A highly fluid magnetic composite material and its preparation method

Abstract

The present invention discloses a highly fluid magnetic composite material and a preparation method thereof. The preparation method includes: providing metal soft magnetic powders with high sphericity, having a first particle size, a second particle size, and a third particle size respectively; grading the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size according to a preset mixing ratio, and weighing a preset weight for mixing to obtain a first mixture; respectively weighing an organic acid accounting for a first weight ratio of the first mixture and a diluent accounting for a second weight ratio of the first mixture, and adding the diluted organic acid to the first mixture to obtain a second mixture; weighing an epoxy resin accounting for a third weight ratio of the first mixture and adding it to the second mixture for mixing; after mixing the epoxy resin and the second mixture for a preset time, a highly fluid magnetic composite material is obtained. The purpose of the present invention is to meet the existing market demand for different specific magnetic composite materials by producing a highly fluid magnetic composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic materials, and particularly relates to a highly fluid magnetic composite material and a preparation method thereof. Background Art

[0002] Magnetic composite materials, as a new type of functional material combining magnetic particles and base materials (such as polymers, metals, etc.), have shown broad application prospects in multiple fields such as electronics, medicine, aerospace, and automobiles. These materials exhibit excellent performance in electronic properties, magnetic properties, and structural characteristics, providing important support for technological innovation and development in various industries.

[0003] As a new type of functional material, magnetic composite materials have shown broad application prospects and huge market potential in multiple fields. With the continuous progress of technology and the continuous expansion of application fields, magnetic composite materials will play an important role in more fields, promoting innovation and development in various industries. In such an application prospect, the present invention proposes a preparation method for a highly fluid magnetic composite material to meet the existing market demand for magnetic composite materials with different characteristics. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a highly fluid magnetic composite material and a preparation method thereof, aiming to meet the existing market demand for magnetic composite materials with different specificities by producing a highly fluid magnetic composite material.

[0005] The first aspect of the present invention lies in providing a preparation method for a highly fluid magnetic composite material, and the preparation method includes:

[0006] Providing metal soft magnetic powders with high sphericity, and the metal soft magnetic powders respectively have a first particle size, a second particle size, and a third particle size; the first particle size is 85 μm - 90 μm, the second particle size is 30 μm - 35 μm, and the third particle size is 8 μm - 12 μm;

[0007] Gradating the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size according to a preset mixing ratio, and weighing a preset weight of the metal soft magnetic powders and adding them into a mixing device for mixing to obtain a first mixture; the mixing ratio of the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size is 1:3:9;

[0008] Weighing an organic acid accounting for a first weight ratio of the first mixture and a diluent accounting for a second weight ratio of the first mixture respectively, mixing the organic acid and the diluent to obtain a diluted organic acid, adding the diluted organic acid to the first mixture and adding it into a mixing device for mixing to obtain a second mixture;

[0009] Weigh the epoxy resin accounting for the third weight ratio of the first mixture, add the epoxy resin to the second mixture and put it into a mixing device for mixing; the molecular weight of the epoxy resin is 20,000 g / mol - 80,000 g / mol;

[0010] After the epoxy resin and the second mixture are mixed for a preset time, a highly fluid magnetic composite material is obtained.

[0011] According to one aspect of the above technical solution, in the step of weighing the preset weight of the metal soft magnetic powder and adding it to the mixing device for mixing to obtain the first mixture, the mixing speed is 50 r / min and the mixing time is 10 min.

[0012] According to one aspect of the above technical solution, the weight of the metal soft magnetic powder weighed for mixing is 10 kg;

[0013] Among them, the first weight ratio of the organic acid in the first mixture is 1%, and the second weight ratio of the diluent in the first mixture is 3%.

[0014] According to one aspect of the above technical solution, the organic acid is acetic acid and the diluent is ethanol.

[0015] According to one aspect of the above technical solution, in the step of adding the diluted organic acid to the first mixture and putting it into a mixing device for mixing to obtain the second mixture, the mixing conditions include:

[0016] Maintain a non-vacuum closed environment, the ambient temperature is 40 °C, and the mixing speed is 50 r / min.

[0017] According to one aspect of the above technical solution, after adding the diluted organic acid to the first mixture and putting it into a mixing device for mixing, the preparation method further includes:

[0018] After mixing the organic acid and the first mixture, sieve it through a 60-mesh sieve to obtain the passivated second mixture.

[0019] According to one aspect of the above technical solution, the third weight ratio of the epoxy resin in the first mixture is 6%;

[0020] Among them, in the step of adding the epoxy resin to the second mixture and putting it into a mixing device for mixing, the mixing conditions include:

[0021] Maintain a non-vacuum closed environment, the ambient temperature is 70 °C, and the mixing speed is 40 r / min.

[0022] According to one aspect of the above technical solution, the mixing time of the epoxy resin and the second mixture is 15 min.

[0023] The second aspect of the present invention lies in providing a highly fluid magnetic composite material, which is prepared by the preparation method described in the above technical solution.

[0024] Compared with the prior art, the beneficial effects of using the highly fluid magnetic composite material of the present invention are as follows:

[0025] 1. Powders with high sphericity are used for mixing. Spherical particles can roll and slide better with each other during the mixing process, making the mixed magnetic composite material have good uniformity and consistency, reducing the friction between particles, and thus improving the fluidity.

[0026] 2. The surface of the powder is treated by organic acid passivation to form a surface layer with organic functional groups on its surface, which has better compatibility with the resin matrix, thereby improving the fluidity.

[0027] 3. A grading ratio of the golden ratio (large, medium, and small in a 1:3:9 golden section ratio) is adopted to achieve good magnetic properties.

[0028] 4. Epoxy resins with special medium molecular weights (20,000 - 80,000 g / mol) are used to ensure the high fluidity of the composite material and an appropriate curing time, prevent premature curing and loss of fluidity due to too small a curing time window, and at the same time make the cured material have certain strength and toughness.

[0029] 5. A diluent is used to dilute the resin, reduce the viscosity of the matrix resin, improve its mixing effect, make the material more evenly dispersed, and prevent the influence on the properties of the composite material caused by uneven dispersion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0031] Figure 1 is a schematic flow chart of the preparation method of the highly fluid magnetic composite material in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is made in conjunction with the drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] The first aspect of the present invention is to provide a method for preparing a highly flowable magnetic composite material, and the preparation method includes:

[0035] Providing metal soft magnetic powders with high sphericity, the metal soft magnetic powders respectively having a first particle size, a second particle size and a third particle size; the first particle size is 85 μm - 90 μm, the second particle size is 30 μm - 35 μm, and the third particle size is 8 μm - 12 μm;

[0036] Carrying out grading on the metal soft magnetic powders corresponding to the first particle size, the second particle size and the third particle size according to a preset mixing ratio, and weighing a preset weight of the metal soft magnetic powders and adding them into a mixing device for mixing to obtain a first mixture; the mixing ratio of the metal soft magnetic powders corresponding to the first particle size, the second particle size and the third particle size is 1:3:9;

[0037] Weighing an organic acid accounting for a first weight ratio of the first mixture and a diluent accounting for a second weight ratio of the first mixture respectively, mixing the organic acid and the diluent to obtain a diluted organic acid, adding the diluted organic acid to the first mixture and adding them into a mixing device for mixing to obtain a second mixture;

[0038] Weighing an epoxy resin accounting for a third weight ratio of the first mixture, adding the epoxy resin to the second mixture and adding them into a mixing device for mixing; the molecular weight of the epoxy resin is 20000 g / mol - 80000 g / mol;

[0039] After mixing the epoxy resin and the second mixture for a preset time, a highly flowable magnetic composite material is obtained.

[0040] Further, in the step of weighing a preset weight of the metal soft magnetic powders and adding them into a mixing device for mixing to obtain a first mixture, the mixing rotation speed is 50 r / min and the mixing time is 10 min.

[0041] Further, the weight of the metal soft magnetic powders weighed for mixing is 10 kg;

[0042] Wherein, the first weight ratio of the organic acid to the first mixture is 1%, and the second weight ratio of the diluent to the first mixture is 3%.

[0043] Further, the organic acid is acetic acid and the diluent is ethanol.

[0044] Further, in the step of adding the diluted organic acid to the first mixture and adding it to a mixing device for mixing to obtain a second mixture, the mixing conditions include:

[0045] Maintaining a non-vacuum sealed environment, an environmental temperature of 40°C, and a mixing speed of 50 r / min.

[0046] Further, after adding the diluted organic acid to the first mixture and adding it to a mixing device for mixing, the preparation method further includes:

[0047] Mixing the organic acid and the first mixture and then passing through a 60-mesh sieve to obtain a passivated second mixture.

[0048] Further, the third weight ratio of the epoxy resin in the first mixture is 6%;

[0049] Among them, in the step of adding the epoxy resin to the second mixture and adding it to a mixing device for mixing, the mixing conditions include:

[0050] Maintaining a non-vacuum sealed environment, an environmental temperature of 70°C, and a mixing speed of 40 r / min.

[0051] Further, the mixing time of the epoxy resin and the second mixture is 15 min.

[0052] The second aspect of the present invention is to provide a highly flowable magnetic composite material, which is prepared by the preparation method described in the above technical solution.

[0053] Compared with the prior art, the beneficial effects of using the highly flowable magnetic composite material and its preparation method shown in the present invention are as follows:

[0054] 1. Using powders with high sphericity for mixing, spherical particles can roll and slide better with each other during the mixing process, making the mixed magnetic composite material have good uniformity and consistency, reducing the friction between particles, and thus improving the fluidity.

[0055] 2. Using organic acid passivation to treat the surface of the powder, so that a surface layer with organic functional groups is formed on its surface, which has better compatibility with the resin matrix, and thus improves the fluidity.

[0056] 3. Using a grading ratio of the golden ratio (large, medium, and small in a 1:3:9 golden section ratio) to achieve good magnetic properties.

[0057] 4. Epoxy resin with a special medium molecular weight (20,000 - 80,000 g / mol) is adopted to ensure the high fluidity of the composite material and an appropriate curing time, prevent premature curing and loss of fluidity due to too small a curing time window, and at the same time endow the cured material with certain strength and toughness.

[0058] 5. A diluent is used to dilute the resin, reduce the viscosity of the matrix resin, improve its mixing effect, make the material disperse more evenly, and prevent the influence of uneven dispersion on the properties of the composite material.

[0059] Example 1

[0060] Please refer to Figure 1 , the first embodiment of the present invention provides a method for preparing a high-fluidity magnetic composite material, including steps S10 - S50:

[0061] Step S10, providing metal soft magnetic powder with high sphericity, and the metal soft magnetic powder has a first particle size, a second particle size and a third particle size respectively.

[0062] Among them, the metal soft magnetic powder can adopt soft magnetic materials permitted in the art, including but not limited to at least one of carbonyl iron powder, Fe-Ni-Mo alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-based amorphous alloy powder, Ni-based amorphous alloy powder, Co-based amorphous alloy powder and Fe-based nanocrystalline powder, and the soft magnetic metal powder must be a powder with high sphericity.

[0063] By way of example rather than limitation, in this embodiment, the metal soft magnetic powder adopts Fe-Si alloy soft magnetic powder, but is not limited to this material, and other unlisted metal soft magnetic powders are equally applicable.

[0064] Specifically, the first particle size of the metal soft magnetic powder is a large particle size powder, its D50 (i.e., the median particle size or median diameter) is 85 μm - 90 μm, the second particle size of the metal soft magnetic powder is a medium particle size powder, its D50 is 30 μm - 35 μm, and the third particle size of the metal soft magnetic powder is a small particle size powder, its D50 is 8 μm - 12 μm.

[0065] Step S20, grading the metal soft magnetic powders corresponding to the first particle size, the second particle size and the third particle size according to a preset mixing ratio, and weighing a preset weight of the metal soft magnetic powder and adding it to a mixing device for mixing to obtain a first mixture.

[0066] In this embodiment, the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size are graded according to a mixing ratio of 1:3:9. Then, 10 kg of metal soft magnetic powders with high sphericity after grading are weighed and poured into a mixing device with a rotation speed of 50 r / min and a mixing time of 10 min.

[0067] Step S30: Weigh the organic acid accounting for the first weight ratio of the first mixture and the diluent accounting for the second weight ratio of the first mixture respectively. Mix the organic acid and the diluent to obtain the diluted organic acid, add the diluted organic acid to the first mixture and put it into a mixing device for mixing to obtain the second mixture.

[0068] In this embodiment, the organic acid is acetic acid, and the first weight ratio of acetic acid in the first mixture is 1%. The diluent is ethanol, and the second weight ratio of ethanol in the first mixture is 3%.

[0069] Specifically, weigh 1% acetic acid and 3% ethanol by weight of the first mixture (i.e., the graded metal soft magnetic powder), mix the two evenly, then pour them into a mixing device, and perform sufficient mixing in a non-vacuum closed space at a temperature of 40°C and a rotation speed of 50 r / min. After determining that the diluent has completely volatilized by the loss-of-weight method, sieve through a 60-mesh sieve to obtain the passivated second mixture, that is, the metal soft magnetic powder passivated by the organic acid.

[0070] Step S40: Weigh the epoxy resin accounting for the third weight ratio of the first mixture, add the epoxy resin to the second mixture and put it into a mixing device for mixing.

[0071] In this embodiment, the epoxy resin is an epoxy resin with a medium molecular weight (20000 g / mol - 80000 g / mol).

[0072] Specifically, weigh 6% of the medium molecular weight epoxy resin by weight of the first mixture (i.e., the graded metal soft magnetic powder), add the epoxy resin to the mixing device to mix with the second mixture, and perform mixing in a non-vacuum closed space at a temperature of 70°C and a rotation speed of 40 r / min.

[0073] In addition, 6% of ethanol by weight of the first mixture (i.e., the graded metal soft magnetic powder) is also added to the mixing device to mix with the second mixture simultaneously with the epoxy resin. Specifically, the epoxy resin and ethanol are pre-mixed evenly and then added to the mixing device to mix with the second mixture.

[0074] Step S50: After mixing the epoxy resin and the second mixture for a preset time, a high-fluidity magnetic composite material is obtained.

[0075] Among them, epoxy resin and ethanol are added to the second mixture, and the mixing time is 15 minutes. After mixing, the mixture is taken out to obtain a highly fluid magnetic composite material, which is used to make magnetic powder types, etc.

[0076] The fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 1.

[0077] The inductance, magnetic permeability, and loss performance of the magnetic composite material prepared by the preparation method shown in this embodiment under different frequencies and magnetic field intensities were tested, and the results are shown in Table 2.

[0078] The fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 3.

[0079] The fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 4.

[0080] Example Two

[0081] The second embodiment of the present invention, which is also Comparative Example One, also provides a preparation method for a highly fluid magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the change in the sphericity of the metal soft magnetic powder, that is, the Fe-Si alloy soft magnetic powder. In this embodiment, Fe-Si alloy soft magnetic powder with low sphericity is used, and the remaining steps, parameters, and the addition amounts of auxiliary materials are the same as those in the first embodiment.

[0082] Among them, the fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 1.

[0083] Example Three

[0084] The third embodiment of the present invention, which is also Comparative Example Two, also provides a preparation method for a highly fluid magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the change in the sphericity of the metal soft magnetic powder, that is, the Fe-Si alloy soft magnetic powder. In this embodiment, crushed Fe-Si alloy soft magnetic powder is used, and the remaining steps, parameters, and the addition amounts of auxiliary materials are the same as those in the first embodiment.

[0085] The fluidity of the magnetic composite materials prepared by the methods shown in the first to third embodiments was tested, and the results are shown in Table 1.

[0086] Table 1

[0087] Sample Weight Pressure Temperature Holding Pressure Time Flow Length Case One 80g 15 Mpa 175℃ 35s 170 mm Case Two 80g 15 Mpa 175℃ 35s 80 mm Case Three 80g 15 Mpa 175℃ 35s 40 mm

[0088] As can be seen from the results in Table 1 above, under the same pressure, temperature, holding time, and weight, the higher the sphericity of the metal soft magnetic powder, the better the fluidity of the magnetic composite material prepared by the same preparation method. For example, the flow length of the magnetic composite material prepared by the preparation method shown in the first embodiment reaches 170 mm, and its fluidity is better than that of the second and third embodiments.

[0089] Example Four

[0090] The fourth embodiment of the present invention, which is also Comparative Example Three, also provides a method for preparing a high-fluidity magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the particle size distribution change of the metal soft magnetic powder, that is, the Fe-Si alloy soft magnetic powder. In this embodiment, all the metal soft magnetic powders are Fe-Si alloy powders with the first particle size (i.e., the large particle size), and its D50 is 85 μm - 90 μm. The addition amounts of the remaining steps, parameters, and auxiliary materials are the same as those in the first embodiment.

[0091] The magnetic composite material prepared by the method of this embodiment is tested for inductance, magnetic permeability, and loss performance under different frequencies and magnetic field strengths. The results are shown in Table 2.

[0092] Example Five

[0093] The fourth embodiment of the present invention, which is also Comparative Example Four, also provides a method for preparing a high-fluidity magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the particle size distribution change of the metal soft magnetic powder, that is, the Fe-Si alloy soft magnetic powder. In this embodiment, all the metal soft magnetic powders are Fe-Si alloy powders with the third particle size (i.e., the small particle size), and its D50 is 8 μm - 12 μm. The addition amounts of the remaining steps, parameters, and auxiliary materials are the same as those in the first embodiment.

[0094] The magnetic composite material prepared by the method of this embodiment is tested for inductance, magnetic permeability, and loss performance under different frequencies and magnetic field strengths. The results are shown in Table 2.

[0095] Example Six

[0096] The sixth embodiment of the present invention, which is also Comparative Example Five, also provides a method for preparing a high-fluidity magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the particle size distribution change of the metal soft magnetic powder, that is, the Fe-Si alloy soft magnetic powder. In this embodiment, the metal soft magnetic powder is a Fe-Si alloy powder with a ratio of the first particle size to the third particle size of 1:2, and its D50 is 8 μm - 12 μm. The addition amounts of the remaining steps, parameters, and auxiliary materials are the same as those in the first embodiment.

[0097] The magnetic composites prepared by the preparation methods shown in the fourth to sixth embodiments were tested for inductance, magnetic permeability, and loss performance at different frequencies and magnetic field intensities. The results are shown in Table 2.

[0098] Table 2

[0099]

[0100] From Table 2, it can be concluded that the size of the powder particle diameter directly affects the magnetic properties of the composite material. In the fourth embodiment, all large-diameter powders are used. Through testing, it is found that the magnetic composite material made of large-diameter powders has a high magnetic permeability, but at the same time, the loss is also very high. In the fifth embodiment, all small-diameter powders are used. Through testing, it is found that the magnetic composite material made of small-diameter powders has a very low loss, but the magnetic permeability is not high. In the sixth embodiment, the powders are graded with conventional particle sizes. Through testing, it is found that the composite material made of the graded powders with large and small particle sizes has a relatively high magnetic permeability and a low loss.

[0101] Combining Table 1 and Table 2, the first embodiment uses the golden ratio of 1:3:9 proposed by the present invention to grade and proportion the metal soft magnetic powders. From the test results, it can be seen that the golden ratio grading and proportioning proposed in the first embodiment of the present invention has a higher magnetic permeability and a lower loss compared to the conventional grading and proportioning.

[0102] Example Seven

[0103] The seventh embodiment of the present invention, which is also Comparative Example Six, also provides a preparation method for a highly fluid magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the type of passivating agent in step S30. In this embodiment, an inorganic acid (phosphoric acid) is used, and the remaining steps, parameters, and the addition amounts of auxiliary materials are the same as those in Example One.

[0104] The magnetic composites prepared by the preparation methods shown in the first embodiment and the seventh embodiment were tested for fluidity. The results are shown in Table 3.

[0105] Table 3

[0106] Sample Weight Pressure Temperature Holding Pressure Time Flow Length Case One 80g 15 Mpa 175℃ 35s 170 mm Case Seven 80g 15 Mpa 175℃ 35s 105m

[0107] From the data results in Table 3, it can be concluded that under the same pressure, temperature, holding time, and weight, passivating the surface of the metal soft magnetic powder with an organic acid results in a better fluidity of the magnetic composite material than passivating the surface of the metal soft magnetic powder with an inorganic acid.

[0108] Example Eight

[0109] The eighth embodiment of the present invention, which is also Comparative Example 7, also provides a method for preparing a highly fluid magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the molecular weight of the epoxy resin in step S40. In this embodiment, a low molecular weight epoxy resin with a molecular weight of 20,000 g / mol or less is used, and the remaining steps, parameters, and addition amounts of auxiliary materials are the same as those in Example 1.

[0110] The fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 4.

[0111] Example 9

[0112] The ninth embodiment of the present invention, which is also Example 8, also provides a method for preparing a highly fluid magnetic composite material. The preparation method shown in this embodiment is basically the same as the preparation method shown in the first embodiment, except for the molecular weight of the epoxy resin in step S40. In this embodiment, a low molecular weight epoxy resin with a molecular weight of 80,000 g / mol or more is used, and the remaining steps, parameters, and addition amounts of auxiliary materials are the same as those in Example 1.

[0113] The fluidity of the magnetic composite material prepared by the preparation method shown in this embodiment was tested, and the results are shown in Table 4:

[0114] Table 4

[0115] Sample Weight Pressure Temperature Holding Pressure Time Flow Length Curing Time Case One 80g 15 Mpa 175℃ 35s 170 mm 1 min 20 s Case Eight 80g 15 Mpa 175℃ 35s 200 mm 20s Case Nine 80g 15 Mpa 175℃ 35s 60 mm 4 min

[0116] From the data results in Table 4, it can be concluded that under the same pressure, temperature, holding time, and weight, using a low molecular weight epoxy resin can make the composite material have ultra-high fluidity, but at the same time, the curing time of the composite material will be very fast, which may cause the composite material to cure prematurely and lose its fluidity; while using a high molecular weight epoxy resin will make the fluidity of the composite material very poor and the curing time will be very long.

[0117] Therefore, using the special medium molecular weight epoxy resin proposed in the first embodiment of the present invention not only ensures the high fluidity of the magnetic composite material, but also ensures an appropriate curing time, which can prevent the magnetic composite material from curing prematurely due to too fast curing time and losing its fluidity. At the same time, it also enables the magnetic composite material to have certain strength and toughness after curing.

[0118] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0119] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A preparation method of a high-fluidity magnetic composite material, characterized in that, The preparation method includes: Providing metal soft magnetic powders with high sphericity, the metal soft magnetic powders having a first particle size, a second particle size, and a third particle size respectively; the first particle size is 85 μm - 90 μm, the second particle size is 30 μm - 35 μm, and the third particle size is 8 μm - 12 μm; Carrying out grading on the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size according to a preset mixing ratio, and weighing a preset weight of the metal soft magnetic powders and adding them to a mixing device for mixing to obtain a first mixture; the mixing ratio of the metal soft magnetic powders corresponding to the first particle size, the second particle size, and the third particle size is 1:3:9; Weighing an organic acid accounting for a first weight ratio of the first mixture and a diluent accounting for a second weight ratio of the first mixture respectively, mixing the organic acid and the diluent to obtain a diluted organic acid, adding the diluted organic acid to the first mixture and adding it to a mixing device for mixing to obtain a second mixture; Weighing an epoxy resin accounting for a third weight ratio of the first mixture, adding the epoxy resin to the second mixture and adding it to a mixing device for mixing; the molecular weight of the epoxy resin is 20000 g / mol - 80000 g / mol; After mixing the epoxy resin and the second mixture for a preset time, a high-fluidity magnetic composite material is obtained.

2. The preparation method of the highly fluid magnetic composite material according to claim 1, characterized in that In the step of weighing a preset weight of the metal soft magnetic powders and adding them to a mixing device for mixing to obtain a first mixture, the mixing rotation speed is 50 r / min and the mixing time is 10 min.

3. The preparation method of the highly fluid magnetic composite material according to claim 1, characterized in that, The weight of the metal soft magnetic powders weighed for mixing is 10 kg; Among them, the first weight ratio of the organic acid in the first mixture is 1%, and the second weight ratio of the diluent in the first mixture is 3%.

4. The preparation method of the highly fluid magnetic composite material according to claim 3, characterized in that The organic acid is acetic acid and the diluent is ethanol.

5. The preparation method of the highly fluid magnetic composite material according to claim 1, wherein In the step of adding the diluted organic acid to the first mixture and adding it to a mixing device for mixing to obtain a second mixture, the mixing conditions include: Maintaining a non-vacuum closed environment, an environmental temperature of 40 °C, and a mixing rotation speed of 50 r / min.

6. The preparation method of the high-fluidity magnetic composite material according to claim 5, wherein After adding the diluted organic acid to the first mixture and adding it to a mixing device for mixing, the preparation method further includes: Mixing the organic acid and the first mixture and passing through a 60-mesh sieve to obtain a passivated second mixture.

7. The preparation method of the highly fluid magnetic composite material according to claim 1, characterized in that, The third weight ratio of the epoxy resin in the first mixture is 6%; Among them, in the step of adding the epoxy resin to the second mixture and adding it to a mixing device for mixing, the mixing conditions include: Maintaining a non-vacuum closed environment, an environmental temperature of 70 °C, and a mixing rotation speed of 40 r / min.

8. The preparation method of the highly fluid magnetic composite material according to claim 7, characterized in that, The mixing time of the epoxy resin and the second mixture is 15 min.

9. A high-fluidity magnetic composite material, characterized in that, The high-fluidity magnetic composite material is prepared by the preparation method according to any one of claims 1 - 8.

Images