Surface characterization and electrochemical behavior of new biomedical Zr-based metal/ceramic composite in fetal bovine serum

Abstract

The aim of this study is to obtain a new Zr-based metal/ceramic composite by heat treatment and to demonstrate the surface properties improvement of new alloy, Zr3Ta, after heat treatment process. The surface characterization and corrosion behavior of ascast and heat-treated Zr3Ta alloy were investigated in fetal bovine serum (FBS) using Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization as electrochemical techniques. As surface characterization techniques we used SEM, X-Ray Diffraction (XRD), Vickers micro-hardness and interferometry measurements. Ion release phenomena were investigated using Inductive Coupling Plasma - Mass Spectrometry technique (ICP-MS). Impedance spectra were represented by Nyquist and Bode diagrams and electrical equivalent circuits were also proposed for obtained results. Electrochemical measurements were carried out in Fetal Bovine Serum at 37°C. XRD analysis was used to identify the chemical composition of the outer oxide layer. After the heat treatment, a zirconium oxide layer of about 50 microns is formed on the alloy surface, which improves corrosion resistance and surface micro-hardness.