaporation and condensation method, and then cooled by steam to obtain ultrafine alloy powder with a D50 particle size of 100-3000nm.

[0020] S2. Under conditions of 50-60℃, anhydrous ethanol is added to ultrafine alloy powder, and the mixture is stirred at a speed of 400-600 r / min. 3-Aminopropyltriethoxysilane and deionized water are added, followed by tetraethyl orthosilicate. The mixture is reacted at 40-60℃ for 2-5 h, washed 2-5 times with anhydrous ethanol, filtered, and dried to obtain a soft magnetic composite material.

[0021] More preferably, the mass ratio of iron to nickel is 1:1-2.

[0022] More preferably, the mass ratio of iron to manganese is 1:0.001-0.02.

[0023] More preferably, the mass ratio of iron to aluminum is 1:0.001-0.02.

[0024] More preferably, the mass ratio of iron to silicon is 1:0.001-0.02.

[0025] More preferably, the mass ratio of iron to chromium is 0.001-0.02.

[0026] More preferably, the ratio of ultrafine alloy powder to anhydrous ethanol is 1g:5-10mL.

[0027] More preferably, the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1g:2-4mL.

[0028] More preferably, the volume ratio of anhydrous ethanol to deionized water is 1:1-6.

[0029] More preferably, the ratio of ultrafine alloy powder to tetraethyl orthosilicate is 1g:1-2mL.

[0030] Preferably, in the preparation of the soft magnetic composite material, a surface modifier is added in step S2 for reaction. The surface modifier includes cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone. Step S2 specifically includes:

[0031] Anhydrous ethanol was added to ultrafine alloy powder at 50-60℃ and stirred at 400-600 r / min. 3-Aminopropyltriethoxysilane and deionized water were then added, followed by tetraethyl orthosilicate. The mixture was reacted at 40-60℃ for 2-5 h, then purged with nitrogen for 30-60 min. Cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone were added, and the mixture was stirred for 24-36 h. The mixture was washed 2-5 times with anhydrous ethanol, filtered, and dried to obtain the soft magnetic composite material. Modification of the silica coating layer using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone may improve the integrity and uniformity of the insulating layer on the surface of the soft magnetic composite material by reducing the surface chemical activity of the silica coating layer and decreasing particle aggregation, thereby improving the DC bias performance and quality factor of the soft magnetic composite material.

[0032] More preferably, the ratio of ultrafine alloy powder to anhydrous ethanol is 1g:5-10mL.

[0033] More preferably, the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1g:2-4mL.

[0034] More preferably, the volume ratio of anhydrous ethanol to deionized water is 1:1-6.

[0035] More preferably, the ratio of ultrafine alloy powder to tetraethyl orthosilicate is 1g:1-2mL.

[0036] More preferably, the mass ratio of ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride is 1:2-4.

[0037] More preferably, the mass ratio of ultrafine alloy powder to 3-aminobenzophenone is 1:2-4.

[0038] Preferably, in the preparation of the soft magnetic composite material, step S2 further modifies the silica coating layer using N-(3-trimethoxysilylpropyl)ethylenediamine. Specifically, step S2 involves...

[0039] Anhydrous ethanol was added to ultrafine alloy powder at 50-60℃ and stirred at 400-600 r / min. 3-Aminopropyltriethoxysilane and deionized water were added, followed by tetraethyl orthosilicate. The mixture was reacted at 40-60℃ for 2-5 h, and nitrogen gas was introduced for 30-60 min. Cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone were added, and the mixture was stirred and reacted for 24-36 h. The mixture was washed 2-5 times with anhydrous ethanol, filtered, and nitrogen gas was introduced again for 30-60 min. An ethanol solution was added and stirred to disperse the mixture. N-(3-trimethoxysilylpropyl)ethylenediamine was added, and the mixture was stirred and reacted at 30-50℃ for 36-60 h. The mixture was washed 2-5 times with anhydrous ethanol, filtered, and dried to obtain a soft magnetic composite material. Modifying the silica coating layer with N-(3-trimethoxysilylpropyl)ethylenediamine is beneficial to the formation of the silica coating layer, further improving the thermal stability and mechanical properties of the insulation layer of the soft magnetic composite material, thereby further improving the DC bias performance and quality factor of the soft magnetic composite material.

[0040] More preferably, the ratio of ultrafine alloy powder to anhydrous ethanol is 1g:5-10mL.

[0041] More preferably, the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1g:2-4mL.

[0042] More preferably, the volume ratio of anhydrous ethanol to deionized water is 1:1-6.

[0043] More preferably, the ratio of ultrafine alloy powder to tetraethyl orthosilicate is 1g:1-2mL.

[0044] More preferably, the mass ratio of ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride is 1:2-4.

[0045] More preferably, the mass ratio of ultrafine alloy powder to 3-aminobenzophenone is 1:2-4.

[0046] More preferably, the mass concentration of the ethanol solution is 50-100%, and the ratio of ultrafine alloy powder to ethanol solution is 1g:5-10mL.

[0047] More preferably, the mass ratio of the ultrafine alloy powder to N-(3-trimethoxysilylpropyl)ethylenediamine is 1:1-2.

[0048] The present invention also discloses a soft magnetic composite material prepared by the above method.

[0049] This invention also discloses the application of soft magnetic composite materials in the preparation of high-performance inductors.

[0050] This invention involves preparing ultrafine alloy powders with a D50 particle size of 100-3000 nm from iron, nickel, manganese, aluminum, silicon, and chromium. The ultrafine alloy powders are then reacted with 3-aminopropyltriethoxysilane and tetraethyl orthosilicate to coat the surface of the ultrafine alloy powders with a silica coating. This silica coating is then modified using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone, and further modified with N-(3-trimethoxysilylpropyl)ethylenediamine. Therefore, this invention provides the following advantages: the soft magnetic composite material prepared by this invention exhibits superior DC bias performance (66.7-82.8%) and a superior quality factor (63.4-96.1). Thus, this invention represents a soft magnetic composite material with excellent DC bias performance and a superior quality factor, along with its preparation method. Attached Figure Description

[0051] Figure 1 The image shows a SEM image of the soft magnetic composite material prepared in Example 1. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0053] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0054] Example 1:

[0055] Preparation of soft magnetic composite materials, including,

[0056] S1. Iron, nickel, manganese, aluminum, silicon, and chromium are smelted into an alloy at high temperature. An evaporative cooling method is used, heating the metal to its boiling point and then cooling it with steam to obtain ultrafine alloy powder with a D50 particle size of 750 nm. The mass ratio of iron to nickel is 1:1, the mass ratio of iron to manganese is 1:0.01, the mass ratio of iron to aluminum is 1:0.01, the mass ratio of iron to silicon is 1:0.01, and the mass ratio of iron to chromium is 0.01.

[0057] S2. At 55℃, anhydrous ethanol was added to the ultrafine alloy powder prepared in step S1, and the mixture was stirred at 500 r / min. 3-Aminopropyltriethoxysilane and deionized water were added, followed by tetraethyl orthosilicate. The mixture was reacted at 50℃ for 3 h, washed three times with anhydrous ethanol, filtered, and dried to obtain the soft magnetic composite material. The ratio of ultrafine alloy powder to anhydrous ethanol was 1 g: 8.5 mL; the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane was 1 g: 4 mL; the volume ratio of anhydrous ethanol to deionized water was 1:3; and the ratio of ultrafine alloy powder to tetraethyl orthosilicate was 1 g: 1.2 mL.

[0058] Example 2:

[0059] Preparation of soft magnetic composite materials, including,

[0060] S1. Iron, nickel, manganese, aluminum, silicon, and chromium are smelted into an alloy at high temperature. An evaporative cooling method is used, heating the metal to its boiling point and then cooling it with steam to obtain ultrafine alloy powder with a D50 particle size of 750 nm. The mass ratio of iron to nickel is 1:1, the mass ratio of iron to manganese is 1:0.01, the mass ratio of iron to aluminum is 1:0.01, the mass ratio of iron to silicon is 1:0.01, and the mass ratio of iron to chromium is 0.01.

[0061] S2. At 55℃, anhydrous ethanol was added to the ultrafine alloy powder prepared in step S1, and the mixture was stirred at 500 r / min. 3-Aminopropyltriethoxysilane and deionized water were added, followed by tetraethyl orthosilicate. The mixture was reacted at 50℃ for 3 h, then nitrogen gas was introduced for 30 min. Cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone were added, and the mixture was stirred for 24 h. The mixture was washed three times with anhydrous ethanol, filtered, and dried to obtain the soft magnetic composite material. The ratio of ultrafine alloy powder to anhydrous ethanol was 1 g: 8.5 mL; the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane was 1 g: 4 mL; the volume ratio of anhydrous ethanol to deionized water was 1:3; the ratio of ultrafine alloy powder to tetraethyl orthosilicate was 1 g: 1.2 mL; the mass ratio of ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride was 1:4; and the mass ratio of ultrafine alloy powder to 3-aminobenzophenone was 1:4.

[0062] Example 3:

[0063] The only difference between this embodiment and Embodiment 2 is the preparation of the soft magnetic composite material.

[0064] The preparation of the soft magnetic composite material was carried out under the same conditions as in Example 2, except that the mass ratio of the ultrafine alloy powder and cyclobutanetetracarboxylic dianhydride was changed to 1:2.

[0065] Example 4:

[0066] The only difference between this embodiment and Embodiment 2 is the preparation of the soft magnetic composite material.

[0067] The preparation of the soft magnetic composite material was carried out under the same conditions as in Example 2, except that the mass ratio of the ultrafine alloy powder and 3-aminobenzophenone was changed to 1:2.

[0068] Example 5:

[0069] The only difference between this embodiment and Embodiment 2 is the preparation of the soft magnetic composite material.

[0070] Preparation of soft magnetic composite materials, including,

[0071] S1. Iron, nickel, manganese, aluminum, silicon, and chromium are smelted into an alloy at high temperature. An evaporative cooling method is used, heating the metal to its boiling point and then cooling it with steam to obtain ultrafine alloy powder with a D50 particle size of 750 nm. The mass ratio of iron to nickel is 1:1, the mass ratio of iron to manganese is 1:0.01, the mass ratio of iron to aluminum is 1:0.01, the mass ratio of iron to silicon is 1:0.01, and the mass ratio of iron to chromium is 0.01.

[0072] S2. At 55°C, anhydrous ethanol was added to the ultrafine alloy powder prepared in step S1, and the mixture was stirred at 500 r / min. 3-Aminopropyltriethoxysilane and deionized water were added, followed by tetraethyl orthosilicate. The mixture was reacted at 50°C for 3 h, and nitrogen gas was introduced for 30 min. Cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone were added, and the mixture was stirred and reacted for 24 h. The mixture was washed three times with anhydrous ethanol, filtered, and nitrogen gas was introduced again for 30 min. An ethanol solution was added and stirred to disperse the mixture. N-(3-trimethoxysilylpropyl)ethylenediamine was added, and the mixture was stirred and reacted at 40°C for 48 h. The mixture was washed three times with anhydrous ethanol, filtered, and dried to obtain the soft magnetic composite material. The ratio of ultrafine alloy powder to anhydrous ethanol is 1 g: 8.5 mL; the ratio of ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1 g: 4 mL; the volume ratio of anhydrous ethanol to deionized water is 1:3; the ratio of ultrafine alloy powder to tetraethyl orthosilicate is 1 g: 1.2 mL; the mass ratio of ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride is 1:4; the mass ratio of ultrafine alloy powder to 3-aminobenzophenone is 1:4; the mass concentration of the ethanol solution is 75%, and the ratio of ultrafine alloy powder to ethanol solution is 1 g: 8 mL; the mass ratio of ultrafine alloy powder to N-(3-trimethoxysilylpropyl)ethylenediamine is 1:2.

[0073] Example 6:

[0074] The only difference between this embodiment and Embodiment 5 is the preparation of the soft magnetic composite material.

[0075] The preparation of the soft magnetic composite material was carried out under the same conditions as in Example 5, except that the mass ratio of the ultrafine alloy powder and N-(3-trimethoxysilylpropyl)ethylenediamine was changed to 1:1.

[0076] Comparative Example 1:

[0077] The only difference between this comparative example and Example 2 is the preparation of the soft magnetic composite material.

[0078] The soft magnetic composite material was prepared under the same conditions as in Example 2, except that 3-aminobenzophenone was not added.

[0079] Comparative Example 2:

[0080] The only difference between this comparative example and Example 2 is the preparation of the soft magnetic composite material.

[0081] The soft magnetic composite material was prepared under the same conditions as in Example 2, except that cyclobutanetetracarboxylic dianhydride was not added.

[0082] Comparative Example 3:

[0083] The only difference between this comparative example and Example 5 is the preparation of the soft magnetic composite material.

[0084] The soft magnetic composite material was prepared under the same conditions as in Example 5, except that cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone were not added.

[0085] Experimental example:

[0086] 1. Material Characterization

[0087] The surface morphology of the soft magnetic composite material prepared in Example 1 was observed using a scanning electron microscope.

[0088] Figure 1 The image shows a SEM image of the soft magnetic composite material prepared in Example 1, with a scale bar of 100 nm. The soft magnetic composite material prepared in Example 1 is in the form of spherical particles with an insulating protective layer on the surface.

[0089] 2. DC bias performance

[0090] Using an LCR precision impedance analyzer with an applied current of 0-10A, the DC bias performance of the soft magnetic composite materials prepared in Examples 1-6 and Comparative Examples 1-3 of this invention under a bias field of 100Oe was measured.

[0091] Table 1 DC bias performance (%)

[0092]

[0093] As shown in Table 1, the DC bias performance of the soft magnetic composite materials prepared in Examples 2-4 of this invention is better than that in Example 1. This is because in the preparation of the soft magnetic composite materials, Examples 2-4 first coated the surface of the ultrafine alloy powder with a silica coating layer, and then modified the silica coating layer with cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone. The DC bias performance of the soft magnetic composite material prepared in Example 2 of this invention is better than that in Examples 3-4, because the amounts of cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone used in the preparation of the soft magnetic composite material are different. This indicates that modifying the silica coating layer with cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone can improve the DC bias performance of the soft magnetic composite material. The DC bias performance of the soft magnetic composite materials prepared in Examples 2-4 of this invention is superior to that in Comparative Examples 1-2. This is because, in the preparation of the soft magnetic composite materials, Examples 2-4 synergistically used cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to modify the silica coating layer, while Comparative Example 1 only used cyclobutanetetracarboxylic dianhydride to modify the silica coating layer, and Comparative Example 2 only used 3-aminobenzophenone to modify the silica coating layer. This indicates that, compared to using cyclobutanetetracarboxylic dianhydride or 3-aminobenzophenone alone to modify the silica coating layer, synergistic modification with cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone can improve the DC bias performance of the soft magnetic composite material.

[0094] The DC bias performance of the soft magnetic composite materials prepared in Examples 5-6 of this invention is superior to that in Example 2. This is because, in the preparation of the soft magnetic composite materials, Examples 5-6 further modified the silica coating layer with N-(3-trimethoxysilylpropyl)ethylenediamine. The DC bias performance of the soft magnetic composite material prepared in Example 5 is superior to that in Example 6, the amount of N-(3-trimethoxysilylpropyl)ethylenediamine used in the preparation of the soft magnetic composite material is different. The DC bias performance of the soft magnetic composite materials prepared in Examples 5-6 is superior to that in Comparative Example 3, only N-(3-trimethoxysilylpropyl)ethylenediamine was used to modify the silica coating layer, without using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to modify the silica coating layer. This indicates that further modification of the silica coating layer with N-(3-trimethoxysilylpropyl)ethylenediamine can further improve the DC bias performance of the soft magnetic composite material.

[0095] 3. Quality Factor

[0096] The quality factor of the soft magnetic composite materials prepared in Examples 1-6 and Comparative Examples 1-3 of this invention was determined using an LCR precision impedance analyzer. The quality factor test frequency was 1MHz and the voltage was 250mVac.

[0097] Table 2 Quality Factors

[0098]

[0099] As shown in Table 2, the quality factor of the soft magnetic composite materials prepared in Examples 2-4 of this invention is better than that in Example 1. This is because in the preparation of the soft magnetic composite materials, Examples 2-4 first coated the surface of the ultrafine alloy powder with a silica coating layer, and then modified the silica coating layer with cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone. The quality factor of the soft magnetic composite material prepared in Example 2 of this invention is better than that in Examples 3-4, because the amounts of cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone used in the preparation of the soft magnetic composite materials are different. This indicates that modifying the silica coating layer with cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone can improve the quality factor of the soft magnetic composite material. The quality factor of the soft magnetic composite materials prepared in Examples 2-4 of this invention is superior to that of Comparative Examples 1-2. This is because, in the preparation of the soft magnetic composite materials, Examples 2-4 synergistically used cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to modify the silica coating layer, while Comparative Example 1 only used cyclobutanetetracarboxylic dianhydride to modify the silica coating layer, and Comparative Example 2 only used 3-aminobenzophenone to modify the silica coating layer. This demonstrates that, compared to using either cyclobutanetetracarboxylic dianhydride or 3-aminobenzophenone alone to modify the silica coating layer, synergistically using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to modify the silica coating layer can improve the quality factor of the soft magnetic composite material.

[0100] The quality factor of the soft magnetic composite materials prepared in Examples 5-6 of this invention is better than that in Example 2 because, in the preparation of the soft magnetic composite materials, Examples 5-6 further modified the silica coating layer with N-(3-trimethoxysilylpropyl)ethylenediamine. The quality factor of the soft magnetic composite material prepared in Example 5 is better than that in Example 6 because the amount of N-(3-trimethoxysilylpropyl)ethylenediamine used in the preparation of the soft magnetic composite material is different. The quality factor of the soft magnetic composite materials prepared in Examples 5-6 is better than that in Comparative Example 3, in the preparation of the soft magnetic composite material, Comparative Example 3 only used N-(3-trimethoxysilylpropyl)ethylenediamine to modify the silica coating layer, without using cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone to modify the silica coating layer. This shows that further modification of the silica coating layer with N-(3-trimethoxysilylpropyl)ethylenediamine can further improve the quality factor of the soft magnetic composite material.

[0101] The conventional operations in the operation steps of this invention are well known to those skilled in the art and will not be described in detail here.

[0102] The embodiments described above provide a detailed explanation of the technical solution of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a soft magnetic composite material, comprising, S1. Iron, nickel, manganese, aluminum, silicon and chromium are smelted into an alloy at high temperature. The alloy is heated to the boiling point by evaporation and condensation method, and then cooled by steam to obtain ultrafine alloy powder with a D50 particle size of 100-3000nm. S2. Under conditions of 50-60℃, anhydrous ethanol is added to ultrafine alloy powder and stirred at a speed of 400-600 r / min. 3-Aminopropyltriethoxysilane and deionized water are added, followed by tetraethyl orthosilicate. The mixture is reacted at 40-60℃ for 2-5 h, and nitrogen gas is introduced for 30-60 min. Cyclobutanetetracarboxylic dianhydride and 3-aminobenzophenone are added, and the mixture is stirred and reacted for 24-36 h. The mixture is washed 2-5 times with anhydrous ethanol, filtered, and dried to obtain a soft magnetic composite material. The mass ratio of the ultrafine alloy powder to cyclobutanetetracarboxylic dianhydride is 1:2-4, and the mass ratio of the ultrafine alloy powder to 3-aminobenzophenone is 1:2-4.

2. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The mass ratio of iron to nickel is 1:1-2.

3. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The mass ratio of iron to manganese is 1:0.001-0.

02.

4. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The mass ratio of iron to aluminum is 1:0.001-0.

02.

5. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The mass ratio of iron to silicon is 1:0.001-0.

02.

6. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The mass ratio of iron to chromium is 0.001-0.

02.

7. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The ratio of the ultrafine alloy powder to 3-aminopropyltriethoxysilane is 1g:2-4mL.

8. The method for preparing a soft magnetic composite material according to claim 1, characterized in that, The ratio of the ultrafine alloy powder to tetraethyl orthosilicate is 1g:1-2mL.

9. A method for preparing a soft magnetic composite material according to any one of claims 1-8, characterized in that, In step S2, after washing with anhydrous ethanol 2-5 times, the silica coating layer is modified with N-(3-trimethoxysilylpropyl)ethylenediamine. Specifically, the process involves: filtration, purging with nitrogen for 30-60 minutes, adding ethanol solution and stirring to disperse, adding N-(3-trimethoxysilylpropyl)ethylenediamine, stirring and reacting at 30-50°C for 36-60 hours, and then washing with anhydrous ethanol 2-5 times.

10. The method for preparing a soft magnetic composite material according to claim 9, characterized in that, The mass concentration of the ethanol solution is 50-100%, and the ratio of ultrafine alloy powder to ethanol solution is 1g:5-10mL.

11. The method for preparing a soft magnetic composite material according to claim 9, characterized in that, The mass ratio of ultrafine alloy powder to N-(3-trimethoxysilylpropyl)ethylenediamine is 1:1-2.

12. The soft magnetic composite material prepared by any of the methods described in claims 1-11.

13. The application of the soft magnetic composite material of claim 12 in the preparation of high-performance inductors.

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