Estimation of DLC Wear Process by Micro Laser Raman Spectroscopy

Abstract

In order to estimate the wear process of diamond-like carbon (DLC) films, a ball on disk test and a micro laser Raman spectroscopy are employed in this study. DLC films are deposited on high-speed tool steel (JIS-SKH51) surfaces by a plasma based ion implantation and deposition (PBII&D). After the ball on disk test with a steel ball (JIS-SUJ2) as an indenter, a mapping measurement using micro laser Raman spectroscopy has been accomplished against both the wear surface of the DLC films and the surface of the indenter. As a result, obvious changes in the structure of the DLC films originating from the contact interface between the substrate and the indenter are observed. This is like to be caused by the graphitization of the DLC films. On the other hand, except for the preceding descriptions, the Raman spectra are almost same to each other and there are no changes in the structure of the DLC films. This means that the effects of the sliding on the changes in the structure can be neglected. In addition, the carbon compounds and the solid solutions of carbon and iron included in the substrate and the indenter hardly influence the Raman spectra with or without sliding.