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.