Abstract:Hydrogen desorption behaviors of zirconium hydride at temperature range of 100−900 ℃ in mixture gases of helium and oxygen was studied by gas phase analysis(GPA). Meanwhile, the morphologies of the oxide scale formed on the surface of zirconium hydride were analyzed by scanning electron microscopy(SEM). The hydrogen desorption is retarded effectively when zirconium hydride is exposed to an oxygen containing atmosphere. Hydrogen desorption in mixed gas of helium and oxygen starts at 525 ℃ and reaches maximum at 660 ℃ and ends eventually at 800 ℃. No hydrogen desorption is found at the temperature range from 800 ℃ to 900 ℃. An oxide scale with approximately 20 μm in thickness formed on the surface of zirconium hydride acts as an effective diffusion barrier.

Key words: zirconium hydride; gas phase analysis(GPA); hydrogen desorption; oxide scale