Abstract

In this study; a novel self-healing concept is considered in order to increase the lifetime of thermal barrier coatings (TBCs) in modern gas turbines. For that purpose; SiC healing particles were introduced to conventional 8YSZ topcoats by using various plasma spray concepts; i.e.; composite or multilayered coatings. All topcoats were sprayed by SG-100 plasma torch on previously deposited NiCrAlY bondcoats produced by conventional atmospheric plasma spraying. Coatings were subjected to thermal conductivity measurements by laser flash method up to 1000°C; isothermal oxidation testing up to 200h at 1100°C and finally thermal cyclic fatigue (TCF) lifetime testing at 1100°C. Microstructural coating evaluation was performed by scanning electronic microscope (SEM); in the as-produced and post high-temperature tested states. This was done to analyze the self-healing phenomena and its influence on the hightemperature performance of the newly developed TBCs.

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