Thermal barrier coating (TBC) systems are receiving a great deal of attention as a result of their ability to enable higher operating temperatures without sacrificing component durability in gas turbine systems. Nonetheless, there are a number of unknowns associated with the failure of TBC systems. In particular, the initiation and propagation of damage has not been observed. In this paper, the microstructural changes in and along the thermally growth oxide layer of a TBC are presented. Specimens were studied primarily after isothermal exposure for 48, 96, 200, and 300 hours at 1100°C and also after thermocyclic exposure. Failure features are discussed and the growth of oxide is quantified. The oxide growth is placed within the context of a parabolic growth model. [S0094-4289(00)01503-6]

Issue Section:
Technical Papers
Keywords:
thermal barrier coatings, gas turbines, high-temperature effects, crystal microstructure, oxidation
Topics:
Damage, Gas turbines, Oxidation, Thermal barrier coatings, Failure, Fracture (Materials), Diffusion (Physics), Separation (Technology)
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Copyright © 2000
 by ASME
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