Electromagnetic sealing material with dielectric and magnetic dual loss function and preparation method thereof

Abstract

The application discloses electromagnetic sealing material with dielectric and magnetic double loss function and a preparation method thereof, and belongs to the electromagnetic material field. TiO2 powder and K2CO3 solution are added into NiCl2 solution to obtain a mixed solution; the mixed solution, B2O3 and carbon black are subjected to plasma ball milling, and vacuum high-temperature calcination is performed to obtain TiB2 powder; the powder is mixed with spherical FeSiAl powder, and plasma ball milling is performed to obtain powder A, which comprises flaky FeSiAl, fibrous and granular TiB2; powder A is mixed with A-151 coupling agent, KH-570 coupling agent and ethanol, and is dried to obtain powder B, which comprises activated FeSiAl and TiB2 powder; powder B is mixed with liquid phenyl silicone rubber, nano cerium oxide, nano titanium dioxide, hydrophobic fumed white carbon black, KH silicon azane curing agent and dibutyltin dilaurate to obtain electromagnetic sealing material with dielectric and magnetic double loss function.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic materials technology, specifically an electromagnetic sealing material with both dielectric and magnetic loss functions and its preparation method. Background Technology

[0002] As various electronic devices and components are developing towards structural-functional integration, the host structure is also exhibiting multi-functional integrated performance characteristics, such as structural load-bearing, shock resistance, electromagnetic shielding, and wave absorption. However, with the increasing integration of equipment and components, problems such as noise interference, insufficient structural matching, and poor reliability in typical environments still exist in the numerous openings, connections, and assembly areas within the host structure. Currently, the main solution to these problems is to use functional sealants with electromagnetic wave absorption capabilities for sealing and bonding between components. However, these sealants are generally composed of powder and adhesive, and their performance is entirely limited by the powder filler content, making it difficult to achieve a comprehensive improvement in strong wave absorption, high adhesion, and high elasticity. Therefore, developing a high-performance electromagnetic sealing material has become an effective means to solve the problems of inter-level structural reliability and electromagnetic compatibility in host systems.

[0003] Currently, the elastic electromagnetic sealing materials used in heterogeneous structural components mainly consist of rubber adhesives with various microwave absorbing agents and processing aids added. The shielding absorption, bonding strength, and mechanical properties of the sealant are coordinated by adjusting the ratio of the microwave absorbing agent to the adhesive. However, due to the high molecular weight and intrinsic viscosity of rubber-based adhesive matrices, there is an upper limit to the total amount of functional fillers that can be added. Increasing the amount of a single filler (dielectric loss type or magnetic loss type) will reduce the amount of another functional filler, weakening the microwave absorption performance of the sealing material. On the other hand, simply increasing the amount of filler will reduce the effective adhesive components, resulting in a significant decrease in the material's bonding strength and flexibility. This makes it difficult to achieve simultaneous improvement in multiple properties of the material, affecting the actual application effect of the final product in the host structure.

[0004] Iron-silicon-aluminum alloys (FeSiAl) possess high permeability, high saturation magnetization, and high Curie temperature; however, when used alone, they suffer from narrow absorption bandwidth, poor impedance matching, and a single loss mechanism. Borides from transition metals, such as titanium diboride (TiB2), exhibit high conductivity, excellent high-temperature oxidation resistance (up to 1000℃), low coefficient of thermal expansion, and superior mechanical properties, along with a positive temperature coefficient of resistance, making them excellent high-temperature conductive ceramic materials. However, while simply combining FeSiAl and TiB2 provides a dual loss mechanism, the excessively high proportion of FeSiAl added can negatively impact the overall performance of electromagnetic sealants. Summary of the Invention

[0005] The purpose of this invention is to prepare an electromagnetic sealing material with both dielectric and magnetic loss mechanisms, which makes the material highly elastic, strong adhesive, and resistant to high temperatures, and can meet the application requirements of high-performance electromagnetic sealing materials in the host structure of various electronic devices and components.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing an electromagnetic sealing material with both dielectric and magnetic loss functions includes the following steps:

[0008] 1) Dissolve NiCl2 powder in deionized water to obtain NiCl2 solution, dissolve K2CO3 powder in deionized water to obtain K2CO3 solution, then add TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to obtain mixed solution;

[0009] 2) The mixed solution, B2O3, and carbon black are added to a ball mill jar and subjected to plasma ball milling. The wet powder is dried and sieved to obtain the original powder.

[0010] 3) The original powder was loaded into a graphite crucible, and after being evacuated and purged with argon in a vacuum atmosphere furnace, TiB2 powder was prepared by calcination at high temperature.

[0011] 4) The TiB2 powder is mixed with spherical FeSiAl powder and then subjected to plasma ball milling to obtain powder A, which contains flake FeSiAl, fibrous and granular TiB2.

[0012] 5) The powder A is ultrasonically mixed with A-151 coupling agent, KH-570 coupling agent and ethanol, stirred and dried at room temperature to obtain powder B, which contains activated FeSiAl and TiB2 powder.

[0013] 6) The powder B is first stirred with liquid phenyl silicone rubber, nano cerium oxide, nano titanium dioxide and hydrophobic fumed silica, then KH silazane curing agent and dibutyltin dilaurate are added and stirred a second time until the mixture is uniform, so as to obtain an electromagnetic sealing material with both dielectric and magnetic loss functions.

[0014] Further, in steps 1) and 2), by mass fraction, there are 15-20 parts of NiCl2 powder, 15-20 parts of K2CO3 powder, 25-40 parts of TiO2 powder, 61-70 parts of B2O3, and 42-48 parts of carbon black.

[0015] Further, in step 1), the TiO2 powder D50 particle size is 5-8 μm, and the mixing time is 0.5-1.5 h.

[0016] Furthermore, in step 2), zirconium oxide grinding balls are used for the ion ball milling treatment. The grinding balls have diameters of 12 mm, 5 mm, and 3 mm, and the mass ratio of these three diameter grinding balls is 1:3:1, 2:5:3, or 1:5:4. Anhydrous ethanol is used as the grinding medium.

[0017] Further, in step 2), the conditions for the plasma ball milling treatment are: ball milling for 10 to 12 hours under an argon atmosphere, a discharge voltage of 12.5 to 15 kV, and a rotation speed of 280 to 350 rpm.

[0018] Furthermore, in step 3), the calcination temperature under high temperature is 1600–1700℃, and the duration is 150–210 min.

[0019] Further, in step 4), by mass fraction, there are 30-60 parts of TiB2 powder and 60-90 parts of spherical FeSiAl powder.

[0020] Furthermore, in step 4), the particle size of the spherical FeSiAl powder D50 is 5.8–8.4 μm.

[0021] Furthermore, in step 4), steel balls are used for the ion ball milling process. The diameter of the grinding balls is 12 mm, 5 mm and 3 mm. The mass ratio of these three diameter grinding balls is 1:3:1, 2:5:3 or 1:5:4. The ball-to-powder ratio (i.e. the mass ratio of the grinding media to the powder) is 80:1 to 100:1, and anhydrous ethanol is used as the grinding media.

[0022] Further, in step 4), the conditions for the plasma ball milling treatment are: ball milling for 10 to 14 hours under an argon atmosphere, a discharge voltage of 10 to 15 kV, and a rotation speed of 200 to 450 rpm.

[0023] Furthermore, in step 5), the concentrations of A-151 coupling agent and KH-570 coupling agent in ethanol are 1.5–2.5 wt%.

[0024] Further, in step 5), by mass fraction, powder A is 80-120 parts, coupling agent A-151 is 0.5-0.75 parts, and coupling agent KH-570 is 0.25-0.5 parts.

[0025] Further, in step 5), the stirring treatment is carried out for 0.5 to 2.5 hours.

[0026] Further, in step 6), by mass fraction, there are 60-95 parts of powder B, 28 parts of liquid phenyl silicone rubber, 1.4-2 parts of nano cerium oxide, 1.6-3 parts of nano titanium dioxide, 1.5 parts of hydrophobic fumed silica, 0.9 parts of KH silazane curing agent, and 0.3 parts of dibutyltin dilaurate.

[0027] Furthermore, in step 6), the phenyl content of the liquid phenyl silicone rubber is 3-5 wt%, and the viscosity of the liquid phenyl silicone rubber slurry is controlled at 1200-1800 cps.

[0028] Furthermore, in step 6), the first stirring is carried out for 0.5 to 1.5 hours, and the second stirring is carried out for 10 to 15 minutes.

[0029] An electromagnetic sealing material with both dielectric and magnetic loss functions is prepared by the above method.

[0030] The core mechanism of this invention is to balance and enhance the electromagnetic loss, adhesion, and other key properties of the material through co-ball milling and structuring of the powder, surface activation, composite filling, and optimization of the comprehensive formulation, thereby achieving the preparation of high-performance electromagnetic sealing materials. The specific mechanism is as follows:

[0031] 1. Co-ball milling structuring treatment: For FeSiAl: plasma co-ball milling transforms spherical FeSiAl powder into sheet-like structures. The sheet-like structure helps to enhance its magnetic loss, thereby improving its electromagnetic attenuation characteristics. For TiB2: plasma co-ball milling can further refine the granular TiB2 powder, increasing its dielectric loss and thus improving the material's electromagnetic attenuation characteristics.

[0032] 2. Surface activation treatment of coupling agent: Activation treatment of the surfaces of FeSiAl and TiB2 enhances the dispersibility and compatibility between the powder and liquid phenyl silicone rubber. This helps to improve the interfacial bonding strength, prevent powder agglomeration, and thus avoid electromagnetic parameter mismatch and local disorder.

[0033] 3. Composite Filling Strategy: By increasing the filling ratio of spherical FeSiAl and TiB2, the ratio of functional phase to binder phase was adjusted, balancing electromagnetic attenuation performance and adhesive properties. Nano-cerium oxide and nano-titanium dioxide, as nano-heat-resistant additives, not only improved the electromagnetic attenuation characteristics of the material but also enhanced its heat resistance.

[0034] 4. Optimization of the overall formulation: Refined TiB2 and plated FeSiAl improved the electromagnetic attenuation performance of the material, while increasing the filler ratio of the adhesive matrix helped the material achieve high adhesion and high elasticity. In addition, the addition of nano-cerium oxide and nano-titanium dioxide further improved the material's adhesion, heat resistance, and flexibility.

[0035] The advantages of the technical solution of the present invention are as follows:

[0036] 1. Enhanced electromagnetic attenuation characteristics: This invention solves the problem of single magnetic loss and low loss of spherical FeSiAl powder. By adopting plasma co-ball milling, FeSiAl powder is made into flakes and dielectric loss type TiB2 powder is introduced, which improves the electromagnetic attenuation characteristics of the sealing material over a wide bandwidth.

[0037] 2. Improved powder dispersibility and interfacial bonding strength: To address the issues of powder agglomeration and adhesion stability after ball milling, this invention uses a coupling agent to treat the powder surface, effectively improving the powder dispersibility in liquid phenyl silicone rubber and enhancing the interfacial bonding strength.

[0038] 3. Balancing Electromagnetic Attenuation and Adhesive Performance: This invention addresses the conflicting relationship between the functional and adhesive phases of electromagnetic sealing materials, achieving a balance between electromagnetic attenuation and adhesive performance. Furthermore, the addition of nano-cerium oxide and nano-titanium dioxide not only ensures overall performance but also improves the material's heat resistance.

[0039] 4. Dual loss mechanism optimization: In terms of dual functionality of dielectric loss and magnetic loss, this invention uses plasma co-ball milling technology to treat TiB2 and FeSiAl, which enhances the broadband attenuation performance of the electromagnetic sealing material.

[0040] 5. Surface modification enhances compatibility: This invention enhances the compatibility and interfacial bonding between TiB2 and FeSiAl by using a two-component coupling agent to modify the surface of the powder.

[0041] 6. Comprehensive Formula Optimization: In the formulation of electromagnetic sealing materials, this invention adjusts the proportion of various raw materials while ensuring strong attenuation, thereby achieving high adhesion, high elasticity, and better heat resistance and flexibility.

[0042] In summary, the method of this invention achieves high-performance electromagnetic attenuation, optimized powder dispersibility, enhanced interfacial bonding, and good heat resistance and elasticity in the preparation of electromagnetic sealing materials. These advantages make it very suitable for meeting the needs of various electronic devices and components. Attached Figure Description

[0043] Figure 1 A flowchart for preparing an electromagnetic sealing material with both dielectric and magnetic loss functions. Detailed Implementation

[0044] To make the various technical features, advantages, or effects of the present invention more apparent and understandable, a detailed description is provided below in conjunction with the accompanying drawings.

[0045] This invention specifically discloses a method for preparing an electromagnetic sealing material with both dielectric and magnetic loss functions, the flowchart of which is shown below. Figure 1As shown, it includes the following steps:

[0046] 1) Weigh 15-20g of NiCl2 powder and 15-20g of K2CO3 powder and dissolve them in deionized water to prepare NiCl2 solution and K2CO3 solution respectively. Then add 25-40g of TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to form a mixed solution.

[0047] 2) Add the mixed solution obtained in step 1), 61.3-69.5 g of B2O3 and 42-48 g of carbon black into a ball mill jar, use anhydrous ethanol as the ball milling medium and zirconium oxide as the grinding ball, and ball mill the mixture for 10-12 h under an argon atmosphere, a discharge voltage of 12.5-15 kV and a rotation speed of 280-350 rpm. After ball milling, dry at 65°C and pass through a 200-mesh sieve to obtain the original powder.

[0048] 3) Weigh 80-100g of the powder obtained in step 2), evacuate the vacuum and purge with argon gas, then calcine at a high temperature of 1600-1700℃ for 150-210 minutes, with an argon gas flow rate of 0.1dm. 3 / min, to obtain TiB2 powder;

[0049] 4) Weigh 30-60g of TiB2 powder obtained in step 3) and mix it with 60-90g of spherical FeSiAl powder. Ball mill the mixture for 10-14h under an argon atmosphere, a discharge voltage of 10-15kV and a rotation speed of 200-450rpm to obtain powder A, which contains flake FeSiAl, fibrous and granular TiB2.

[0050] 5) Weigh 80-120g of powder A obtained in step 4), 0.5-0.75g of A-151 coupling agent, 0.25-0.5g of KH-570 coupling agent and ethanol, mix ultrasonically, stir for 0.5-2.5h, and dry at room temperature to obtain powder B, which contains activated FeSiAl and TiB2 powders.

[0051] 6) Weigh 60-95g of powder B obtained in step 5), 28g of liquid phenyl silicone rubber, 1.4-2g of nano cerium oxide, 1.6-3g of nano titanium dioxide, and 1.5g of hydrophobic fumed silica. Stir for 0.5-1.5h, then add 0.9g of KH silazane curing agent and 0.3g of dibutyltin dilaurate. Stir for 10-15min to obtain an electromagnetic sealing material with both dielectric and magnetic loss functions.

[0052] Specific embodiments are given below, with a pair of examples as a control. The complex permittivity of the liquid phenyl silicone rubber used in the embodiments and the comparative examples is 3.0 to 0.02 J, and the complex permeability is 1.1 to 0.02 J.

[0053] Example 1

[0054] 1) Weigh 15g of NiCl2 powder and 15g of K2CO3 powder and dissolve them in deionized water to prepare NiCl2 solution and K2CO3 solution. Then add 25g of TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to form a mixed solution.

[0055] 2) Add the mixed solution, 61.3g B2O3 and 42g carbon black into a ball mill jar, and ball mill the mixture with anhydrous ethanol as the ball milling medium. Under an argon atmosphere, at a discharge voltage of 12.5kV and a rotation speed of 280rpm, the mixture is ball milled for 10h. After ball milling, the mixture is dried at 65℃ and passed through a 200-mesh sieve to obtain the original powder.

[0056] 3) Weigh 80g of the original powder, evacuate it under vacuum, and then calcine it at 1600℃ for 180min with an argon flow rate of 0.1dm. 3 / min, to obtain TiB2 powder;

[0057] 4) Weigh 60g of TiB2 powder and 90g of spherical FeSiAl powder and mix them together. Under an argon atmosphere, at a discharge voltage of 15kV and a rotation speed of 450rpm, ball mill them together for 14h to obtain powder A.

[0058] 5) Weigh 100g of ball-milled powder A (i.e., TiB2 powder and flake FeSiAl powder), 0.5g of A-151 coupling agent, 0.25g of KH-570 coupling agent and ethanol, mix them, stir for 2.5h, and dry at room temperature to obtain powder B.

[0059] 6) Weigh 72g of powder B (i.e., TiB2 powder and flake FeSiAl powder after coupling treatment), 28g of liquid phenyl silicone rubber, 2g of nano cerium oxide, 3g of nano titanium dioxide, and 1.5g of hydrophobic fumed silica. After stirring for 1.5h, add 0.9g of KH silazane curing agent and 0.3g of dibutyltin dilaurate. Stir for 15min to obtain electromagnetic sealing material.

[0060] Example 2

[0061] 1) Weigh 20g of NiCl2 powder and 20g of K2CO3 powder and dissolve them in deionized water to prepare NiCl2 solution and K2CO3 solution. Then add 40g of TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to form a mixed solution.

[0062] 2) Add the mixed solution, 69.5g B2O3 and 48g carbon black into a ball mill jar, and ball mill the mixture with anhydrous ethanol as the ball milling medium. Under an argon atmosphere, at a discharge voltage of 15kV and a rotation speed of 350rpm, the mixture is ball milled for 12h. After ball milling, the mixture is dried at 65℃ and passed through a 200-mesh sieve to obtain the original powder.

[0063] 3) Weigh 100g of the original powder, evacuate it under vacuum, and then calcine it at 1700℃ for 210min with an argon flow rate of 0.1dm. 3 / min, to obtain TiB2 powder;

[0064] 4) Weigh 30g of TiB2 powder and 60g of spherical FeSiAl powder and mix them together. Under an argon atmosphere, at a discharge voltage of 10kV and a rotation speed of 200rpm, ball mill them together for 12h to obtain powder A.

[0065] 5) Weigh 80g of ball-milled powder A (i.e., TiB2 powder and flake FeSiAl powder), 0.75g of A-151 coupling agent, 0.5g of KH-570 coupling agent and ethanol, mix them, stir for 0.5h, and dry at room temperature to obtain powder B.

[0066] 6) Weigh 60g of powder B (i.e., TiB2 powder and flake FeSiAl powder after coupling treatment), 28g of liquid phenyl silicone rubber, 1.4g of nano cerium oxide, 2.1g of nano titanium dioxide, and 1.5g of hydrophobic fumed silica. After stirring for 1.0h, add 0.9g of KH silazane curing agent and 0.3g of dibutyltin dilaurate. Stir for 13min to obtain electromagnetic sealing material.

[0067] Example 3

[0068] 1) Weigh 18g of NiCl2 powder and 18g of K2CO3 powder and dissolve them in deionized water to prepare NiCl2 solution and K2CO3 solution. Then add 37g of TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to form a mixed solution.

[0069] 2) Add the mixed solution, 63.8g B2O3 and 45g carbon black into a ball mill jar, and ball mill the mixture with anhydrous ethanol as the ball milling medium. Under an argon atmosphere, at a discharge voltage of 13.5kV and a rotation speed of 300rpm, the mixture is ball milled for 11h. After ball milling, the mixture is dried at 65℃ and passed through a 200-mesh sieve to obtain the original powder.

[0070] 3) Weigh 90g of the original powder, evacuate it under vacuum, and then calcine it at 1650℃ for 150min with an argon flow rate of 0.1dm. 3 / min, to obtain TiB2 powder;

[0071] 4) Weigh 50g of TiB2 powder and 80g of spherical FeSiAl powder and mix them together. Under an argon atmosphere, at a discharge voltage of 12.5kV and a rotation speed of 350rpm, ball mill them together for 10h to obtain powder A.

[0072] 5) Weigh 120g of ball-milled powder A (i.e., TiB2 powder and flake FeSiAl powder), 0.7g of A-151 coupling agent, 0.3g of KH-570 coupling agent and ethanol, mix them, stir for 1.0h, and dry at room temperature to obtain powder B;

[0073] 6) Weigh 95g of powder B (i.e., TiB2 powder and flake FeSiAl powder after coupling treatment), 28g of liquid phenyl silicone rubber, 2.0g of nano cerium oxide, 1.6g of nano titanium dioxide, and 1.5g of hydrophobic fumed silica. After stirring for 0.5h, add 0.9g of KH silazane curing agent and 0.3g of dibutyltin dilaurate. Stir for 10min to obtain electromagnetic sealing material.

[0074] Comparative Example 1

[0075] 1) Weigh 15g of NiCl2 powder and 15g of K2CO3 powder and dissolve them in deionized water to prepare NiCl2 solution and K2CO3 solution. Then add 25g of TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to form a mixed solution.

[0076] 2) Add the mixed solution, 61.3g B2O3 and 42g carbon black into a ball mill jar, and ball mill the mixture with anhydrous ethanol as the ball milling medium. Under an argon atmosphere, at a discharge voltage of 12.5kV and a rotation speed of 280rpm, the mixture is ball milled for 10h. After ball milling, the mixture is dried at 65℃ and passed through a 200-mesh sieve to obtain the original powder.

[0077] 3) Weigh 80g of the original powder, evacuate it under vacuum, and then calcine it at 1600℃ for 180min with an argon flow rate of 0.1dm. 3 / min, to obtain TiB2 powder;

[0078] 4) Weigh 36g TiB2 powder, 36g spherical FeSiAl powder, 28g liquid phenyl silicone rubber, and 1.5g hydrophobic fumed silica. After stirring for 0.5h, add 0.9g KH silazane curing agent and 0.3g dibutyltin dilaurate. Stir for 10min to obtain electromagnetic sealing material.

[0079] The test results of electromagnetic parameters, attenuation coefficient, bonding performance, thermal weight loss, and elongation at break in Examples 1-3 and Comparative Example 1 are listed in Table 1. As can be seen from the test data in Table 1, because steps 4) and 5) were omitted in Comparative Example 1, the powder was not ball-milled, resulting in no enhancement of electromagnetic properties; and because no interface treatment was performed, the bonding strength and toughness were relatively weak.

[0080] Table 1. Test results of electromagnetic properties, adhesive properties, flexibility, and heat resistance of electromagnetic sealing materials.

[0081]

[0082] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should be covered within the protection scope of the present invention, which is defined by the claims.

Claims

1. A method for preparing an electromagnetic sealing material with both dielectric and magnetic loss functions, characterized in that, Includes the following steps: 1) Dissolve NiCl2 powder in deionized water to obtain NiCl2 solution, dissolve K2CO3 powder in deionized water to obtain K2CO3 solution, then add TiO2 powder and K2CO3 solution to NiCl2 solution and mix thoroughly to obtain mixed solution; 2) The mixed solution, B2O3, and carbon black are added to a ball mill jar and subjected to plasma ball milling. The wet powder is dried and sieved to obtain the original powder. 3) The original powder was loaded into a graphite crucible, and after being evacuated and purged with argon in a vacuum atmosphere furnace, TiB2 powder was prepared by calcination at high temperature. 4) The TiB2 powder is mixed with spherical FeSiAl powder and subjected to plasma ball milling to obtain powder A, which contains flake FeSiAl, fibrous and granular TiB2. 5) The powder A is ultrasonically mixed with A-151 coupling agent, KH-570 coupling agent and ethanol, stirred and dried at room temperature to obtain powder B, which contains activated FeSiAl and TiB2 powder. 6) The powder B is first stirred with liquid phenyl silicone rubber, nano cerium oxide, nano titanium dioxide and hydrophobic fumed silica, then KH silazane curing agent and dibutyltin dilaurate are added and stirred a second time until the mixture is uniform, so as to obtain an electromagnetic sealing material with both dielectric and magnetic loss functions.

2. The method as described in claim 1, characterized in that, In steps 1) and 2), by mass fraction, there are 15-20 parts of NiCl2 powder, 15-20 parts of K2CO3 powder, 25-40 parts of TiO2 powder, 61-70 parts of B2O3, and 42-48 parts of carbon black; the D50 particle size of TiO2 powder is 5-8 μm, and the mixing time is 0.5-1.5 h.

3. The method as described in claim 1, characterized in that, In step 2), zirconia grinding balls were used for plasma ball milling, and anhydrous ethanol was used as the grinding medium. The conditions for plasma ball milling were: ball milling for 10 to 12 hours under an argon atmosphere, a discharge voltage of 12.5 to 15 kV, and a rotation speed of 280 to 350 rpm.

4. The method as described in claim 1, characterized in that, In step 3), the calcination temperature is 1600~1700℃ and the duration is 150~210min under high temperature conditions.

5. The method as described in claim 1, characterized in that, In step 4), by mass fraction, there are 30-60 parts of TiB2 powder and 60-90 parts of spherical FeSiAl powder, with a D50 particle size of 5.8-8.4 μm for the spherical FeSiAl powder.

6. The method as described in claim 1, characterized in that, In step 4), steel balls are used for plasma ball milling with a ball-to-material ratio of 80:1 to 100:1, and anhydrous ethanol is used as the ball milling medium. The conditions for plasma ball milling are: ball milling for 10 to 14 hours under an argon atmosphere, a discharge voltage of 10 to 15 kV, and a rotation speed of 200 to 450 rpm.

7. The method as described in claim 1, characterized in that, In step 5), by mass fraction, powder A is 80-120 parts, A-151 coupling agent is 0.5-0.75 parts, and KH-570 coupling agent is 0.25-0.5 parts; The concentrations of A-151 coupling agent and KH-570 coupling agent in ethanol are 1.5~2.5wt%; the mixture is stirred for 0.5~2.5h.

8. The method as described in claim 1, characterized in that, In step 6), by mass fraction, there are 60-95 parts of powder B, 28 parts of liquid phenyl silicone rubber, 1.4-2 parts of nano cerium oxide, 1.6-3 parts of nano titanium dioxide, 1.5 parts of hydrophobic fumed silica, 0.9 parts of KH silazane curing agent, and 0.3 parts of dibutyltin dilaurate; the phenyl content of the liquid phenyl silicone rubber is 3-5 wt%, and the viscosity of the liquid phenyl silicone rubber slurry is controlled at 1200-1800 cps.

9. The method as described in claim 1, characterized in that, In step 6), the first stirring lasts 0.5 to 1.5 hours, and the second stirring lasts 10 to 15 minutes.

10. An electromagnetic sealing material with both dielectric and magnetic loss functions, characterized in that, It is prepared by the method described in any one of claims 1 to 9.

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