Design of Ti-6Al-4V alloy surface properties by galvanostatic electrochemical treatment in a deep eutectic solvent Ethaline

• Published in: Surface & coatings technology Vol. 429; p. 127936
• Main Authors: Kityk, A., Protsenko, V., Danilov, F., Bobrova, L., Hnatko, M., Pavlik, V., Šoltýs, J., Labudová, M., Rusková, M., Pangallo, D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-01-2022; Elsevier BV
• Subjects: Acidic oxides; Bio-compatibility; Chemical composition; Choline; Corrosion resistance; Current density; Deep eutectic solvent; Electrochemical treatment; Electrolytic cells; Ethylene glycol; Eutectics; Low currents; Oxidation; Oxide coatings; Roughness; Solvents; Surface properties; Surface topography; Titanium alloy; Titanium alloys; Titanium base alloys; Wettability; Titanium alloy; Deep eutectic solvent; Surface topography; Electrochemical treatment; Roughness; Bio-compatibility
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2021.127936

This study demonstrates the possibility of the design of Ti-6Al-4V alloy surface properties by galvanostatic electrochemical treatment in a deep eutectic solvent Ethaline (a eutectic mixture of choline chloride and ethylene glycol in molar ratio 1:2, respectively) at the temperature of 25 °C. A short-time anodic treatment in Ethaline in a wide range of current densities (2–50 mA cm−2) provides formation of surface oxide films with controllable chemical composition, roughness and wettability, improved corrosion resistance and with biologically-inspired topography. It was found that a unique feature of this electrolyte in comparison with traditional acidic ones is that oxidation is not observed during electrochemical processing of titanium alloy. It was shown that formation of microrough structure on Ti-6Al-4V alloy surfaces is observed at relatively low current densities (2–15 mA cm−2) of the electrochemical treatment; formation of nanorough structure occurs at higher current densities (20–50 mA cm−2). It was found that all treated samples did not demonstrate any cytotoxic effect and have good cells adhesion and cells viabilities. Bacterial resistance of Ti-6Al-4V alloy samples can be controllably adjusted and increased by the surface leveling in Ethaline at high current densities.
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•Galvanostatic electrochemical treatment of Ti-6Al-4V alloy in Ethaline•Electrochemical treatment in Ethaline affects the chemical composition, morphology and topography of the surface layer•Electrochemically treated surfaces exhibited a much higher corrosion resistance•All treated samples did not demonstrate any cytotoxic effect and have good cells adhesion and cells viabilities•Bacterial resistance of Ti-6Al-4V alloy samples can be increased by the surface leveling in Ethaline