Microstructure, Mechanical and Anticorrosive Properties of a New Implant Alloy in Simulated Human Body Environment

摘要

The corrosion resistance of the new ternary Ti-15Zr-5Nb alloy was correlated with its microstructure, surface structure and composition of its native passive film and of the film formed after 1500 soaking hours in Ringer solutions of different pH values. Nobler passive behaviour of alloy in comparison with Ti was determined due to its more compact passive film (containing TiO_2, Ti_2O_3, ZrO_2 and N_b2O_5 oxides). EIS spectra depicted a predominantly capacitive behaviour, a passive film formed by two layers. After 1500 soaking hours, XPS, SEM and EDX revealed the same protective oxides and Ca_3(PO_4)_2 compound (precursor of hydroxyapatite) deposited on the alloy surface.