Destructive effects of environmental factors on the properties of radio reflective coating for antenna reflectors from the polymeric composite materials

In this case study the influence of destructive environmental factors such as humidity, temperature and UV radiation on the adhesive strength, microstructure and properties of coatings of radio-reflectivity antenna reflectors made of polymeric composite materials (PCM) has been analyzed. For the test samples we used carbon and fiberglass units with various reinforcement schemes. Radio-reflective coated surfaces are multi-layer composition, which has been applied by vacuum metallization method via magnetron usage. For the coating we’ve designed the layout drawing for the vacuum chamber, which enables a multi-layer coating process to be applied to large surface area of a product per load. This helps to improve the quality and performance of the coating process. Sputtering of one- and two-layer coatings on samples of carbon fiber and fiberglass has been made for the research purposes. When the coating process was completed, the samples were tested in climatic chamber. Studies of adhesion strength of coated samples before and after environmental tests have shown that the double-layered coated samples have greater cohesive strength than the monolayer. In single-layer coating adhesion is 1-2score at the bilayer - 0-1 score in ISO 2490. A noticeable influence of destructive factors on the adhesion strength is not revealed. Morphology and elemental analysis of the coating showed that the coating is distributed uniformly over the surface and noticeable changes after the test in a climatic chamber have been detected. Therefore, it could be concluded that the coatings deposited according to the proposed technology are resistant to the environment and can be used as coatings radio-reflectivity terrestrial reflector antenna.