Characterization of biomimetic calcium phosphate coatings on Ti6Al4V alloy

Abstract

Metals are widely used for manufacturing bone implants because of their high mechanical strength. However, metals are just biotolerable materials and they are not able to directly bond to living bone. On the other hand, bioactive materials do form direct chemical bonds to living bone, but do not have suitable mechanical properties. The combination of high mechanical strength and bioactivity may be reached through the coating of metallic substrates with hydroxyapatite (HA). Several methods can be employed for the deposition of HA coatings on metals, among them: ion sputtering, plasma spray, sol-gel, electrodeposition and biomimetic. Biomimetic method is particularly attractive because physiological conditions are reproduced during the formation of the HA coating. One aspect that affects the quality of a coating is its adhesion to the substrate, however adhesion strength of biomimetic coatings have been scarcely studied. The aim of this work was to study the effect of the substitution of G glass, employed in the conventional biomimetic method during the nucleation stage, by a solution of sodium silicate on the chemical and morphological characteristics, and the adhesion of biomimetic coatings deposited on Ti6Al4V alloy. The obtained coatings were analyzed by Diffuse Reflectance
FTIR spectroscopy (DRIFT), scanning electron microscopy (SEM) and adhesion test according to ASTM C 633 -79 standard.