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Multilayer type electromagnetic wave absorber and manufacturing method thereof

An absorber, electromagnetic wave technology, applied in the direction of magnetic objects, chemical instruments and methods, circuits, etc., can solve the problems of limited wave absorption performance, poor flexibility, unsuitable for high hardness, etc.

Active Publication Date: 2010-12-01
ADVANCED TECHNOLOGY & MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The manufacture of this type of absorber requires the soft magnetic metal used as the absorber to have good plastic deformation ability, however, this is not suitable for materials with high hardness and plastic deformation ability such as amorphous alloys
In addition, in this absorber, since the filling rate of the absorber is as high as 75%, the reflection effect on electromagnetic waves is significant, resulting in limited absorbing performance.
[0009] To sum up, most of the absorbers in the prior art are made of powdered absorber powder, which has limited application due to its poor flexibility
In addition, because the absorber in the prior art is formed by a single absorber, it often has a narrow absorbing frequency range

Method used

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  • Multilayer type electromagnetic wave absorber and manufacturing method thereof
  • Multilayer type electromagnetic wave absorber and manufacturing method thereof
  • Multilayer type electromagnetic wave absorber and manufacturing method thereof

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Experimental program
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Effect test

preparation example Construction

[0052] Preparation of multi-layer absorber

[0053] Then the glass-coated silk absorber is used as the surface layer of the multi-layer absorber, and the flat amorphous alloy powder absorber is used as the middle layer, and the glass-coated silk absorber and the flat amorphous alloy powder absorber are obtained by lamination. Multi-layer absorber composed of crystal alloy powder absorber.

[0054] When the electromagnetic wave is incident on the multi-layer absorber, the surface layer absorbs part of the electromagnetic wave first, and because of its low reflection coefficient, it can continue to transmit most of the unabsorbed electromagnetic wave to the middle layer, thereby continuing to produce the absorbing effect. When the electromagnetic wave is reflected from the surface of the intermediate layer, it passes through the glass-coated silk layer again, so that further electromagnetic wave absorption occurs. In this way, the incident electromagnetic waves are mostly absor...

Embodiment 1

[0060] Preparation of Fe by Water Atomization 74 Cr 2 Mo 2 sn 2 P 8 Si 6 B 4 C 2 Soft magnetic powder, whose X-ray diffraction results show that it is an amorphous structure, such as figure 1 shown. Among them, the process of preparing amorphous alloy powder by water atomization method is as follows: use 5 atmospheres of high-pressure water to crush the metal droplets and quickly cool them, and dry the atomized products in a vacuum oven at 180 ° C for 8 hours , and sieve the dried product to obtain 200-325 mesh near-spherical amorphous alloy powder.

[0061] The obtained nearly spherical amorphous alloy powder was subjected to wet ball milling in a planetary ball mill with a ball-to-material ratio of 4:1 and a rotational speed of 400 rpm, adding absolute ethanol as a dispersion medium. After ball milling for 12 h, the nearly spherical amorphous powder was flattened into a flat powder with an average thickness of 1 μm and an average diameter of 50 μm. Subsequently, th...

Embodiment 2

[0074] The flat amorphous alloy powder of this embodiment adopts iron-based amorphous alloys of different compositions, and is prepared into powder by the same atomization method as in Embodiment 1. Alloy compositions are Fe 72 Cr 1 Mo 1 sn 2 P 15 Si 1 B 7.5 C 0.5 , Fe 72 Cr 5 Mo 3 sn 2 P 3 Si 2 B 12 C 1 , Fe 72 Cr 1 Mo 1 sn 3 P 8 Si 8 B 1 C 6 , Fe 73 Cr 2 Nb 5 sn 2 P 2 Si 8 B 6 C 2 , Fe 74 Cr 2 Mo 2 sn 2 P 10 Si 4 B 4 C 2 , Fe 76 Cr 1 Mo 1 Al 4 P 8 Si 8 B 1 C 1 , Fe 78 Cr 1 Mo 1 sn 2 P 8 Si 8 B 1 C 1 . The atomized powder was wet-milled in a planetary ball mill with a ball-to-material ratio of 5:1, a rotational speed of 400 rpm, and a milling time of 14 hours. Subsequently, the powder is heat-treated in a vacuum heat treatment, and the process parameter is 420° C. for 1 hour.

[0075] The thermoplastic polyurethane was dissolved by nitrogen methyl formamide as an organic solvent to prepare a coating with a thermoplastic ...

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Abstract

The invention provides a multilayer type electromagnetic wave absorber which comprises (a) two surface layers and (b) an intermediate layer, wherein the two surface layers mainly comprise a glass-coated yarn wave absorbent and a polymer substrate; the intermediate layer is positioned between the surface layers, and the intermediate layer mainly comprises a flat type amorphous alloy powder wave absorbent and a polymer substrate. The invention also provides a method for preparing the multilayer type electromagnetic wave absorber.

Description

technical field [0001] The present invention relates to a multi-layer electromagnetic wave absorber and a manufacturing method thereof, in particular, to a multi-layer electromagnetic wave absorber having electromagnetic wave absorption characteristics in the 10MHz-8.5GHz frequency band and a manufacturing method thereof. Background technique [0002] The high frequency, integration, and miniaturization of electronic equipment and devices have aggravated the problem of electromagnetic compatibility. Electromagnetic compatibility issues not only affect the safety and reliability of electronic equipment, but also endanger human health and ecosystems. [0003] The problem of electromagnetic compatibility has attracted the attention of industrialized countries in the world, especially since the 1970s, a lot of theoretical research and experimental work have been carried out. Furthermore, it proposes a new subject of how to make electronic equipment or systems operate normally i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H05K9/00H01F1/14H01F10/00H01F10/13C09K3/00B32B27/04
Inventor 李德仁卢志超刘开煌刘天成张亮陈征张宏浩张俊峰周少雄
Owner ADVANCED TECHNOLOGY & MATERIALS CO LTD
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