Fatima Bir

In this work, hydroxyapatite ( HA ) and fluorohydroxyapatite ( FHA ) coatings have been successfully synthesized with an electrochemical deposition method, using pulsed current deposition mode on smooth and rough 316L stainless steel implant surfaces. The impact of the variation of the current density was also studied. The surface morphology and chemical composition of the coatings were characterized by scanning electron microscopy associated with energy‐dispersive X‐ray spectroscopy ( SEM ‐ EDX ), and X‐ray photoelectron spectroscopy ( XPS ). The structural characterization is carried out by X‐ray diffraction ( XRD ) and Fourier‐transformed infrared ( FT ‐ IR ) spectroscopy. Furthermore, thickness, roughness, and wettability of the coating are determined. The experimental results showed that the electrodeposition on rough surface promotes deposition of dense and homogeneous layers. It also shows that uniform and smooth films were obtained at low current densities compared to high current densities. Potentiodynamic polarization results in simulated body fluid ( SBF ) indicate that the coatings thickness and the incorporation of the fluorine ions into hydroxyapatite crystals play an important role in improving the corrosion resistance of the substrate. Moreover, cyclic voltammetry studies clearly suggest that the addition of H ₂ O ₂ and F ⁻ ions into the electrolyte solution catalyses a reduction reactions and favorites fluorohydroxyapatite formation.