EFFECTS OF ELECTRODE DISTANCE ON MECHANICAL AND TRIBOLOGICAL PROPERTIES OF HYDROGENATED DLC FILMS DEPOSITED BY DC-PULSE PECVD

Abstract

Hydrogenated diamond-like carbon (DLC) films were deposited by DC-pulse plasma-enhanced chemical vapor deposition (PECVD) under the different electrode distances. Effects of the electrode distances on the microstructural, mechanical, and tribological properties of the obtained films were investigated by high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), nano-indenter, and reciprocating ball-on-disc tester, respectively. The results indicate that the thickness of the films decreased with the increased electrodes distances. The films have the highest internal stress, highest hydrogen concentration, and lowest friction coefficient at the 54[Formula: see text]mm electrode distance, which are resulted from the highest sp3 content formed at this feature distance. The wear rates also have similar variations. The film formed at 54[Formula: see text]mm distance also shows the lowest hardness and elastic modulus with values of 6.2 and 29.1[Formula: see text]GPa.