FURTHER IMPROVING THE MECHANICAL AND HIGH-TEMPERATURE TRIBOLOGICAL PROPERTIES OF SILICON-DOPED DIAMOND-LIKE CARBON FILM BY TUNGSTEN INCORPORATION

As an excellent solid lubrication material, the poor high-temperature tribological properties of diamond-like carbon (DLC) films severely limit their applications. In this study, tungsten (W) was incorporated into Si-doped DLC films fabricated via reactive magnetron sputtering. The effect of the W content ranging from 0 to 13.12 at.% on the film structure, bonding states, mechanical and high-temperature tribological properties of Si and W co-doped DLC (Si-W-DLC) films has been investigated. The results show that a small amount of tungsten incorporation (4.45 at.%, Si-W-L-DLC) increases the mechanical properties of the Si-W-L-DLC film without a significant decrease in the fraction of sp(3) content. The incorporation of 4.45 at.% W improves the wear resistance and stabilizes the friction coefficient curves at temperatures up to 400(degrees)C. The high residual stress caused by the highly distorted C-W bond and the low friction coefficient attributed to the formation of WO3 on the sliding surface should be responsible for the excellent tribological performance of the Si-W-L-DLC film. It is believed that the Si and W co-doped DLC film can provide another strategy for expanding the high-temperature application of DLC films.