Triggering the hydroxyapatite deposition on the surface of PEO-coated Ti-6Al-4V alloy via the dual incorporation of Zn and Mg ions

The study examined the surface properties of bioactive element coatings fabricated on Ti-6Al-4V alloy via plasma electrolytic oxidation (PEO). With this aim, Zn and Mg were incorporated into the porous surface via PEO treatment using pulsed DC power supply at 320 V for 300 s in electrolytes with Zn+2 and Mg+2 ions at different contents, such as 0.01 and 0.03 M. The existence of Zn+2 and Mg+2 ions was found to be an important parameter affecting the microstructural development and the coating properties. By adding of 0.01 M of Zn2+ with 0.03 M of Mg2+ ions into the electrolyte, the surface of the coating become smoother with less porosity than those obtained in other samples. Therefore, this sample showed the best corrosion performance as compared to other samples despite the presence of cracks. The in vitro examinations showed that the bone formation and the proliferation of osteoblasts on the surface of the samples formed in the electrolyte with 0.01 M and 0.03 M of Zn2+ ions were better than other samples due to the high fractions of anatase, higher roughness, and good wettability. (C) 2019 Elsevier B.V. All rights reserved.