Microstructural features resulting from isothermal and thermocyclic exposure of a thermal barrier coating

Thermal barrier coating (TBC) systems are receiving a great deal of attenti on as a result of their ability to enable higher operating temperatures wit hout 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 observe d. In this paper, the microstructural changes in and along the thermally gr owth oxide layer of a TBC are presented. Specimens were studied primarily a fter isothermal exposure for 48, 96, 200, and 300 hours at 1100 degreesC an d also after thermocyclic exposure. Failure features are discussed and the growth of oxide is quantified. The oxide growth is placed within the contex t of a parabolic growth model. [S0094-4289(00)01503-6].