Sliding wear characteristics of the diamond-like carbon films on alloy substrates

This study used an un-balanced magnetron sputtering system to deposit different thickness of diamond-like carbon (DLC) film on Co-Cr-Mo and Ti-6A1-4V alloy substrate. Wear test, Raman spectroscopy analysis, nano-indentation test and morphology of contact surface were conducted to evaluate the tribological performance of these films for bio-medical applications. The ring-on-disk wear testing shows that the thicker film leads to the lower friction coefficient and higher wear resistance. In the testing process, the fluctuating friction coefficient of DLC coated Co-Cr-Mo substrate was less than that of DLC coated Ti-6Al-4V substrate. Raman spectroscopy analysis and nano-indentation test provide the underlying mechanism for the enhancement of the wear resistance. The DLC coated Co-Cr-Mo substrate provides better wear resistance than the DLC coated Ti-6Al-4V substrate owing to better adhesion of DLC film to the Co-Cr-Mo substrate.