FeSiAl soft magnetic composite material and preparation method thereof

Abstract

The invention belongs to the technical field of electronic materials, and particularly relates to a FeSiAl soft magnetic composite material and a preparation method thereof.The preparation method comprises the steps that 1, FeSiAl powder, a silane coupling agent and organic silicon resin are mixed to obtain coated powder; (2) carrying out heat treatment on the coated powder to obtain FeSiAl-coated Al2SiO5 powder; and (3) mixing the FeSiAl-coated Al2SiO5 powder with a lubricant, and carrying out annealing heat treatment to obtain the FeSiAl soft magnetic composite material. The FeSiAl soft magnetic composite material prepared by the method has high magnetic conductivity and lower loss, the insulating layer is compact, the corrosion resistance is excellent, and the preparation method is simple in process, simple and convenient in equipment, short in coating treatment time, high in efficiency, low in cost and suitable for large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of electronic materials technology, specifically relating to FeSiAl soft magnetic composite materials and their preparation methods. Background Technology

[0002] FeSiAl soft magnetic composite materials have become key candidate materials for metal magnetic powder cores due to their high saturation magnetic induction, low coercivity, low magnetic loss, and controllable cost. However, as application environments become increasingly harsh, their weather resistance, especially corrosion resistance, needs further improvement. One important way to improve weather resistance is through the insulating coating layer and its process; therefore, there is still room for optimization in the insulating coating process.

[0003] Insulation coating is a core technology for improving the resistivity of FeSiAl materials and suppressing eddy current losses, and it is also an important way to improve weather resistance. Among existing technologies, Chinese invention patent 200610011392.7 discloses a ball milling process for coating mica powder and kaolin, but mechanical mixing results in the insulation layer and matrix only being physically bonded, making it prone to breakage during pressing. Chinese invention patent 201811551830.8 uses a method of passivating with phosphoric acid followed by composite organic silica gel water and inorganic additives, which improves the uniformity of coating, but the heat resistance of the organic components is insufficient. Chinese invention patent 202410301877.8 generates an insulation layer using nitric acid ethanol passivation solution, but its resistivity is lower than that of Al2O3. Chinese invention patent 202310515878.8 uses alkaline solution high-temperature treatment to generate Al2O3 in situ, but the process conditions are harsh. Chinese invention patent 202411804798.5 uses Sn / Bi / In salt coating to generate a composite insulation layer, but the cost is high. None of the above methods can satisfy the dual requirements of "high insulation" and "high weather resistance".

[0004] Therefore, developing a coating method based on in-situ reaction to generate high resistivity oxides, achieving a uniform and dense insulating layer with a strong bond to the matrix and improved weather resistance, is of great significance for promoting the application of FeSiAl soft magnetic composite materials in a wider range of fields. Summary of the Invention

[0005] Based on this, the present invention provides a FeSiAl soft magnetic composite material and its preparation method. In this invention, FeSiAl powder is coated with organosilicon resin. After heat treatment, the coated powder generates SiO2 on the one hand, and the released oxygen reacts with Al in the FeSiAl matrix to generate Al2O3 in situ on the other hand. Under the action of heat, a dense Al2SiO5 composite insulating layer is further formed. This method solves the problem of preparing high-performance FeSiAl soft magnetic composite materials with simple insulating coating process, high insulation and weather resistance of coating layer, dense and uniform coating layer, controllable thickness, and strong bonding with matrix metal.

[0006] To achieve the above objectives, the present invention can adopt the following technical solutions:

[0007] This invention provides a method for preparing FeSiAl soft magnetic composite materials, the method comprising:

[0008] (1) FeSiAl powder, silane coupling agent and organosilicon resin are mixed to obtain coated powder;

[0009] (2) Heat-treat the coated powder to obtain FeSiAl@Al2SiO5 powder;

[0010] (3) FeSiAl@Al2SiO5 powder and lubricant were mixed and then subjected to annealing heat treatment to obtain FeSiAl soft magnetic composite material.

[0011] Preferably, the above preparation method satisfies one or more of the following conditions:

[0012] (a1) The silane coupling agent is selected from one or more combinations of KH550, KH560 or KH570;

[0013] (b1) The organosilicon resin is selected from one or more combinations of methyl silicone resin, methylphenyl silicone resin or phenyl silicone resin;

[0014] (c1) The lubricant is selected from zinc stearate and / or lithium stearate.

[0015] Preferably, the above preparation method satisfies one or more of the following conditions:

[0016] (a2) The amount of silane coupling agent added is 0.1 wt.% to 2 wt.% of the FeSiAl powder;

[0017] (b2) The amount of silicone resin added is 0.1 wt.% to 3.0 wt.% of the FeSiAl powder;

[0018] (c2) The amount of lubricant added is 0.2 wt.% to 1.2 wt.% of the FeSiAl@Al2SiO5 powder.

[0019] Preferably, the above preparation method satisfies one or more of the following conditions:

[0020] (a3) In step (2), the heat treatment temperature is 800℃~1100℃; and / or the heat treatment time is 10min~120min;

[0021] (b3) In step (3), the annealing heat treatment temperature is 400℃~800℃; and / or the annealing heat treatment time is 30min~120min.

[0022] Preferably, in the above preparation method, the FeSiAl@Al2SiO5 powder and lubricant are mixed and then pressed before annealing.

[0023] More preferably, in the above preparation method, the pressing pressure is 800MPa to 2200MPa; and / or the holding time is 0 to 5s.

[0024] Preferably, in the above preparation method, in step (3), annealing heat treatment is performed in a protective atmosphere.

[0025] More preferably, in the above preparation method, the protective atmosphere is argon and / or nitrogen.

[0026] In another aspect, the present invention provides a FeSiAl soft magnetic composite material prepared by the above-described preparation method.

[0027] The beneficial effects of this invention include:

[0028] (1) In this invention, the FeSiAl powder coated with organosilicon resin is heat-treated. After the organosilicon resin is thermally decomposed, it generates SiO2 and releases oxygen. The oxygen combines with Al atoms in the matrix metal to generate Al2O3. Under the action of heat, it further forms a dense Al2SiO5 composite oxide insulating layer, which has higher insulation, voltage breakdown resistance and corrosion resistance. It is uniformly distributed, dense and has a high coverage on the surface of the metal soft magnetic powder. The bonding force between the insulating layer and the FeSiAl metal soft magnetic powder is strong and the coating thickness is controllable. The FeSiAl soft magnetic composite material prepared has high magnetic permeability, lower loss and corrosion resistance.

[0029] (2) The preparation method of FeSiAl soft magnetic composite material of the present invention is simple in process, easy in equipment, short in coating time, high in efficiency and low in cost, and suitable for large-scale production. Attached Figure Description

[0030] Figure 1 Here is a SEM image of the FeSiAl powder prepared in Example 1;

[0031] Figure 2 This is an EDS surface scan of the elemental distribution of the FeSiAl powder prepared in Example 1;

[0032] Figure 3 This is a SEM image of the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder in Example 1;

[0033] Figure 4 This is an EDS surface scan of the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder in Example 1;

[0034] Figure 5SEM image of the cross-section of the FeSiAl@Al2SiO5 soft magnetic composite powder in Example 1;

[0035] Figure 6 This is an EDS line scan of the cross-section of the FeSiAl@Al2SiO5 soft magnetic composite powder in Example 1. Detailed Implementation

[0036] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. Singular expressions include plural expressions unless they have a distinct meaning in the context. As used herein, it should be understood that terms such as “comprising,” “having,” “including,” are intended to indicate the presence of features, numbers, operations, components, parts, elements, materials, or combinations thereof. The terminology of the invention is disclosed in the specification and is not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials, or combinations thereof may be present or added. As used herein, “ / ” may be interpreted as “and” or “or,” depending on the context.

[0038] In a first aspect, embodiments of the present invention provide a method for preparing FeSiAl soft magnetic composite materials, the method comprising:

[0039] (1) FeSiAl powder, silane coupling agent and organosilicon resin are mixed to obtain coated powder;

[0040] (2) Heat-treat the coated powder to obtain FeSiAl@Al2SiO5 powder;

[0041] (3) FeSiAl@Al2SiO5 powder and lubricant were mixed and then subjected to annealing heat treatment to obtain FeSiAl soft magnetic composite material.

[0042] It should be noted that in this invention, the FeSiAl powder coated with organosilicon resin undergoes thermal decomposition after heat treatment, generating SiO2 and releasing oxygen. The oxygen combines with Al atoms in the matrix metal to form Al2O3, which further forms a dense Al2SiO5 composite oxide insulating layer under heat. This layer exhibits higher insulation, voltage breakdown resistance, and corrosion resistance. It is uniformly and densely distributed on the surface of the metal soft magnetic powder, with high coverage. The bonding force between the insulating layer and the FeSiAl metal soft magnetic powder is strong. The resulting FeSiAl soft magnetic composite material possesses high permeability, lower loss, and high corrosion resistance. Simultaneously, the incompletely decomposed residual organic resin can improve formability.

[0043] In some specific examples, the silane coupling agent in the above preparation method is selected from one or more combinations of KH550, KH560 or KH570.

[0044] It should be noted that in this invention, the role of the silane coupling agent is to improve the interfacial bonding between FeSiAl powder and organosilicon resin, thereby enhancing the adhesion and uniformity of the coating layer. Furthermore, the silane coupling agent is known in the art, such as one or more combinations of KH550, KH560, or KH570.

[0045] In some specific examples, the amount of silane coupling agent added in the above preparation method is 0.1 wt.% to 2 wt.% of the FeSiAl powder.

[0046] It should be noted that the amount of silane coupling agent added can be 0.1 wt.% to 2 wt.% of FeSiAl powder, such as 0.5 wt.%, 1 wt.%, or 1.5 wt.%.

[0047] In some specific examples, in the above preparation method, the organosilicon resin is selected from one or more combinations of methyl silicone resin, methylphenyl silicone resin, or phenyl silicone resin.

[0048] It should be noted that the role of the organosilicon resin is as an initial coating agent, providing insulation; it decomposes at high temperatures and participates in the reaction to generate an Al2SiO5 insulating layer. It should be understood that the organosilicon resin used in this invention is known in the art, such as one or more combinations of methyl silicone resin, methylphenyl silicone resin, or phenyl silicone resin.

[0049] In some specific examples, in the above preparation method, the amount of organosilicon resin added is 0.1 wt.% to 3.0 wt.% of FeSiAl powder.

[0050] It should be noted that the amount of silicone resin added can be 0.1 wt.% to 3.0 wt.% of FeSiAl powder, such as 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2 wt.%, or 2.5 wt.%.

[0051] In some specific examples, the lubricant used in the above preparation method is selected from zinc stearate and / or lithium stearate.

[0052] It should be noted that the lubricant in this invention serves to reduce friction during pressing, thereby improving the density and formability of the preform. Furthermore, the lubricant is known in the art, such as zinc stearate and / or lithium stearate.

[0053] In some specific examples, the amount of lubricant added in the above preparation method is 0.2 wt.% to 1.2 wt.% of the FeSiAl@Al2SiO5 powder.

[0054] It should be noted that the amount of lubricant added can be 0.2wt.% to 1.2wt.% of FeSiAl@Al2SiO5 powder, for example, 0.5wt.%, 0.7wt.%, or 1wt.%.

[0055] In some specific examples, in the above preparation method, in step (2), the heat treatment temperature is 800℃~1100℃; and / or the heat treatment time is 10min~120min.

[0056] It should be noted that in step (2), the heat treatment temperature is 800℃-1100℃, such as 850℃, 900℃, 950℃, 1000℃ or 1050℃, etc.; the heat treatment time can be 10min~120min, such as 50min, 70min or 100min, etc., depending on the reaction conditions.

[0057] In some specific examples, in the above preparation method, in step (3), the annealing heat treatment temperature is 400℃~800℃; and / or the annealing heat treatment time is 30min~120min.

[0058] It should be noted that in step (3), the annealing heat treatment temperature can be 400℃~800℃, such as 450℃, 500℃, 550℃, 600℃, 650℃, 700℃ or 750℃, etc.; the annealing heat treatment time can be 30min~120min, such as 50min, 70min or 100min, etc., and the specific time can be selected according to the reaction conditions.

[0059] In some specific examples, in the above preparation method, FeSiAl@Al2SiO5 powder and lubricant are mixed, pressed first, and then annealed.

[0060] In some specific examples, the pressing pressure in the above preparation method is 800 MPa to 2200 MPa; and / or the holding time is 0 to 5 s.

[0061] In some specific examples, in the above preparation method, step (3) involves annealing heat treatment in a protective atmosphere.

[0062] It should be noted that, in order to prevent powder oxidation at high temperatures, annealing heat treatment must be carried out in a protective atmosphere, usually nitrogen or argon.

[0063] In a first aspect, embodiments of the present invention provide a FeSiAl soft magnetic composite material prepared by the above-described preparation method.

[0064] It should be noted that the FeSiAl soft magnetic composite material sample prepared by this invention has good frequency characteristics, and the magnetic permeability has good stability as the frequency increases; it has low magnetic loss at high frequencies and excellent DC bias characteristics.

[0065] To better understand the present invention, specific examples are provided below to further illustrate the content of the present invention, but the content of the present invention is not limited to the examples below.

[0066] Preparation Examples

[0067] In the following examples, the silicone resins (silicone oils) used are methyl silicone resin, methyl phenyl silicone resin, and phenyl silicone resin, all manufactured by Hubei Xin Si Hai Chemical Co., Ltd.

[0068] Example 1

[0069] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.5Si-6.0Al and melted at 1540℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0070] (2) Weigh 100g of FeSiAl powder with a particle size of 30μm, slowly put it into a container, then add 0.5wt.% (0.5g) KH550, stir evenly, then add 1.0wt.% (1g) of organomethyl silicone resin and stir evenly to obtain coated powder.

[0071] (3) The coated powder was heated at 850℃ for 50 min to obtain core-shell FeSiAl@Al2SiO5 soft magnetic composite powder;

[0072] (4) Add 0.5wt.% zinc stearate lubricant to the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0073] (5) The ring-shaped compact was heat-treated at 720°C for 50 min in an Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain the FeSiAl soft magnetic composite material.

[0074] Example 2

[0075] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition Fe-9.3Si-6.1Al and melted at 1530℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0076] (2) Weigh 100g of FeSiAl powder with a particle size of 24μm, slowly put it into a container, then add 0.6wt.% (0.6g) KH570, stir evenly, then add 1.4wt.% (1.4g) of organic methyl phenyl silicone resin and stir evenly to obtain coated powder;

[0077] (3) The coated powder was heated at 900℃ for 40 min to obtain core-shell FeSiAl@Al2SiO5 soft magnetic composite powder;

[0078] (4) Add 0.6wt.% zinc stearate lubricant to the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under 1800MPa pressure.

[0079] (5) The ring-shaped compact was heat-treated at 700℃ for 60 min in Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain FeSiAl soft magnetic composite material.

[0080] Example 3

[0081] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.0Si-6.2Al and melted at 1510℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0082] (2) Weigh 100g of FeSiAl powder with a particle size of 36μm, slowly put it into a container, then add 0.3wt.% (0.3g) KH560, stir evenly, then add 1.6wt.% (1.6g) of organic phenyl silicone resin and stir evenly to obtain coated powder.

[0083] (3) The coated powder was heated at 1000℃ for 30 min to obtain core-shell FeSiAl@Al2SiO5 soft magnetic composite powder;

[0084] (4) Add 0.4wt.% zinc stearate lubricant to the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder and mix evenly. Then press it into a ring-shaped compact (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2200MPa.

[0085] (5) The ring-shaped compact was heat-treated at 740℃ for 40 min in Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain FeSiAl soft magnetic composite material.

[0086] Example 4

[0087] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition Fe-9.1Si-6.2Al and melted at 1510℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0088] (2) Weigh 100g of FeSiAl powder with a particle size of 28μm, slowly put it into a container, then add 0.7wt.% (0.7g) KH550, stir evenly, then add 1.8wt.% (1.8g) of organomethyl silicone resin and stir evenly to obtain coated powder;

[0089] (3) The coated powder was heated at 1100℃ for 30 min to obtain core-shell FeSiAl@Al2SiO5 soft magnetic composite powder;

[0090] (4) Add 0.6wt.% zinc stearate lubricant to the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder and mix evenly. Then press it into a ring-shaped compact (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0091] (5) The ring-shaped compact was heat-treated at 710℃ for 50 min in Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain FeSiAl soft magnetic composite material.

[0092] Comparative Example 1

[0093] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.5Si-6.0Al and melted at 1540℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0094] (2) Weigh 100g of FeSiAl powder with a particle size of 30μm, slowly put it into a container, then add 0.5wt.% (0.5g) KH550, stir evenly, then add 1.0wt.% (1g) of organomethyl silicone resin and stir evenly to obtain coated powder.

[0095] (3) Add 0.5wt.% zinc stearate lubricant to the coated powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0096] (4) The ring-shaped compact was heat-treated at 720°C for 50 min in an Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain the FeSiAl soft magnetic composite material.

[0097] Comparative Example 2

[0098] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.5Si-6.0Al and melted at 1540℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0099] (2) Weigh 100g of FeSiAl powder with a particle size of 30μm, slowly put it into a container, then add 0.5wt.% (0.5g) of SiO2 powder with a particle size of 20nm, add a small amount of steel balls, the ball-to-material weight ratio is 1:1, the mixer speed is 180r / min, and after mixing for 400min, FeSiAl coated powder is obtained.

[0100] (3) Add 0.5 wt.% KH550 to FeSiAl coated powder, stir evenly, then add 1.0 wt.% organic methyl phenyl silicone resin and stir evenly to obtain coated powder;

[0101] (4) Add 0.5wt.% zinc stearate lubricant to the coated powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0102] (5) The ring-shaped compact was heat-treated at 720°C for 40 min in an Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain the FeSiAl soft magnetic composite material.

[0103] Comparative Example 3

[0104] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.5Si-6.0Al and melted at 1540℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0105] (2) Weigh 100g of FeSiAl powder with a particle size of 30μm, slowly put it into a container, then add 0.5wt.% (0.5g) of Al2O3 powder with a particle size of 30nm, add a small amount of steel balls, the ball-to-material weight ratio is 1:1, the mixer speed is 180r / min, and after mixing for 400min, FeSiAl coated powder is obtained.

[0106] (3) Add 0.5 wt.% KH550 to FeSiAl coated powder, stir evenly, then add 1.0 wt.% organic phenyl silicone resin and stir evenly to obtain coated powder;

[0107] (4) Add 0.5wt.% zinc stearate lubricant to the coated powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0108] (5) The ring-shaped compact was heat-treated at 720°C for 40 min in an Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain the FeSiAl soft magnetic composite material.

[0109] Comparative Example 4

[0110] (1) Fe, Si and Al elements are placed in a vacuum induction melting furnace with the composition of Fe-9.5Si-6.0Al and melted at 1540℃. Then, FeSiAl powder is obtained by spraying with nitrogen.

[0111] (2) Weigh 100g of FeSiAl powder with a particle size of 30μm, slowly put it into a container, then add 0.4wt.% (0.4g) of 20nm SiO2 and 0.4wt.% (0.4g) of 30nm Al2O3 powder, add a small amount of steel balls, the ball-to-material weight ratio is 1:1, the mixer speed is 180r / min, and after mixing for 400min, FeSiAl coated powder is obtained.

[0112] (3) Add 0.5 wt.% KH550 to FeSiAl coated powder, stir evenly, then add 1.0 wt.% organic phenyl silicone resin and stir evenly to obtain coated powder;

[0113] (4) Add 0.5wt.% zinc stearate lubricant to the coated powder and mix evenly. Press it into a ring-shaped blank (outer diameter 27mm * inner diameter 15mm * height 11mm) under a pressure of 2000MPa.

[0114] (5) The ring-shaped compact was heat-treated at 720°C for 40 min in an Ar atmosphere; then cooled to room temperature in the furnace (the furnace was kept ventilated during the cooling process to room temperature (to prevent the sample from being oxidized)) to obtain the FeSiAl soft magnetic composite material.

[0115] Characterization test

[0116] The SEM morphology and EDS surface scan images of the FeSiAl powder obtained in step (1) of Example 1 are shown below. Figure 1 , Figure 2 As shown in Table 1.

[0117] Table 1. Element content on the surface of atomized FeSiAl raw powder particles

[0118]

[0119] In addition, the SEM morphology and EDS surface scan images of the core-shell FeSiAl@Al2SiO5 soft magnetic composite powder prepared in step (3) of Example 1 are shown below. Figure 3 , Figure 4 As shown in Table 2.

[0120] Table 2. Element content on the surface of FeSiAl@Al2SiO5 coated powder

[0121]

[0122] In addition, the SEM and EDS line scan images of the cross-section of the FeSiAl@Al2SiO5 soft magnetic composite powder obtained in step (3) of Example 1 are shown below. Figure 5 and Figure 6 As shown.

[0123] Performance testing

[0124] The FeSiAl soft magnetic composite material samples prepared in Examples 1 to 4, as well as the FeSiAl soft magnetic composite material samples prepared in Comparative Examples 1 to 2, were subjected to magnetic permeability and magnetic loss tests using a SY-8218 AC BH analyzer. Electrochemical corrosion analysis was performed using an electrochemical workstation. The performance of the obtained samples is shown in Table 3 (B). max =50mT).

[0125] Table 3. Properties of the composite materials prepared in Examples 1 to 4 and Comparative Examples 1 to 4

[0126]

[0127] From Table 3 above, we can see that:

[0128] Compared with existing FeSiAl soft magnetic composite materials (prepared in Comparative Example 1), the FeSiAl soft magnetic composite material samples prepared in Examples 1 to 4 have better frequency characteristics, with better stability of magnetic permeability as the frequency increases; lower magnetic loss at high frequencies; better DC bias characteristics; and lower Icorr values, indicating better corrosion resistance.

[0129] Compared with existing FeSiAl soft magnetic composite materials (prepared in Comparative Example 2), the FeSiAl soft magnetic composite material samples prepared in Examples 1 to 4 have better magnetic permeability and frequency characteristics. The magnetic permeability has better stability with increasing frequency; it has lower magnetic loss at high frequencies; and the DC bias is comparable. The lower Icorr value indicates better corrosion resistance. The process used is milder, shorter in cycle and more efficient.

[0130] Compared with existing FeSiAl soft magnetic composite materials (prepared in Comparative Example 3), the FeSiAl soft magnetic composite material samples prepared in Examples 1 to 4 have better magnetic permeability and frequency characteristics. The magnetic permeability has better stability with increasing frequency; it has lower magnetic loss at high frequencies; and the DC bias is comparable. The lower Icorr value indicates better corrosion resistance. The process used is milder, shorter in cycle and more efficient.

[0131] Compared with existing FeSiAl soft magnetic composite materials (prepared in Comparative Example 4), the FeSiAl soft magnetic composite material samples prepared in Examples 1 to 4 have better magnetic permeability and frequency characteristics. The magnetic permeability has better stability with increasing frequency; it has lower magnetic loss at high frequencies; and the DC bias is comparable. The lower Icorr value indicates better corrosion resistance. The process used is milder, shorter in cycle and more efficient.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing FeSiAl soft magnetic composite materials, characterized in that, Preparation methods include: (1) FeSiAl powder, silane coupling agent and organosilicon resin are mixed to obtain coated powder; (2) Heat-treat the coated powder to obtain FeSiAl@Al2SiO5 powder; (3) FeSiAl@Al2SiO5 powder and lubricant were mixed and then subjected to annealing heat treatment to obtain FeSiAl soft magnetic composite material.

2. The preparation method according to claim 1, characterized in that, The preparation method satisfies one or more of the following conditions: (a1) The silane coupling agent is selected from one or more combinations of KH550, KH560 or KH570; (b1) The organosilicon resin is selected from one or more combinations of methyl silicone resin, methylphenyl silicone resin or phenyl silicone resin; (c1) The lubricant is selected from zinc stearate and / or lithium stearate.

3. The preparation method according to claim 2, characterized in that, The preparation method satisfies one or more of the following conditions: (a2) The amount of silane coupling agent added is 0.1 wt.% to 2 wt.% of the FeSiAl powder; (b2) The amount of silicone resin added is 0.1 wt.% to 3.0 wt.% of the FeSiAl powder; (c2) The amount of lubricant added is 0.2 wt.% to 1.2 wt.% of the FeSiAl@Al2SiO5 powder.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The preparation method satisfies one or more of the following conditions: (a3) In step (2), the heat treatment temperature is 800℃~1100℃; and / or the heat treatment time is 10min~120min; (b3) In step (3), the annealing heat treatment temperature is 400℃~800℃; and / or the annealing heat treatment time is 30min~120min.

5. The preparation method according to any one of claims 1 to 3, characterized in that, FeSiAl@Al2SiO5 powder and lubricant are mixed, pressed first, and then annealed.

6. The preparation method according to claim 5, characterized in that, The pressing pressure is 800MPa to 2200MPa; and / or the holding time is 0 to 5s.

7. The preparation method according to claim 1, 2, 3 or 6, characterized in that, In step (3), annealing heat treatment is performed in a protective atmosphere.

8. The preparation method according to claim 7, characterized in that, The protective atmosphere is argon and / or nitrogen.

9. The FeSiAl soft magnetic composite material prepared by any one of the preparation methods according to claims 1 to 8.

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