In this study, Ta1-xOx coatings were deposited by reactive magnetron sputtering aiming at the
enhancement of the electrochemical stability stainless steel 316L. The coatings were produced using
variable oxygen content in order to determine its influence on the films morphological features and corrosion resistance. Structural and morphological characteristics were correlated with the corrosion
behavior in artificial saliva. Potentiodynamic and electrochemical impedance spectroscopy tests were
complemented with X-ray photoelectron spectroscopy to determine the electrochemical behavior of the
coatings. The results reveal a more protective behavior of the coatings as the oxygen amount increases in
the films, as well as pitting inhibition in the coated stainless steel, independently of the
film composition.
A synergetic effect between Ta2O5 and phosphate-based passive layers is suggested as the protective
mechanisms of the coatings; while the more active electrochemical behavior of low oxygen content
films is evidenced as a consequence of the metallic tantalum on the surface with a more open morphology and
larger density of defects on the surface.This research is sponsored by FEDER funds through the program COMPETE – Programa Operacional Factores de Competitividade – by national funds through FCT – Fundação para a Ciência e a Tecnologia , in the framework of the Strategic Projects PEST-C/FIS/UI607/2013, and PEst-C/EME/UI0285/2013, and with a PhD fellowship SFRH/BD/98199/2013.
The authors thank the financial support by IAPMEI funds through QREN – Implantes dentários inteligentes – SMARTDENT, Projeto Vale Inovação n. 2012/24005 and by MCTI/CNPQ N 16/2012 TECNOLOGIAS INOVADORAS NA PRODUÇÃO, PROTOTIPAGEM E/OU AUMENTO DE ESCALA EM NANOTECNOLO-
GIA – Desenvolvimento de Titânio e Liga de Titânio Nano-estruturados com Tratamentos de Superfície para Aplicação em Implantes Ósseos
