Ultra-low friction of TiC/a-C composite coatings

Ultra-low coefficient of friction with a statistically averaged value of 0.0067 was observed during the tribological test on TiC/a-C composite coating synthesized by gas–solid interaction of Ti metal with CH4 gas in a thermogravimetric analyzer. Ultra-low friction behavior appeared due to transformation of D-band associated with disordered carbon lattice obtained at lower synthesis temperatures (1050 and 1150 °C) to graphitic G-band mode, which steam from ordered atomic layering occurring at higher synthesis temperature of 1250 °C.

► Synthesis of TiC/a-C nanocomposite coatings by CH4 gas carburization of titanium specimen.
► Chemical structure of the composite coatings is found to vary with synthesis temperature.
► At low synthesis temperature (1050 and 1150 °C), disorder induced mode of D-band is prominent.
► At higher temperature (1250 °C), intensity of graphitic G-band mode has high attributes to ordered atomic layering of C network.
► Ultra-low coefficient of friction of 0.0067 and high wear resistance of 1.3×10−9 mm3/Nm were measured.