Oxidation behavior of TiNi shape memory alloy at 450–750 °C

The isothermal oxidation behavior of a commercial TiNi shape memory alloy (SMA) in pure oxygen over the temperature range of 450–750 °C was studied. The oxidation products were identified by X-ray diffraction (XRD). Characterization of the specimens after oxidation was conducted using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The oxidation kinetics at different temperature was studied, according to parabolic and logarithmic laws. The mechanism and activation energy of oxidation were discussed based on the oxidation kinetics. The spallation of the multi-layer scale formed during oxidation was analyzed by growth induced thermal stresses.