Failure behavior study of EB-PVD TBCs under salt spray corrosion and thermal shock cycles

Abstract

Thermal barrier coatings (TBCs) are the most used methods to protect the internal hot end components of aeroengines for their improved thermal efficiency. Because of the severe service environment of TBCs, their spalling failure poses a problem. In recent years, studies on the erosion resistance of TBCs in marine atmosphere have attracted much attention. The study made an initial attempt in building a simulation experiment of aeroengine TBCs under marine atmospheric circumstances to explore the effect of thermal shock on the performance of TBCs under salt spray corrosion. The experimental results show that electron beam-physical vapor deposition (EB-PVD) Y2O3-stabilized ZrO2 (YSZ), one of the mainstream TBCs technologies, produced 20% of the surface spalling area after 300 thermal shock cycles under the simulated experimental conditions of salt spray corrosion and thermal shock. By testing and analyzing the failure samples and combining the results of SEM, EDS, and XRD, it was found that the ceramic layer and thermally grown oxide (TGO) are partly dissolved, thus dispersing coatings’ particles, but the phase structure does not change significantly, indicating the fine anticorrosion property of EB-PVD TBCs.