Influence of impurities in Al2O3 ceramics on hot corrosion resistance against molten salt

This report describes an investigation of the influence of impurities of Al2O3 on the hot corrosion resistance against V2O5–Na2SO4 molten salt. Thickness of damage zone in Al2O3 ceramics whose purity is high depends on the holding time linearly. On the other hand, thickness of damage zone in Al2O3 whose purity is relative low depends on square root of holding time. In the impurities, SiO2 affected the corrosion rate of Al2O3 especially. Grain boundaries are suffered from hot corrosion. SiO2 would influence the diffusion rate of corrosive elements through grain boundaries and the corrosion rate.