TGO formation and failure mode of TBC systems comprising PVD-Al interlayers
In this work, the stage formation of TGO layers and the failure mode of TBC systems with PVD-Al interlayers are described. The study uses thermal cycling tests with maximum temperatures of 1,150 °C. The phases and thickness of the TGOs are investigated by SEM/EDS and Raman after 1, 5, 10, 20, 40, 80 and 130 thermo cycles. The results plot the interface change and crack formation as a function of the thermal cycle number, which allows a correlation between TGO growth and maximum crack length.