Deposition and tribological behaviour of sputtered carbon hard coatings

The exceptional tribological properties of low deposition temperature sputtered carbon coatings (Graphit-iC coatings) have been recently reported. This paper describes the latest development of these coatings and particularly how, by an optimisation of the deposition parameters, it has been possible to obtain relative soft to very hard coatings with extremely low specific wear rates. The coatings have been deposited in a closed field unbalanced magnetron sputter ion plating (CFUBMSIP) installation. By applying the appropriate conditions of deposition, carbon coatings with hardness from 1500 to 4000 HV can be routinely deposited. Preliminary analytical results are presented in order to characterise such hard coatings: high-resolution transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis are some of the different techniques used for this work. Finally, a number of the applications are reported with tribological test results.