CN110283429B - Flaky ferrite electromagnetic composite material and preparation method thereof - Google Patents
Flaky ferrite electromagnetic composite material and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a flaky ferrite electromagnetic composite material and a preparation method thereof. The preparation method takes the flaky ferrite prepared by ball milling, a coupling modifier, resin, a curing agent and a diluent as raw materials, and the raw material components are mixed and molded to prepare the composite material; wherein, the process conditions for preparing the flaky ferrite by ball milling are as follows: carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-500 r/min; the steel balls comprise 8mm diameter steel balls and 6mm diameter steel balls. The invention adopts a ball milling method to prepare the sheet ferrite powder, the sheet ferrite powder is compounded with epoxy resin through coupling modification, and the electromagnetic load composite material is molded by using an autoclave process or ultrasonic curing, shows higher electromagnetic parameters at 1-18GHz, and can be widely applied to electronic equipment in various fields such as radar, navigation, satellite communication, electronic countermeasure, broadcast television, mobile communication and the like.
Description
Technical Field
The invention relates to the technical field of electromagnetic function composite materials, in particular to a flaky ferrite electromagnetic composite material and a preparation method thereof.
Background
With the rapid development of high-end electronic devices, the technical requirements for the performance of electronic components in the devices are higher and higher. The electromagnetic interference between components in a limited space is unavoidable, the electromagnetic interference has serious interference on the communication function of an antenna system, the transmission strength of signals is weakened, and even the antenna is completely failed, so that the problem is effectively solved by adding electromagnetic shielding materials with high magnetic conductivity and magnetic loss between the components.
The ferrite has the characteristics of low price, simple preparation process, good wave-absorbing performance and the like, and is a more and more mature microwave attenuation absorbent currently researched. The loss of the ferrite to electromagnetic waves includes both dielectric loss and magnetic loss, the most dominant loss mechanism being ferromagnetic natural resonance absorption in residual loss.
At present, most of ferrite powder obtained in the traditional production is in a spherical structure. However, as the frequency bands used in equipment units have increased, spherical ferrite materials have been difficult to satisfy.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
The invention aims to bond and compound ferrite powder with a sheet structure and epoxy resin, provides a preparation method of a functional composite material with excellent electromagnetic property, and meets the application in the aspects of high-performance electronic components and novel electromagnetic materials.
In order to achieve the purpose, the invention provides the following technical scheme:
a preparation method of a flaky ferrite electromagnetic composite material is characterized in that flaky ferrite prepared by ball milling, a coupling modifier, resin, a curing agent and a diluent are used as raw materials, and the raw material components are mixed and molded to prepare the composite material;
wherein, the process conditions for preparing the flaky ferrite by ball milling are as follows:
carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-500 r/min;
the steel balls comprise 8mm diameter steel balls and 6mm diameter steel balls.
Preferably, the mass ratio of the ferrite powder, the steel balls, the ball milling aid and the volatile solvent is (100- > 130): (350-500): (0.01-0.05): (200-);
preferably, the mass ratio of the ferrite powder, the steel balls, the ball-milling assistant and the volatile solvent is (115- & lt 120-): (400-450): (0.02-0.03): (250-300).
Preferably, the mass ratio of the 8mm diameter steel ball to the 6mm diameter steel ball is 5: 7.
Preferably, the ferrite is a fesai ferrite;
the ball-milling auxiliary agent is calcium stearate; and/or
The volatile solvent is acetone.
Preferably, the mass ratio of the plate-like ferrite to the resin is (70-80): (15-25), preferably (75-80): (15-20);
the mass of the coupling modifier is 0.2-0.5wt% of the mass of the flaky ferrite;
the mass of the curing agent is 20-25wt% of the mass of the resin; and/or
The mass of the diluent is 15-20wt% of the mass of the resin.
Preferably, the coupling modifier is 3-aminopropyltriethoxysilane; and/or
The resin is epoxy resin.
Preferably, the molding is an autoclave curing molding method, the pressure condition is 1-5MPa, and the temperature condition is 110-120 ℃; or
The molding adopts an ultrasonic curing molding method, and the temperature condition is 90-100 ℃.
Preferably, the preparation method comprises the following steps:
(1) ball milling: carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-plus-500 r/min, wherein the rigid balls comprise steel balls with the diameter of 8mm and steel balls with the diameter of 6mm to obtain flaky ferrite;
(2) coupling modification: mixing a coupling modifier with the flaky ferrite prepared in the step (1) to obtain the flaky ferrite after coupling treatment;
(3) preparing slurry: mixing the flaky ferrite prepared in the step (2) with resin, a curing agent and a diluent to obtain mixed slurry;
(4) a forming step: and (4) curing and molding the mixed slurry prepared in the step (3) to obtain the composite material.
Preferably, in the step of formulating the slurry, mixing is performed with vacuum assistance; or
Ultrasonic dispersing at 80-90 deg.C and 40-50 kHz.
The sheet ferrite electromagnetic composite material is prepared by the preparation method provided by the invention, and has the following properties:
real part of the relative complex permittivity: 36.88 to 66.22;
imaginary part of the relative complex dielectric constant: 7.51-34.02;
real part of relative complex permeability: 0.47-3.42;
imaginary part of the relative complex permeability: 0.43-6.64.
Advantageous effects
The technical scheme of the invention has the following advantages:
the invention adopts a ball milling method to prepare the sheet ferrite powder, the sheet ferrite powder is compounded with epoxy resin through coupling modification, and the electromagnetic load composite material is molded by using an autoclave process or ultrasonic curing, shows higher electromagnetic parameters at 1-18GHz, and can be widely applied to electronic equipment in various fields such as radar, navigation, satellite communication, electronic countermeasure, broadcast television, mobile communication and the like.
According to the preparation method provided by the invention, the flaky ferrite obtained by ball milling and resin are compounded to prepare the electromagnetic composite material, and the specific ball milling process is adopted to endow the flaky ferrite with excellent electromagnetic parameters in a 1-18GHz frequency band, so that the composite material compounded with the resin can show excellent electromagnetic performance in the 1-18GHz frequency band; in addition, the flaky ferrite prepared by the specific ball milling process can also realize better impedance matching with resin, so that the problem that the optimal design of impedance matching is difficult to realize is avoided.
The average grain diameter (finger length) of the flaky ferrite prepared by the ball milling process is 30-35 mu m, the flaky ferrite with the grain diameter can be easily molded in the later molding stage without large pressure condition, so that the preparation process is more convenient.
The preparation method provided by the invention comprises the following steps of in a ball milling stage, according to the mass ratio of the ferrite powder, the steel balls, the ball milling auxiliary agent and the volatile solvent being (100-: (350-500): (0.01-0.05): (200-300) ball milling is carried out according to the material mixing relationship, so that the uniformity of the particle size and the uniformity of the electromagnetic performance of the ball-milled flaky ferrite are ensured. More preferred ingredient relationship is as follows: the mass ratio of the ferrite powder to the steel balls to the ball-milling auxiliary agent to the volatile solvent is (115-: (400-450): (0.02-0.03): (250-300), under the same other conditions, the particle size of the flaky ferrite obtained by ball milling under the burdening relation is most uniform and the electromagnetic performance is most uniform.
When the preparation method provided by the invention is used for ball milling of steel balls with the diameter of 8mm and steel balls with the diameter of 6mm according to the mass ratio of 5:7, the uniformity of the granularity and the uniformity of the electromagnetic performance of the ball-milled flaky ferrite are ensured.
In order to give consideration to material performance and process operability, the preparation method provided by the invention comprises the following steps of: (15-25) compounding.
Drawings
FIG. 1 is an SEM topography of a flaky FeSiAl powder.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The invention provides a preparation method of a flaky ferrite electromagnetic composite material in a first aspect, wherein the preparation method takes flaky ferrite prepared by ball milling, a coupling modifier, resin, a curing agent and a diluent as raw materials, and the raw material components are mixed and molded to prepare the composite material; wherein, the process conditions for preparing the flaky ferrite by ball milling are as follows: carrying out ball milling on ferrite powder, steel balls, ball milling aids and volatile solvents for 7-8h (any value in the range can be 7h, 7.5h and 8h) at the rotating speed of 400-500r/min (any value in the range can be 400r/min, 410r/min, 420r/min, 430r/min, 440r/min, 450r/min, 460r/min, 470r/min, 480r/min, 490r/min and 500 r/min); the steel balls comprise 8mm diameter steel balls and 6mm diameter steel balls.
According to the preparation method provided by the invention, the flaky ferrite obtained by ball milling and resin are compounded to prepare the electromagnetic composite material, and the specific ball milling process is adopted to endow the flaky ferrite with excellent electromagnetic parameters in a 1-18GHz frequency band, so that the composite material compounded with the resin can show excellent electromagnetic performance in the 1-18GHz frequency band; in addition, the flaky ferrite prepared by the specific ball milling process can also realize better impedance matching with resin, so that the problem that the optimal design of impedance matching is difficult to realize is avoided.
The inventor also finds that the average particle size (referred to as sheet length) of the sheet ferrite prepared by the ball milling process is 30-35 μm, and the sheet ferrite with the particle size can be easily molded in a later molding stage without large pressure conditions, so that the preparation process is more convenient.
In addition to the ball milling rotation speed, the size of the used steel balls and the ball milling time, the inventor suggests that in the ball milling stage, the mass ratio of the ferrite powder, the steel balls, the ball milling auxiliary agent and the volatile solvent is (100-: (350-500): (0.01-0.05): (200-300) ball milling is carried out according to the material mixing relationship, so that the uniformity of the particle size and the uniformity of the electromagnetic performance of the ball-milled flaky ferrite are ensured. More preferred ingredient relationship is as follows: the mass ratio of the ferrite powder to the steel balls to the ball-milling auxiliary agent to the volatile solvent is (115-: (400-450): (0.02-0.03): (250-300), under the same other conditions, the particle size of the flaky ferrite obtained by ball milling under the burdening relation is most uniform and the electromagnetic performance is most uniform. The ball milling aid is preferably calcium stearate. The volatile solvent is preferably acetone. Specifically, the above components may be used in any amount within the above ranges in the compounding relationship. For example, the ferrite powder may have a mass number of 100, 105, 110, 115, 120, 125, 130; for example, the mass number of the steel ball may be 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500; for example, the mass number of the ball milling aid may be 0.01, 0.02, 0.03, 0.04, 0.05; for example, the volatile solvent may have a mass number of 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300.
In some preferred implementations, the mass ratio of the 8mm diameter steel ball to the 6mm diameter steel ball is 5: 7. The inventors also found that when 8mm diameter steel balls and 6mm diameter steel balls are used in this mass ratio, the ball milling effect is optimum, and the uniformity of the particle size and the uniformity of the electromagnetic properties of the sheet ferrite after ball milling are ensured.
In some preferred embodiments, the mass ratio of the ferrite flakes to the resin is (70-80): (15-25), preferably (75-80): (15-20). In order to obtain a large magnetic loss, it is an effective means to increase the amount of the ferrite flakes added. As the amount of the flake ferrite added increases, the magnetic loss of the composite material increases. However, when the amount of the additive is too large, the difficulty of dispersion and the difficulty of subsequent molding are both greatly increased. Therefore, from the viewpoint of process operability, it is proposed to mix the ferrite flakes and the resin in a mass ratio of (70 to 80): (15-25) compounding. The resin can be epoxy resin. The epoxy resin generates a product with a three-dimensional network structure under the action of a curing agent, and shows various excellent performances. Specifically, the above components may be used in any amount within the above ranges in the compounding relationship. For example, the mass number of the plate-shaped ferrite may be 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80. For example, the mass number of the resin may be 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25. In practice, the coupling modifier is preferably mixed with the ferrite flakes, and the ferrite flakes are subjected to a coupling modification treatment and then mixed with the resin. The advantages of this operation are: the flaky structure of the flaky ferrite obtained after ball milling ensures that the flaky ferrite is not easy to disperse when being mixed with resin which is a material with certain viscosity, and the problem can be avoided to a great extent after coupling modification. In addition, when the sheet ferrite and the resin are mixed, the mixture may be subjected to ultrasonic dispersion under vacuum assistance or ultrasonic waves under 80 to 90 ℃ (80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃, 90 ℃), 40 to 50kHz (40 kHz, 41kHz, 42kHz, 43kHz, 44kHz, 45kHz, 46kHz, 47kHz, 48kHz, 49kHz, 50 kHz).
In some preferred embodiments, the mass of the coupling modifier is 0.2 to 0.5wt% of the mass of the ferrite flakes, and may be any value within this range, for example, may be 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%. The coupling modifier is preferably 3-aminopropyl triethoxysilane, also known as KH550 or KH-550, and coupling modification of the flaky ferrite by using KH-550 is beneficial to improving the binding force between the ferrite and resin, so that the mechanical property of the composite material is improved. The mass of the curing agent is 20 to 25wt% of the mass of the resin, and may be any value within this range, for example, 20wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%. The curing agent may be selected from those commonly used in the art for curing epoxy resins, for example, 2-ethyl-4-methylimidazole. The mass of the diluent is 15 to 20wt% of the mass of the resin, and may be any value within this range, for example, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%. The diluent may be selected from those commonly used in the art for epoxy resins, such as the commercially available 501 diluent.
In some preferred embodiments, the preparation method can be carried out according to the following preparation process:
(1) ball milling: carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-plus-500 r/min, wherein the rigid balls comprise steel balls with the diameter of 8mm and steel balls with the diameter of 6mm to obtain flaky ferrite;
(2) coupling modification: mixing a coupling modifier with the flaky ferrite prepared in the step (1) to obtain the flaky ferrite after coupling treatment;
(3) preparing slurry: mixing the flaky ferrite prepared in the step (2) with resin, a curing agent and a diluent to obtain mixed slurry;
(4) a forming step: and (4) curing and molding the mixed slurry prepared in the step (3) to obtain the composite material.
More fully, the preparation method provided by the invention can comprise the following preparation steps:
(1) ball milling: and (3) ball-milling the ferrite powder, the steel balls, the ball-milling auxiliary agent and the volatile solvent for 7-8h at the rotating speed of 400-plus-500 r/min, wherein the rigid balls comprise steel balls with the diameter of 8mm and steel balls with the diameter of 6mm to obtain the flaky ferrite. The mass ratio of the ferrite powder, the steel balls, the ball-milling assistant and the volatile solvent is preferably (100-) -130: (350-500): (0.01-0.05): (200- & ltSUB & gt-300) & lt 115- & gt-120 & lt 115- & gt): (400-450): (0.02-0.03): (250-300). The mass ratio of the steel ball with the diameter of 8mm to the steel ball with the diameter of 6mm is preferably 5: 7. The ball milling aid can be calcium stearate. The volatile solvent may be acetone.
(2) Coupling modification: and (3) mixing the coupling modifier with the flaky ferrite prepared in the step (1) to obtain the flaky ferrite subjected to coupling treatment. The coupling modifier is preferably 3-aminopropyltriethoxysilane, the mass of which is 0.2-0.5wt% of the mass of the flaky ferrite.
(3) Preparing slurry: and (3) mixing the flaky ferrite prepared in the step (2) with resin, a curing agent and a diluent to obtain mixed slurry. In this step, the mass ratio of the plate-like ferrite to the resin is preferably (70-80): (15-25), more preferably (75-80): (15-20). The mass of the curing agent is preferably 20 to 25wt% of the mass of the resin. The mass of the diluent is preferably 15 to 20wt% of the mass of the resin. The mixing can be carried out with the aid of vacuum assistance, i.e.with the aid of vacuum assistance or by means of ultrasound, with ultrasound dispersion at temperatures of from 80 to 90 ℃ and at from 40 to 50 kHz.
(4) A forming step: and (4) curing and molding the mixed slurry prepared in the step (3) to obtain the composite material. The molding may be carried out by autoclave curing molding under a pressure condition of 1 to 5MPa (any value within the range, for example, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa), a temperature condition of 110 ℃ to 120 ℃ (any value within the range, for example, 110 ℃, 111 ℃, 112 ℃, 113 ℃, 114 ℃, 115 ℃, 116 ℃, 117 ℃, 118 ℃, 119 ℃, 120 ℃), or ultrasonic curing molding under a temperature condition of 90 to 100 ℃ (any value within the range, for example, 90 ℃, 91 ℃, 92 ℃, 93 ℃, 94 ℃, 95 ℃, 96 ℃, 97 ℃, 98 ℃, 99 ℃, 100 ℃).
The invention provides a flaky ferrite electromagnetic composite material in a second aspect, which is prepared by the preparation method provided by the invention, and the composite material has the following properties:
real part of the relative complex permittivity: 36.88 to 66.22;
imaginary part of the relative complex dielectric constant: 7.51-34.02;
real part of relative complex permeability: 0.47-3.42;
imaginary part of the relative complex permeability: 0.43-6.64, can be widely applied to electronic equipment in various fields such as radar, navigation, satellite communication, electronic countermeasure, broadcast television, mobile communication and the like.
The following are examples of the present invention.
Example 1
18g of epoxy resin, 4g of 501 diluent and 3g of 2-ethyl-4-methylimidazole are weighed and mixed and stirred for 0.5 hour at normal temperature.
Subsequently, 75g of untreated FeSiAl powder was added, and 0.24g of KH-550 was further added, followed by mixing and stirring for 8 hours with vacuum assistance, to obtain a mixed slurry.
And finally, pouring the mixed slurry into a mold, and carrying out autoclave curing molding under the pressure of 1.2MPa and at the temperature of 110 ℃ to finally obtain the ferrite/epoxy resin composite material.
Example 2
400g of steel balls (167 g of steel balls with the diameter of 8mm and 233g of steel balls with the diameter of 6 mm) and 120g of FeSiAl powder are mixed, then 0.02g of calcium stearate and 250mL of acetone are added together and then placed in a ball milling tank, high-energy ball milling is carried out for 7.5h at the fixed rotating speed of 450r/min, and the sheet ferrite with the average sheet length of 30-35 mu m is obtained, and the microscopic morphology of the sheet ferrite refers to figure 1.
Weighing 18g of epoxy resin, 4g of 501 diluent and 3g of 2-ethyl-4-methylimidazole, mixing and stirring at normal temperature for 0.5h, then adding 75g of ball-milled flaky FeSiAl powder, adding 0.24gKH-550, and mixing and stirring under the assistance of vacuum for 8h to obtain mixed slurry.
And finally, pouring the composite slurry into a mold, and curing and molding the composite slurry in an autoclave under the pressure of 1.2MPa and at the temperature of 110 ℃ to finally obtain the sheet FeSiAl/epoxy resin composite material.
Example 3
400g of steel balls (167 g of steel balls with the diameter of 8mm and 233g of steel balls with the diameter of 6 mm) and 120g of FeSiAl powder are mixed, then 0.02g of calcium stearate and 250mL of acetone are added together and then placed in a ball milling tank, and high-energy ball milling is carried out for 7.5h at the fixed rotating speed of 450r/min, so as to obtain the flaky ferrite with the average length of 30-35 mu m.
Weighing 18g of epoxy resin, 4g of 501 diluent and 3g of 2-ethyl-4-methylimidazole, mixing and stirring for 0.5h at normal temperature, then adding 75g of ball-milled flaky FeSiAl powder, adding 0.24gKH-550, and placing in an ultrasonic disperser at 80 ℃ and 40kHz to slowly stir for 2h to obtain mixed slurry.
Finally, performing ultrasonic curing for 1.5h at the temperature of 90-100 ℃ to finally obtain the sheet FeSiAl/epoxy resin composite material.
Example 4
400g of steel balls (167 g of steel balls with the diameter of 8mm and 233g of steel balls with the diameter of 6 mm) and 120g of FeSiAl powder are mixed, then 0.02g of calcium stearate and 250mL of acetone are added together and then placed in a ball milling tank, and high-energy ball milling is carried out for 7.5h at the fixed rotating speed of 450r/min, so as to obtain the flaky ferrite with the average length of 30-35 mu m.
Weighing 18g of epoxy resin, 4g of 501 diluent and 3g of 2-ethyl-4-methylimidazole, mixing and stirring at normal temperature for 0.5h, then adding 58g of ball-milled flaky FeSiAl powder, adding 0.18gKH-550, and mixing and stirring under the assistance of vacuum for 6h to obtain mixed slurry.
And finally, pouring the mixed slurry into a mold, and carrying out autoclave curing molding under the pressure of 1.2MPa and at the temperature of 110 ℃ to finally obtain the sheet FeSiAl/epoxy resin composite material.
Table 1 describes the preparation process of examples 1 to 4.
TABLE 1
| Numbering | Whether or not to ball mill | Dosage of flaky FeSiAl powder | Amount of epoxy resin used |
| Example 1 | Whether or not | 75g* | 18g |
| Example 2 | Is that | 75g | 18g |
| Example 3 | Is that | 75g | 18g |
| Example 4 | Is that | 58g | 18g |
Note that: here 75g refers to the amount of unskibbled fesai powder.
The composites obtained in examples 1 to 4 were tested for electromagnetic parameters as SJ20512-1995 and the results of the electromagnetic parameter tests are shown in Table 2.
TABLE 2
Note: ε' is the real part of the relative complex permittivity; ε "is the imaginary part of the relative complex permittivity; μ' is the real part of the relative complex permeability; μ "is the imaginary part of the relative complex permeability; tan σdElectrical loss tangent angle; tan σmIs the magnetic loss tangent angle.
As can be seen from the comparison of the test results of example 1 (without ball milling) and examples 2 and 3, the sheet FeSiAl/epoxy resin composite material obtained after the ball milling treatment has higher magnetic permeability and dielectric constant at a high frequency point.
As can be seen from the comparison of the results of example 2 and example 3, the composite material prepared by ultrasonic curing has higher magnetic loss.
As can be seen from the comparison of the results of example 3 and example 4, the magnetic loss of the composite material increases as the amount of the flaky ferrite added increases. It is understood from the comparison results of example 1 and example 4 that the effect of significantly improving the magnetic loss of the composite material cannot be achieved when the filling amount of the ferrite is low. However, too much ferrite is not easily added, and too much ferrite causes too high viscosity, poor dispersion uniformity, difficulty in removing bubbles, and poor workability. In the preparation process, the flaky ferrite and the resin (70-80): (15-25), and most preferably according to the proportion of (75-80): (15-20) the magnetic conductivity and magnetic loss of the composite material can be obviously improved, and the difficulty of the preparation process can be reduced.
Example 5
The preparation method is basically the same as that of example 2, except that: the coupling modifier used was KH-570 (chemical name: gamma- (methacryloyloxy) propyltrimethoxysilane).
Example 6
The preparation method is basically the same as that of example 2, except that: the rotating speed during ball milling is 600 r/min.
Example 7
The preparation method is basically the same as that of example 2, except that: the ball milling time is 9 h.
Example 8
The preparation method is basically the same as that of example 2, except that: the steel balls used in the ball milling contained 200g of steel balls having a diameter of 5mm + 200g of steel balls having a diameter of 3 mm.
TABLE 3
The invention adopts a ball milling method to prepare the sheet ferrite powder, is compounded with epoxy resin through coupling modification, applies an autoclave process or ultrasonic curing molding (preferably ultrasonic curing molding) electromagnetic load composite material, shows higher electromagnetic parameters in a frequency band of 1-18GHz, and can be widely applied to electronic equipment in various fields of radar, navigation, satellite communication, electronic countermeasure, broadcast television, mobile communication and the like.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. The preparation method of the flaky ferrite electromagnetic composite material is characterized in that the flaky ferrite prepared by ball milling, a coupling modifier, resin, a curing agent and a diluent are used as raw materials, and the raw material components are mixed and molded to prepare the composite material; wherein the coupling modifier is 3-aminopropyl triethoxysilane; the resin is epoxy resin;
wherein, the process conditions for preparing the flaky ferrite by ball milling are as follows:
carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-500 r/min;
the steel balls comprise steel balls with the diameter of 8mm and steel balls with the diameter of 6 mm; wherein the mass ratio of the steel ball with the diameter of 8mm to the steel ball with the diameter of 6mm is 5: 7;
the mass ratio of the ferrite powder to the steel balls to the ball-milling auxiliary agent to the volatile solvent is (100-) -130: (350-500): (0.01-0.05): (200-);
the mass ratio of the flaky ferrite to the resin is (70-80): (15-25); wherein the average particle diameter of the flaky ferrite is 30-35 μm.
2. The preparation method according to claim 1, wherein the mass ratio of the ferrite powder, the steel balls, the ball milling aid and the volatile solvent is (115- & 120): (400-450): (0.02-0.03): (250-300).
3. The method of claim 2, wherein the ferrite is a fesai ferrite;
the ball-milling auxiliary agent is calcium stearate; and/or
The volatile solvent is acetone.
4. The production method according to claim 1, wherein the mass ratio of the flake ferrite to the resin is (75-80): (15-20);
the mass of the coupling modifier is 0.2-0.5wt% of the mass of the flaky ferrite;
the mass of the curing agent is 20-25wt% of the mass of the resin; and/or
The mass of the diluent is 15-20wt% of the mass of the resin.
5. The preparation method as claimed in claim 1, wherein the molding is performed by autoclave curing molding under pressure conditions of 1-5MPa and temperature conditions of 110-120 ℃; or
The molding adopts an ultrasonic curing molding method, and the temperature condition is 90-100 ℃.
6. The production method according to any one of claims 1 to 5, characterized by comprising the steps of:
(1) ball milling: carrying out ball milling on ferrite powder, steel balls, a ball milling aid and a volatile solvent for 7-8h at the rotating speed of 400-plus-500 r/min, wherein the steel balls comprise steel balls with the diameter of 8mm and steel balls with the diameter of 6mm to obtain flaky ferrite;
(2) coupling modification: mixing a coupling modifier with the flaky ferrite prepared in the step (1) to obtain the flaky ferrite after coupling treatment;
(3) preparing slurry: mixing the flaky ferrite prepared in the step (2) with resin, a curing agent and a diluent to obtain mixed slurry;
(4) a forming step: and (4) curing and molding the mixed slurry prepared in the step (3) to obtain the composite material.
7. The method according to claim 6, wherein in the step of preparing the slurry, mixing is performed with vacuum assistance; or
Ultrasonic dispersing at 80-90 deg.C and 40-50 kHz.
8. A sheet-shaped ferrite electromagnetic composite material, characterized by being prepared by the preparation method of any one of claims 1 to 7, and having the following properties:
real part of the relative complex permittivity: 36.88 to 66.22;
imaginary part of the relative complex dielectric constant: 7.51-34.02;
real part of relative complex permeability: 0.47-3.42;
imaginary part of the relative complex permeability: 0.43-6.64.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20050007101A (en) * | 2003-07-11 | 2005-01-17 | 에이비씨 타이완 일렉트로닉스 코포레이션 | Epoxy resin of electromagnetic interference suppression and manufacturing method thereof and an inductor applied in the electromagnetic interference suppression |
| CN104575894A (en) * | 2013-10-28 | 2015-04-29 | 深圳光启创新技术有限公司 | Light magnetic material, preparation method thereof and wave-absorbing plate |
| CN106793725A (en) * | 2016-12-12 | 2017-05-31 | 浙江工业大学 | A kind of ferrite polymer composite and preparation method and application |
| CN108298973A (en) * | 2018-03-01 | 2018-07-20 | 北京环境特性研究所 | One kind is based on graphene/ferritic passive frequency control material and preparation method thereof |
| CN109721281A (en) * | 2019-01-24 | 2019-05-07 | 航天特种材料及工艺技术研究所 | A kind of feeding network electromagnetic load composite material and preparation method |
-
2019
- 2019-07-19 CN CN201910653696.0A patent/CN110283429B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20050007101A (en) * | 2003-07-11 | 2005-01-17 | 에이비씨 타이완 일렉트로닉스 코포레이션 | Epoxy resin of electromagnetic interference suppression and manufacturing method thereof and an inductor applied in the electromagnetic interference suppression |
| CN104575894A (en) * | 2013-10-28 | 2015-04-29 | 深圳光启创新技术有限公司 | Light magnetic material, preparation method thereof and wave-absorbing plate |
| CN106793725A (en) * | 2016-12-12 | 2017-05-31 | 浙江工业大学 | A kind of ferrite polymer composite and preparation method and application |
| CN108298973A (en) * | 2018-03-01 | 2018-07-20 | 北京环境特性研究所 | One kind is based on graphene/ferritic passive frequency control material and preparation method thereof |
| CN109721281A (en) * | 2019-01-24 | 2019-05-07 | 航天特种材料及工艺技术研究所 | A kind of feeding network electromagnetic load composite material and preparation method |
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