Preparation, characterization and infrared emissivity properties of polymer derived coating formed on 304 steel

High infrared emissivity coatings were prepared on 304 steel by pyrolyzing reactions with poly(hydridomethylsiloxane) (PHMS) and Al/HW powders. The microstructure, phase and chemical composition of the coatings were determined by SEM, XRD and EDS techniques. The infrared emissive properties at wavelength 3–20 μm of the coatings pyrolyzed at 600 and 800 °C on the steels were investigated. It was found that the 800 °C pyrolyzed coating exhibited a slightly higher infrared emissivity value than that of the 600 °C pyrolyzed coating, which was attributed to the complete conversion of Al to Al2O3 and pyrolysis of PHMS into SiO2, as well as the enhancement of photon emission by HW. Comparatively, the uncoated steel indicated a much lower infrared emissivity value about 0.2 in 8–14 μm.