LAUSR

Abstract The pore filling behavior in yttria-stabilized zirconia air plasma sprayed (APS) thermal barrier coatings (TBCs) during calcium-magnesium-alumino-silicate (CMAS) infiltration process was investigated. After fully infiltration, the total porosity of the coating decreased. However, the total porosity of the top region increased due to severe microstructural change. For the bottom region, whose microstructure did not change significantly, its total porosity dropped and almost all crack network disappeared, but 48 vol. % of globular pores still existed and larger globular pores were more likely to remain. This study indicates that introducing relatively large globular pores into APS TBCs may mitigate CMAS damage.