Study of resistance performance of Al(2)O(3)–ZnO–Y(2)O(3) thermal control coating exposed to vacuum-ultraviolet irradiation

As deep space exploration moves farther and farther away, thermal control coating of the in-orbit spacecraft will suffer a serious vacuum-ultraviolet radiation environment, which seriously threatens the reliability of the spacecraft in orbit. Therefore, it is important to improve the vacuum-ultraviolet resistance performance of the thermal control coating. In this work, the inorganic Al(2)O(3)–ZnO–Y(2)O(3) thermal control coating was in situ fabricated on a 6061 aluminum alloy surface by PEO technology, and its vacuum-ultraviolet resistance performance was investigated. The results show that the Al(2)O(3)–ZnO–Y(2)O(3) thermal control coating has a good resistance performance to vacuum-ultraviolet radiation, which is mainly because the large extinction coefficients of the ZnO and Y(2)O(3) materials in the ultraviolet band are conducive to improving the ultraviolet resistance performance. Furthermore, the life prediction model of the Al(2)O(3)–ZnO–Y(2)O(3) thermal control coating shows that its Δα(s) value first slightly increases and then tends to be stable with the increase of ultraviolet irradiation time from 0 ESH to 25 000 ESH, and the maximum variation of Δα(s) is about 0.0536. This work provides a material basis and technical support for the thermal control system of spacecraft with long life and high reliability.