The study of nano-dispersed graphite particles size and shape effect on electrical conductance and thermal resistance of carbonaceous coating

Аuthors

Prokof'ev M. V.^1*, Zhuravlev S. Y.^2**

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Scientific-production enterprise «Radiostrim», 4, Volokolamskoe shosse, Moscow, 125080, Russia

*e-mail: mikepro1953@rambler.ru
**e-mail: osan193@yandex.ru

Abstract

This work is devoted to the study of activated graphite structural characteristics and coatings on mineral fibers. It considers metallized coatings obtained by fabric vacuum spraying-up as an alternative to carbon coatings, and examines their properties, advantages and disadvantages.

By the time variation of the preliminary grinding, temperature and oxidation time the optimal conditions of chemical activation of graphite powders and particles with high particle diameter to thickness ratio were determined. Physical characteristics and thermal resistance of coatings on basalt and glass fibers were determined using various techniques of colloid graphite particles aqueous and alcohol dispersions current-conducting material coatings. Basalt fibers over glass ones substantial advantages, such as adhesion reduction due to acid nature of graphite activation, were revealed herewith.

By X-ray structure analysis and laser diffraction technique, we determined the original graphite pastes characteristics and found that graphite particles sizes and anisotropy parameters had decisive impact on the possibility of thermal shockproof radar absorbent materials formation. The X-ray structure analysis data allows make the main conclusion confirming the well-known fact that in the process of graphite powder high temperature activation the structural compression of a material and partial burnout of amorphous component occurs. According to coatings microstructure study by scanning electronic microscopy we can conclude that the films are formed by carbon particles agglomeration (flaking plates).

The paper considers various types of chemically activated graphite, which have vital structural and morphological differences. They can be formalized by the relationship of a flat particle diameter to its thickness. The possibility of obtaining thermal shockproof coating by impaction of particles with high anisotropy, i. e. planar size to thickness ratio was revealed.

The volumetric radar absorbent carbon materials of a composite fiber texture studied in the paper, which are either thermal shockproof or stable to high power electromagnetic emission, can be implemented for protection and electromagnetic compatibility provision of airspace electronic equipment. Radar absorbent carbon materials are stable under conditions of vacuum and radioactive impacts.

Keywords:

chemically activated graphite, shockproof coatings on mineral fibers

References

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