Synthesis and characterization of hydroxyapatite-based coatings for medical implants obtained on chemically modified Ti6Al4V substrates

► Hydroxyapatite coatings used for medical implants. ► Coatings were formed by thermal substrate method. ► Chemical pretreatment was used for surface modification for improvement of surface adhesion and bioactivity of coatings. ► NaOH and H2O2 treatments induce fast formation of a uniform amorphous HA coating on the metal. ► HF pretreatment induced coatings with high cristallinity.