An investigation on hot corrosion behavior of YSZ-Ta2O5 in Na2SO4 + V2O5 salt at 1100 °C

This study compares the hot corrosion performance of yttria stabilized zirconia (YSZ), and YSZ-Ta2O5 (TaYSZ) composite samples in the presence of molten mixture of Na2SO4 + V2O5 at 1100 °C. For YSZ, the reaction between NaVO3 and Y2O3 produces YVO4 and leads to the transformation of tetragonal ZrO2 to monoclinic ZrO2. For TaYSZ, minor amounts of NaTaO3, TaVO5 and Ta9VO25 are formed as the hot corrosion products with only traceable amounts of YVO4. Due to the synergic effect of doping of zirconia with both Y2O3 and Ta2O5, the TaYSZ sample has a much better hot corrosion resistance than YSZ.