Impedance spectroscopy analysis of yttria‐stabilized zirconia thermal barrier coatings during high‐temperature oxidation

Abstract The degradation of thermal barrier coatings on Inconel alloy 601, prepared using air plasma spraying deposition and exposed to 1100°C in the atmosphere, was investigated using impedance spectroscopy. The thickness of the thermally grown oxide (TGO) layer in the thermal barrier coating, which was prepared with yttria‐stabilized zirconia as the surface layer, was observed to increase as the oxidation process occurred at high temperatures. It is important to note that the thermal barrier coating may fracture and fail over time due to the continuous thickening of the TGO. In order to assess the thickness of the TGO, we propose a potential method that utilizes AC impedance data, scanning electron microscopy, and energy spectrum analysis.