Relationships between the thermal stability, friction, and wear properties of reactively sputtered Si–aC:H thin films

The friction and wear performance were correlated with the thermal stability of reactively sputtered Si–aC:H thin films containing various Si and H concentrations. The average steady-state friction coefficients as measured by dry sliding pin-on-disk tests decreased with increasing Si and H content. Furthermore, the films with high Si and H formed thick transfer films as compared to the films with little or no Si and H content. Minimums in average ball abrasion rate and average film wear rate were observed at the Si/C = 0.10 film composition. The most intense and distinct “graphitic” Raman peaks were collected from the Si/C = 0.10 transfer film debris. In addition, the Si/C = 0.10 film also had the most distinguishable graphitic Raman signature after annealing in air at 500 °C compared to the other Si–aC:H films, suggesting a possible relationship between the nature of transfer films resulting from dry sliding in air and the bulk films that were annealed in air.