Characterization of Thermal-Barrier Coatings in Turbine Blades by Confocal Raman Imaging Microscopy

Thermal-barrier coatings (TBCs) are refractory-oxide ceramic coatings applied to metallic components in the hottest sections of gas-turbine engines, enabling operation at elevated gas temperatures critical to improving engine efficiency and performance. As demands on TBC systems continue to grow, advanced characterization techniques are essential for understanding coating microstructure, phase composition, and stress states across the complex multilayer architectures of these coatings.

In this work, confocal Raman imaging microscopy was applied to the analysis of TBCs in turbine blades. The technique enabled spatially resolved chemical and structural characterization of the individual TBC layers with high spectral and spatial resolution, yielding information on phase distribution and stress across the coating system. Sample preparation requirements and analytical considerations for practical blade analysis will also be discussed.