Investigation of hydroxyapatite (HAP) containing coating on grade 2 titanium alloy prepared by plasma electrolytic oxidation (PEO) at low voltage

In this work, plasma electrolytic oxidation (PEO) process was used to produce bioactive coatings, mainly composed by hydroxyapatite (Hap) and titanium oxide, on grade 2 alloy. All PEO treatments were carried out using a maximum voltage of 315 V, lower value in comparison with the works present literature, thus resulting more environmentally friendly process. The effects coatings KOH addition electrolyte working direct or pulsed current mode, also investigated. morphology elemental composition characterised scanning electron microscopy (SEM), whereas phase analysis X-ray diffraction (XRD). corrosion resistance properties investigated open circuit potential measuraments, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) tests. Moreover, cell-adhesion biological tests performed. SEM evidenced presence needle-shape crystals hydroxyapatite, as confirmed XRD, that totally partially filled pores layer. test showed an improvement behaviour coated samples untreated sample. Cell-Adhesion excellent cytocompatibility human cells cell adhesion