Solid lubricating film/oil or grease complex system II: Tribological properties of DLC film

DLC film was prepared by magnetron-sputtering. Lubricants used at space technology, i.e. chlorophenyl-butyl with methyl terminated silicon oil (code as 114^# oil), trifluorinated-butyl with methyl terminated silicon oil (code as 115^# oil), poly-α-olefin (code as PAO(201) oil), perfluorinated polyether (code as PFPE oil), and the related grease formulated by PTFE powders, code as KK-4 grease, KK-5 grease, KK-P(201) grease and 601EF grease were synthesized or prepared. Friction and wear properties of the DLC film as well as the DLC film coated with 114^# oil, 115^# oil, PAO(201) oil PFPE oil or KK-4 grease, KK-5 grease, KK-P(201) grease and 601EF grease were investigated on a UMT-2MT tribo-meter. The worn surfaces of the film were observed by a Micro-XAM three-dimensional profilometer. It was found that the starting friction coefficient, steady friction coefficient and the wear life of DLC dry-film were about 0.26, 0.12 and 600 m, respectively. The friction and wear properties of solid lubricating DLC film/oil or grease complex lubrication systems were much better than that of DLC dry-film. The friction coefficient reduced by about 2 to 6 times compared to that of DLC dry-film, and their wear life increused more than 10 time as compared to pure DLC film, exceeded 7560 m. The complex lubrication systems exhibit excellent friction and wear performance, and are potentional good lurbricating system for space industry.