The Electrochemical Impedance Spectroscopy and Wettability Analysis of Ti6Al4V Alloy Modified by Atomic Layer Deposition ALD Method

The purpose of the article was to evaluate the physicochemical properties of the Ti6Al4V titanium alloy with a zinc oxide layer deposited by the atomic layer deposition method. The surface modification promotes changes in the chemical character of the surface according to two basis wettability states, namely the Wenzel state and the Cassie–Baxter state. To evaluate the mechanisms of wettability changes, the contact angle measurements and the surface free energy calculations (according to the Owens–Wendt methods) were performed. It was found, based on X-ray photoelectron spectroscopy, that the hydrophobic properties of the oxide layer are related to the presence of metal cations, oxygen anions, and hydroxyl groups on the surface. Additionally, the method of electrochemical impedance spectroscopy was used to define the morphological peculiarities of the coating on the basis of the registered impedance spectra.