Current Status of Ceramic Layers of Thermal Barrier Coatings for Engine Turbine Blades and the Preparation Technology

ZrO₂ based ceramics, rare earth zirconates, aluminates, tantalates, niobates, perovskites and A₆B₂O₁₇ ceramics, are often used as ceramic layer materials of thermal barrier coatings for engine turbine blades. These layers can effectively reduce the working temperature of the metal substrate of the turbine blades, thereby increasing the allowable working temperature of the engine and extending the service life of the blades. The research progress on the microstructure improvement and performance enhancement of the aforementioned ceramic layer materials for thermal barrier coatings is reviewed, and preparation methods of atmospheric plasma spraying and electron beam-physical vapor deposition are summarized and compared. It is pointed out that future research directions are focused on the improvement of matching thermal expansion coefficients between ceramic materials and the blade substrate material by rare earth doping modification, and on the increase of the fracture toughness and the decrease of thermal conductivity of the ceramic materials. The existing preparation methods should be optimized by parameter adjustments or integration of different processes, so as to obtain cost-effective and stable ceramic layers of thermal barrier coatings.