2016 Volume 61 Issue 9 Pages 627-635
The boundary lubrication properties of cobalt (Co), cerium (Ce), magnesium (Mg), nickel (Ni) and titanium (Ti)-containing hydrogen-free sputtered diamond-like carbon (DLC) films were investigated using a ball-on-disk tribometer and compared with those of diamond, FCVA (filtered cathodic vacuum arc) DLC, P-CVD (plasma chemical vapor deposition) DLC and sputtered DLC films. The friction coefficients of the Co, Ce, Mg and Ti-containing DLC films and diamond film are much lower than those of the metal-free sputter-, FCVA- and P-CVD DLC films under polyalphaolefin (PAO) lubricant with and without a glycerol monooleate (GMO) additive. Moreover, under boundary lubrication using PAO with GMO, DLC films containing an appropriate quantity of Co have the lowest friction coefficient of µ = 0.02 among all the tested films. Low-friction and low viscoelastic tribo products formed on the sliding surface of Co-containing DLC films were observed by atomic force microscopy (AFM) with a force modulation methods.
