High magnetic permeability integrally formed material and preparation method thereof, and preparation method of integrally formed inductor

Abstract

The present invention discloses a high-permeability one-piece molded material, a preparation method thereof, and a method for preparing an one-piece molded inductor. The preparation method comprises: a first alloy powder preparation step; a first alloy powder treatment step, wherein the first alloy powder is sintered in a mixed atmosphere of nitrogen and oxygen at 300-400°C; a second alloy powder preparation step; a powder mixing step; and a granulation step to form granulated powder. By designing the components of the first alloy powder and performing the corresponding sintering treatment, as well as designing the components and particle size of the second alloy powder, the present invention can produce an one-piece molded material with high magnetic permeability and high saturation current, and is easy to process and facilitates mass production.

Description

Technical Field

[0001] The present invention relates to the technical field of soft magnetic alloy material preparation, and in particular to an integrally formed material and a preparation method thereof, and a preparation method of an integrally formed inductor. Background Art

[0002] With the development of miniaturization of inductors, especially the widespread application of integrated molded inductors, inductors have put forward higher requirements for the magnetic permeability and saturation current of materials. As inductors are miniaturized, the pressing requirements for integrated inductors are also getting higher and higher. The powder particles obtained by the conventional material granulation process are generally coarse, among which powder particles larger than 100μm account for a large proportion of the total mass of the powder, and the distribution of large particles is not concentrated enough, and the particle morphology is irregular, which makes filling difficult. During pressing, the filling density within the filled powder is low, which leads to low pressing density. The pressing density determines the magnetic permeability and saturation current of the inductor, which ultimately leads to low product performance. In addition, in addition to the granulated powder, the magnetic properties of the material itself also need to be further improved in line with the performance requirements to meet the performance requirements of the inductor.

[0003] Therefore, it is necessary to develop new high-performance high-saturation soft magnetic material technologies.

[0004] It should be noted that the information disclosed in the above background technology section is only used to understand the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] To overcome the aforementioned shortcomings of the prior art, the present invention provides a method for preparing a high magnetic permeability one-piece molded material, comprising:

[0006] An alloy powder preparation step is to prepare an alloy material having a composition and content of 90.75wt% to 93.74wt% Fe, 1.5wt% to 2.5wt% Si, 4.5wt% to 5.5wt% B, 0.1wt% to 0.5wt% C, 0.01wt% to 0.10wt% Mn, 0.10wt% to 0.50wt% P and 0.05wt% to 0.15wt% Zn and mix the mixture uniformly;

[0007] an alloy powder treatment step of sintering the alloy powder in a mixed gas atmosphere of nitrogen and oxygen at 300-400° C.;

[0008] The second alloy powder preparation step comprises preparing an alloy material having a composition and content of 95.5 wt% to 97.8 wt% Fe, 1.0 wt% to 2.0 wt% Si, 1.0 wt% to 1.5 wt% Cr, 0.1 wt% to 0.5 wt% B and 0.1 wt% to 0.5 wt% P and mixing the alloy material uniformly;

[0009] a powder mixing step of adding 10 wt% to 40 wt% of the alloy powder 2 and 0.05 wt% to 0.15 wt% of silicon dioxide powder to the alloy powder 1 to form a mixed powder;

[0010] In the granulation step, the mixed powder is added with epoxy resin, phenolic resin and curing agent and granulated to form granulated powder.

[0011] The present invention may also adopt the following optional / preferred solutions:

[0012] The alloy powder 1 is spherical particles with a particle size of 8 μm to 53 μm, and the alloy powder 2 is spherical particles with a particle size of 6 μm to 10 μm. In the powder mixing step, the particle size of the silicon dioxide is 20 nm to 80 nm.

[0013] Before the granulation step, a mixture of the epoxy resin, the phenolic resin and the mixed powder is prepared into a slurry by adding acetone accounting for 15 wt% to 25 wt% of the mixed powder.

[0014] In the alloy powder first processing step, the volume ratio of nitrogen to oxygen is 10:1 to 20:1.

[0015] The granulation step adopts an atomization granulation method, the atomization speed of the atomization granulation is 6000-10000 rpm, the air inlet temperature is 110°C-150°C, and the air outlet temperature is 80°C-100°C.

[0016] In the granulation step, the epoxy resin is added in an amount of 1.0 wt% to 1.5 wt% of the mixed powder, and the curing agent is added in an amount of 0.05 wt% to 0.1 wt% of the mixed powder.

[0017] The epoxy resin is a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, and the bisphenol A epoxy resin accounts for 10wt% to 50wt% of the mixed resin; the curing agent is a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, and the methylhexahydrophthalic anhydride accounts for 20wt% to 60wt% of the mixed curing agent.

[0018] In the granulated powder, particles with a particle size of 58 μm to 75 μm account for 55 wt % to 70 wt %.

[0019] The present invention also provides a high magnetic permeability one-piece molded material, which is a high magnetic permeability one-piece molded material prepared by any of the above methods for preparing a high magnetic permeability one-piece molded material.

[0020] The present invention further provides a method for preparing an integrally molded inductor, comprising a step of preparing an integrally molded material and a step of press molding. The step of preparing the integrally molded material adopts any of the above methods for preparing an integrally molded material with high magnetic permeability.

[0021] One or more technical solutions provided in the embodiments of this application have at least the following beneficial effects compared to the prior art:

[0022] By designing the components of the alloy powder one and performing corresponding sintering treatment, as well as designing the components and particle size of the alloy powder two, the present invention can prepare an integrally formed material with high magnetic permeability and high saturation current, and is easy to process and conducive to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a SEM (Scanning Electron Microscope) image of the granulated powder before compression;

[0024] Figure 2 This is the SEM picture of the granulated powder after compression. DETAILED DESCRIPTION

[0025] A method for preparing a composite material comprises the following steps:

[0026] The first alloy powder preparation step involves preparing an alloy material with the following components and contents: 90.75wt% to 93.74wt% Fe, 1.5wt% to 2.5wt% Si, 4.5wt% to 5.5wt% B, 0.1wt% to 0.5wt% C, 0.01wt% to 0.10wt% Mn, 0.10wt% to 0.50wt% P, and 0.05wt% to 0.15wt% Zn, and mixing them uniformly. The first alloy powder processing step involves sintering the alloy powder in a mixed atmosphere of nitrogen and oxygen at 300 to 400°C. This step controls the thickness and uniformity of the oxide film by controlling the oxygen ratio, thereby maintaining insulating and rust-proof properties while maintaining uniform air gaps between particles and increasing the material's saturation current. In the first alloy powder processing step, a volume ratio of nitrogen to oxygen of 10:1 to 20:1 can better control the thickness and uniformity of the oxide film to an ideal level. The second alloy powder preparation step involves preparing an alloy material having components and contents of 95.5 to 97.8 wt% Fe, 1.0 to 2.0 wt% Si, 1.0 to 1.5 wt% Cr, 0.1 to 0.5 wt% B, and 0.1 to 0.5 wt% P, and uniformly mixing the components. The powder mixing step involves adding 10 to 40 wt% of the second alloy powder and 0.05 to 0.15 wt% of silicon dioxide powder to the first alloy powder to form a mixed powder, wherein the particles of the second alloy powder are smaller than those of the first alloy powder. The granulation step involves adding epoxy resin, phenolic resin, and their curing agent to the mixed powder and granulating the resulting powder to form a granulated powder. By designing the components of the alloy powder one and performing corresponding sintering treatment, as well as designing the components and particle size of the alloy powder two, the present invention can prepare an integrally formed material with high magnetic permeability and high saturation current, and is easy to process and conducive to mass production.

[0027] Among them, the alloy powder 1 preferably uses spherical particles with a particle size of 8μm to 53μm, and the alloy powder 2 preferably uses spherical particles with a particle size of 6μm to 10μm. In the powder mixing step, the particle size of the silicon dioxide is preferably 20nm to 80nm. By having different and specific particle sizes of each component and coordinating the above preparation steps, the magnetic permeability and saturation characteristics of the material can be further improved. In addition, before the granulation step, the mixture of the epoxy resin, the phenolic resin and the mixed powder is prepared into a slurry by adding acetone accounting for 15wt% to 25wt% of the mixed powder. The viscosity of the slurry is 1000 to 3000cps. The slurry obtained in this way is granulated, which is more conducive to obtaining granulated powder that meets the expected effect. For example, the particles with a particle size of 58μm to 75μm in the granulated powder account for 55wt% to 70wt%.

[0028] The atomization granulation method used in the granulation step can refine the granulated powder, thereby increasing the powder filling capacity in a narrow space and further improving the density of the compression molding. In combination with the components and contents of the embodiment of the present invention, the atomization speed of the atomization granulation can be 6000-10000 rpm, the air inlet temperature can be 110°C-150°C, and the air outlet temperature can be 80°C-100°C, which can achieve a better refinement effect. Furthermore, in the granulation step, when the epoxy resin is added in an amount of 1.0wt%-1.5wt% of the mixed powder and the curing agent is added in an amount of 0.05wt%-0.1wt% of the mixed powder, it is more conducive to obtaining a granulated powder that meets the desired effect. The epoxy resin is preferably a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, and the bisphenol A epoxy resin accounts for 10wt%-50wt% of the mixed resin. The curing agent is preferably a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, and the methylhexahydrophthalic anhydride accounts for 20 wt % to 60 wt % of the mixed curing agent.

[0029] The following is combined with Figure 1-2 It should be emphasized that the following description is only exemplary and is not intended to limit the scope of the present invention and its application.

[0030] Example 1

[0031] An alloy material was selected, with a composition of 93.74 wt% Fe, 1.5 wt% Si, 4.5 wt% B, 0.1 wt% C, 0.01 wt% Mn, 0.10 wt% P, and 0.05 wt% Zn. The alloy material was an alloy powder (hereinafter referred to as alloy powder 1), and the alloy powder 1 had a spherical particle size of 8 μm to 53 μm.

[0032] The alloy powder was placed in a sintering furnace containing a mixture of nitrogen and oxygen at 400° C. for 1 hour. The volume ratio of nitrogen to oxygen in the mixture was 10:1.

[0033] The sintered alloy powder 1 was added with 10 wt% of another 10 μm alloy powder (hereinafter referred to as alloy powder 2), wherein the composition of alloy powder 2 was 97.8 wt% Fe, 1.0 wt% Si, 1.0 wt% Cr, 0.1 wt% B, and 0.1 wt% P. After mixing in a ball mill, 0.05 wt% of silica powder was added to form a mixed powder, wherein the particle size of the silica was 80 nm.

[0034] The mixed powder is added with epoxy resin, phenolic resin, and a curing agent to form granulated powder, which is then pressed at 900 MPa to form a magnetic ring. The epoxy resin is added in an amount of 1.0 wt% of the mixed powder, and the curing agent is added in an amount of 0.05 wt% of the mixed powder. The epoxy resin is a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, with the bisphenol A epoxy resin accounting for 50 wt% of the mixed resin. The curing agent is a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, with the methylhexahydrophthalic anhydride accounting for 20 wt% of the mixed curing agent.

[0035] In this embodiment, the epoxy resin and the mixed powder were mixed to form a slurry by adding acetone (15 wt% of the powder) before granulation. The slurry had a viscosity of 3000 cps. The atomizing speed for granulation was 10,000 rpm, the air inlet temperature was 110°C, the air outlet temperature was 80°C, and the particles of 58 to 75 μm in size accounted for 55 wt% of the granulated powder.

[0036] The magnetic ring is then placed in air to solidify to form a final product, wherein the solidification temperature is 150° C. and the solidification time is 2 hours.

[0037] Example 2

[0038] An alloy material was selected, with a composition of 90.75 wt% Fe, 2.5 wt% Si, 5.5 wt% B, 0.5 wt% C, 0.10 wt% Mn, 0.50 wt% P, and 0.15 wt% Zn. The alloy material was an alloy powder (hereinafter referred to as alloy powder 1), and the alloy powder 1 had a particle size of 8 μm to 53 μm and was spherical.

[0039] The alloy powder was placed in a sintering furnace containing a mixture of nitrogen and oxygen at 300° C. and sintered for 3 hours. The volume ratio of nitrogen to oxygen in the mixture was 20:1.

[0040] The sintered alloy powder 1 was added with 40 wt% of another 6 μm alloy powder (hereinafter referred to as alloy powder 2) having a composition of 95.5 wt% Fe, 2.0 wt% Si, 1.5 wt% Cr, 0.5 wt% B, and 0.5 wt% P. The mixture was then mixed in a ball mill. 0.15 wt% of silica powder was then added to form a mixed powder. The silica had a particle size of 20 nm.

[0041] The mixed powder is then granulated with epoxy resin, phenolic resin, and a curing agent to form a granulated powder, which is then pressed at 900 MPa to form a magnetic ring. The epoxy resin is added in an amount of 1.5 wt% of the mixed powder, and the curing agent is added in an amount of 0.1 wt% of the mixed powder. The epoxy resin is a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, with the bisphenol A epoxy resin accounting for 10 wt% of the mixed resin. The curing agent is a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, with the methylhexahydrophthalic anhydride accounting for 60 wt% of the mixed curing agent.

[0042] In this embodiment, the mixture of the resin and alloy powders was prepared into a slurry by adding acetone accounting for 25 wt% of the mixed powder before granulation. The viscosity of the slurry was 1000 cps. The atomizing speed for granulation was 6000 rpm, the air inlet temperature for granulation was 150°C, the air outlet temperature for granulation was 100°C, and the particles of the granulated powder having a particle size of 58 μm to 75 μm accounted for 70 wt% of the granulated powder.

[0043] The magnetic ring is then placed in air for curing to form a final product, wherein the curing temperature is 200° C. and the curing time is 0.5 hours.

[0044] Example 3

[0045] An alloy material was selected, with a composition of 92.35 wt% Fe, 2.0 wt% Si, 5.0 wt% B, 0.25 wt% C, 0.05 wt% Mn, 0.25 wt% P, and 0.10 wt% Zn. The alloy material was an alloy powder (hereinafter referred to as alloy powder 1), and the alloy powder 1 had a particle size of 8 μm to 53 μm and was spherical.

[0046] The alloy powder was placed in a sintering furnace containing a mixture of nitrogen and oxygen at 350° C. for 1 hour. The volume ratio of nitrogen to oxygen in the mixture was 15:1.

[0047] The sintered alloy powder 1 is added with 25wt% of another alloy powder with a particle size of 8um (hereinafter referred to as alloy powder 2), the composition of alloy powder 2 is 96.75wt% Fe, 1.5wt% Si, 1.25wt% Cr, 0.25wt% B, 0.25wt% P. After mixing in a ball mill, 0.10wt% of silica powder is added to form a mixed powder, wherein the particle size of silica is 50nm.

[0048] The mixed powder is added with epoxy resin, phenolic resin, and a curing agent to form a granulated powder, and then pressed at 900 MPa to form a magnetic ring. The epoxy resin is added in a proportion of 1.25wt% of the mixed powder, and the curing agent is added in a proportion of 0.08wt% of the mixed powder. The epoxy resin is a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, with the bisphenol A epoxy resin accounting for 25wt% of the mixed resin, and the curing agent is a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, with the methylhexahydrophthalic anhydride accounting for 45wt% of the mixed curing agent.

[0049] In this embodiment, prior to granulation, the epoxy resin and the mixed powder were mixed to form a slurry by adding acetone accounting for 20 wt% of the mixed powder. The slurry had a viscosity of 2000 cps. The atomizing speed for granulation was 8000 rpm, the air inlet temperature for granulation was 125°C, the air outlet temperature for granulation was 90°C, and the particles of the granulated powder having a particle size of 58 μm to 75 μm accounted for 63 wt% of the granulated powder.

[0050] The magnetic ring is then placed in air to solidify to form a final product, wherein the solidification temperature is 180° C. and the solidification time is 1 hour.

[0051] Comparative Example 1

[0052] This comparative example is a conventional method in the prior art, and is as follows:

[0053] An alloy material is selected, and its composition is 91.8 wt% Fe, 2.5 wt% Si, 5.2 wt% B, and 0.5 wt% C. The alloy material is alloy powder, and the alloy powder is spherical particles with a particle size of 8 μm to 53 μm.

[0054] The alloy powder is mixed with carbonyl iron powder with a particle size of 8 μm to obtain a mixed powder, wherein the carbonyl iron powder accounts for 30 wt % of the alloy powder.

[0055] The mixed powder was added into bisphenol A epoxy resin accounting for 1.5 wt % to form granulated powder, and then pressed at 900 MPa to form a magnetic ring.

[0056] The magnetic ring is placed in air and cured to form a final product, wherein the curing temperature is 180° C. and the curing time is 1 hour.

[0057] The particle size distribution of the granulated powder obtained in each embodiment was tested by a laser particle size analyzer, and the results are shown in Table 1 below:

[0058] Table 1

[0059] Test items Parameter unit Example 1 Example 2 Example 3 Comparative Example 1 ≥0.106mm wt% 0.4 0.3 0.4 20.5 0.075mm~0.106mm wt% 4.5 5.2 5.1 14.1 0.063mm~0.075mm wt% 56.3 62.9 57.0 31.0 0.045mm~0.063mm wt% 22.6 19.6 21.2 31.6 ≤0.045mm wt% 16.2 12 16.3 2.80

[0060] The performance of the heat-treated magnetic ring was evaluated. The number of winding turns N = 26 Ts. The initial magnetic permeability μi (1V / 1MHz) and the current point at which the initial magnetic permeability dropped by 30% (saturation current) were tested using a 3260B LCR meter. The collapse strength of the magnetic ring was tested using an electronic universal testing machine SH-100. The results are shown in Table 2 below.

[0061] Table 2

[0062] Test items Parameter unit Example 1 Example 2 Example 3 Comparative Example 1 Magnetic permeability (1V / 1MHz) - 45 41 43 36 Saturation current A 7.3 8.2 7.6 6.7

[0063] The material obtained in Comparative Example 1 is significantly higher in magnetic permeability than the comparative example, and the saturation current is also significantly improved, which shows that the preparation method of each embodiment of the present invention can obtain an integrally formed material with high magnetic permeability and high saturation current.

[0064] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for preparing a high magnetic permeability integrally formed material, characterized in that: include: An alloy powder preparation step is to prepare an alloy material having a composition and content of 90.75wt% to 93.74wt% Fe, 1.5wt% to 2.5wt% Si, 4.5wt% to 5.5wt% B, 0.1wt% to 0.5wt% C, 0.01wt% to 0.10wt% Mn, 0.10wt% to 0.50wt% P and 0.05wt% to 0.15wt% Zn and mix the mixture uniformly; an alloy powder processing step of sintering the alloy powder in a mixed gas atmosphere of nitrogen and oxygen at 300 to 400° C.; the volume ratio of nitrogen to oxygen is 10:1 to 20:1; The second alloy powder preparation step comprises preparing an alloy material having a composition and content of 95.5 wt% to 97.8 wt% Fe, 1.0 wt% to 2.0 wt% Si, 1.0 wt% to 1.5 wt% Cr, 0.1 wt% to 0.5 wt% B and 0.1 wt% to 0.5 wt% P and mixing the alloy material uniformly; a powder mixing step of adding 10 wt% to 40 wt% of the alloy powder II and 0.05 wt% to 0.15 wt% of silicon dioxide powder to the alloy powder I to form a mixed powder, wherein the particle size of the particles of the alloy powder II is smaller than the particle size of the particles of the alloy powder I; In the granulation step, the mixed powder is added with epoxy resin, phenolic resin and curing agent and granulated to form granulated powder.

2. The method for preparing a high magnetic permeability integrally formed material according to claim 1, wherein: The alloy powder 1 is spherical particles with a particle size of 8 μm to 53 μm, and the alloy powder 2 is spherical particles with a particle size of 6 μm to 10 μm. In the powder mixing step, the particle size of the silicon dioxide is 20 nm to 80 nm.

3. The method for preparing a high magnetic permeability integrally formed material according to claim 1, wherein: Before the granulation step, a mixture of the epoxy resin, the phenolic resin and the mixed powder is prepared into a slurry by adding acetone accounting for 15 wt% to 25 wt% of the mixed powder.

4. The method for preparing a high magnetic permeability integrally formed material according to claim 1, wherein: The granulation step adopts an atomization granulation method, the atomization speed of the atomization granulation is 6000-10000 rpm, the air inlet temperature is 110°C-150°C, and the air outlet temperature is 80°C-100°C.

5. The method for preparing a high magnetic permeability integrally formed material according to claim 1, wherein: In the granulation step, the epoxy resin is added in an amount of 1.0 wt% to 1.5 wt% of the mixed powder, and the curing agent is added in an amount of 0.05 wt% to 0.1 wt% of the mixed powder.

6. The method for preparing the high magnetic permeability integrally formed material according to claim 5, wherein: The epoxy resin is a mixed resin of bisphenol A epoxy resin and bisphenol S epoxy resin, and the bisphenol A epoxy resin accounts for 10wt% to 50wt% of the mixed resin; The curing agent is a mixed curing agent of methylhexahydrophthalic anhydride and hexahydrobenzoic anhydride, and the methylhexahydrophthalic anhydride accounts for 20wt% to 60wt% of the mixed curing agent.

7. The method for preparing a high magnetic permeability integrally formed material according to claim 1, wherein: In the granulated powder, particles with a particle size of 58 μm to 75 μm account for 55 wt % to 70 wt %.

8. A high magnetic permeability integrally formed material, characterized in that: The high magnetic permeability one-piece molded material is prepared by the preparation method of the high magnetic permeability one-piece molded material according to any one of claims 1 to 7.

9. A method for preparing an integrally molded inductor, comprising a step of preparing an integrally molded material and a step of pressing and molding, wherein: The step of preparing the one-piece molding material adopts the method for preparing the high magnetic permeability one-piece molding material according to any one of claims 1-7.

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