Hot corrosion behavior of Mg\(_{2}\)SiO\(_{4}\) ceramic exposed to molten Na\(_{2}\)SO\(_{4}\) at 900℃ to 1100℃

Abstract

Thermal barriers are used as protective coating for critical components working at high temperature of gas turbines. Forsterite (Mg2SiO4) ceramic is proposed by researchers as a novel thermal barrier coating (TBC), due to its low thermal conductivity and good thermal expansion. Hot corrosion results from the molten salts effect on the TBC’s surface, accumulated during the combustion processes. In this study, Mg2SiO4 samples were exposed to Na2SO4 molten salt at 900℃, 1000℃ and 1100℃ for 6 h in air. Samples were investigated and compared using scanning electron microscope (SEM) and X-Ray diffractometer (XRD). MgSO4 was the predominant corrosion product observed on the surface of the samples. Na2Mg5Si12O30 was also observed at 1000℃ and 1100℃, and Na2SiO3 appeared only on sample treated at 900℃.