Effect of chromium doping on high temperature tribological properties of silicon-doped diamond-like carbon films

Amorphous carbon films were deposited by means of closed-field unbalanced magnetron sputtering (CFUBMS). The silicon content was fixed at 1.3 at. %, while the chromium content was increased by modification of the current applied to the chromium magnetrons, with two doping levels, 0.3 and 2.7 at. %. Both, hardness and thermal stability were found to decrease as result of increasing chromium. Ball-on-disk tests revealed friction coefficients of 0.06 at room temperature with similar specific wear rate in all films (~4 × 10−13 m3 N−1 m−1). Increasing annealing temperatures were found to reduce the coefficient of friction compared to room temperature values, while increasing the specific wear rate for all films. [Display omitted] •Chromium doping reduced the relative fraction of Si–O–C, which plays a role in the friction.•Hardness, reduced Young's modulus and the C–C sp3 fraction were found to be reduced as result of increasing chromium doping.•Increasing chromium content reduced the thermal stability of the films and promoted the clustering of the films.•Specific wear rate was increased for the chromium containing films as result of increasing temperature.