Study On Structure And Properties Of Ti-doping Diamond-Like Carbon Films Prepared By Filtered Cathodic Vacuum Arc

The Ti-containing diamond-like carbon films (Ti-DLC) were deposited by filtered cathodic vacuum arc technique. The film microstructures were evaluated by using an atomic force microscope (AFM), the films are dense and smooth.The surface composition and structure were investigated by EPMA, Raman spectra, XRD and XPS. The decreasing of the C2H2 flow rate and the increasing of the arc current are both the reasons for the increasing of the Ti content, and the second one plays a more important role. The contents of Ti are almost doubled when the arc current were increased from 45 A to 65A, on the both conditions where the C2H2 flow rate is 60sccm and 1 OOsccm. Raman spectra proved that the structure of Ti-DLC films is Ti-containing amorphous carbon films, the intensity of D and G bands decreased by increasing the content of titanium. With the increasing of the content of Ti, the G site and the ID/IG ratio increase and less sp3C bond is formed. The rusult of the XRD showed that the nanocomposite structure of TiC nanocrytals, which is dispersing in the amorphous DLC films, was found in the films with higher Ti content. The result of the XPS revealed that the titanium is existed with the TiC state essentially in the film.The hardness of the films were measured by microhardness tester and the results showed that the hardness values of the films varied between 1591 and 2195. The residual stress were measured by substrate curvature method, and the residual stress of the film were found to decrease gradually as a function of the higher content of the titanium in the film. The tribological properties of the films were investigated on the UMT-2 type friction tester. With the contect of Ti rising, the friction coefficient of the films is on the increase, from 0.125 to 0.169.