Tribological Properties of Tetrahedral Carbon Films Deposited by Filtered Cathodic Vacuum Arc Technique

Abstract

AbstractTa-C films have been deposited using FCVA technique. The hardness and Young's modulus of the films on both silicon and sapphire substrates are determined by an ultra low load depth sensing nanoindenter to examine their dependence on the carbon ion energy. An optimum ion energy around 80 to 90 eV has been found, which coincides with the energy at which the sp3 content and film density reach maximum values. At this ion energy, the hardness, modulus and critical load of a 60 nm film on sapphire exhibit maximum values of 60 GPa, 580 GPa and 7 mN, respectively, whilst the frictional coefficient shows a minimum of 0.16.