Effects of Sputtering Current of Cr on Tribological Properties of Graphite-like Carbon Coating

Graphite-like carbon coating was deposited by closed field unbalanced magnetron sputter ion plating technique with different sputtering current on Cr target. Hardness, adhesion, friction coefficient and specific wear rate of the coating was tested and the microstructure of the coating was observed by SEM and TEM. The results indicate that variation of the sputtering current of Cr not only changed the chemical composition of the coatings but also greatly affected microstructure of the coatings. With increasing Cr current, the cross-section of the coatings developed from fibrous to columnar. The incorporation of Cr led to a periodic muhilayered structure in the graphitelike carbon coatings. Variation of the chemical composition and microstructure induced different tribological properties of the graphite-like carbon coatings.