Tribological Characteries of DLC film in Sliding Contacts under Different Lubrication Conditions

Diamond-like carbon (DLC) films are well known for their high hardness, low friction and excellent wear resistance. Therefore, DLC film coating can contribute to improving mechanical and tribological properties of materials. The objective of this study is to investigate the effect of solid and liquid lubrication on friction and wear performance of selected solid lubricating coatings, comparative experiments have been carried out on chemical vapor deposited hydrogenated diamond-like carbon (DLC) films against Si3N4 ball, using a ball-on-disk tribo-tester under the conditions of room temperature and different lubrication conditions. Surface morphology of coatings were investigated by atom force microscope (AFM), friction coefficient (COF) and wear rate of solid films be analyzed also. It was shown that the friction be greatly reduced when the solid film lubricated with oil and grease simultaneously compared to lubricated singly at the start-up or under boundary lubrication conditions. The effect of lubrication oil to the wear resistance property of MoS2 DLC was better than lubrication grease.