Effects of pulsed current and H2O2 amount on the composition of electrodeposited calcium phosphate coatings

Calcium phosphate coatings on Ti6Al4V substrates were elaborated by pulsed electrodeposition with hydrogen peroxide (H2O2) into electrolyte. The surface morphology and the chemical composition of the coatings were characterized by scanning electron microscopy (SEM) associated to Energy Dispersive X-ray Spectroscopy (EDXS) for X-ray microanalysis. The obtained results were systematically confirmed at the nanometre scale analysis using scanning transmission electron microscopy (STEM). Moreover, X-ray diffraction (XRD) was performed in order to identify the coatings phases. The results showed that pulsed electrodeposition without H2O2 into electrolyte followed by heat treatment favoured coatings made of two phases which are stoichiometric hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP). On the other hand the addition of an optimized H2O2 amount into electrolyte led to adherent and uniform coatings mainly made of stoichiometric hydroxyapatite (HAP).