Influence of superficial CeO2 coating on high temperature oxidation behavior of Ti–6Al–4V

Highlights: ► The superficial CeO2 coating on Ti–6Al–4V alloys was prepared by dipping the alloy specimens several times in a slurry mixture of CeO2 and ethanol in order to attain a scale thickness of ∼0.2 mm. ► The high temperature oxidation behavior of the coated and uncoated alloys have been studied in the range of 923–1223 K in dry air under isothermal as well as cyclic conditions. ► The mechanism of oxide scale growth and the formation of complex oxides have been investigated by X-ray diffraction and scanning electron microscopy. - Abstract: The effect of superficial CeO2 coating on the oxidation behavior of Ti–6Al–4V has been studied under isothermal and cyclic heating conditions in the temperature range of 923–1223 K in dry air. During the early periods of exposure, the oxide scale grows obeying near linear followed by near parabolic kinetics and consists of alternate layers of α-Al2O3 and TiO2. The mass gain of the uncoated alloys is found to be two times higher than that of the coated one in the temperature range of 923–1123 K up to 36 h of exposure. The scale composition on the bare or coated alloy is found to depend both on the temperature and on the time of exposure. During cyclic exposure, the scale suffers spallation for both the bare and the coated alloy, which has been attributed to insufficient plasticity of the scale.