Hydrophobicity and tribological properties of Al2O3/PTFE composite coating

Al 2 O 3 /polytetrafluoroethylene (PTFE) composite coating was prepared on titanium alloy by cathode plasma electrolytic deposition (CPED) and impregnation method, to improve the hydrophobicity and tribological properties. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis of the coating indicate that PTFE penetrates into the interior of the coating and is well bonded to titanium alloy substrate by cross-linking with Al 2 O 3 ceramic coating. The contact angles were measured by contact angle measurement, and the tribological properties of the composite coating were evaluated by sliding wear test. The surface of the composite coating is found to possess good hydrophobicity with a water contact angle of 140°. The results also indicate an improved tribological properties of Al 2 O 3 /PTFE composite coating at room temperature with a steady friction coefficient as low as 0.05. The self-lubricating anti-wear composite coating is expected to solve fouling problems and poor wear resistance of titanium alloys.