Characterization of ZrO2 ceramic coatings on ZrH1.8 prepared in different electrolytes by micro-arc oxidation

Abstract

ZrO2 ceramic coatings were directly prepared on the surface of ZrH1.8 in silicate and phosphate electrolytes by micro-arc oxidation (MAO) technique, respectively. The microstructure, chemical composition and phase composition of ZrO2 ceramic coatings were investigated by X-ray diffraction (XRD), energy-dispersive spectrometry (EDS) and scanning electron microscopy (SEM). The anti-permeation effect was measured by means of vacuum dehydrogenation experiment. It is found that the coating fabricated in phosphate electrolyte is more compact than that in silicate electrolyte. The coatings fabricated on the surface of ZrH1.8 are composed of M-ZrO2, T-ZrO2 and C-ZrO2. EDS analysis indicates that the coatings are mainly composed of O and Zr. Vacuum dehydrogenation experiment shows that the permeation reduction factor (PRF) of coating prepared in phosphate electrolyte is superior to that in the silicate electrolyte, and the PRF value reaches up to 11.2, which can enhance the resistance effect of hydrogen significantly.