Characterization and surface properties of a new titanium bio alloy

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

C Vasilescu, S I Drob, P Osiceanu, J M Calderon Moreno and P Drob

Accepted Abstracts: Material Sci Eng

Abstract :

A novel Ti-15Ta-5Zr alloy was synthesized; this possesses an α+β stable, homogeneous, biphasic microstructure (determined by optical microscopy, X-ray diffraction - XRD and scanning electron microscopy - SEM) The alloy presents a fine lamellar structure with typical lamella thicknesses in the submicron range. Its passive film contains the protective oxides of all constituent elements (TiO2, Ti2O3, Ta2O5 and ZrO2 determined by X-ray photoelectron spectroscopy - XPS) and is more compact and thicker (8.5+1 nm) than that of Ti (1.5-3 nm). The corrosion behaviour (by cyclic and linear polarization and electrochemical impedance spectroscopy - EIS) in Ringer solution was studied. Main electrochemical parameters presented more favorable values for alloy in comparison with Ti, denoting an easier, more rapid, stronger passivation of the Ti-15Ta-5Zr alloy. The alloy polarization resistance reached higher value (about 180 kΩ cm2) than that of Ti (about 18 kΩ cm2) that represents a very corrosion resistant material. Main corrosion parameters attested a nobler behaviour, lower corrosion rates (of about 70 times smaller than those of Ti) proving a more capacitive, resistant passive film on the Ti-15Ta-5Zr alloy surface. EIS spectra described a passive film formed by two layers: an inner, barrier, compact layer and an outer, porous layer; in the pores of this layer can be incorporated species from the human biofluid (bioactivity). An electric equivalent circuit with two time constants was fitted: the first time constant is represented by resistance and capacitance of the barrier layer and the second one is illustrated by porous layer resistance and capacitance.

Biography :

C Vasilescu has completed his PhD at the age of 29 years from Institute of Physical Chemistry ?Ilie Murgulescu? of Romanian Academy and postdoctoral studies from Paul Sabatier University, Toulouse, France. She is Senior Researcher at Institute of Physical Chemistry ?Ilie Murgulescu?, Bucharest, Romania. She has as research fields Physical Chemistry and Electrochemistry and obtained original results with significant impact in the domain of the corrosion of different materials and coatings for industrial and biomedical applications. She has published more than 85 papers in reputed journals.