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

Abstract

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–WL-DLC) increases the mechanical properties of the Si–WL-DLC film without a significant decrease in the fraction of sp3 content. The incorporation of 4.45 at.% W improves the wear resistance and stabilizes the friction coefficient curves at temperatures up to 400∘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–WL-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.