Si添加およびTi添加DLC/DLC摺動のトライボロジー特性

Abstract

Diamond-like carbon (DLC) films have been widely applied to machine components of many types. DLC has excellent tribological properties, but it must be improved to reduce friction further. Deposition with a different element-doped DLC on both sides of a sliding surface is expected to produce a superior friction coefficient. Therefore, we investigated the tribological properties of different element-doped DLC/DLC sliding to achieve sliding with lower friction. For our study, we used Plasma-Based Ion Implantation and Deposition (PBIID) to prepare three DLC films of pure-DLC, Si-DLC, and Ti-DLC. Each DLC film bond structure was analyzed using Raman spectroscopy. Hardness and roughness were measured by nano-indentation and atomic force microscopy. Regarding their tribological properties, friction coefficients were measured using ball-on-disk friction tests. Subsequently the chemical elements in wear tracks were analyzed using energy dispersive x-ray spectroscopy. Results obtained through the study revealed the following. (1) Different kinds of DLC/DLC sliding achieved a much lower friction coefficient than a single kind of DLC/DLC sliding. (2) Occurrence of mild wear particles functioned as a solid lubricant. The particles effectively reduced the friction coefficient. (3) Adhesion of wear particles was observed in wear tracks after Si-DLC/Ti-DLC sliding. (4) Friction coefficients of the Si-DLC/Ti-DLC sliding were the lowest, about 0.021, by appropriate adhesion of the wear particles.