Preparation and Micro-tribological Behavior of Hydrophobic Composite Films on Surface of Ti-6Al-4V Titanium Alloy

6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-dithiol monosodium (TES) and 6-(N-allyl-1,1,2,2-tetrahydroperfluorodecylamino)-1,3,5-triazine-2,4-dithiol monosodium (ATP) were used to formation of TES-SAMs and TES-ATP composite films on the surface of Ti-6Al-4V titanium alloy by the self-assembled monolayers (SAMs) method and polymer plating technique. The structures of TES-SAMs and TES-ATP composite films were characterized by X-ray photoelectron spectroscopy, contact angle meter, spectroscopic ellipsometer, atomic force microscopy. The UMT-2 tribometer and digital microscopy were utilized to investigate the micro-tribological properties of the films. The experimental results show that the thicknesses of TES-SAMs and TES-ATP composite films were 3.9 and 22.2 nm and their contact angles of distilled water were 94.5°and 130.5°, respectively, which indicates the surfaces of TES-SAMs and TES-ATP composite films were hydrophobic. The friction coefficient was effectively reduced from 0.50for substrate to 0.23 of TES-SAMs and 0.17 of TES-ATP composite films. Moreover, TES-ATP composite films possessed excellent antiwear ability. Therefore, this novel technology is provided to improve the tribological properties in MEMS/NEMS.