Characterization of Ti-6Al-4V and Ti-35Nb-5TA-7Zr alloys. Effects of surface treatments and fluoride exposure

Abstract

Titanium and Ti-based alloys, especially Ti-6Al-4V, are widely accepted for the manufacture of orthopedic and dental implants due to their excellent mechanical, physical and chemical. However, a new generation of alloys, without aluminum and vanadium, has aroused the interest in Medicine. In the oral environment, the success with the use of these alloys relies on the chemical composition, structure and bioactivity of the metal surfaces, as well as corrosion resistance and tribological properties of the alloy. Thus, the aim of this study is to characterize the alloys Ti-35Nb-7Zr-5Ta-and Ti-6Al-4V by electrochemical, mechanical and tribological analysis. The alloys will be analyzed before and after the surface treatment (functionalization, and doping), and in different media (artificial saliva and sodium fluoride). The surfaces of the alloys will be characterized by analysis of chemical composition (X-ray Fluorescence Microscopy and/or Plasma Emission Spectrometry), the crystal structure (X-ray Diffraction), the phase morphology (Optical Microscopy) and topography surface (Scanning Electron Microscopy and Atomic Force Microscopy). The electrochemical properties will be determined by means of Open Circuit Potential vs. time, Potentiodynamic Polarization Curves and Electrochemical Impedance Spectroscopy. The mechanical tests will be: Vickers hardness, tensile strength, mechanical cycling, and fracture analysis. Tribocorrosion will be made in pin-disk system with fretting between 30 microns and 2 mm and a load of 1N.