Enhanced hydrogen barrier performance of ZrH1.8 via yttria-zirconia composite film developed through the ECD-MAO technique

Abstract

To address the inherent shortcomings of the direct micro-arc oxidation method, this study employed a combination of electroplating and micro-arc oxidation techniques. This approach successfully fabricated a hydrogen permeation barrier film on the surface of ZrH1.8, featuring a yttria-stabilized zirconia (YSZ) composite oxide. The prepared composite film layer underwent thorough evaluations, encompassing assessments of its microstructure, phase structure, adhesion strength, thickness, barrier properties, and hydrogen permeation performance. The findings indicated that the electroplated yttrium layer contributes to the stabilization of the tetragonal phase of zirconia (T-ZrO2) during the micro-arc oxidation process, thereby enhancing the discharge behavior of the film layer. By employing this treatment method, the content of T-ZrO2 in the film layer increased to 26.70%, and the film became denser with a thickness of 60.93 μm. Additionally, the adhesion strength between the film layer and the substrate significantly improved, reaching 75.95 N, with a hardness of 393.24 HV. Furthermore, the film layer exhibited an increased hydrogen release temperature of 680 °C, demonstrating excellent performance as a hydrogen permeation barrier.