Structure and Tribological Properties of DLC Films Deposited by DC-RF-PECVD

Diamond-like carbon films were successfully deposited on Si substrate by direct current radio frequency plasma enhanced chemical vapor deposition (DC-RF-PECVD). The microstructure and morphology of the DLC film were investigated by means of Raman spectroscopy, X-ray photoelectron spectroscopy, infrared spectrometry, and atomic force microscopy. The friction and wear behaviors of the DLC film sliding against a Si_3N_4 ball at different loads and velocities were examined on a UMT-2MT test rig. The morphologies of the wear scar of the film and of the counterpart Si_3N_4 ball were observed on a scanning electron microscope. It was found that the film prepared by DC-RF-PECVD had typical hydrogenated diamond-like characteristics and was very much smooth and compact. It showed good friction-reducing and antiwear behavior as sliding against a Si_3N_4 ball, while the applied load and sliding velocity had great effects on the friction and wear behavior of the DLC film. Moreover, the friction and wear behavior of the DLC film was also dependent on its transfer film formed on the worn surface of the counterpart Si_3N_4 ball.