Corrosion and Wear Properties of Ti/Tetrahedral Amorphous Carbon Multilayered Coating

The titanium and tetrahedral amorphous carbon (Ti/ta-C) multilayered coating has been deposited by combination of cathodic arc evaporation and magnetron sputtering employing graphite and titanium targets with constant substrate bias voltage of −110 V. Coating has been developed with titanium and tetrahedral amorphous carbon alternatively on silicon and stainless steel 202 substrates with total thickness of 936 nm. The coating has been characterized by field emission scanning electron microscopy, energy-dispersive spectroscopy, atomic force microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Coating properties have been investigated by nanoindentation, potentiodynamic polarization and reciprocating wear studies. Observed average hardness values of the multilayered coating are 15.6 ± 1.7 and 17 ± 3.6 GPa at 1 and 2 mN loads, respectively. The Ti/ta-C multilayered coating exhibits enhanced corrosion resistance with better passive behavior in 3.5% NaCl solution, and corrosion potential is observed to move more positive values. The reciprocating wear studies demonstrate very low coefficient of friction of 0.07−0.2 at 2, 5, 7 and 10 N loads.