Magnetic property regulation and control method for soft magnetic composite material, soft magnetic composite material and application

Abstract

The invention belongs to the technical field of soft magnetic material preparation and application, and discloses a soft magnetic composite material magnetic performance regulation and control method, a soft magnetic composite material and application, the regulation and control method comprises the steps that two or more than two of carbonyl iron powder, iron-based amorphous alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-Ni-Mo alloy powder and Fe-Ni alloy powder are mixed into a mixture, and the mixture is stirred to be uniform; and mixing according to the mass ratio to regulate and control the magnetic performance of the soft magnetic composite material obtained based on the mixed soft magnetic powder so as to obtain the metal soft magnetic composite material meeting the required magnetic performance. According to the intrinsic magnetic performance of different types of metal soft magnetic powder, two or more kinds of powder with different saturation magnetization intensity are selected to be compounded according to a certain proportion, so that the saturation magnetization intensity, the effective magnetic conductivity, the direct current bias performance, the power loss and other magnetic performance of the soft magnetic composite material are regulated and controlled; and the comprehensive application performance of the soft magnetic composite material is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of soft magnetic material preparation and application, and more specifically, relates to a method for regulating magnetic properties of a soft magnetic composite material, a soft magnetic composite material and an application thereof. Background Art

[0002] Soft magnetic composites (SMC) are mainly prepared by mixing insulating coated metal soft magnetic powder with a binder, compression molding and annealing.

[0003] At present, the types of metal soft magnetic powders used in mainstream applications include carbonyl iron powder, iron-based amorphous alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-Ni-Mo alloy powder, Fe-Ni alloy powder, etc. Each powder has different application characteristics and advantages. For example, carbonyl iron powder has the characteristics of high saturation magnetization and high magnetic permeability; the resistivity of iron-based amorphous alloy powder is relatively high, which can effectively reduce eddy current loss under high frequency; Fe-Si alloy powder has good DC bias characteristics, which is beneficial to increase the saturation current of magnetic components; Fe-Si-Al alloy powder has small magnetocrystalline anisotropy and magnetostriction coefficient, which is beneficial to reduce magnetic loss; the Cr element in Fe-Si-Cr alloy powder can improve the corrosion resistance of the material, etc. It is not difficult to understand that the use of the above single type of metal soft magnetic powder is often difficult to meet the comprehensive performance design requirements of soft magnetic composite materials (magnetic powder core) and magnetic components. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a method for regulating the magnetic properties of a soft magnetic composite material, a soft magnetic composite material and an application thereof, the purpose of which is to improve the comprehensive application performance of the soft magnetic composite material by regulating the magnetic properties of the soft magnetic composite material.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for regulating magnetic properties of a soft magnetic composite material is provided, comprising:

[0006] Mixing two or more of carbonyl iron powder, iron-based amorphous alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-Ni-Mo alloy powder, and Fe-Ni alloy powder according to a mass ratio to control the magnetic properties of a soft magnetic composite material obtained based on the mixed soft magnetic powder to obtain a metal soft magnetic composite material that meets the required magnetic properties;

[0007] The magnetic properties include one or more of saturation magnetization, effective magnetic permeability, resistivity, DC bias performance, and magnetic loss.

[0008] Furthermore, a soft magnetic composite material is obtained based on the mixed soft magnetic powder, comprising:

[0009] The mixed soft magnetic powder is granulated with a binder, and then subjected to compression molding, curing and annealing treatments in sequence to obtain the soft magnetic composite material.

[0010] Furthermore, before the mixed soft magnetic powder is granulated with a binder, the process further comprises:

[0011] The mixed soft magnetic powder is subjected to surface coating modification and then granulated with a binder.

[0012] Furthermore, the binder is at least one of epoxy resin, silicone resin and phenolic resin.

[0013] Furthermore, the amount of the binder is 0.2% to 8% of the mass of the mixed soft magnetic powder.

[0014] Furthermore, the molding pressure of the compression molding is 200MPa-2000MPa.

[0015] Furthermore, the temperature of the curing and annealing treatment is 150°C to 900°C.

[0016] According to a second aspect of the present invention, there is provided a soft magnetic composite material, wherein the soft magnetic composite material is obtained by regulating the magnetic properties of the soft magnetic composite material according to any one of the methods for regulating the magnetic properties of the soft magnetic composite material according to the first aspect.

[0017] According to a third aspect of the present invention, there is provided an application of a soft magnetic composite material, including: using the soft magnetic composite material as a metal magnetic powder core, or as an integrally formed inductor; wherein the soft magnetic composite material is the soft magnetic composite material described in the second aspect.

[0018] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0019] (1) The present invention provides a control idea and method for the magnetic properties of a soft magnetic composite material to obtain the desired magnetic properties. The present invention selects the types and mixing ratios of different metal soft magnetic powders for compounding according to the intrinsic magnetic properties of different types of metal soft magnetic powders to control the saturation magnetization intensity, effective magnetic permeability, DC bias performance, power loss and other magnetic properties of the soft magnetic composite material, thereby obtaining the desired magnetic properties, which can meet the comprehensive performance design requirements of soft magnetic composite materials and magnetic components and improve the comprehensive application performance of soft magnetic composite materials.

[0020] (2) The method for regulating the magnetic properties of the soft magnetic composite material of the present invention can establish a correspondence between the magnetic properties of the soft magnetic composite material and the composition of the composite powder (the type of metal soft magnetic powder and its mixing ratio) by selecting different types and mixing ratios of metal soft magnetic powders. This can specifically guide the composition design of the soft magnetic composite material, making the regulation and optimization of its magnetic properties more targeted, which is beneficial to improving the research and development efficiency of products such as metal magnetic powder cores and one-piece molded inductors.

[0021] (3) Preferably, the mixed soft magnetic powder is surface-coated and modified before being granulated with a binder, which can improve the surface resistivity and oxidation resistance of the metal soft magnetic powder and thus reduce high-frequency loss.

[0022] (4) Preferably, the magnetic properties of the soft magnetic composite material are jointly controlled by adjusting the types of soft magnetic metal powders and their mixing ratios, the corresponding binder dosage, the molding pressure or the curing and annealing temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a SEM photo of a mixed soft magnetic powder in an embodiment of the present invention.

[0024] Figure 2 This is an EDS energy spectrum of a mixed soft magnetic powder in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] The embodiment of the present invention provides a method for controlling magnetic properties of a soft magnetic composite material, comprising:

[0027] Two or more metal soft magnetic powders such as carbonyl iron powder, iron-based amorphous alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-Ni-Mo alloy powder, and Fe-Ni alloy powder with different saturation magnetizations are mixed in a certain mass ratio to control the magnetic properties of the soft magnetic composite material obtained based on the mixed soft magnetic powders, so as to obtain a metal soft magnetic composite material that meets the required magnetic properties; wherein the magnetic properties of the soft magnetic composite material include at least one of saturation magnetization, effective magnetic permeability, resistivity, DC bias performance, and magnetic loss.

[0028] The mass ratio of the mixture is related to the required magnetic properties. In the embodiment of the present invention, the saturation magnetization intensity (M s ) is tested using a vibrating sample magnetometer (VSM). The effective magnetic permeability (μ e ) tested by impedance analyzer (LCR).

[0029] The soft magnetic composite material obtained by mixing soft magnetic powders comprises:

[0030] The mixed soft magnetic powder is granulated with a binder, and then subjected to compression molding, curing and annealing treatments in sequence to obtain a soft magnetic composite material.

[0031] As a preferred implementation manner, the binder is at least one of epoxy resin, silicone resin and phenolic resin.

[0032] As a preferred implementation, the amount of binder used is 0.2% to 8% of the mass of the mixed soft magnetic powder. The amount of binder used will affect the magnetic properties of the resulting composite magnetic core material.

[0033] As a preferred implementation, the molding pressure is 200MPa-2000MPa. The curing and annealing temperature is 150°C-900°C, and the atmosphere is nitrogen, argon or air.

[0034] As a preferred implementation method, before the mixed soft magnetic powder is granulated with a binder, the process also includes: surface coating and modification of the mixed soft magnetic powder, and then granulation with a binder to improve the surface resistivity and oxidation resistance of the metal soft magnetic powder, thereby reducing high-frequency losses.

[0035] As a preferred implementation method, a series of soft magnetic composite powders with continuously changing magnetic properties can be obtained by selecting different types and mixing ratios of metal soft magnetic powders to meet the dynamic magnetic property design requirements of the soft magnetic composite materials under different application states, such as saturation magnetization, effective magnetic permeability, resistivity, DC bias performance, magnetic loss, etc. That is, the present invention realizes the establishment of a corresponding relationship between the magnetic properties (such as effective magnetic permeability) of the soft magnetic composite material and its composite powder composition (type of metal soft magnetic powder and its mixing ratio) starting from the intrinsic magnetic parameter of the saturation magnetization of the metal soft magnetic powder, which can specifically guide the composition design of the soft magnetic composite material, making its magnetic property regulation and optimization more targeted, and is conducive to improving the research and development efficiency of products such as metal magnetic powder cores and integrally formed inductors.

[0036] Furthermore, an embodiment of the present invention also provides a soft magnetic composite material, wherein the soft magnetic composite material is obtained according to the above-mentioned method for regulating the magnetic properties of the soft magnetic composite material.

[0037] Furthermore, an embodiment of the present invention also provides an application of a soft magnetic composite material, including: using the soft magnetic composite material described above in the embodiment of the present invention as a magnetic core product such as a metal magnetic powder core and an integrally formed inductor.

[0038] The following specific examples are used to prepare a soft magnetic composite material core to further illustrate the method of the present invention. In the relevant embodiments of the present invention, carbonyl iron powder (A), Fe-Cr-Si-B amorphous alloy powder (B), Fe-Si alloy powder (C), and Fe-Si-Al alloy powder (D) are used for experiments. In other embodiments, the type and mass ratio of the metal soft magnetic material can also be selected according to the required magnetic properties of the composite material.

[0039] Example 1

[0040] (1) Powder A and powder B are mixed in a mass ratio of 1:2, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0041] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa. In other embodiments, other molding pressures such as 200 MPa, 400 MPa, 900 MPa, 1500 MPa, and 2000 MPa may also be selected, and the molding pressure may also affect the magnetic properties of the composite magnetic core material obtained.

[0042] (3) Curing the molded magnetic core at 200°C in a nitrogen atmosphere oven for 1 hour to obtain the desired soft magnetic composite magnetic core. In other embodiments, the curing and annealing temperatures may also be selected from other temperatures such as 150°C, 300°C, 400°C, 600°C, 900°C, etc. The curing and annealing temperatures may also affect the magnetic properties of the obtained composite magnetic core material.

[0043] (4) The magnetic properties of the core samples were tested and characterized. The magnetic properties in the relevant embodiments of the present invention are exemplified by saturation magnetization intensity and effective magnetic permeability. The relevant experimental results are shown in Table 1.

[0044] Example 2

[0045] (1) Powder A and powder B are mixed in a mass ratio of 1:1, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0046] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa.

[0047] (3) The molded magnetic core is cured in a nitrogen atmosphere oven at 200° C. for 1 hour to obtain the desired soft magnetic composite material magnetic core.

[0048] (4) The magnetic properties of the core samples were tested and characterized. The relevant experimental results are shown in Table 1.

[0049] Example 3

[0050] (1) Powder A and powder B are mixed in a mass ratio of 2:1, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0051] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa.

[0052] (3) The molded magnetic core is cured in a nitrogen atmosphere oven at 200° C. for 1 hour to obtain the desired soft magnetic composite material magnetic core.

[0053] (4) The magnetic properties of the core samples were tested and characterized. The relevant experimental results are shown in Table 1.

[0054] Example 4

[0055] (1) Powder C and powder D are mixed in a mass ratio of 1:1, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0056] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa.

[0057] (3) The molded magnetic core is cured in a nitrogen atmosphere oven at 200° C. for 1 hour to obtain the desired soft magnetic composite material magnetic core.

[0058] (4) The magnetic properties of the core samples were tested and characterized. The relevant experimental results are shown in Table 1.

[0059] Example 5

[0060] (1) Powder A, powder B and powder C are mixed in a mass ratio of 1:1:3, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0061] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa.

[0062] (3) The molded magnetic core is cured in a nitrogen atmosphere oven at 200° C. for 1 hour to obtain the desired soft magnetic composite material magnetic core.

[0063] (4) The magnetic properties of the core samples were tested and characterized. The relevant experimental results are shown in Table 1.

[0064] Example 6

[0065] (1) Powder A, powder B, powder C and powder D are mixed in a mass ratio of 1:1:1:1, and a binder (a mixed solution of silicone resin and acetone solvent) is added to the mixed powder and stirred thoroughly. After the solvent is completely evaporated, the mixture is sieved to obtain a composite granulated powder.

[0066] (2) The composite granulated powder is placed in a mold and pressed into a magnetic core at 600 MPa.

[0067] (3) The molded magnetic core is cured in a nitrogen atmosphere oven at 200° C. for 1 hour to obtain the desired soft magnetic composite material magnetic core.

[0068] (4) The magnetic properties of the core samples were tested and characterized. The relevant experimental results are shown in Table 1.

[0069] Table 1 Magnetic properties of metal soft magnetic powder types and their mixing ratios

[0070]

[0071] The SEM photos (particle morphology) and EDS spectra (main chemical elements) of a group of metal soft magnetic mixed powders investigated by the present invention are as follows: Figure 1 and Figure 2 As shown, Figure 1 This is the SEM photo of a mixed powder of carbonyl iron powder (A) and amorphous alloy powder (B) in a mass ratio of 1:1. Figure 2 The EDS spectrum of the mixed powder with a mass ratio of carbonyl iron powder (A) to amorphous alloy powder (B) of 1:1. The saturation magnetization intensity M of the mixed powder obtained in Examples 1-6 of the present invention s And the effective magnetic permeability μ of the soft magnetic composite core e As shown in Table 1, by changing the type and mass ratio of soft magnetic powder, a series of mixed powders with saturation magnetization intensity can be obtained, thereby effectively regulating the effective magnetic permeability μ of the soft magnetic composite core. e .

[0072] Intrinsic magnetic permeability μ of metal soft magnetic powder i Its saturation magnetization M s There is a relationship between them as shown in formula (1), where β is the damping coefficient of magnetic domain motion, l is the domain wall width, and f0 is the relaxation frequency. On the other hand, the soft magnetic composite material is composed of metal soft magnetic powder and non-magnetic phases such as binders, and its effective magnetic permeability μ e The intrinsic magnetic permeability μ of metal soft magnetic powder i There is a relationship (2) between them, where g is the mass fraction of the non-magnetic phase inside the composite material.

[0073]

[0074] It can be seen that the saturation magnetization intensity M of the mixed powder can be effectively adjusted by compounding different types of metal soft magnetic powders. s and intrinsic magnetic permeability μ i Combined with the adjustment of the process parameters of soft magnetic composite materials (binder dosage, molding pressure, annealing temperature, etc.), efficient regulation of the effective magnetic permeability of soft magnetic composite materials and improvement of their comprehensive performance can be achieved.

[0075] In the embodiment of the present invention, the saturation magnetization of the mixed powder obtained in embodiment 1 to embodiment 3 ranges from 174.2 to 199.1 emu / g, and the effective magnetic permeability of the composite material under typical process conditions corresponds to a range of 30.4 to 41.6. By further increasing or decreasing the relative proportion of powders with different saturation magnetization strengths, a larger adjustment range of the effective magnetic permeability of the soft magnetic composite material can be achieved. The effective magnetic permeabilities of the soft magnetic composite materials obtained in embodiment 2 and embodiment 6 are 34.2 and 34.9, respectively, and the two values ​​are comparable, reflecting that under the design premise of meeting the specific requirements of the effective magnetic permeability (device inductance), it can be achieved through a variety of compounding schemes of metal soft magnetic powders, and its high design flexibility is conducive to further optimizing the DC bias characteristics, power loss and other comprehensive application performance of the soft magnetic composite material.

[0076] The present invention provides a control idea and method for the magnetic properties of a soft magnetic composite material to obtain the desired magnetic properties. The present invention selects the types and mixing ratios (mass fractions) of different metal soft magnetic powders for compounding according to the intrinsic magnetic properties of different types of metal soft magnetic powders to control the magnetic properties of the soft magnetic composite material, such as the saturation magnetization intensity, effective magnetic permeability, DC bias performance, power loss, etc., to obtain the desired magnetic properties, thereby improving the comprehensive application performance of the soft magnetic composite material.

[0077] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the magnetic properties of a soft magnetic composite material, characterized in that: include: Mixing two or more of carbonyl iron powder, iron-based amorphous alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-Ni-Mo alloy powder, and Fe-Ni alloy powder according to a mass ratio to control the magnetic properties of a soft magnetic composite material obtained based on the mixed soft magnetic powder to obtain a metal soft magnetic composite material that meets the required magnetic properties; The magnetic properties include one or more of saturation magnetization, effective magnetic permeability, resistivity, DC bias performance, and magnetic loss.

2. The method for controlling magnetic properties of soft magnetic composite materials according to claim 1, characterized in that: The soft magnetic composite material is obtained based on the mixed soft magnetic powder, including: The mixed soft magnetic powder is granulated with a binder, and then subjected to compression molding, curing and annealing treatments in sequence to obtain the soft magnetic composite material.

3. The method for controlling the magnetic properties of a soft magnetic composite material according to claim 2, characterized in that: Before the mixed soft magnetic powder is granulated by a binder, the method further comprises: The mixed soft magnetic powder is subjected to surface coating modification and then granulated with a binder.

4. The method for controlling magnetic properties of soft magnetic composite materials according to claim 2, characterized in that: The binder is at least one of epoxy resin, silicone resin and phenolic resin.

5. The method for controlling the magnetic properties of a soft magnetic composite material according to any one of claims 2 to 4, characterized in that: The amount of the binder is 0.2% to 8% of the mass of the mixed soft magnetic powder.

6. The method for controlling magnetic properties of soft magnetic composite materials according to claim 5, characterized in that: The molding pressure of the compression molding is 200MPa-2000MPa.

7. The method for controlling magnetic properties of soft magnetic composite materials according to claim 5, characterized in that: The temperature of the curing and annealing treatment is 150°C to 900°C.

8. A soft magnetic composite material, characterized in that: The soft magnetic composite material is obtained by regulating the magnetic properties of the soft magnetic composite material according to any one of claims 1 to 7.

9. An application of a soft magnetic composite material, characterized in that: include: The soft magnetic composite material is used as a metal magnetic powder core, or as an integrally formed inductor; wherein the soft magnetic composite material is the soft magnetic composite material according to claim 8.

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