Effects of calcium–magnesium–alumina–silicate and NaCl melting sequence on corrosion resistance of thermal barrier coatings

Calcium–magnesium–alumina–silicate (CMAS) and/or molten salt corrosion have attracted increased attention, which is an important cause of thermal barrier coating (TBC) failure. In this study, the effect of CMAS and NaCl melting sequence on the corrosion mechanisms of yttria-stabilized zirconia (YSZ) TBCs was revealed through experiments and finite element simulations. The YSZ TBCs were prepared via atmospheric plasma spraying. Subsequently, the CMAS and NaCl corrosion experiments of the TBCs were conducted at 1250°C. Results indicated that the melting sequence of CMAS and NaCl could influence the TBC failure mode. The coating failure modes after CMAS + NaCl mixed corrosion and NaCl melting followed by CMAS melting were buckling failures. Conversely, the coating failure mode was observed to be spalling failures. This study provides data support for the optimization of TBC systems in complex corrosive environments.