Effects of substrate temperature and reactive gas flow rate on the crystalline ceramic phases formation and tribological properties of W-Ti-Co-C-N thin films produced by co-sputtering

The present study investigates the deposition condition of W-Ti-Co-C-N thin films made by magnetron co-sputtering. The central composite design of experiments was applied for analyzing the effect of substrate temperature (X1) and nitrogen gas flow rate (X2) on the mechanical properties. Nanoindentation, sliding wear test (ball-on-disk method), scanning electron microscopy, atomic force microscopy, and X-ray diffraction techniques were employed to evaluate the tribological properties and microstructure of the thin films. The optimum values of variables were found to be in the range of 500 degrees C < X1 and 6.5 < X2 < 9 sccm, giving a high hardness of 36.5 GPa, while the friction coefficient and wear rate have the lowest amount of 0.10 and 4 x 10(-8) mm(3)/N.m, respectively.