2 / 17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material and preparation method thereof

Abstract

The invention discloses a 2: 17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material and a preparation method thereof. The method sequentially comprises the following steps: 1) screening 2: 17 type rare earth soft magnetic powder, performing insulation coating, mixing with polyurethane, and performing magnetic field orientation to obtain a thin ring green body; (2) Fe-based soft magnetic powder is sieved and mixed with polyurethane, and then a thin ring green body is obtained through magnetic field orientation; (3) alternately stacking the 2: 17 type rare earth soft magnetic thin ring green bodies and the Fe-based soft magnetic thin ring green bodies in the direction perpendicular to the plane of the thin ring green bodies; and 4) carrying out hot press molding on the laminated soft magnetic composite material. Based on the high-frequency characteristic of the 2: 17 type rare earth soft magnetic material and the high magnetic conductivity characteristic of the Fe-based soft magnetic material, collaborative optimization of the magnetic conductivity and the cut-off frequency is achieved within the ultra-wideband range from MHz to GHz, the problem that the magnetic conductivity of a traditional soft magnetic composite material is attenuated along with the frequency is effectively solved, high-frequency loss is greatly reduced, and the service life of the soft magnetic composite material is prolonged. And a solution is provided for high-frequency soft magnetic components (such as inductors and transformers) with high magnetic performance and low power consumption.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the technical field of magnetic material preparation, in particular to a preparation method of 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material. BACKGROUND

[0002] The rapid iteration of key fields such as information, communication, energy and transportation continues to drive soft magnetic composites to develop in the direction of high frequency and miniaturization. The rapid rise of wide-bandgap semiconductors (such as SiC, GaN) has put forward higher requirements on soft magnetic composites, which need to balance high permeability, low loss and wide frequency band. Specifically, 1) permeability stability: high permeability needs to be maintained in the target frequency band (such as 1-100MHz) to avoid the sharp decline of magnetic properties due to the increase of frequency; 2) loss controllability: it is urgent to suppress the magnetic hysteresis loss, eddy current loss and residual loss at high frequency to avoid the heating of soft magnetic composites leading to system failure; 3) frequency band adaptability: the working cutoff frequency ( μ ) needs to cover the actual application frequency band of wide-bandgap devices, breaking the mutual restriction of permeability and cutoff frequency. f c ) needs to cover the actual application frequency band of wide-bandgap devices, breaking the mutual restriction of permeability and cutoff frequency.

[0003] Fe-based soft magnetic material as a common metal soft magnetic material has the advantages of high permeability and low coercivity ( H c ) at low frequency (kHz and below), but when the working frequency is higher than MHz, the internal magnetic moment of Fe-based soft magnetic material cannot keep up with the change of external field, resulting in a sharp decline in permeability. On the other hand, the size of eddy current inside the material increases exponentially at high frequency, resulting in a sharp rise in magnetic loss. Patent CN113192717A discloses a metal soft magnetic composite material and a preparation method thereof, wherein the composite material prepared by taking pure Fe magnetic powder as the matrix and nickel-zinc ferrite as the insulating coating layer has a high permeability of 65 at high frequency, but the permeability starts to decline at 1MHz, limiting the high-frequency application.

[0004] 2:17 type rare earth soft magnetic material (such as Y2Co 17 , Ce2(Fe 0.6 Co 0.4 ) 17 , etc.) greatly suppresses the magnetic resonance phenomenon at high frequency by introducing planar magnetic crystal anisotropy or conical magnetic crystal anisotropy, providing a new path for improving the cutoff frequency of soft magnetic material. Patent CN115623766A discloses a preparation method and application of rare earth high-frequency soft magnetic material, which involves Ce2Co 17 , Nd2Co 17 , Y2Co 17The 2:17 type rare earth soft magnetic material has a resonance frequency of up to 10 GHz at high frequency, but its magnetic permeability is relatively low, only about 1.5, which is due to the inevitable increase of the anisotropy field of the material, which increases the coercive force, thereby reducing the intrinsic magnetic permeability of the material and rapidly increasing the hysteresis loss.

[0005] Through comparative analysis of the key magnetic performance parameters of Fe-based soft magnetic materials and 2:17 type rare earth soft magnetic materials, it can be seen that the two types of materials have complementary advantages: the former has high magnetic permeability but low cutoff frequency, and the latter has high cutoff frequency but low magnetic permeability. The effective integration of the two types of materials and the synergistic optimization of the magnetic performance are conducive to breaking through the bottleneck problem that the performance of the current high-frequency soft magnetic material is difficult to consider. Patent CN118888241A discloses a kind of iron-based multi-powder soft magnetic composite material and its preparation method, three different types of iron-based magnetic powder are selected for physical mixing, and a soft magnetic composite material with low, medium and high frequency loss and good DC bias characteristics is prepared. However, there are problems such as powder morphology and particle size mismatch, interface bonding strength, and magnetic flux incompatibility caused by magnetic permeability difference between Fe-based soft magnetic powder and 2:17 type rare earth soft magnetic powder. The traditional magnetic powder physical mixing technical route is difficult to realize the effective integration of the two types of materials. Therefore, it is particularly important to give full play to the performance advantages of various soft magnetic materials and break through the matching preparation technology of different types of soft magnetic materials for the development of high-frequency soft magnetic materials with excellent comprehensive performance. SUMMARY

[0006] Based on the above background, the present application provides a preparation method of 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material, which is prepared by a series of processes such as magnetic powder pretreatment, mixing polyurethane, thin ring green body acquisition, alternating stacking and hot pressing forming, and has high magnetic permeability and high cutoff frequency. The preparation method comprises the following main steps: 1) 2:17 type rare earth soft magnetic powder is screened, coated with insulation, and mixed with polyurethane to obtain a thin ring green body after magnetic field orientation; 2) Fe-based soft magnetic powder is screened and mixed with polyurethane to obtain a thin ring green body after magnetic field orientation; 3) The 2:17 type rare earth soft magnetic thin ring green body and the Fe-based soft magnetic thin ring green body are alternately stacked along the direction perpendicular to the plane of the thin ring green body; 4) Hot pressing forming of the laminated soft magnetic composite material.

[0007] According to the preferred scheme of the present application, the process of step 1) of screening, insulating coating and mixing 2:17 type rare earth soft magnetic powder with polyurethane to obtain a thin ring green body after magnetic field orientation comprises the following substeps: 1.1) The particle size of the 2:17 type rare earth soft magnetic powder is controlled to be 10-20 μm after screening; 1.2) Add phosphoric acid accounting for 1-3wt% of the mass of 2:17 type rare earth soft magnetic powder to acetone with purity ≥99%, and uniformly distribute the phosphoric acid in the acetone under ultrasonic stirring at room temperature; 1.3) Add the sieved 2:17 type rare earth soft magnetic powder to the mixed solution obtained in step 1.2), and simultaneously ultrasonic stir until the solution is completely evaporated to obtain the 2:17 type rare earth soft magnetic powder after insulation coating; 1.4) Add polyurethane powder accounting for 3-5wt% of the mass of 2:17 type rare earth soft magnetic powder to acetone, and ultrasonic stir at room temperature until the polyurethane powder is completely dissolved; 1.5) Add the 2:17 type rare earth soft magnetic powder after insulation coating in step 1.3) to the mixed solution obtained in step 1.4), and simultaneously ultrasonic stir until the acetone is completely evaporated to obtain a 2:17 type rare earth soft magnetic powder-polyurethane mixture; 1.6) In the process of magnetic field orientation, a plane rotating magnetic field is used to make the 2:17 type rare earth soft magnetic powder-polyurethane mixture directionally arrange in a mold to form a 2:17 type rare earth soft magnetic thin ring green body with a thickness range of 100-200μm, and the thickness direction of the thin ring green body is perpendicular to the plane direction of the thin ring green body; the magnetic field size is 0.8-1.2T, and the orientation time of a single thin ring green body is 30-60s.

[0008] According to the preferred scheme of the present application, the process of step 2) that the Fe-based soft magnetic powder is sieved and mixed with polyurethane and then obtains a thin ring green body through magnetic field orientation includes the following sub-steps: 2.1) Control the particle size of the Fe-based soft magnetic powder to be 10-20μm after sieving; 2.2) Add polyurethane powder accounting for 3-5wt% of the mass of the magnetic powder to acetone, wherein the solid-liquid ratio of the polyurethane powder and acetone is 1:100-1:200g / mL, and ultrasonic stir at room temperature until the polyurethane powder is completely dissolved; 2.3) Add the sieved Fe-based soft magnetic powder in step 2.1) to the mixed solution obtained in step 2.2), and simultaneously ultrasonic stir until the acetone is completely evaporated to obtain a Fe-based soft magnetic powder-polyurethane mixture; 2.4) In the process of magnetic field orientation, a plane rotating magnetic field is used to make the Fe-based soft magnetic powder-polyurethane mixture directionally arrange in a mold to form a Fe-based soft magnetic thin ring green body with a thickness range of 100-200μm, and the thickness direction of the thin ring green body is perpendicular to the plane direction of the thin ring green body; the magnetic field size is 0.8-1.2T, and the orientation time of a single thin ring green body is 30-60s.

[0009] According to a preferred embodiment of the present invention, in step 3), during the alternating stacking of the 2:17 type rare earth soft magnetic thin ring green blank and the Fe-based soft magnetic thin ring green blank in a direction perpendicular to the plane of the thin ring green blank, the number of thin ring green blanks determines the thickness of the final composite material. The number of 2:17 type rare earth soft magnetic powder thin ring green blank and Fe-based soft magnetic powder thin ring green blank are 5-15 layers respectively.

[0010] According to a preferred embodiment of the present invention, in step 4) the hot pressing process of the laminated soft magnetic composite material, the laminated soft magnetic composite material blank is placed in the mold, and the interlayer densification and molding are achieved by hot pressing. The hot pressing temperature is 80-100℃ and the pressure is 600-1200MPa.

[0011] The technical solution of this invention has the following main advantages: (1) This invention innovatively proposes a layered design concept, and combines the advantages of 2:17 type rare earth soft magnetic materials and Fe-based soft magnetic materials, successfully breaking through the performance inversion relationship between permeability and cutoff frequency of soft magnetic materials at high frequencies. The prepared material has both high permeability ( μ >18), high cutoff frequency ( f c (≥1GHz), providing new ideas for the design of high-frequency, high-performance magnetic components.

[0012] (2) This invention selectively performs phosphoric acid passivation treatment on 2:17 type rare earth soft magnetic powder and adopts a periodic stacked design. From the two dimensions of magnetic powder particle insulation and interlayer isolation, the internal interconnected conductive network of the composite material is divided into numerous localized conductive units surrounded by insulating boundaries, which greatly suppresses eddy current loss. On the other hand, the Fe-based soft magnetic layer, which mainly plays the role of high magnetic permeability, maintains its intrinsic excellent magnetic properties. Its contribution to magnetic permeability is not reduced due to passivation treatment, thus achieving simultaneous optimization of eddy current loss and magnetic permeability of the stacked composite material.

[0013] (3) The layered configuration design concept proposed in this invention has universal applicability regardless of the material system. The core advantage of this configuration lies in its customizable modular design freedom, that is, the material selection, thickness ratio, and stacking sequence of different functional layers can be flexibly adjusted and optimized according to specific application scenarios (such as power inductors, electromagnetic interference suppression components, and microwave absorbers). Therefore, this design framework can be widely applied to various material systems such as rare earth soft magnetic materials, crystalline Fe-based soft magnetic materials, and amorphous nanocrystalline soft magnetic materials, demonstrating good design flexibility and technical scalability, and providing a technical solution for the development and preparation of novel soft magnetic composite materials. Attached Figure Description

[0014] Figure 1 In Example 1 of this invention, Ce2(Fe) 0.6 Co 0.4) 17 Process flow diagram of FeNi laminated soft magnetic composite material; Figure 2 In Example 1 of this invention, Ce2(Fe) 0.6 Co 0.4 ) 17 Physical image of FeNi laminated soft magnetic composite material; Figure 3 In Example 1 of this invention, Ce2(Fe) 0.6 Co 0.4 ) 17 Cross-sectional SEM images and EDS surface scan analysis of FeNi laminated soft magnetic composite materials; Figure 4 In Example 1 of this invention, Ce2(Fe) 0.6 Co 0.4 ) 17 High-frequency magnetic spectrum and magnetic loss results of FeNi laminated soft magnetic composite material. Specific implementation methods The following examples provide those skilled in the art with guidance on how to manufacture and evaluate the invention. These examples are merely illustrative of the present disclosure and do not limit its scope. While every effort has been made to ensure accuracy regarding numerical values ​​(e.g., quantities, temperatures, etc.), some errors and deviations should be considered. Unless otherwise stated, temperatures are in °C or at ambient temperature, and pressures are at or near atmospheric pressure.

[0015] All embodiments of this invention employ the proposed method for preparing 2:17 type rare-earth soft magnetic / Fe-based soft magnetic laminated composite materials. This method selectively passivates the 2:17 type rare-earth soft magnetic powder with phosphoric acid and uses a periodic laminated design. From the perspectives of magnetic powder particle insulation and interlayer isolation, the interconnected conductive network inside the composite material is divided into numerous localized conductive units surrounded by insulating boundaries, greatly suppressing eddy current losses. On the other hand, the Fe-based soft magnetic layer, which mainly plays a role in high permeability, maintains its intrinsic excellent magnetic properties, and its contribution to permeability is not reduced due to passivation treatment, achieving simultaneous optimization of eddy current losses and permeability in the laminated composite material. This successfully breaks through the performance inversion relationship between permeability and cutoff frequency of soft magnetic materials at high frequencies. The following is a detailed description of the preparation method, which includes the following steps: 1) 2:17 type rare earth soft magnetic powder is screened, insulated and coated, and then mixed with polyurethane and oriented by magnetic field to obtain thin ring green body; In an embodiment of the present invention, step 1) further includes the following sub-steps: 1.1) The particle size of the 2:17 type rare earth soft magnetic powder is controlled to be 10-20μm after sieving; 1.2) Add 1-3 wt% of phosphoric acid (based on the mass of 2:17 type rare earth soft magnetic powder) to acetone with a purity ≥99%, with a phosphoric acid concentration ≥85%. The ratio of phosphoric acid to acetone is 1:100-1:200 g / mL. Stir the mixture with ultrasound at room temperature to ensure that the phosphoric acid is evenly distributed in the acetone. 1.3) Add the sieved 2:17 type rare earth soft magnetic powder to the mixed solution obtained in step 1.2), and stir ultrasonically until the solution is completely evaporated to obtain the 2:17 type rare earth soft magnetic powder with insulating coating. 1.4) Add 3-5 wt% of polyurethane powder (based on the mass of 2:17 type rare earth soft magnetic powder) to acetone. The solid-liquid ratio of polyurethane powder to acetone is 1:100-1:200 g / mL. Stir ultrasonically at room temperature until the polyurethane powder is completely dissolved. 1.5) Add the 2:17 type rare earth soft magnetic powder after insulation coating in step 1.3) to the mixed solution obtained in step 1.4), and stir ultrasonically until the acetone is completely evaporated to obtain a 2:17 type rare earth soft magnetic powder-polyurethane mixture. 1.6) During the magnetic field orientation process, a planar rotating magnetic field is used to orient the 2:17 type rare earth soft magnetic powder-polyurethane mixture in the mold to form a 2:17 type rare earth soft magnetic thin ring green body with a thickness range of 100-200μm. The magnetic field strength is 0.8-1.2T and the orientation time of a single thin ring green body is 30-60s.

[0016] 2) Fe-based soft magnetic powder is sieved, mixed with polyurethane, and then oriented by a magnetic field to obtain a thin ring green body; In an embodiment of the present invention, step 2) further includes the following sub-steps: 2.1) The Fe-based soft magnetic powder is sieved to control the particle size to 10-20 μm; 2.2) Add 3-5 wt% of polyurethane powder to acetone (purity ≥ 99%), wherein the solid-liquid ratio of polyurethane powder to acetone is 1:100-1:200 g / mL, and ultrasonically stir at room temperature until the polyurethane powder is completely dissolved. 2.3) Add the Fe-based soft magnetic powder after sieving in step 2.1) to the mixed solution obtained in step 2.2) and stir ultrasonically until the acetone is completely evaporated to obtain the Fe-based soft magnetic powder-polyurethane mixture. 2.4) During the magnetic field orientation process, a planar rotating magnetic field is used to orient the Fe-based soft magnetic powder-polyurethane mixture within the mold to form a Fe-based soft magnetic thin ring green body with a thickness range of 100-200μm. The magnetic field strength is 0.8-1.2T, and the orientation time for a single thin ring green body is 30-60s.

[0017] 3) Alternately stack 2:17 type rare earth soft magnetic thin rings and Fe-based soft magnetic thin ring green blanks; the number of thin ring green blanks determines the thickness of the final composite material. The number of 2:17 type rare earth soft magnetic powder thin ring green blanks and Fe-based soft magnetic powder thin ring green blanks are 5-15 layers respectively.

[0018] 4) Hot pressing of laminated soft magnetic composite material: The laminated soft magnetic composite material blank is placed in a mold and the interlayer densification and molding are achieved by hot pressing. The hot pressing temperature is 80-100℃ and the pressure is 600-1200MPa.

[0019] The following examples illustrate the preparation method of the present invention in detail.

[0020] Example 1 Ce2(Fe 0.6 Co 0.4 ) 17 The preparation process of FeNi laminated soft magnetic composite material is as follows (process flow diagram is shown). Figure 1 As shown in the image): For Ce2(Fe 0.6 Co 0.4 ) 17 The magnetic powder is sieved to control the particle size to 10μm. 2) Add 0.06g of phosphoric acid to 6mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved Ce2(Fe)2. 0.6 Co 0.4 ) 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain phosphoric acid passivated Ce2(Fe) powder. 0.6 Co 0.4 ) 17 Magnetic powder; 3) Weigh 0.1g of polyurethane powder, dissolve the polyurethane powder in 10mL of acetone, and ultrasonically stir until the powder is completely dissolved. Then add phosphoric acid passivated Ce2(Fe)2 to the solution. 0.6 Co 0.4 ) 17 Magnetic powder was continuously ultrasonically stirred until acetone was completely evaporated to obtain Ce2(Fe). 0.6 Co 0.4 ) 17 - Polyurethane mixture; 4) The obtained Ce2(Fe) 0.6 Co 0.4 ) 17 - The polyurethane mixture was added in batches to a magnetically oriented mold, 0.15g at a time, and oriented for 60s under a magnetic field of 1.2T, ultimately obtaining a Ce2(Fe) film with a thickness of approximately 200μm. 0.6 Co 0.4 )17 Thin ring green blank (actual object as shown) Figure 2 As shown); 5) The FeNi magnetic powder was sieved to control the particle size to 10μm; 6) Weigh 2.0g of sieved FeNi magnetic powder and 0.1g of polyurethane powder. Dissolve the polyurethane powder in 10mL of acetone and stir ultrasonically until the powder is completely dissolved. Then add the weighed FeNi magnetic powder and continue to stir ultrasonically until the acetone is completely evaporated to obtain the FeNi-polyurethane mixture. 7) The obtained FeNi-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.15g added each time. Simultaneously, orientation was carried out under a magnetic field of 1.2T for 60s, ultimately yielding a FeNi thin ring green body with a thickness of approximately 200μm (see physical example). Figure 2 As shown); 8) Take 5 layers of Ce2(Fe) 0.6 Co 0.4 ) 17 Thin ring green billets and FeNi thin ring green billets are periodically stacked and placed in a ring mold, then held at 1200 MPa and 100 °C for a period of time to finally obtain Ce2(FeNi ... 0.6 Co 0.4 ) 17 / FeNi laminated soft magnetic composite material.

[0021] In the preparation of Ce2(Fe 0.6 Co 0.4 ) 17 During the process of creating the FeNi laminated soft magnetic composite material, the following characterization and testing were performed: 1) Observe Ce2(Fe) in Example 1 0.6 Co 0.4 ) 17 The cross-sectional microstructure of the FeNi laminated soft magnetic composite material, including its SEM images and EDS surface scan analysis, is shown below. Figure 3 As shown, the EDS surface scan results clearly reveal a periodic elemental distribution, which is a direct reflection of the multilayer configuration. Meanwhile, Ce2(Fe) 0.6 Co 0.4 ) 17 The O content in the EDS surface scan of the Ce2(Fe) layer was significantly higher than that in the FeNi layer, which is due to the presence of Ce2(Fe) content. 0.6 Co 0.4 ) 17 The result of passivation of magnetic powder with phosphoric acid.

[0022] 2) The Ce2(Fe) prepared in Example 1 was tested. 0.6 Co0.4 ) 17 The high-frequency magnetic spectrum and magnetic loss results of the FeNi laminated soft magnetic composite material are as follows: Figure 3 As shown, Ce2(Fe) designs without stacking were additionally tested. 0.6 Co 0.4 ) 17 Comparing soft magnetic composite materials and FeNi soft magnetic composite materials, it was found that after the layered design, Ce2(Fe 0.6 Co 0.4 ) 17 The FeNi laminated soft magnetic composite material combines the advantages of both materials, possessing both high initial permeability and an ultra-high cutoff frequency. The real part of its complex permeability is 18.2 at 1 MHz, and its operating cutoff frequency is greater than 1 GHz. Simultaneously, the material exhibits the lowest total loss of 229.84 kW / m at 3 MHz and 10 mT. 3 .

[0023] Example 2 Y2Co 17 The preparation process of the FeSiAl laminated soft magnetic composite material is as follows: 1) Regarding Y2Co 17 The magnetic powder is sieved to control the particle size to 15μm. 2) Add 0.06g of phosphoric acid to 12mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved Y2Co. 17 Magnetic powder was continuously ultrasonically stirred until acetone was completely evaporated, yielding phosphoric acid passivated Y2Co. 17 Magnetic powder; 3) Weigh 0.08g of polyurethane powder, dissolve the polyurethane powder in 16mL of acetone, and sonicate until the powder is completely dissolved. Then add phosphoric acid passivated Y2Co to the solution. 17 Magnetic powder was continuously ultrasonically stirred until acetone was completely evaporated to obtain Y2Co. 17 - Polyurethane mixture; 4) The obtained Y2Co 17 - The polyurethane mixture was added in batches to a magnetically oriented mold, 0.1 g at a time, and oriented for 50 s under a magnetic field of 1.0 T, ultimately yielding a Y2Co layer with a thickness of approximately 150 μm. 17 Thin ring green blank; 5) The FeSiAl magnetic powder was sieved to control the particle size to 15μm; 6) Weigh 2.0g of sieved FeSiAl magnetic powder and 0.08g of polyurethane powder. Dissolve the polyurethane powder in 16mL of acetone and ultrasonically stir until the powder is completely dissolved. Then add the weighed FeSiAl magnetic powder and continue ultrasonic stirring until the acetone is completely evaporated to obtain the FeSiAl-polyurethane mixture. 7) The obtained FeSiAl-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.1g added each time, and oriented for 50s under a magnetic field of 1.0T, finally obtaining a FeSiAl thin ring green body with a thickness of about 150μm. 8) Take 7 layers of Y2Co respectively 17 Thin ring green blanks and FeSiAl thin ring green blanks were periodically stacked and placed in a ring mold, and held under pressure at 1000 MPa and 90℃ for a period of time to finally obtain Y2Co with an outer diameter of 12.2 mm, an inner diameter of 6.01 mm, and a thickness of 2.12 mm. 17 / FeSiAl laminated soft magnetic composite material.

[0024] Y2Co was tested 17 High-frequency performance of FeSiAl laminated soft magnetic composite material: real part of complex permeability is 35.5 at 1MHz, operating cutoff frequency is greater than 1GHz, and total loss is 584.3kW / m at 3MHz and 10mT. 3 After loss separation, the loss is mainly hysteresis loss.

[0025] Example 3 Nd2Fe 17 The preparation process of the FeSi laminated soft magnetic composite material is as follows: 1) For Nd2Fe 17 The magnetic powder is sieved to control the particle size to 20μm. 2) Add 0.05g of phosphoric acid to 5mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved Nd2Fe. 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain phosphoric acid passivated Nd2Fe. 17 Magnetic powder; 3) Weigh 0.06g of polyurethane powder, dissolve the polyurethane powder in 6mL of acetone, and ultrasonically stir until the powder is completely dissolved. Then add phosphoric acid passivated Nd2Fe 17 Magnetic powder was continuously ultrasonically stirred until acetone was completely evaporated to obtain Nd2Fe. 17 - Polyurethane mixture; 4) The obtained Nd2Fe 17- The polyurethane mixture was added in batches to a magnetically oriented mold, 0.2g each time, and oriented for 30s under a magnetic field of 0.8T, ultimately obtaining Nd2Fe with a thickness of approximately 400μm. 17 Thin ring green blank; 5) The FeSi magnetic powder was sieved to control the particle size to 20μm; 6) Weigh 2.0g of sieved FeSi magnetic powder and 0.06g of polyurethane powder. Dissolve the polyurethane powder in 6mL of acetone and stir ultrasonically until the powder is completely dissolved. Then add the weighed FeSi magnetic powder and continue to stir ultrasonically until the acetone is completely evaporated to obtain the FeSi-polyurethane mixture. 7) The obtained FeSi-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.2g added each time, and oriented for 30s under a magnetic field of 0.8T, finally obtaining a FeSi thin ring green body with a thickness of about 400μm. 8) Take three layers of Nd2Fe respectively 17 Thin ring green blanks and FeSi thin ring green blanks were periodically stacked and placed in a ring mold, and held under pressure and temperature of 600 MPa and 80 °C for a period of time to finally obtain Nd2Fe with an outer diameter of 12.3 mm, an inner diameter of 5.91 mm, and a thickness of 2.35 mm. 17 / FeSi laminated soft magnetic composite material.

[0026] Nd2Fe was tested 17 High-frequency performance of FeSi multilayer soft magnetic composite material: The real part of the complex permeability is 20.1 at 1MHz, the operating cutoff frequency is greater than 1GHz, and the total loss at 3MHz and 10mT is 504.9kW / m. 3 .

[0027] Example 4 Nd2(Fe 0.4 Co 0.6 ) 17 The preparation process of FeSiB laminated soft magnetic composite material is as follows: 1) For Nd2(Fe 0.4 Co 0.6 ) 17 The magnetic powder is sieved to control the particle size to 18μm. 2) Add 0.04g of phosphoric acid to 8mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved Nd2(Fe)2. 0.4 Co 0.6 ) 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain phosphoric acid passivated Nd2(Fe) powder. 0.4 Co 0.6 )17 Magnetic powder; 3) Weigh 0.075g of polyurethane powder, dissolve the polyurethane powder in 10mL of acetone, and ultrasonically stir until the powder is completely dissolved. Then add phosphoric acid passivated Nd2(Fe)2. 0.4 Co 0.6 ) 17 Magnetic powder was continuously ultrasonically stirred until acetone was completely evaporated to obtain Nd2(Fe). 0.4 Co 0.6 ) 17 - Polyurethane mixture; 4) The obtained Nd2(Fe 0.4 Co 0.6 ) 17 - The polyurethane mixture was added in batches to a magnetically oriented mold, 0.15 g at a time, and oriented for 45 s under a magnetic field of 1.1 T, ultimately obtaining a Nd2(Fe)2 matrix with a thickness of approximately 200 μm. 0.4 Co 0.6 ) 17 Thin ring green blank; 5) The FeSiB magnetic powder was sieved to control the particle size to 18μm; 6) Weigh 2.0g of sieved FeSiB magnetic powder and 0.075g of polyurethane powder. Dissolve the polyurethane powder in 10mL of acetone and stir ultrasonically until the powder is completely dissolved. Then add the weighed FeSiB magnetic powder and continue to stir ultrasonically until the acetone is completely evaporated to obtain the FeSiB-polyurethane mixture. 7) The obtained FeSiB-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.15g added each time, and oriented for 45s under a magnetic field of 1.1T, finally obtaining a FeSiB thin ring green body with a thickness of about 200μm. 8) Take 5 layers of Nd2(Fe) 0.4 Co 0.6 ) 17 Thin ring green blanks and FeSiB thin ring green blanks were periodically stacked and placed in a ring mold, then held at 850 MPa and 95 °C for a period of time to finally obtain Nd2(FeSiB) thin ring green blanks with an outer diameter of 12.13 mm, an inner diameter of 6.02 mm, and a thickness of 2.01 mm. 0.4 Co 0.6 ) 17 / FeSiB laminated soft magnetic composite material.

[0028] Nd2(Fe) was tested 0.4 Co 0.6 ) 17High-frequency performance of FeSiB multilayer soft magnetic composite material: real part of complex permeability is 30.7 at 1MHz, operating cutoff frequency is greater than 1GHz, and total loss is 414.1kW / m at 3MHz and 10mT. 3 .

[0029] Example 5 (La 0.2 Y 0.8 )2Co 17 The preparation process of the FeCuNbSiB laminated soft magnetic composite material is as follows: (La) 0.2 Y 0.8 )2Co 17 The magnetic powder is sieved to control the particle size to 20μm. 2) Add 0.045g of phosphoric acid to 5mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved (La) powder. 0.2 Y 0.8 )2Co 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain phosphoric acid passivated (La). 0.2 Y 0.8 )2Co 17 Magnetic powder; 3) Weigh 0.085g of polyurethane powder, dissolve the polyurethane powder in 15mL of acetone, and ultrasonically stir until the powder is completely dissolved. Then add phosphoric acid passivated (La) 0.2 Y 0.8 )2Co 17 Magnetic powder, while continuously ultrasonically stirred, until acetone is completely evaporated to obtain (La) 0.2 Y 0.8 )2Co 17 - Polyurethane mixture; 4) The obtained (La) 0.2 Y 0.8 )2Co 17 - The polyurethane mixture was added in batches to a magnetically oriented mold, 0.12 g at a time, and oriented for 60 s under a magnetic field of 0.9 T, ultimately obtaining a (La) coating with a thickness of approximately 180 μm. 0.2 Y 0.8 )2Co 17 Thin ring green blank; 5) The FeNi magnetic powder was sieved to control the particle size to 20μm; 6) Weigh 2.0g of sieved FeCuNbSiB magnetic powder and 0.085g of polyurethane powder. Dissolve the polyurethane powder in 15mL of acetone and stir ultrasonically until the powder is completely dissolved. Then add the weighed FeNi magnetic powder and continue to stir ultrasonically until the acetone is completely evaporated to obtain the FeCuNbSiB-polyurethane mixture. 7) The obtained FeCuNbSiB-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.12g added each time, and oriented for 60s under a magnetic field of 0.9T, finally obtaining a FeCuNbSiB thin ring green body with a thickness of about 180μm. 8) Take 5 layers respectively (La) 0.2 Y 0.8 )2Co 17 Thin ring green blanks and FeCuNbSiB thin ring green blanks were periodically stacked and placed in a ring mold, then held at 1000 MPa and 100℃ for a period of time to finally obtain a (La) ring green blank with an outer diameter of 11.95 mm, an inner diameter of 6.06 mm, and a thickness of 1.87 mm. 0.2 Y 0.8 )2Co 17 / FeCuNbSiB laminated soft magnetic composite material.

[0030] Tested (La) 0.2 Y 0.8 )2Co 17 High-frequency performance of FeCuNbSiB multilayer soft magnetic composite material: The real part of the complex permeability is 28.1 at 1MHz, the operating cutoff frequency is greater than 1GHz, and the total loss at 3MHz and 10mT is 499.61kW / m. 3 .

[0031] Example 6 (Ce 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 The preparation process of the FeSiCr laminated soft magnetic composite material is as follows: For (Ce) 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 The magnetic powder is sieved to control the particle size to 15μm. 2) Add 0.02g of phosphoric acid to 4mL of acetone, stir ultrasonically until homogeneous, and then add 2.0g of sieved (Ce) solution. 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2) 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain phosphoric acid passivated (Ce) powder. 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 Magnetic powder; 3) Weigh 0.07g of polyurethane powder, dissolve the polyurethane powder in 7mL of acetone, and ultrasonically stir until the powder is completely dissolved. Then add phosphoric acid passivated (Ce) to the solution. 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 Magnetic powder is continuously ultrasonically stirred until acetone is completely evaporated to obtain (Ce). 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 - Polyurethane mixture; 4) The obtained (Ce) 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 - The polyurethane mixture was added in batches to a magnetically oriented mold, 0.18 g at a time, and oriented for 40 s under a magnetic field of 1.0 T, ultimately obtaining a (Ce) layer with a thickness of approximately 250 μm. 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 Thin ring green blank; 5) The FeSiCr magnetic powder was sieved to control the particle size to 15μm; 6) Weigh 2.0g of sieved FeSiCr powder and 0.07g of polyurethane powder. Dissolve the polyurethane powder in 7mL of acetone and stir ultrasonically until the powder is completely dissolved. Then add the weighed FeSiCr magnetic powder and continue to stir ultrasonically until the acetone is completely evaporated to obtain the FeSiCr-polyurethane mixture. 7) The obtained FeSiCr-polyurethane mixture was placed into a magnetically oriented mold in batches, with 0.18g added each time, and oriented for 40s under a magnetic field of 1.0T, finally obtaining a FeSiCr thin ring green body with a thickness of about 250μm. 8) Take 4 layers (Ce) respectively 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17Thin ring green blanks and FeSiCr thin ring green blanks were periodically stacked and placed in a ring mold, then held at 650 MPa and 85℃ for a period of time to finally obtain (Ce) ring green blanks with an outer diameter of 12.2 mm, an inner diameter of 5.98 mm, and a thickness of 2.05 mm. 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 / FeSiCr laminated soft magnetic composite material.

[0032] Tested (Ce) 0.5 Pr 0.5 )2(Fe 0.8 Co 0.2 ) 17 The high-frequency performance of the FeSiCr multilayer soft magnetic composite material is as follows: the real part of the complex permeability is 19.5 at 1 MHz, the operating cutoff frequency is greater than 1 GHz, and the total loss at 3 MHz and 10 mT is 554.5 kW / m. 3 .

[0033] As can be seen from the examples, the composite material prepared by the present invention has both high initial magnetic permeability ( μ i >18), high cutoff frequency ( f c >1GHz) and low power loss (3MHz, 10mT) P cv <600kW / m 3 These characteristics allow for the fabrication of magnetic core components for high-frequency soft magnetic power devices. In summary, the embodiments are merely illustrative of the technical solutions of this invention and not intended to limit it. Those skilled in the art can modify or make equivalent substitutions to the technical solutions of this invention without departing from the spirit and scope of the invention. The scope of protection of this invention should be determined by the claims.

Claims

1. A method for preparing a 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminate composite material, characterized in that, The preparation method includes the following steps: 1) 2:17 type rare earth soft magnetic powder is screened, insulated and coated, and then mixed with polyurethane and oriented by magnetic field to obtain thin ring green body; 2) Fe-based soft magnetic powder is sieved, mixed with polyurethane, and then oriented by a magnetic field to obtain a thin ring green body; 3) Type 2:17 rare earth soft magnetic thin ring green blanks and Fe-based soft magnetic thin ring green blanks are alternately stacked along a direction perpendicular to the plane of the thin ring green blank; 4) Hot pressing of laminated soft magnetic composite materials.

2. The preparation method of the 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material according to claim 1, characterized in that, Step 1) includes: 1.1) The particle size of the 2:17 type rare earth soft magnetic powder is controlled to be 10-20μm after sieving; 1.2) Add 1-3 wt% of phosphoric acid (based on the mass of 2:17 type rare earth soft magnetic powder) to acetone with a purity ≥99%, and ultrasonically stir at room temperature to ensure that the phosphoric acid is evenly distributed in the acetone. 1.3) Add the sieved 2:17 type rare earth soft magnetic powder to the mixed solution obtained in step 1.2), and stir ultrasonically until the solution is completely evaporated to obtain the 2:17 type rare earth soft magnetic powder with insulating coating. 1.4) Add 3-5 wt% of polyurethane powder (based on the mass of 2:17 type rare earth soft magnetic powder) to acetone, wherein the solid-liquid ratio of polyurethane powder to acetone is 1:100-1:200 g / mL, and ultrasonically stir at room temperature until the polyurethane powder is completely dissolved. 1.5) Add the 2:17 type rare earth soft magnetic powder after insulation coating in step 1.3) to the mixed solution obtained in step 1.4), and stir ultrasonically until the acetone is completely evaporated to obtain a 2:17 type rare earth soft magnetic powder-polyurethane mixture. 1.6) During the magnetic field orientation process, a planar rotating magnetic field is used to orient the 2:17 type rare earth soft magnetic powder-polyurethane mixture in the mold to form a 2:17 type rare earth soft magnetic thin ring green body with a thickness range of 100-200μm. The magnetic field strength is 0.8-1.2T and the orientation time of a single thin ring green body is 30-60s.

3. The preparation method of the 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material according to claim 1, characterized in that, Step 2) includes: 2.1) The Fe-based soft magnetic powder is sieved to control the particle size to 10-20 μm; 2.2) Add 3-5 wt% of polyurethane powder to acetone, wherein the solid-liquid ratio of polyurethane powder to acetone is 1:100-1:200 g / mL, and ultrasonically stir at room temperature until the polyurethane powder is completely dissolved. 2.3) Add the Fe-based soft magnetic powder after sieving in step 2.1) to the mixed solution obtained in step 2.2) and stir ultrasonically until the acetone is completely evaporated to obtain the Fe-based soft magnetic powder-polyurethane mixture. 2.4) During the magnetic field orientation process, a planar rotating magnetic field is used to orient the Fe-based soft magnetic powder-polyurethane mixture within the mold to form a Fe-based soft magnetic thin ring green body with a thickness range of 100-200μm. The magnetic field strength is 0.8-1.2T, and the orientation time for a single thin ring green body is 30-60s.

4. The preparation method of the 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material according to claim 1, characterized in that: Step 3) During the alternating stacking of 2:17 type rare earth soft magnetic thin ring green blank and Fe-based soft magnetic thin ring green blank along the direction perpendicular to the plane of the thin ring green blank, the number of thin ring green blanks determines the thickness of the final composite material. The number of 2:17 type rare earth soft magnetic powder thin ring green blank and Fe-based soft magnetic powder thin ring green blank are 5-15 layers respectively.

5. The preparation method of the 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material according to claim 1, characterized in that: Step 4) During the hot pressing process of the laminated soft magnetic composite material, the laminated soft magnetic composite material blank is placed in the mold, and the interlayer densification and molding are achieved by hot pressing. The hot pressing temperature is 80-100℃ and the pressure is 600-1200MPa.

6. A 2:17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material prepared by the method of any one of claims 1-5.

7. The laminated composite material according to claim 6, characterized in that, The laminated composite material has magnetic permeability μ >18. Cutoff Frequency f c ≥1GHz.

8. The application of the laminated composite material according to claim 6 in the preparation of power inductors, electromagnetic interference suppression components, and microwave absorbers.

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