Deposition of WS₂/DLC Nano-composite Films and Their Tribological Properties

Abstract

In recent years, diamond-like carbon (DLC) films are attracting attention as excellent tribomaterials due to their excellent characteristics, such as their high hardness, smooth surface, antiwear property, and lubrication characteristics, and they are used in various fields. However, both the friction coefficient and endurance life of DLC films are in sufficient, depending on the application environment. Therefore, in this study, with the aim of improving tribological characteristics, we fabricated WS₂/DLC films by co-sputtering under various conditions, using a multicathode sputtering system, with graphite and WS₂ as targets. Cross sections of the films fabricated were observed by transmission electron microscopy. In addition, the composition and structure of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Measurement of the friction and wear characteristics of the films was performed using a ball-on-disk friction tester. As a result, we found that the films show a nano-dispersed structure, a nano-layered structure or a random-layered structure, depending on the deposition conditions. Films having a nano-dispersed structure or nano-layered structure show friction and wear characteristics superior to those of a DLC-only film.