STRUCTURE AND TRIBOLOGICAL PERFORMANCE OF CARBON OVERLAYER FILMS

The structure and mechanical performance of sputtered amorphous and hydrogenated amorphous carbon films have been investigated. Raman spectroscopy of the overlayer films shows that the sp3 content of the hydrogenated amorphous carbon films was higher than that of the amorphous carbon films. The hydrogenated amorphous carbon films were harder than amorphous carbon films. The abrasion resistance and friction buildup characteristics in drag tests were also superior for hydrogenated carbon films. The experimental results suggest that tribochemical wear is the dominant wear mode in amorphous carbon films whereas abrasive wear may be the operative mode in hydrogenated amorphous carbon films.