Hot corrosion resistance of oxide-doped yttria-stabilized zirconia powder in V2O5 molten salt

Abstract

The hot corrosion resistance of 8 wt.% yttria-stabilized zirconia (8YSZ) powder, modified with CaO, MgO, Ta₂O₅, and TiO₂ at concentrations of 5, 10, and 15 wt.%, was systematically investigated in a molten vanadium pentoxide (V₂O₅) environment at 900°C and 1100°C for 48 h. The modified 8YSZ samples, coated with V₂O₅, underwent thermal cycling totaling 12 cycles. Results revealed susceptibility to hot corrosion for all doped 8YSZ powders, attributed to tetragonal ZrO₂ destabilization, forming monoclinic ZrO₂. Remarkably, 8YSZ/CaO demonstrated exceptional resistance to hot corrosion when exposed to a temperature of 900°C. The corrosion product found in the 8YSZ/Ta₂O₅ material was determined to be tetragonal Zr_0.66Y0.17Ta_0.17O₂. Although, 8YSZ/TiO₂ undergoes deterioration at 900°C, it exhibits improved resistance at 1100°C, resulting in the formation of TiVO_4.