Effect of substrate bias voltage on the mechanical and tribological properties of low concentration Ti-containing diamond like carbon films

摘要

Ti containing hydrogenated diamond like carbon films (Ti-DLC) was deposited on Si substrates at room temperature by magnetron sputtering Ti-twin target in methane and argon mixture atmosphere via changing the substrate bias voltage. The Ti atomic concentration in the film is less than 0.57% and exists mainly in the form of metallic titanium rather than TiC, confirmed by XPS analysis. The internal compressive stress of the film decreases monotonically with the substrate bias voltage increase. However, the hardness values of the film keep at level (12 GPa) without almost any obvious change with the increase of the substrate bias voltage. Furthermore, Ti-containing DLC film prepared at -1600 V substrate bias voltage shows an extremely low wear rate (～10~(-9) mm~3/Nm) and low friction coefficient (0.09).