الفهرس | Only 14 pages are availabe for public view |
Abstract This study provides a simple and effective way to greatly decrease the emissivity of the coating, which may promote the application of low infrared emissivity coatings. Low infrared emissivity coatings are synthesized by using flake (copper, Aluminum) particles and acrylic resin as pigments and binders respectively. The powder coating is categorized into two groups. In the first group, Ball milling is utilized via two different approaches. In the first approach, the ratio between Cu and balls during the preparation period is constant to achieve the nano-flake size. While the second approach is based on the change, of this ratio to reach flake and high flake micro shape Cu powder. The thermal signature is highly affected by variation in Cu content (30%, 40%, 50%, and 60%) at different temperature degrees (50ºC, 70ºC, 90ºC). The results indicate that the optimized Cu particles are several flaky micron-sized and exhibit the minimum coating emissivity of 0.456 and 0.610 at 3-5 & 8-12 µm respectively. Second group Ball milling is applied to prepare Al nano flake. The obtained data indicate that the perfect percentage for the filler (Al) concentrations are ranging from 35 wt. % to 40 wt. %. The Al fine flake powder particle gives the lowest infrared emissivity of 0.385 µm and 0.412 µm at 3-5 µm & 8-12 µm, respectively. The impact parameters that affect the emissivity of the coating such as the content of powder, coating thickness, spin coating, particle size, and ball milling time are systematically studied, in the first and second groups. |