TRIBOLOGICAL PROPERTIES OF POLISHED DIAMOND FILMS

Despite the rapid progress being made in the synthesis of diamond films and recent interest in polishing of diamond films, no systematic measurements of friction and wear on polished diamond films have been reported. In the present study, chemomechanical and laser polishing techniques are used, and friction and wear data on the chemomechanically polished diamond films are presented. With the chemomechanical polishing technique used in this study, the rms roughness of hot filament chemical vapor deposited diamond films can be reduced from about 657 to about 170 nm with rounding off of sharp asperities with no change in the diamond structure. The polished films exhibit coefficient of friction (approximately 0.1) and wear rates much lower than that of unpolished films. Friction and wear properties of the polished films are comparable to that of single-crystal natural diamond. Based on this study, it is concluded that polished films are potential candidates for tribological applications.