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 bather coatings. Thermochemical attack of the salt mixture Na2SO4-30 mol% NaVO3 on ZrO2-8 mol% YO1.5 (8YSZ) at 1100 degrees 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-ZrO2 and YVO4 were the main corrosion products after hot corrosion test at 1100 degrees C. The results obtained from SEM and EDS observations have shown that large polyhedron crystals of m-ZrO2 and rod-like crystals of YVO4 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. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.