An organic-inorganic composite coated metal wave-absorbing filler and its preparation method

Abstract

The invention belongs to the technical field of electromagnetic absorbers, in particular to an organic-inorganic composite coated metal wave-absorbing filler and a preparation method thereof. The preparation method of the present invention is to utilize the sol-gel method, take the surface-activated micron-sized flaky carbonyl iron powder as the core, ammonia water as the catalyst, and pass tetraethoxysilane (TEOS) and perfluorooctyltriethoxysilane The hydrolysis and co-condensation of (PC 9757) form a layer of nano-scale organic-inorganic hybrid coating layer on the surface of the powder. The Si‑O‑Si bonds and perfluorooctyl chains in the cladding interweave into a network structure in three dimensions. The hybrid layer is uniform and dense, and has good physical barrier effect. After coating, the heat resistance, electrochemical corrosion resistance, acid resistance and hydrophobicity of the coated powder are significantly improved, and it also has good magnetic properties. The invention provides a basis for the application and development of the high-performance flaky modified carbonyl iron powder.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic absorbers, and relates to a magnetic metal wave-absorbing filler, in particular to an organic-inorganic composite coated metal wave-absorbing filler and a preparation method thereof, which is a development and application of high-performance modified flake carbonyl iron powder. Applications provide the basis. Background technique [0002] Modern stealth technology refers to the technology that effectively suppresses the characteristic signal of a specific target in a certain detection environment, making it difficult to be accurately detected in a certain spectral frequency range. With the development of advanced detection technology, the stealth capabilities of aircraft, missiles, ships, armor and other large military equipment need to be improved urgently. In terms of anti-radar, stealth materials usually refer to the use of coatings that can absorb radar waves, so that most of the dete...

AI Technical Summary

Problems solved by technology

In previous studies, many scholars used tetraethoxysilane (TEOS) as a single silicon source, and coated SiO on the surface of carbonyl iron powder particles. 2 , to obtain uniform and dense SiO 2 layer, but purely inorganic SiO 2 The thickness of the layer is often 50-80nm to achieve good corrosion resistance, and the thicker modified layer will greatly reduce the magnetic properties, and the inorganic SiO 2 The hydrophobicity of the coating layer is poor, and the stability in acidic solution is not good

[0007] In the current research, the heat resistance of the pure organic modification layer such as resin, rubber or conductive polymer is poor, and the thermal stability of carbonyl iron powder is not significantly improved, and the modification process conditions are relatively harsh. The application of powder modification is greatly restricted

In terms of organic-inorganic hybrid coating modification, tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) or other organic substances are commonly used for hybrid coating of iron powder, but the common organic The influence of the inorganic hybrid coating modification layer on the magnetic properties of carbonyl iron powder is generally more obvious

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