ABSTRACT
Lower thermal conductivity (TC) and better erosion resistance (ER) of high-temperature protective coatings are an imperative requirement of extending the durability and life of hot-section components of gas turbine engines. For the former, the lower TC possesses the capability of significantly increasing the inlet temperature of the gas turbine to enhance the efficiency of the engine and reduce the emission pollution; for the latter, better erosion resistance of coatings can survive the harsh environment. In this chapter, the six-phase model of porous thermal barrier coatings (TBCs) was used to evaluate thermal conductivity of ceramics topcoat of TBCs. By combining temperature-processing-dependent thermal physical and elastic moduli, fatigue and physics-based subcritical crack growth formulae were applied to analyzing failure behavior and predicting the life of APS-TBCs. Finally, the erosion resistance and the cutting-deformation wear erosion model were combined to assess the erosion rate of oxidation resistant coatings at elevated temperatures. This multi-mechanics-based approach establishes the foundation for the design and development of high-temperature protective coatings of gas turbine engines.
