High-Temperature Cyclic Oxidation of Single and Dual-Layer CSZ: ZrO2-25 wt% CeO2-2.5 wt% Y2O3/MAC: MoSi2 + Al2O3 + CSZ Self-healing TBCs at 1100 degrees C

High-temperature oxidation has been regarded as a major challenge in the degradation of thermal barrier coatings (TBCs). The present study introduces a new TBC (CSZ: ZrO2-25 wt% CeO2-2.5 wt% Y2O3/MAC: MoSi2 + Al2O3 + CSZ) with enhanced resistance to high-temperature oxidation compared to the conventional CSZ TBC. Conventional single-layer CSZ TBC and dual-layer CSZ/MAC self-healing TBC were deposited using an atmospheric plasma spray (APS) technique on IN738LC substrates with a NiCrAlY bond coat. The high-temperature cyclic oxidation testing was performed in air at 1100 degrees C with 4 h in each cycle. Phase and microstructural investigations of the coatings by XRD and FESEM/EDS methods before and after the high-temperature cyclic oxidation testing indicated the better performance of CSZ/MAC self-healing TBC (relative to conventional CSZ TBC) in preventing the diffusion of oxygen. The microstructural analysis indicated that the growth rate of TGO layer was considerably slower for dual-layer CSZ/MAC self-healing TBC due to reduced oxygen infiltration and crack propagation and, therefore, has a better high-temperature performance. [GRAPHICS] .

Automated summary

This study introduces a new thermal barrier coating (CSZ: ZrO2-25 wt% CeO2-2.5 wt% Y2O3/MAC: MoSi2 + Al2O3 + CSZ) with enhanced resistance to high-temperature oxidation compared to traditional CSZ TBC.