Abstract
A double-layer film, in which the top layer was a diamond-like carbon (DLC) film and the bottom layer was a compositionally graded film of silicon and carbon compounds with decreasing C/Si atomic ratio to a substrate, was successfully formed on a Ti-6Al-4V substrate by an ionization deposition method. In the film deposition process, a benzene vapor was used for the DLC deposition as a source gas, and hexamethyldisiloxane and benzene vapors were used as source gasses for the compositionally graded film of silicon and carbon compounds. The results of ball-on-disk and scratching tests showed that the double-layer film with graded composition provided a low friction coefficient, high wear resistance and good adhesion with the Ti-6Al-4V substrate compared to a single-layer DLC film. The DLC-based double-layer film developed in this study is much effective in wide applications of the Ti-6Al-4V alloy for which the use to antifriction components has been difficult.
