Degradation of CeO2 and TiO2 co-stabilized ZrO2 by the V2O5 molten salts and Na2SO4 + V2O5 molten salts

Abstract

In this study, (Ce0.15Ti0.05)Zr0.80O2 (CTZ) with the tetragonal (t) phase was fabricated by solid-state reaction, and the destabilization resistance of CTZ ceramic was investigated in V2O5, and Na2SO4 + V2O5 molten salts, respectively. After CTZ was corroded in V2O5 molten salt at 700 °C for 2 h, ZrV2O7 and CeVO4 were formed, and the t phase was the main crystalline phase on the CTZ surface. After CTZ was corroded in V2O5 molten salt at 800 °C or 900 °C for 2 h, the amount of CeVO4 increased significantly, and CTZ surface underwent a more corrosion degradation than at 700 °C. After CTZ was corroded in Na2SO4 + V2O5 molten salts at 700 °C or 800 °C for 2 h, the hot corroded products were m-ZrO2 and CeVO4. However, after CTZ was corroded in Na2SO4 + V2O5 molten salts at 800 °C for 10 h or 900 °C for 2 h or 10 h, a new phase of CeO2 was formed due to the mineralization effect. The destabilization of CTZ ceramic under hot corrosion was mainly caused by the chemical interaction and phase transformation.