Tailoring the stoichiometry in NdNbO ₄ for advanced thermal barrier coating applications

Abstract RENbO 4 ceramics have the potential to serve as a viable alternative to YSZ for advanced thermal barrier coatings. However, the fabrication of stoichiometric plasma spray RENbO 4 coatings remains unexplored. Herein, we proposed a strategy to deposit a stoichiometric NdNbO 4 coating using the atmospheric plasma spray technique. This was accomplished by the addition of excess Nb 2 O 5 in feedstock powder to compensate for the evaporated Nb 2 O 5 during the plasma spray process. The influence of powder composition and critical plasma spray parameters (CPSP) on the microstructure and phase formation of NdNbO 4 coatings were characterized. Further, quantitative assessment of Nb 2 O 5 evaporation with varying plasma parameters was also characterized using energy‐dispersive X‐ray fluorescence spectroscopy. Moreover, the support vector machines (SVM) model was used to construct a relation between the initial powder composition, CPSP, and stoichiometry of the coating. This strategy can be used for the fabrication of stoichiometric RENbO 4 coatings for next‐generation thermal barrier coatings.