Thermal barrier coating life modeling in aircraft gas turbine engines

Analytical models for predicting ceramic thermal barrier coating (TBC) spalling life in aircraft gas turbine engines are presented, Electron beam/physical vapor-deposited and plasma-sprayed TBC systems are discussed, An overview of the following TBC spalling mechanisms is presented: (1) metal oxidation at the ceramic/metal interface, (2) ceramic/metal interface stresses caused by radius of curvature and interface roughness, (3) material properties and mechanical behavior, (4) component design features, (5) temperature gradients, (6) ceramic/metal interface stress singularities at edges and corners, and (7) object impact damage, Analytical models for TBC spalling life are proposed based on observations of TBC spalling and plausible failure theories, Spalling was assumed to occur when the imposed stresses exceed the material strength (at or near the ceramic/metal interface), Knowledge gaps caused by lack of experimental evidence and analytical understanding of TBC failure are noted, The analytical models are considered initial engineering approaches that capture observed TBC spalling failure trends.