Tribology of fluorinated diamond‐like carbon coatings: first principles calculations and sliding experiments

Abstract

ABSTRACTSliding contact experiments and first principles calculations were conducted to study tribological properties of aluminium and fluorinated diamond‐like carbon (F‐DLC) surfaces. Sliding tests between Al and an F‐DLC coating generated a low coefficient of friction (COF) of 0.09–0.14 and led to the formation of carbonaceous transfer layers containing AlF3 on the Al surfaces as determined by X‐ray photoelectron spectroscopy. An interface model that examined the interactions between Al (111) and F‐terminated diamond (111) surfaces revealed that F atoms would transfer to the Al surface in increasing quantities with an increase in the contact pressure and the F transfer would lead to the formation of a stable AlF3 compound at the Al surface. The generation of repulsive forces between two F‐passivated surfaces as a result of the F transfer to the Al surface was shown to be responsible for the low COF between Al and F‐DLC. Copyright © 2012 John Wiley & Sons, Ltd.