Effects of atomic oxygen exposure on the tribological performance of ZrO2-reinforced polyimide nanocomposites for low earth orbit space applications.

The effects of atomic oxygen exposure on pure polyimide and nano-ZrO 2 reinforced polyimide composites were investigated in a ground-based simulation facility. The experimental results indicated that the surface structure of both pure polyimide and ZrO 2 /polyimide composites were destroyed by atomic oxygen attack, but the addition of nano-ZrO 2 particles in polyimide could obviously decrease the mass loss, which showed that ZrO 2 could enhance the atomic oxygen resistance. The results of ZrO 2 /polyimide composites before and after atomic oxygen exposure showed that atomic oxygen irradiation aggravated the friction and wear of the ZrO 2 /polyimide composites. The wear mechanism was mainly abrasive particles wear arising from the ZrO 2 -rich layer on the surface of composites. The ZrO 2 /polyimide composites with 1 wt% nano-ZrO 2 owns the lowest varying rate of the friction coefficient and wear rate before and after atomic oxygen exposure, which showed stable friction and wear properties and was expected to become a kind of potential tribological materials for practical spacecraft designation. [ABSTRACT FROM AUTHOR]