Effect of Y2O3 content on microstructure and corrosion behavior of ZrO2 coatings in liquid Lead-Bismuth eutectic

The microstructure and corrosion resistance of Y2O3 doped ZrO2 coatings are investigated in static liquid leadbismuth eutectic (LBE) at 550-650 degrees C for 5000 h. The addition of Y2O3 facilitates the crystallization of the ZrO2 coating, and the coating is composed of c-ZrO2. The hardness and elastic modulus of the coating increase with increasing Y2O3 content. The ZrO2 coatings doped with 5 and 6 mol.% Y2O3 undergo dissolution corrosion due to stress-induced cracks and spallation during the corrosion process at 550 degrees C. In contrast, ZrO2 coating doped with the 4 mol.% Y2O3 maintains a dense and intact structure even after 5000 h of corrosion at 550-650 degrees C. Therefore, the results show that the ZrO2 coating doped with 4 mol.% Y2O3 has good corrosion resistance and can be used as a potential fuel cladding protective coating for lead-cooled faster reactor (LFR) reactor applications.