Development of Alumina Coatings on Ni-Cr Superalloy Turbine Blades Enhanced by Thoria-Integrated Yttria and Ceria-Stabilized Zirconia Nanoparticles for High-Temperature Thermal Barrier Coatings and Corrosion Resistance

Thermal Barrier Coatings, often known as thermal barrier coatings (TBCs), are widely used in gas turbine engines in order to increase engine efficiency and extend component life. The primary goal of this research project is to create an alumina coating using micron-sized powders on Ni-Cr superalloy turbine blade material and TBC. The top layer of the TBC system will be composed of Thoria-integrated Yttria and Ceria-stabilized Zirconia nanoparticles. With the exception of cubic stabilized zirconia as a component, TBCs for high-temperature applications can scale up surface temperatures to 1200 °C. The main objective of the present endeavor is to create 8 mol.% Yttria-stabilized Zirconia with 24 mol.% Ceria (24Ce-8YSZ) combined with Thoria-Yttria and Ceria-Stabilized Zirconia (T-YCSZ). For the purpose of YCSZ ceramics from their cores, a wet chemical route powder synthesis technique was used. Separately, thoria was created from its nitrate and mixed with YCSZ to enhance its properties for use in high-temperature coatings. Thoria-integrated Yttria and Ceria-stabilized Zirconia (T-YCSZ) nanoparticles are used as the top layer in the TBC system to create TBC. When coated turbine blades were subjected to corrosion studies, better outcomes were shown than with untreated blades. The coated surface shows an astounding 91.6% diminution in corrosion current density (μA cm⁻²) compared to the substrate being its uncoated version. Apart from this, it presents the anodic Tafel slope (mV dec⁻¹) about 3.7 as well as the cathodic Tafel slope (mV dec⁻¹) about 3.3 that is more than 3 times higher. Hence, this will inhibit the corrosion initiation and propagation. Furthermore, the corrosion potential (mV) is more positive and displays a major, favorable deviation toward a resting state. What more, the resistivity of the nonstoichiometric lattice was almost 22.4% times greater, corresponding to a significant change of the charge transfer resistivity measurements for the corrosion processes. Besides that, the capacitance of the CdS/CNT-CuO JSC has a drop of 82.0% or μF cm⁻², indicating a considerable inhibition to surface charge arousal. From the data as a whole, a significant readout of these observations can be interpreted as the source of corrosion control by the coat is already strengthened further with the help of the coating on top of the substrate.