Applying Titania and Hydroxyapatite coating on Ti-6Al-4V by PEO and hydrothermal processes and investigating its corrosion behavior in simulated body environment

Abstract

Titania porous bioceramic coating covered by hydroxyapatite causes the substrate to be more corrosion resistant and biocompatible. In this study, Ca and P contained titania was coated on Ti-6Al-4V alloy substrate by applying plasma electrolytic oxidation (PEO) with changing parameters such as time and voltages. After obtaining optimized sample, then it was treated hydrothermally at different time intervals until hydroxyapatite crystals were nucleated on titania porosities. Morphology and cross section, chemical composition, topography and hardness of the coating were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Atomic force microscope (AFM) and nano indentation test, respectively. Also, the corrosion behaviors of the coating were studied by polarization and electrochemical impedance spectroscopy. According to the obtained results, hydrothermal treatment on optimized sample causes the formation of hydroxyapatite crystals in Titania porosities. These crystals are in nanometric dimensions and lumped shape. In addition, the coating on the substrate caused an increase in corrosion resistance of the sample in simulated body environment considerably

Keywords

• Plasma electrolytic oxidation (PEO)
• hydrothermal treatment
• . Ti-6Al-4V
• Hydroxyapatite
• Corrosion properties

20.1001.1.22285946.1389.1.1.1.5

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