Low-loss feisi al magnetic powder core material for magnetoelectric elements, method of manufacture and use

Abstract

The application provides a low-loss FeSiAl magnetic powder core material for a magnetoelectric element, a preparation method and application, and comprises the following steps: placing FeSiAl metal particles in acetone to clean and remove residual oil stains on surfaces of the FeSiAl metal particles; mixing the FeSiAl metal particles, an organic coating agent and an inorganic coating agent with an acetone solution to obtain a mixture; placing the mixture in a water bath to heat and stir until the acetone is completely volatilized, and obtaining a dried powder; and pressing the dried powder into a green body, and performing annealing treatment in a protective atmosphere to obtain the FeSiAl magnetic powder core material. The preparation method is simple in process and low in cost, and the prepared FeSiAl magnetic powder core material has the characteristics of high magnetic permeability, high resistivity and low loss.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of magnetic materials for magnetoelectric devices, and relates to a low-loss FeSiAl magnetic powder core material for magnetoelectric elements, a preparation method and applications. BACKGROUND

[0002] FeSiAl magnetic powder core material has the characteristics of high saturation magnetic induction, high permeability frequency stability, high DC superposition resistance, etc., and is an indispensable magnetic material for processing current signals and realizing power transmission and conversion, and is widely used in various magnetoelectric elements such as inductors and transformers. However, since the main component of FeSiAl magnetic powder core material is high-conductivity FeSiAl metal particles, the resistivity of FeSiAl magnetic powder core material is low, and the eddy current loss of the magnetic core will increase sharply at high frequencies, resulting in heating of the magnetic core and deterioration of the performance of the magnetoelectric element.

[0003] Insulation coating is an effective method to reduce the eddy current loss of FeSiAl magnetic powder core. The principle is to wrap a layer of high-resistance insulating layer on the surface of the conductive metal particles to block the conduction process between the metal particles, thereby increasing the resistivity of the material. There are two types of insulation coating commonly used, organic coating and inorganic coating. Organic coating refers to using organic matter (such as phenolic resin, silicone resin and epoxy resin) to coat the surface of the magnetic metal particles. Organic matter usually has a higher resistivity and better performance in establishing an insulating layer between the conductor particles, but it is also easily damaged at high forming pressure or annealing temperature. Inorganic coating refers to using high-resistance inorganic materials to wrap the magnetic metal particles. Compared with organic coating, inorganic materials have better temperature stability, and the coated FeSiAl magnetic powder core can be annealed at a higher temperature to eliminate the stress introduced during the forming process and obtain better magnetic properties.

[0004] Common inorganic coating materials are various oxides such as SiO2, Al2O3, MoO3, Y2O3, MgO and MnO. In the patent “FeSiAl soft magnetic composite material and preparation method thereof” (CN 116825466 A), a preparation method of FeSiAl soft magnetic composite material is disclosed. By appropriately increasing the Al content and reducing the Fe content in the composition design, FeSiAl soft magnetic powder is prepared, the prepared FeSiAl powder is mixed uniformly with iron oxide, and Al2O3 insulating layer is generated by Al thermal reaction through heating, thereby improving the insulation of the product. However, in this method, due to the difficulty in controlling the Al thermal reaction process, the uniformity of the generated Al2O3 insulating layer is poor, resulting in a small increase in the resistivity of the material. The lowest loss is 338 kW / m3 at 100 kHz 50mT. In addition, this method is relatively complex, requires too many steps and raw materials, and is not suitable for industrial mass production. SUMMARY

[0005] To address the aforementioned problems, this invention provides a low-loss FeSiAl magnetic powder core material for magnetoelectric components, its preparation method, and its applications. By selecting FeSiAl particles with non-uniform particle sizes and coating them with high-resistivity, high-stability AlN nanoparticles, a high-resistivity and stable AlN insulating layer is constructed. Combined with a segmented, multi-step annealing method, stress introduced during the pressing process is effectively eliminated, resulting in a FeSiAl magnetic powder core material with high resistivity and low loss. Furthermore, this preparation method requires simple raw materials and involves few process steps, making it suitable for mass production.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a low-loss FeSiAl magnetic powder core material for magnetoelectric components, comprising:

[0008] The FeSiAl metal particles were cleaned in acetone to remove residual oil from their surface.

[0009] FeSiAl metal particles, organic coating agent and inorganic coating agent are mixed with acetone solution to obtain a mixture;

[0010] The mixture was heated and stirred in a water bath until the acetone was completely evaporated, resulting in a dried powder.

[0011] The dried powder was pressed into a green blank and annealed under a protective atmosphere to obtain FeSiAl magnetic powder core material.

[0012] Furthermore, the main material FeSiAl metal particles contain 84.5~84.8% Fe, 9.3~9.6% Si, and the balance is Al; the organic coating agent is epoxy resin, accounting for 1.8~2.0 wt% of the main material weight; the inorganic coating agent is AlN nanoparticles, accounting for 1.5~2.0 wt% of the main material weight.

[0013] Furthermore, the main material is a mixture of FeSiAl metal particles of different sizes, with a particle size distribution range of 5~30µm; the inorganic coating agent AlN particles are nanoparticles with a particle size of less than 100nm.

[0014] Furthermore, the FeSiAl metal particles are cleaned in acetone to remove residual oil from their surface. This process includes:

[0015] FeSiAl metal particles were placed in acetone solution and ultrasonically cleaned for 15 minutes. After ultrasonic cleaning, the top layer of solution was removed, and the precipitate was placed in a fume hood for air drying for 24 hours.

[0016] Further, the FeSiAl metal particles, the organic coating agent and the inorganic coating agent are mixed with an acetone solution, specifically including:

[0017] During the mixing process, the organic coating agent is first mixed with the acetone solution, and after the organic coating agent is completely dissolved, the main material and the inorganic coating agent are poured into the acetone solution.

[0018] Further, the mixture is heated and stirred in a water bath until the acetone is completely volatilized, and a dry powder is obtained, including:

[0019] The mixed solution is heated in a 50oC water bath while stirring with a stirrer until the acetone is completely volatilized. After the acetone is volatilized, the powder is crushed and sieved through a 40 mesh sieve.

[0020] Further, the dry powder is pressed into a green body and annealed in a protective atmosphere to obtain a FeSiAl magnetic powder core material, including:

[0021] The powder is placed in a mold and pressed into a green body at a pressure of 1800MPa; the green body is annealed in a nitrogen protective atmosphere.

[0022] Further, a segmented heat preservation method is used during annealing, and the specific annealing curve is as follows: in the first stage, the temperature is raised from 50℃ to 300℃ at a rate of 2℃ / min; in the second stage, the temperature is raised to 300℃ and held for 1h; in the third stage, the temperature is raised from 300℃ to 700℃ at a rate of 1.5℃ / min; in the fourth stage, the temperature is raised to 700℃ and held for 1h; in the fifth stage, the temperature is lowered from 700℃ to 50℃ at a rate of 2℃ / min.

[0023] In a second aspect, the application provides a low-loss FeSiAl magnetic powder core material for magneto-electric elements, which is prepared by the preparation method.

[0024] In a third aspect, the application provides the use of the low-loss FeSiAl magnetic powder core material for magneto-electric elements as described, for magneto-electric elements.

[0025] Compared with the prior art, the application has the following technical effects:

[0026] The application provides a low-loss FeSiAl magnetic powder core material for magneto-electric elements, which is composed of a main material, an organic coating agent and an inorganic coating agent. The main material is FeSiAl metal particles with a particle size distribution interval of 5-30 µm. In the forming process, small-particle-size FeSiAl particles can be filled between large-particle-size FeSiAl particles, thereby improving the density and saturation magnetization of the FeSiAl magnetic powder core. The organic coating agent is epoxy resin, and the inorganic coating agent is AlN nanoparticles, which can form a thin and uniform composite insulating layer on the surface of the FeSiAl particles, thereby improving the overall resistivity of the material. Based on the above components, a high-density and high-resistivity FeSiAl magnetic powder core material can be prepared, and the core loss is effectively suppressed.

[0027] The application further provides a preparation method of the low-loss FeSiAl magnetic powder core material for magneto-electric elements. First, the FeSiAl metal particles are cleaned with acetone to remove the oil stains attached to the surface, and a high-purity main material is obtained. Then, the organic coating agent is dissolved in acetone, and the main material and the inorganic coating agent are poured into the acetone solution to form a mixed solution. Next, the mixed solution is heated and stirred in a water bath, so that the organic coating agent and the inorganic coating agent are fully wrapped on the surface of the FeSiAl particles. Finally, the green compact formed by compression molding is placed in a tube furnace and annealed in multiple steps under nitrogen protection. The core technology of the application is that the high-resistance AlN nanoparticles are used as the inorganic coating agent, and the water bath heating and stirring are combined, so that the AlN nanoparticles can be uniformly distributed on the surface of the FeSiAl particles to form a thin and uniform insulating layer, thereby significantly improving the resistivity of the FeSiAl magnetic powder core material. At the same time, due to the high temperature stability of AlN, there is no need to worry about its volatilization or decomposition at high temperatures, so that the FeSiAl magnetic powder core can be annealed at a relatively high temperature to fully eliminate stress without damaging the insulating coating layer. In addition, the preparation method of the low-loss FeSiAl magnetic powder core material provided by the application has simple raw materials and few process steps, and can be applied to mass production. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 SEM images of samples in examples 1-4 and comparative examples 1 and 2

[0029] Figure 2 Element distribution of the sample in example 4 DETAILED DESCRIPTION

[0030] The application provides a low-loss FeSiAl magnetic powder core material for a magnetoelectric element and a preparation method thereof. The core idea of the application is: based on organic + inorganic composite coating, an insulating coating layer with thin thickness and high resistance is constructed on the surface of FeSiAl metal magnetic particles by using epoxy resin and AlN nanoparticles, the resistivity of the whole material is improved, and the eddy current loss is effectively suppressed; at the same time, a segmented multi-step holding method is adopted in the sintering process, so that the stress introduced in the pressing process is fully released, and excellent electromagnetic performance is obtained. The prepared FeSiAl magnetic powder core material has the characteristics of high magnetic permeability, high resistivity, low loss and the like. The preparation process comprises the following steps:

[0031] S1, FeSiAl particles are placed in an acetone solution and ultrasonic cleaning is performed. FeSiAl metal particles are weighed in a beaker, acetone solution is added until the FeSiAl particles are completely immersed, and the beaker is placed in an ultrasonic cleaner for ultrasonic cleaning for 15 minutes. After ultrasonic cleaning, the top layer of acetone solution is removed, and the precipitate is placed in a fume hood for air drying for 24 hours;

[0032] S2, the cleaned FeSiAl particles, organic coating agent and inorganic coating agent are mixed with acetone solution. During the mixing process, the weight of the FeSiAl particles is calculated, 1.8-2.0wt% epoxy resin is first mixed with acetone solution, and then 1.5-2.0wt% AlN nanoparticles are poured into the acetone solution after the epoxy resin is completely dissolved in the acetone solution;

[0033] S3, the mixed solution is placed in a 50oC water bath for heating, and a stirrer is used for stirring at a speed of 50 revolutions per minute until the acetone is volatilized, and then the powder is crushed and sieved through a 40 mesh sieve;

[0034] S4, the sieved powder is placed in a mold and pressed into a ring-shaped green body and a circular plate-shaped green body under a pressure of 1800MPa, and then the green body is placed in a tube furnace and annealed under nitrogen protection, and the annealing process adopts a segmented holding method, and the annealing temperature is 700oC;

[0035] The annealed FeSiAl magnetic powder core sample is tested for related performance by using the following equipment:

[0036] The inductance L of the ring-shaped sample obtained in step S4 is tested by using an LCR meter with a model of Tonghui TH2826A, the test condition is 1kHz 600mV, and the effective permeability μe of the ring-shaped sample is calculated according to the formula μe=L∙le∙10-2 / (0.4π∙Ae∙N2), wherein le is the effective magnetic circuit length of the ring-shaped sample, Ae is the effective magnetic circuit area of the ring-shaped sample, and N is the number of turns of the coil;

[0037] The resistance R of the wafer-shaped sample obtained in step S4 was tested by using an LCR instrument of Tonghui TH2826A, the test condition was 1 kHz 600 mV, and the resistivity p of the wafer-shaped sample was calculated according to the formula p = RS / d, wherein d was the wafer thickness, and S was the wafer area;

[0038] The loss of the ring-shaped sample obtained in step S4 was tested by using a BH analyzer of SY-8218, the test condition was 50 kHz 100 mT, 100 kHz 100 mT;

[0039] The microstructure and element distribution of the ring-shaped sample obtained in step S4 were characterized by using a scanning electron microscope of Hitachi TM3030Plus.

[0040] The content of the present application will be described in detail below through specific examples.

[0041] Example

[0042] Table 1: Sample composition and proportion of examples 1-4

[0043]

[0044] Comparative example

[0045] Table 2: Sample composition and proportion of comparative examples 1 and 2

[0046]

[0047] Example 1

[0048] A low-loss FeSiAl magnetic powder core material, the preparation steps are as follows:

[0049] S1, FeSiAl particles were placed in acetone solution and ultrasonic cleaned. 50g of FeSiAl particles were weighed in a beaker, 100mL of acetone solution was added to completely immerse the FeSiAl particles, and the beaker was placed in an ultrasonic cleaner for ultrasonic cleaning for 15min. After ultrasonic cleaning, the top layer of acetone solution was removed, and the precipitate was placed in a fume hood for air drying for 24h;

[0050] S2, the cleaned FeSiAl particles, organic coating agent and inorganic coating agent were mixed with acetone solution. During the mixing process, according to the weight of FeSiAl particles, first 2.0wt% of epoxy resin was mixed with acetone solution, after the epoxy resin was completely dissolved in the acetone solution, then FeSiAl particles and 1.5wt% of AlN nanoparticles were poured into the acetone solution;

[0051] S3, the mixed solution is placed in a 50°C water bath for heating while stirring is performed using a stirrer at a stirring speed of 50 revolutions per minute until the acetone volatilizes, and then the powder is crushed and sieved through a 40-mesh sieve;

[0052] S4, the sieved powder is placed in a mold to press into a ring-shaped green compact and a disc-shaped green compact under a pressure of 1800 MPa, and then the green compacts are placed in a tube furnace for annealing under nitrogen protection, the annealing process adopts a segmented heat preservation method, and the annealing temperature is 700°C;

[0053] Example 2

[0054] A low-loss FeSiAl magnetic powder core material, the preparation steps are as follows:

[0055] S1, FeSiAl particles are placed in an acetone solution and ultrasonic cleaning is performed. 50g of FeSiAl particles are weighed in a beaker, 100mL of acetone solution is added to completely immerse the FeSiAl particles, and the beaker is placed in an ultrasonic cleaner for ultrasonic cleaning for 15min. After ultrasonic cleaning, the top layer of acetone solution is removed, and the precipitated portion is placed in a fume hood for air drying for 24h;

[0056] S2, the cleaned FeSiAl particles, organic coating agent and inorganic coating agent are mixed with acetone solution. During the mixing process, according to the weight of the FeSiAl particles, first mix 2.0wt% of epoxy resin with acetone solution, and then add FeSiAl particles and 1.7wt% of AlN nanoparticles into the acetone solution after the epoxy resin is completely dissolved in the acetone solution;

[0057] S3 and S4 steps are the same as in Example 1.

[0058] Example 3

[0059] A low-loss FeSiAl magnetic powder core material, the preparation steps are as follows:

[0060] S1, FeSiAl particles are placed in an acetone solution and ultrasonic cleaning is performed. 50g of FeSiAl particles are weighed in a beaker, 100mL of acetone solution is added to completely immerse the FeSiAl particles, and the beaker is placed in an ultrasonic cleaner for ultrasonic cleaning for 15min. After ultrasonic cleaning, the top layer of acetone solution is removed, and the precipitated portion is placed in a fume hood for air drying for 24h;

[0061] S2, the FeSiAl particles after cleaning, organic coating agent and inorganic coating agent are mixed with acetone solution. During the mixing process, 2.0wt% epoxy resin is mixed with acetone solution first, and then the FeSiAl particles and 1.8wt% AlN nanoparticles are poured into the acetone solution after the epoxy resin is completely dissolved in the acetone solution;

[0062] S3, S4 steps are completely same as example 1.

[0063] Example 4

[0064] A low-loss FeSiAl magnetic powder core material, the preparation steps are as follows:

[0065] S1, the FeSiAl particles are put into acetone solution and ultrasonic cleaning. 50g FeSiAl particles are weighed in a beaker, 100mL acetone solution is added to completely immerse the FeSiAl particles, and the beaker is placed in an ultrasonic cleaner for ultrasonic cleaning for 15min. After ultrasonic cleaning, the top layer of acetone solution is removed, and the precipitated part is placed in a fume hood for air drying for 24h;

[0066] S2, the FeSiAl particles after cleaning, organic coating agent and inorganic coating agent are mixed with acetone solution. During the mixing process, 2.0wt% epoxy resin is mixed with acetone solution first, and then the FeSiAl particles and 2.0wt% AlN nanoparticles are poured into the acetone solution after the epoxy resin is completely dissolved in the acetone solution;

[0067] S3, S4 steps are completely same as example 1.

[0068] Comparative example 1

[0069] A low-loss FeSiAl magnetic powder core material, the preparation steps are as follows:

[0070] S1, the FeSiAl particles are put into acetone solution and ultrasonic cleaning. 50g FeSiAl particles are weighed in a beaker, 100mL acetone solution is added to completely immerse the FeSiAl particles, and the beaker is placed in an ultrasonic cleaner for ultrasonic cleaning for 15min. After ultrasonic cleaning, the top layer of acetone solution is removed, and the precipitated part is placed in a fume hood for air drying for 24h;

[0071] S2, the FeSiAl particles after cleaning, organic coating agent and inorganic coating agent are mixed with acetone solution. During the mixing process, 2.0wt% epoxy resin is mixed with acetone solution first, and then the FeSiAl particles are poured into the acetone solution after the epoxy resin is completely dissolved in the acetone solution;

[0072] Steps S3 and S4 are exactly the same as in Example 1.

[0073] Comparative Example 2

[0074] A low-loss FeSiAl magnetic powder core material is prepared by the following steps:

[0075] S1. Place the FeSiAl particles in an acetone solution and perform ultrasonic cleaning. Weigh 50g of FeSiAl particles into a beaker, add 100mL of acetone solution until the FeSiAl particles are completely submerged, and place the beaker in an ultrasonic cleaner for ultrasonic cleaning for 15 minutes. After ultrasonic cleaning, remove the top layer of acetone solution, and place the precipitate in a fume hood to air dry for 24 hours.

[0076] S2. Mix the cleaned FeSiAl particles, organic coating agent, and inorganic coating agent with acetone solution. During the mixing process, calculate based on the weight of FeSiAl particles, first mix 2.0wt% epoxy resin with acetone solution until the epoxy resin is completely dissolved in acetone solution, then pour the FeSiAl particles and 2.5wt% AlN nanoparticles into acetone solution;

[0077] Steps S3 and S4 are exactly the same as in Example 1.

[0078] The microstructures of the FeSiAl magnetic powder cores in the above embodiments and comparative examples are as follows: Figure 1 As shown in Table 3, the relevant performance parameters are shown in Table 4, and the energy dispersive spectroscopy (EDS) analysis results of Example 4 are shown in Table 3. Figure 2 As shown.

[0079] Table 3 Electromagnetic properties of samples from Examples 1-4 and Comparative Examples 1 and 2

[0080]

[0081] Table 4 shows the loss separation results of samples from Examples 1-4 and Comparative Examples 1 and 2 under the condition of 100 kHz and 100 mT.

[0082]

[0083] Depend on Figure 1 SEM image, Figure 2 As can be seen from the elemental distribution and the electromagnetic performance parameters of Examples 1-4 in Table 3, the FeSiAl magnetic powder core material prepared by this invention has high density, few pores, a thin and uniformly distributed insulating layer, high resistivity, and low loss. At 100 kHz and 100 mT, the loss is below 435 kW / m³. Among them, the sample of Example 3 exhibits the best overall performance, with a higher initial permeability, higher resistivity, and lowest loss.

[0084] By comparing Example 1 with Example 2, it can be seen that the content of inorganic coating agent AlN nanoparticles is increased to 1.7wt% based on Example 1. Although the magnetic permeability decreases due to the introduction of non-magnetic phase, the hysteresis loss increases to 314 kW / m3, but at the same time the resistivity is increased, the eddy current loss is suppressed, and the total loss is reduced from 435 kW / m3 to 413 kW / m3.

[0085] By comparing Example 2 with Example 3, it can be seen that the content of inorganic coating agent AlN nanoparticles is further increased to 1.8wt% based on Example 2. The magnetic permeability decreases, the hysteresis loss increases, but at the same time the resistivity is significantly increased, the eddy current loss is reduced to 74 kW / m3, thereby the total loss is reduced to 394 kW / m3.

[0086] By comparing Example 3 with Example 4, it can be seen that the content of inorganic coating agent AlN nanoparticles is further increased to 2.0wt% based on Example 3. Although the resistivity is further increased, the eddy current loss is reduced to 52 kW / m3, but due to the decrease of magnetic permeability, the hysteresis loss increases to 364 kW / m3, resulting in the total loss increasing to 416 kW / m3.

[0087] By comparing Comparative Example 1 with Example 1, it can be seen that the content of inorganic coating agent AlN nanoparticles is reduced to 0.0wt% based on Example 1. Although the magnetic permeability increases slightly and the hysteresis loss decreases slightly, due to the decrease of the insulation effect of the coating layer, the resistivity decreases significantly, the eddy current loss increases to 244 kW / m3, resulting in the total loss increasing to 510 kW / m3.

[0088] By comparing Comparative Example 2 with Example 4, it can be seen that the content of inorganic coating agent AlN nanoparticles is further increased to 2.5wt% based on Example 4. Although the resistivity increases to 1.15Ω·m and the eddy current loss is only 50 kW / m3, due to the increase of the hysteresis loss to 451 kW / m3, the total loss increases to 502 kW / m3.

[0089] From the above data, it can be seen that in the preparation process of the low-loss FeSiAl magnetic powder core material of the present application, high-resistance AlN nanoparticles are used as inorganic coating agents to form a thin and uniform insulating layer, which significantly increases the resistivity of the FeSiAl magnetic powder core material, and at the same time the content of AlN nanoparticles is strictly controlled, and combined with the segmented multi-step sintering method, the magnetic permeability of the FeSiAl magnetic powder core is not decreased too much, so that the prepared FeSiAl magnetic powder core material has the characteristics of high magnetic permeability, high resistivity and low loss.

[0090] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A method for the production of low-loss FeSiAl magnetic powder core material for magnetoelectric elements, characterized in that, The method comprises the following steps: FeSiAl metal particles are placed in acetone for cleaning to remove residual oil stains on the surface of the FeSiAl metal particles; FeSiAl metal particles, organic coating agent and inorganic coating agent are mixed with an acetone solution to obtain a mixture; The mixture is placed in a water bath for heating and stirring until the acetone is completely volatilized to obtain a dried powder; The mixture is placed in a water bath for heating and stirring until the acetone is completely volatilized to obtain a dried powder, comprising: The mixed solution is placed in a 50oC water bath for heating while stirring with a stirrer until the acetone is completely volatilized. After the acetone is volatilized, the powder is crushed and sieved through a 40-mesh sieve; The dried powder is pressed into a green body and annealed in a protective atmosphere to obtain a FeSiAl magnetic powder core material; The main material FeSiAl metal particles contain 84.5-84.8% Fe, 9.3-9.6% Si, and the balance Al; the organic coating agent is epoxy resin, accounting for 1.8-2.0wt% of the weight of the main material; and the inorganic coating agent is AlN nanoparticles, accounting for 1.5-2.0wt% of the weight of the main material; The main material is composed of FeSiAl metal particles with different particle sizes, and the particle size distribution range is 5-30 µm; the inorganic coating agent AlN particles are nanoparticles with a particle size of less than 100 nm; In the annealing process, a segmented heat preservation method is adopted, and the specific annealing curve is as follows: in the first stage, the temperature is raised from 50℃ to 300℃ at a rate of 2℃ / min; in the second stage, the temperature is raised to 300℃ and kept for 1h; in the third stage, the temperature is raised from 300℃ to 700℃ at a rate of 1.5℃ / min; in the fourth stage, the temperature is raised to 700℃ and kept for 1h; and in the fifth stage, the temperature is lowered from 700℃ to 50℃ at a rate of 2℃ / min.

2. The method of claim 1, wherein the low-loss FeSiAl magnetic powder core material for a magnetoelectric element is prepared by the steps of: The FeSiAl metal particles are placed in acetone for cleaning to remove residual oil stains on the surface of the FeSiAl metal particles, specifically comprising: ​ The FeSiAl metal particles are placed in acetone and ultrasonically cleaned for 15 minutes. After ultrasonic cleaning, the top layer of the solution is removed, and the precipitate is placed in a fume hood for air drying for 24 hours.

3. The method of claim 1, wherein the low-loss FeSiAl magnetic powder core material for a magnetoelectric element is prepared by the steps of: The FeSiAl metal particles, organic coating agent and inorganic coating agent are mixed with an acetone solution, specifically comprising: ​ During the mixing process, the organic coating agent is first mixed with the acetone solution, and then the main material and the inorganic coating agent are poured into the acetone solution after the organic coating agent is completely dissolved.

4. The method of claim 1, wherein the low-loss FeSiAl magnetic powder core material for a magnetoelectric element is prepared by the steps of: The dried powder is pressed into a green body and annealed in a protective atmosphere to obtain a FeSiAl magnetic powder core material, comprising: ​ The powder is placed in a mold and pressed into a green body at a pressure of 1800MPa; and the green body is annealed in a nitrogen protective atmosphere.

5. A low-loss FeSiAl magnetic powder core material for magneto-electric elements, characterized by, The low-loss FeSiAl magnetic powder core material for magnetoelectric elements is prepared by the method according to any one of claims 1 to 4.

6. Use of a low-loss FeSiAl magnetic powder core material for magneto-electric elements according to claim 5, characterized in that, For magnetoelectric elements.

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