Magnetron sputtering of nanocomposite (Ti,Cr)CN/DLC coatings

Superhard nanocrystalline (Ti, Cr)CN/DLC coatings were prepared through co-sputtering of Ti, Cr and graphite targets in an argon/nitrogen atmosphere. Results from both transmission electron microscopy (TEM) and grazing incident X-ray diffraction (GIXRD) indicated that the grain size of (TiCr)CxNy crystals was approximately 10–20 nm. X-ray photoelectron spectroscopic studies confirmed that an increase in the sputtering power at the Ti target not only increased the Ti composition in the film but also brought about an increase in sp3 bonding in DLC matrix, in agreement with the raising hardness with Ti sputtering power. Film hardness and elastic modulus were measured with a nano-indenter, and film hardness reached 40 GPa. Tribological behaviors of the films were evaluated using a ball-on-disk tribometer, and the films demonstrated properties of low-friction and good wear resistance.