Characteristics of hydroxyapatite coating on Ti-6Al-4V substrate fabricated via sequent H2O2-oxidizing and RF-sputtering processes

Abstract

In this study, we created a hydroxyapatite (HAp) coating layer on top of the Ti-6Al-4V substrate via sequent H2O2-oxidizing and RF-sputtering processes and determining the effect of H2O2-oxidizing state to the adhesion between HAp coating layer and Ti-6Al-4V substrate. The results showed that the H2O2-oxidized Ti-6Al-4V surface is rough and porous, which increases the adhesion strength of the HAp coating layer on the alloy substrate. The shear strength value of the HAp/H2O2-oxidized Ti-6Al-4V substrate was 69.3 MPa, significantly higher than that of the HAp/original Ti-6Al-4V substrate (12.9 MPa). The X-ray photoelectron spectroscopy (XPS) proved the denser HAp coating layer covered the TiO2/Ti-6Al-4V substrate, consequently effectively prevented releasing of the unwanted toxic elements from the metallic implant.