High-temperature corrosion behavior of zirconia ceramic in molten Na2SO4+NaVO3 salt mixture

Degradation due to molten salt attack is one of the failure mechanisms of thermal barrier coatings . Thermochemical attack of the salt mixture Na 2 SO 4 –30   mol% NaVO 3 on ZrO 2 –8   mol% YO 1.5 (8YSZ) at 1100   °C for different times was investigated. In the present study, 8YSZ powder was synthesized using co-precipitation route. The graded morphologies and phase compositions were examined using SEM, XRD and Raman before and after hot corrosion test. The results obtained from XRD have shown that m-ZrO 2 and YVO 4 were the main corrosion products after hot corrosion test at 1100   °C. The results obtained from SEM and EDS observations have shown that large polyhedron crystals of m-ZrO 2 and rod-like crystals of YVO 4 formed as hot corrosion products after hot corrosion test for 6   h and 24   h. The phase transformation and chemical interaction are the primary corrosion mechanisms for degradation of 8YSZ ceramic.