A microwave frequency band electromagnetic wave absorber and preparation method thereof

Abstract

The invention belongs to the technical field of electronic materials, and particularly relates to a microwave frequency band (0.5GHz-18GHz) electromagnetic wave absorbent and a preparing method thereof. The absorbent is made of pure ferrum, pure aluminum, pure chromium and polycrystalline silicon. By mass, larger than or equal to 65% but smaller than or equal to 78% of pure Fe, larger than or equal to 5% but smaller than or equal to 12% of pure aluminum, larger than or equal to 2% but smaller than or equal to 12% of pure chromium and larger than or equal to 8% but smaller than or equal to 16% of polycrystalline silicon are molten, and nanocrystalline / amorphous biphase particles with the grain size of 10-50 nm are formed. According to the prepared absorbent, when an electromagnetic absorption material is prepared with the 30-40% of absorbent and paraffin as an auxiliary material, on the frequency band of 0.5 GHz-18 GHz, magnetic conductivity [mu]'max is larger than or equal to 7 but smaller than or equal to 8, and [mu]''max is larger than or equal to 4 but smaller than or equal to 5. The technology is simple, operability is high, and cost is low. The absorbent is suitable for batched production.

Description

technical field [0001] The invention belongs to the technical field of electronic materials, and in particular relates to an electromagnetic wave absorbing agent in a microwave frequency band (0.5GHz-18GHz) and a preparation technology thereof. Background technique [0002] As one of the keys to stealth technology, microwave-absorbing materials can not only improve the survivability and effective strike capability of weapons, but also have been widely used in civilian fields such as microwave electronic devices, electromagnetic radiation protection, and secure communications. [0003] According to the different loss mechanisms, absorbing materials are divided into three types: resistive type, electric loss type and magnetic loss type. Electromagnetic wave absorbing materials use magnetic loss or electric loss absorbers as the main material, and are equipped with certain adhesives and various additives. The absorber mainly determines the quality of the absorbing material and...

AI Technical Summary

Problems solved by technology

But due to Snoek relationship limit of , although the initial permeability of conventional materials μ i higher, but due to the cut-off frequency f o It is limited to low frequency, so that in the microwave field, the magnetic permeability of the material is very low, and there is little potential for further improvement, and there is a low frequency "bottleneck"

At the same time, material preparation mainly relies on sintering and grinding technology, the process is relatively simple, and the stability is not good

At present, when the volume content of the absorbent is 35% and the adhesive is paraffin, the magnetic permeability μ' max Probably around 5, μ″ max It is about 3.5, which cannot meet the needs of modern technology and needs to be further improved.

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