Microstructure and tribological properties of Ti-contained amorphous carbon film deposited by DC magnetron sputtering

Abstract

Pure amorphous carbon (a-C) film and that with a small amount of Ti were deposited on high speed steel (W18Cr4V) substrates by means of dc closed field unbalanced magnetron sputtering. The chemical composition and microstructure of the a-C films were performed using x-ray photoelectron spectroscopy, x-ray diffraction, Raman spectra, and transmission electron microscopy. The mechanical and tribological properties were evaluated using a nanoindentor, Rockwell and scratch tests, and a conventional ball-on-disk tribometer, respectively. The pure a-C film showed the high hardness (53 GPa), elastic modulus (289 GPa), but the poor adhesive strength. When adding a small amount of Ti to the a-C film, both the adhesive strength and the tribological properties were improved. The Ti contained a-C film had the low wear rate (1.9×10−17 m3 N−1 m−1) and friction coefficient in humid air.