Wave-absorbing material and preparation method thereof

A technology of wave absorbing material and carbonyl iron powder, applied in the field of wave absorbing material, can solve the problems of limiting the practical application range of carbonyl iron powder, large eddy current effect, increasing the density of wave absorbing material, etc., and achieving electromagnetic parameters and wave absorbing performance. , suppress the skin effect, improve the effect of impedance matching

Inactive Publication Date: 2015-04-22
HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

like figure 1 As shown, most of the carbonyl iron powders in industrial applications are spherical particles with a peculiar "onion head" microstructure (this form of carbonyl iron powder can be called conventional carbonyl iron powder); it not only has a high It has high magnetic permeability and good saturation magnetization, and it also has the characteristics of low price and high industrial production efficiency; however, because carbonyl iron powder has the characteristics of soft magnetic materials, it also has high density, easy oxidation, high dielectric constant, eddy current The disadvantages such as large effect, so this greatly limits the practical application range of carbonyl iron powder
[0004] In the prior art, it is usually possible to reduce or suppress the eddy current effect by reducing the thickness of the material. However, due to the high dielectric constant of carbonyl iron powder, reducing the thickness of carbonyl iron powder will cause impedance mismatch problems. This will still reduce the absorbing performance of carbonyl iron powder
In addition, the content of wave absorbing agent in the existing wave absorbing material is relatively high, usually greater than 60wt%, sometimes even exceeding 80wt%, which not only increases the density of the wave absorbing material, but also increases the production cost

Method used

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  • Wave-absorbing material and preparation method thereof
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  • Wave-absorbing material and preparation method thereof

Examples

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preparation example Construction

[0034] (1) A preparation method of a wave-absorbing material

[0035] Such as figure 2 Shown, a kind of preparation method of absorbing material can specifically comprise the following steps:

[0036] Step A: put the carbonyl iron powder in a conventional form into a ball mill for ball milling, so as to obtain flake carbonyl iron powder.

[0037] Specifically, this step A may include the following steps:

[0038] Step A1. Prepare a mixture of conventional carbonyl iron powder and absolute ethanol at a weight ratio of 1:2 to 1:3; among them, conventional carbonyl iron powder with a particle size of 0.5 to 8 μm is best selected. Iron powder, its microscopic appearance can be as follows figure 1 shown.

[0039] Step A2, put the prepared mixture into a ball mill, the weight ratio of the ball to material is 5:1-10:1, the speed of the ball mill is 400-500rpm, and the flake carbonyl iron powder is obtained after ball milling for 4-8 hours; , the balls in the ball mill are prefe...

Embodiment 1

[0052] A method for preparing a wave-absorbing material may specifically include the following steps:

[0053] Step 1, mix 30g such as figure 1 The carbonyl iron powder in the conventional form shown (the particle size of the carbonyl iron powder in the conventional form is between 0.5 and 8 μm) is mixed with 90ml of absolute ethanol, and put into the spherical tank of the planetary ball mill; Put corundum balls of different diameters, the weight ratio of balls to materials is 10:1, and mill at a speed of 450rpm for 6 hours to obtain flaky carbonyl iron powder with a thickness of about 100nm.

[0054] Step 2, take 20g of the flaky carbonyl iron powder obtained in the above step 1, and put 170ml of deionized water into the reactor, then add solid sodium hydroxide to the reactor until the pH value in the reactor is equal to 12, thereby A reaction system with a pH equal to 12 was formed.

[0055] Step 3. Allow the reaction system formed in step 2 to react at 170° C. for 6 hours...

Embodiment 2

[0058] A preparation method of a wave-absorbing material, the difference from Example 1 is that what is formed in step 2 is a reaction system with a pH value equal to 13 (the reaction system can be controlled by adjusting the amount of sodium hydroxide solid added). pH value); finally, composite wave-absorbing materials of flaky carbonyl iron powder and ferroferric oxide can be obtained.

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Abstract

The invention discloses a wave-absorbing material and a preparation method thereof. The preparation method comprises the following steps of putting carbonyl iron powder in a routine form into a ball mill, carrying out ball milling to obtain sheet-shaped carbonyl iron powder, adding the sheet-shaped carbonyl iron powder into a reactor, adding deionized water and sodium hydroxide solids into the reactor to obtain a reaction system having a pH value of 11-14, carrying out a reaction of the reaction system at a temperature of 150-190 DEG C for 4-8h, carrying out cooling to a room temperature, collecting the cooled reaction products by a magnet, and carrying out drying to obtain the sheet-shaped carbonyl iron powder-ferriferrous oxide composite wave-absorbing material. The preparation method improves impedance matching, keeps or improves a magnetic loss capability and inhibits the skin effect so that the wave-absorbing material has good wave-absorbing performances in a wide frequency range.

Description

technical field [0001] The invention relates to the field of wave-absorbing materials, in particular to a method for preparing a wave-absorbing material and the prepared wave-absorbing material. Background technique [0002] In recent years, absorbing materials have played an important role in military "stealth" technology, improving electromagnetic compatibility performance, preventing electromagnetic radiation, and preventing information leakage. For a wave-absorbing material, material quality, impedance matching, magnetic loss capability, and frequency range that can absorb electromagnetic waves are all key factors to measure the performance of the wave-absorbing material. [0003] At present, Carbonyl Iron Powder (CIP) is widely used as an important wave absorbing agent in the field of wave absorbing materials. Such as figure 1 As shown, most of the carbonyl iron powders in industrial applications are spherical particles with a peculiar "onion head" microstructure (thi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K3/00
Inventor 刘强春戴建明邹键张敏孙玉平
Owner HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
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