Calcium-magnesium-alumino-silicate (CMAS) degradation of EB-PVD thermal barrier coatings: Characterization of CMAS damage on ex-service high pressure blade TBCs

► Ex service high pressure turbine blades are investigated. ► CMAS infiltrates the TBC inter-columnar gaps down to the TGO oxide layer. ► Large vertical separations and delamination cracks are observed in the infiltrated TBC. ► Dissolution of TBC in the CMAS melt and formation of an interfacial phase are observed. ► CMAS composition is determined and compared to other published CMAS.