Damage evolution of TBC system under in-phase thermo-mechanical tests

摘要

In-phase thermo-mechanical tests (TMF) of EB-PVD Y_2O_3-ZrO_2 thermal barrier coating (TBC) system (8 wt% Y_2O_3-ZrO_2/CoNiCrAlY/IN-738 substrate) were done under a through-the-thick-direction thermal gradient from TBC surface temperature at 1150 ℃ to substrate temperature at 1000 ℃ Deformation and failure behaviors of the TBC system were observed at the macroscopic and microscopic scales and damage evolution of the system under in-phase thermo-mechanical test was discussed. Special attention was paid to TBC layer cracking, thermally grown oxide (TGO) layer formation and void formation in bond coat and substrate. Effect of TMF conditions on the damage evolution behaviors was also discussed.