Microstructure, mechanical properties and wetting behavior of F: Si–C–N films as bio-mechanical coating grown by DC unbalanced magnetron sputtering

A systematic structure and properties investigation on the deposition of fluorinated silicon–carbon–nitride (Si–C–N) films under varying CF4 flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of fluorine and carbon-doped on growth characteristics and mechanical properties in the film was observed. The chemical bonding configurations, surface topography and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), Raman and infrared spectroscopies, atomic force microscopy (AFM) and nano-indentation technique and CSM pin-on-disk tribometer. It was found that the as-deposited F: Si–C–N films are amphipathic nature, and large variations took place these films’ deposition rate, composition, microstructure and mechanical properties when CF4 flows varied from 0 to 9 sccm. At CF4 gas flow rate 9 sccm, the F: Si–C–N coatings demonstrated a fluorine content of 5.95 at.% and a moderate friction coefficient of 0.03. It is obvious from the hardness results that the F: Si–C–N coating enhances the hardness of the Co–Cr–Mo alloy to approximately 16.3 GPa on a smoother surface. The tribological characterization of Co–Cr–Mo alloy with F: Si–C–N coating sliding against ultrahigh molecular weight polyethylene (UHMWPE) counter-surface in fetal bovine serum, shows that the wear resistance of the F: Si–C–N coated Co–Cr–Mo alloy/UHMWPE sliding pair show much obviously improvement over that of uncoated Co–Cr–Mo alloy/UHMWPE sliding pair. The F: Si–C–N and Si–N films have potential properties for joint surface modification applications.

► The F: Si–C–N film coating on Co–Cr alloy as bio-mechanical coating was put forward.
► Significant role of F and C doped on structure and properties in the film was observed.
► The as-deposited F: Si–C–N films are amphipathic nature.
► F: Si–C–N coatings show improvement in the tribological behavior over the uncoated Co–Cr–Mo.
► Compared with Co–Cr alloy, F: Si–C–N films could improve hardness enhances 1.7 times.