2.2. Thermal oxidation and its kinetics
TO of the Ti–15Mo alloy was carried out in an air atmosphere using a muffle furnace (Furnace & Ceramics, Ajeon Heating Indus-trial Co., LTD., Korea) at 500 and 650◦C for 8, 16, 24 and 48 h and, at 800◦C for 8 h. The rate of heating was kept constant at 5◦C min−1 for all the experiments. The process sequence employed during the thermal oxidation of Ti–15Mo alloy is shown in Fig. 1. After TO, the samples were cooled inside the furnace at its natural rate of cooling.Subsequently, they were cleaned using a bristle brush to remove the loose oxide scales on the surface in order to avoid their influence in the estimation of hardness, water contact angle and corrosion behavior. The kinetics of oxidation was determined from the mass gain during thermal oxidization of Ti–15Mo alloy at 650◦C, measured as a function of time. The mass gain estimated as a function of time was tested using various models and the most suitable model was identified.