Production of Radar Absorbing Composite Materials Using Carbon Nanotubes

Abstract

In order to increase the combat effectiveness of any platform or long-range munition in use today, it is necessary to reduce its visibility to radar. In this sense, important development in radar systems started after World War II. The interaction between electromagnetic waves at radar frequencies and different materials was investigated, electromagnetic radiation absorption mechanism; it has been observed that the materials consist of electrical, magnetic and dielectric properties. In line with this information, radar absorbing material design studies gained momentum. A significant development in radar systems of stealth technology made radar absorbing materials RAMs gaining a long-standing interest as a possible way to disguise aircrafts and submarines from radar systems. Carbon nanotubes and magnetic materials such as Fe, Ni, and Co have attracted researchers' significant interest as radar absorbers. In recent years, numerous studies have been made using carbon nanotubes due to their unique properties. However, few studies have considered the influence of both particle size and weight fraction. This work aims to produce material with unique properties such as solid absorption, low weight/thickness, and cost-effective, minimizing the reflection of electromagnetic waves using a polymeric composite structure reinforced with carbon nanotubes. Carbon nanotubes with different particles sizes of 8 nm,18 nm, and 78 nm were mixed with polyester in different weight fractions of 1%, 2%, and 3%. Three different composites structures were prepared in single, double, and three layers. Composites were characterized using XRD, SEM, and network analyzer in the frequency range of 8 to12 GHz. According to the results, it was observed that radar absorption increased with the increase in grain size, but the number of layers had no linear effect on the results. Network analyzer results show that the minimum reflection loss value at 9.9 GHz with a thickness of 1.5 mm is −33.1 dB, and the effective bandwidth is 9.9 GHz. Multi-layer carbon nanotubes composites might be a potential radar absorber because of their flexibility to adjust their absorption band to fit different applications in different frequency bands by modifying their particle sizes and weight.