Role of base pressure on the structural and nano-mechanical properties of metal/diamond-like carbon bilayers

The influence of base pressure on the structural and nano-mechanical properties of plasma produced metal (Cu and Ti)/diamond-like carbon (DLC) bilayers is reported. All of these samples show the formation of micro and nano-structured morphology with very low average roughness (less than 1 nm). The Cu/DLC and Ti/DLC bilayers deposited at low base pressure exhibit comparatively higher hardness and better nano-mechanical properties than the ones grown at higher base pressure. Highest hardness as ~49 GPa is obtained in Ti/DLC bilayer grown at low base pressure condition. Several other nano-mechanical parameters are also examined and correlated with each other. Present investigation will be useful to understand the role of base pressure on the properties of DLC coatings and may enhance its industrial application in term of hard and protective coatings.