Electrochemical deposition of a hydroxyapatite layer onto the surface of porous additively manufactured Ti6Al4V scaffolds

Successful acceptance of biomaterials by a patient's body significantly depends on an interaction between the surface and the biological components of the host environment. In the case of orthopedic scaffolds, surface treatment may improve their osseointegration. This study deals with the electrochemical deposition of ceramic hydroxyapatite (HAp) coatings onto additively manufactured titanium specimens with a porous structure. The specimens of three different types (pore sizes of 200, 400, and 600 μm) were modeled using CAD software and fabricated using the Ti6Al4V titanium alloy. HAp coatings were electrochemically deposited onto the surface of un-annealed specimens using four different experimental conditions. Based on the results and optimization of the conditions with the un-annealed specimens, ideal conditions were selected for the coating of the annealed specimens. The nature of the ceramic layer on un-annealed and annealed samples was compared. Surface morphology and distribution of ceramic coatings on the surface of the specimens were compared and evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). The un-annealed specimens exhibited more compact surfaces and larger deposits of nanocrystalline HAp when compared to the annealed specimens. The results indicate that electrochemical deposition is a suitable method for the production of a ceramic coating layer onto the surface of porous titanium specimens with promising potential for clinical applications.