Photostability of Reflecting Coatings Based on the ZrO_2 Powders Doped with SrSiO_3

摘要

The effect of doping with SrSiO_3 in the range of 1 to 17.5 mass % on the reflectance spectra and integral solar absorptance factor of ZrO_2 powders and their stability at ultraviolet irradiation were investigated. It was founded that the powders doped with 1 mass % of SrSiO_3 possess the greater photostability. Two types of thermal control coatings were fabricated. The first one was based on the undoped ZrO_2 pigment and the second one was based on the ZrO_2 pigment doped by 1 mass % of SrSiO_3. The comparative investigations of their optical properties and photostability show that the coating based on doped pigment is more effective than the coating with undoped pigment. The prediction of optical properties degradation for these coatings was made for a lifetime of 10 years according to obtained data. This prediction may be used for altitudes of 600-800 km, for which the main damaging factor is ultraviolet radiation of the sun.