| Summary: | Dry film lubricant (DFL) coatings are widely used to reduce coefficients of friction and damage in highly loaded contacts. This work investigates the behaviour of a commercially available MoS2-based DFL in a cylinder-on-flat contact geometry with a fretting amplitude of 300 µm. Cylinders with radii of 15 mm, 80 mm and 160 mm along with DFL thicknesses between 12 µm and 86 µm were utilized. Three stages in the lifetime of the system were investigated; in the first stage, the DFL wore with a volumetric rate that was proportional to the number of cycles (under a given load), until the thickness of the DFL was reached. In the second stage, a thin low friction surface layer existed, with its durability being proportional to the contact pressure. In the third stage, metal-metal contact resulted in short-term instabilities in the coefficient of friction and the DFL system was said to have failed.
|