XRD and XPS characterization of superplastic TiO₂ coatings prepared on Ti6Al4V surgical alloy by an electrochemical method

Abstract

X-ray diffraction (XRD) and X-Ray photoelectron spectroscopy (XPS), in conjunction with argon ion etching, were used to characterize the microstructure and the chemical composition of alkoxy-derived TiO₂ coatings prepared on Ti6Al4V surgical alloy by an electrochemical method. The as-deposited oxide coatings prepared at room temperature (up to 40 μm thick) were amorphous, but transformed into nanocrystalline anatase at 550°C. Using a micro-indentation technique, it was found that nanocrystalline anatase coatings were ductile, permitting significant plastic deformation at room temperature. The XPS data also revealed the presence of significant proportion of physisorbed (OH) and chemisorbed H₂O (i.e. Ti−OH) on the oxide surface, indicating that these coatings, similar to sol-gel-prepared titania, may serve as reactive substrates for heterogeneous nucleation of apatite under physiological conditions.