Preparation and Damage Behavior of High-performance Radar Absorbing Coating

A microwave absorbing coating for radar with excellent performance was prepared by using carbonyl iron powder as absorbent and polyurethane as binder. Then a vector network analyzer, the electromagnetic simulation software of Ansoft HFSS and a bow frame test system were used to study the electromagnetic properties, damage model and microwave absorbing performance of the coating. The results indicate that the coating has excellent absorbing performance under the condition of vertical incidence. When the coating thickness is 0.8 mm, its reflection loss peak reaches −8 dB in the range of 7.2~12.8 GHz. It also has excellent absorbing performance under the condition of oblique incidence. When the thickness of the coating is 0.8mm and the incidence angle is 60°, its reflection loss peaks reach −10 dB in the range of 5.5~18 GHz. Compared with such failure modes as layered debonding, the effect of damage shedding on the absorbing performance is more obvious. With the increase of damage shedding area, the absorption intensity of the coating (especially X band) decreases obviously, and the minimum reflection loss peak moves to high frequency. The research on the damage behavior of the high-performance microwave absorbing coating, such as shedding and delamination, is of great practical and military significance for the maintenance of microwave absorbing coatings and the establishment of failure evaluation criteria.