Influence of Reaction Time on Hydrogen Resistance Film on the Surface of ZrH_1.8 in Aluminate System

Micro-arc oxidation process was conducted on ZrH_1.8 in the electrolyte composed of NaAlO₂ to fabricate hydrogen resistance film. The as-prepared film was then characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), and vacuum dehydrogenation experiment. The influences of reaction time on thickness, micro-morphology, structure, and hydrogen resistance properties of the hydrogen resistance film on the surface of ZrH_1.8 were investigated. The results show that the thickness of the surface film increases from 78.4 μm to 152.8 μm with the oxidation time changing from 7.5 min to 15 min. The film is composed of M-ZrO₂, T-ZrO₂ and C-ZrO₂, and the oxidation time has no obvious influence on its structure. The film comprises of an exterior loose layer and an interior layer by substrate. When the oxidation time is 10 min, the obtained film is compact and uniform, and has a moderate thickness, showing an excellent hydrogen permeation resistance, of which the Permeation Reduction Factor (PRF) value reaches up to the maximum of 20.