Corrosion behaviour of Ti-Nb-Sn shape memory alloys in different simulated body solutions

The corrosion resistance of Ti-Nb-Sn alloys in the 0.9% NaCl physiological and Hank's solutions with different pH values (2.4, 5.4, 7.4) at 37 degrees C were investigated by means of open circuit potential (OCP), Tafel and anodic polarization techniques. The compositions of the passive films were analysed by X-ray photoelectron spectroscopy (XPS). The OCP was found to stabilize within several hours for Ti-Nb-Sn alloys in the Hank's solution but continued to increase in the 0.9% NaCl solution. Tafel results indicated that the corrosion current densities were in the magnitude of below 1 mu A/cm(2). Anodic polarization curves demonstrated a wide passive region. XPS analysis results revealed that the passive film mainly consisted of TiO2, Nb2O5 and SnO2. These observations suggest that Ti-Nb-Sn alloys have a large potential for biomedical applications. (c) 2006 Elsevier B.V. All rights reserved.Nanoscience & NanotechnologyMaterials Science, MultidisciplinaryMetallurgy & Metallurgical EngineeringSCI(E)EICPCI-S(ISTP)