Hot corrosion behaviour of the γ‐Y ₂ Si ₂ O ₇ ceramic exposed to NaVO ₃ or V ₂ O ₅ molten salt

The hot corrosion behaviour of the γ-Y2Si2O7 ceramic exposed to NaVO3 or V2O5 molten salt was studied at 1000–1300°C. YVO4 was identified as the corrosion product due to the chemical interaction of the two corrosive agents with the γ-Y2Si2O7 ceramic. Although YVO4 produced in the two corrosion reactions had the same crystallographic structure, they had different morphologies. YVO4 produced by the corrosion of NaVO3 with the γ-Y2Si2O7 ceramic showed a rod-like shape, whereas it was particle-shaped in the corrosion reaction of V2O5 with the γ-Y2Si2O7 ceramic. Additionally, the degradation of γ-Y2Si2O7 ceramic by V2O5 was more severe than that by NaVO3, and the thickness of the corrosion layer significantly increased with temperature. In this study, a model describing the formation of the corrosion product was established, and the formation of YVO4 with different morphologies in the two corrosion reactions was explained based on the growth characteristics of the YVO4 crystals.