The purpose of this study is to investigate the electrochemical response of Al2O3-MoO2-TiO2 oxide films fabricated on 6061 Al alloy by plasma electrolytic oxidation (PEO). The coatings were fabricated under alternating current conditions using an alkalinesilicate- molybdate electrolyte with TiO2, and the results were compared to those without TiO2. Microstructure observations revealed that when TiO2 was added to the electrolyte, the average size and area fraction of the micro-pores of the oxide layer coated in the electrolyte incorporating TiO2 were respectively smaller. The results of potentiodynamic polarization test in 3.5 wt% NaCl solution clearly indicated that the corrosion resistance of the oxide films was significantly improved by the incorporation of TiO2 particles. High corrosion resistance of the Al2O3-MoO2-TiO2 oxide films was also revealed by impedance tests and analyzed in relation to the equivalent circuit model. (C) 2016 The Electrochemical Society. All rights reserved.