Effect of Cerium Content on Hydrogen Resistance of ZrH1.8 MAO Coatings

Abstract:

The ceria-stabilized zirconia (CSZ) coating with an excellent hydrogen resistance performance was prepared by micro-arc oxidation (MAO) with cerium addition. The thickness, bonding strength, morphology, phase structure, chemical valence, and hydrogen resistance of ceramic coatings were investigated by coating thickness gauge, auto-scratch tester, scanning electron microscopy, energy dispersive X-ray spectrometer, X-ray diffraction, and X-ray photoelectron spectroscopy, and vacuum dehydrogenation experiment. Results show that CSZ ceramic coatings are mainly composed of monoclinic zirconia (m-ZrO₂), tetragonal zirconia (t-ZrO₂), and t-Zr_0.82Ce_0.18O₂. With increasing the cerium content, the thickness of coating is increased. When the cerium content is 9mol%, the thickness of CSZ ceramic coating reaches the maximum of 135.5 μm, the bonding force is 52.46 N, and the hydrogen permeation reduction factor (PRF) is 19, which indicates an excellent hydrogen resistance. The cerium addition inhibits the phase transformation from t-ZrO₂ to m-ZrO₂, thereby promoting the formation of stable t-ZrO₂ at elevated temperatures.