Evaluation of tribological properties of diamond-like carbon thin film prepared by the hot cathode pig discharge type plasma-enhanced CVD method on experiment and molecular dynamics simulation

Abstract

This paper describes the effect of density of Diamond-Like Carbon (DLC) thin film on tribological property. DLC thin films having the density of 1.9-2.5 g/cm3 were prepared on (111) of Silicon surface by the hot cathode PIG Discharge Type Plasma-Enhanced CVD method. Ball-on- disk friction experiments were carried out using diamond ball. The friction coefficients increased from 0.05 to 0.20 with increasing film density in the density range below 2.185 g/cm3, but those did not change above 2.185 g/cm 3. The specific wear value also increased with increasing film density. The effect of film density on tribological property between DLC thin film and diamond pin was examined by molecular dynamics simulation. The diamond pin slides to uniaxial direction on DLC thin film having the density 1.5-3.0 g/cm3. Atoms of DLC thin film having the density of 1.5 g/cm 3 were moved most actively. Atomic movement being like to shear deformation was observed during frictional processes. The effect of film density on friction coefficients in MD simulations was similar to that in experiments qualitatively.