Electrochemical corrosion of Ti-Al2O3 biocomposites in Ringer's solution

Corrosion in human body can cause changes in materials structure and release of undesirable products which may bring about complications such as toxicity and inflammation, and jeopardize the mechanical stability of the prosthesis. In biomaterials engineering, attempt has been made on design and manufacture of implant materials with less corrosion, and reduced complications. In the present study, corrosion characteristics of titanium-alumina composites (25 vol% and 50 vol% Al2O3) fabricated by spark plasma sintering were analyzed by polarization and electrochemical impedance spectroscopy. Physiological Ringer's solution was used as corrosion medium. The corrosion experiments were conducted in two time intervals. Pure titanium was also fabricated and analyzed for comparison. Furthermore, the samples were immersed in Ringer's solution for about 50 days and then characterized by scanning electron microscope (SEM). From the results of corrosion tests, it was indicated that pure Ti and the Ti-25% Al2O3 had fully passive behavior and experienced breakdown at high voltage in the test potential region. The composite with 25% Al2O3 content also showed superior corrosion resistance. The SEM images of the samples after long time immersion revealed both corroded regions and deposition zones on the surfaces. (C) 2018 Published by Elsevier B.V.