Hydrophobic, anticorrosion, and frictional properties of F-DLC films prepared by magnetron sputtering

Fluorine-doped diamond-like films (F–DLC) were prepared through the RF magnetron sputtering technique, and the effects of different F contents on their components, structure, and properties were investigated. Doping with F was found to induce a transition from the sp3C phase of the three-dimensional spatial structure to the sp2C phase of the two-dimensional polymer structure in the DLC films, generating a C–Fx bonding group. The use of reasonable sputtering parameters to regulate film components and structure yielded films with excellent hydrophobicity and corrosion resistance. The water contact angle, corrosion current density, and coefficient of friction of the films were 101.2°, 3.0207 × 10−8 A∙cm−2, and 0.08, respectively. Further analysis revealed that the excellent hydrophobicity and corrosion resistance of the films were mainly due to the surface roughness of the films, together with the increase in two-dimensional polymer and C–Fx (x = 1,2,3) bonding structures within the films. The films had a low coefficient of friction that was attributable to their reduced C–C bond content, C–Fx bond replacement in the σ-suspension cement that was suspended during film friction, and the graphite-like transfer film generated during friction.