Influence of bias voltage on microstructure and properties of Al-containing diamond-like carbon films deposited by a hybrid ion beam system

Al-containing diamond-like carbon films were deposited using a hybrid ion beam system composed of an anode-layer ion source and a magnetron sputtering with various bias voltages. XPS, TEM and Raman spectroscopy were applied to characterize the film composition, microstructure, and carbon atom bond. Nano-indentation and ball-on-disk tribo-tester were also used to study the mechanical properties and tribological behavior, respectively. The results showed that the bias voltage played a significant role on the microstructure of the films, and nano-stripe structures were observed in the DLC films, which resulted in the relatively high hardness of the films. The friction tests revealed that the films possessed a superior friction performance with a friction coefficient of about 0.02. Specially, the film with the nano-stripe clusters exhibited a good wear resistance, though those nano-clusters seemed to increase the friction coefficient.