Investigation of crystalline and amorphous MoS2 based coatings: Towards developing new coatings for space applications

The study focus on understanding what governs the tribological behavior of dry lubricated contact to find out the keys to develop new coatings for space applications. Firstly conducted on sputtered columnar MoS2 coatings and amorphous MoS2+Ti coatings, experiments show that contamination modulates the 3rd body rheology and helps controlling the 3rd body generation (particle size and amount). To dissociate the role of both Ti and the coating microstructure in the tribological behavior of the coatings, a sputtered amorphous MoS2 coating is studied. The study confirms the beneficial impact of the addition of a controlled amount of contamination on their tribological behavior. It also brings some recommendations to design coatings for space applications in terms of microstructure, addition of metal and gaseous dopant, etc.