Oxidation‐Based Model for Thermal Barrier Coating Life

A procedure is described for modeling the lives of thermal barrier coatings subjected to high‐temperature environments. The model is used to calculate cycles‐to‐failure as a function of heating cycle duration. It is based on the presumption that oxidation is the single important time‐dependent factor which limits the life of these coatings, and that oxidation‐induced strains combine with cyclic strains to promote slow crack growth in the ceramic layer. Good agreement is obtained between calculated and experimental lives for specimens tested in a furnace. This shows that an oxidation‐based approach is promising. The importance of reproducible specimen preparation is also discussed.