Effect of scandia content on the hot corrosion behavior of Sc2O3 and Y2O3 co-doped ZrO2 in Na2SO4 + V2O5 molten salts at 1000 °C

The effect of Sc2O3 content on the hot corrosion behavior of x mol.% Sc(2)O(3-)1.5 mol.% Y2O3 co-doped ZrO2 ceramics (ScYSZ) in Na2SO4 + V2O5 (50/50 wt.%) molten salts at 1000 degrees C was investigated. The experiments revealed that the hot corrosion resistance and phase stability of the ScYSZ ceramics increase with the Sc2O3 content as results of the enhanced strength of rare earth-oxygen bond and the increased prohibition effect on the vanadate penetration due to the small ionic radius of Sc3+ and the weak reactivity of Sc2O3 with vanadates. The hot corrosion mechanism was also discussed.