Anode Voltage on Hydrogen Permeation Barrier Performance of Zirconium Hydride with Micro-arc Oxidation

Technology of micro-arc oxidation was applied on ZrH1.8 in the electrolyte composed of NaAlO2+NaOH+ Na(2)EDTA in constant voltage mode. The film was characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), and vacuum dehydrogenation experiment, respectively. The influences of anode voltage (350 to 425 V) on surface and cross-sectional morphology, structure, and hydrogen resistance properties of the hydrogen resistance film on the surface of ZrH1.8 were investigated. The micro-arc oxidation process can be divided into four stages: anodic oxidation, spark discharge, micro-arc oxidation and flameout. The results reveal that film obtained in the electrolyte is composed of inner dense layer and outer loose layer, and proportion of the dense layer is about 80%. Grain sizes and growth rate of the film increase while the d-spacing decreases with the increase of the anode voltage, and the thickness of the film is increased from 122 to 150 mu m. However, anode voltage has no obvious influence on the structure of the film. The prepared film is composed of M-ZrO2 and T-ZrO2. When the anode voltage is 400 V, the permeation reduction factor value reaches the maximum of 20.