Oxidation behaviour of zirconium hydride and its influence on the thermal desorption kinetics

The oxidation kinetics of zirconium hydride powder in air was studied over the temperature range of 100-300 °C. The oxidation kinetic parameters were obtained and a controlling mechanism was proposed. The XPS depth profile analysis was consistent with a layered structure of the oxide film. The evolution of oxygen concentration profile allowed to estimate the diffusion coefficient of oxygen in zirconium oxide. Thermal desorption behaviours of pre-oxidized ZrH2 were studied using simultaneous thermogravimetry and thermal desorption spectroscopy (TG-TDS). The phase transformation sequence during dehydrogenation process of pre-oxidized ZrH2 was established and a corresponding shrinking core model was proposed.