Creep effects on early damage initiation in a TBC system

High temperature superalloys coated with thermal barrier coating (TBC) may induce creep effects in different layers such as in the bond coat and the thermally grown oxide (TGO) layer. The effects of creep deformation in these layers were investigated on the magnitude of residual stresses in these layers. Results indicated that the residual stress after creep was considerably higher when compared with the stress without creep. This larger value of stresses is likely to enhance the initiation of microcracks and debonding of the TBC leading to spallation.