Structural, mechanical and tribological behavior of fullerene-like carbon film

Hydrogenated carbon films containing fullerene-like structures (FL-C:H) were synthesized using magnetron sputtering of a graphite target in methane and argon atmospheres. The results indicate clearly that a substantial part of the film is made up of fragments of such fullerene-like structures mixed in a hydrogenated amorphous carbon matrix. The film exhibits excellent mechanical properties with a hardness of 27.4 GPa and almost complete elastic recovery (as high as 95%). The tribological properties of the FL-C:H film were tested and compared with a-C:H and a-C films. The results show that the lowest friction coefficient of the FL-C:H film, about 0.02, is recorded in oxygen environment. The ranges of dispersion of the friction coefficient for the FL-C:H film are merely 0.02 in different testing environments, much lower than that of a-C:H and a-C films, which indicates the friction-coefficient-insensitivity of the FL-C:H film to different atmospheres.