Titanium alloys show attractive properties for biomedical applications where the most important factors are biocompatibility, corrosion resistance, low modulus of elasticity, very good strength-to-weight ratio, reasonable formability and osseointegration. The aim of this study was to investigate the effects of Zr content (7.5 and 15 wt%) on microstructure and corrosion resistance of Ti-30Nb-Zr as-cast alloy samples. The corrosion tests were carried out in a 0.9% NaCl (0.15 mol L-1) solution at 25 degrees C and neutral pH range. A horizontal centrifuged solidification set-up was used to obtain as-cast samples with a fine dendritic arrangement. In order to evaluate the corrosion behavior, electrochemical impedance spectroscopy (EIS), polarization curves and an equivalent circuit analysis were used. It was found that the as-cast microstructure tends to have the dendrite arm spacings reduced with increasing Zr content. The results have shown that the addition of Zr to a Ti-30Nb alloy has been efficient to stabilize the beta phase. The resulting impedance parameters and passive current densities have shown that the Ti-30Nb alloys sample without Zr addition presents a higher surface reactivity which can induce a better osseointegration than those containing Zr. (c) 2007 Elsevier Ltd. All rights reserved.53628092817