Improvement of High Temperature Behavior of Conventional Zirconia Thermal Barrier Coatings by Cerium Oxide Stabilizer

Thermal barrier coatings (TBCs) as one of the high temperature coatings are widely used to improve the performance of the blades of turbine engines and in particular gas turbines. The purpose of this study was to investigate the thermo-mechanical properties, hot corrosion resistance and high temperature oxidation of conventional zirconia TBC coatings and improve their performance by adding cerium oxide stabilizer to the compound. For this purpose, CoNiCrAlY/YSZ and CoNiCrAlY/CYSZ coatings were applied to substrates of IN738LC by atmospheric plasma spraying. Thermomechanical behavior of the coatings was investigated by measuring the thermal expansion of the coatings. Hot corrosion behavior and oxidation of the coatings by furnace method were investigated at 1050 °C and 1100 °C with 4-hour cycles, with and without the applied of a mixture of corrosive salts (Na2SO4 -V2O5 ). The results showed that CYSZ coating has a higher thermal expansion coefficient than YSZ coating. Microstructural and phase studies of coatings by SEM/EDS and XRD analysis before and after hot corrosion and oxidation tests showed better resistance to CYSZ coating than YSZ coatings.