Damage quantification in TBCs by photo-stimulated luminescence spectroscopy

A procedure is described for assessing the extent of damage in an electron beam vapor deposited (EBPVD) thermal barrier coating (TBC) based on the quantitative analysis of its photo-stimulated luminescence spectrum. In contrast to purely statistical fitting procedures, the analysis procedure uses experimental calibrations of the effect of stress on the principal features of a luminescence spectrum. Luminescence spectra from a thermally cycled TBC are used to illustrate the procedure and derive estimates of the thermal cycling induced damage.