Failure Analysis of Thermal Corrosion Cycling of EB-PVD YSZ Thermal Barrier Coatings Exposed to Molten NaCl

Abstract

NaCl is the most abundant salt in seawater, thermal barrier coatings (TBCs) face the challenge of chloride salt hot corrosion in the marine environment. In this work, we focus on evaluating the thermal corrosion cycling of 9 wt.% Y2O3-ZrO2 (YSZ) exposed to NaCl molten salt. YSZ was prepared by electron beam–physical vapor deposition (EB-PVD). The result showed that the thermal cycling life of YSZ coating in the presence of NaCl molten salt was significantly shortened. The shortening of the service life of the coating can be ascribed to the collective effects of the thickening of thermal growth oxide and the degradation of the bond coating.