Characterization and hot corrosion behavior of the La2(Zr0.7Ce0.3)2O7/8YSZ:Eu double ceramic layer coating prepared by atmospheric plasma spraying

A La2(Zr0.7Ce0.3)2O7/8YSZ:Eu (LZ7C3/8YSZ:Eu) double ceramic layer coating was prepared via an atmospheric plasma spraying (APS) method, and hot corrosion tests of volcanic ash on the coating were carried out. The hot corrosion behavior of the dual layer coating system was studied. At high temperatures, the molten volcanic ash spreads out on the coating surface, and chemical reaction between LZ7C3 and volcanic ash happens. Upon cooling, the molten volcanic ash solidifies resulting in the accumulation of stress, which in turn leads to crack formation and spallation. The spallation of the LZ7C3/8YSZ:Eu coating takes place in the coating surface in a layer by layer manner due to splats structure in APS coating. In addition, it was found that the luminescence sublayer could be used to provide details regarding the state of the hot corrosion process in the double ceramic layer coating.