Determination of the growth stress and strain in α-Al2O3 scales during the oxidation of Fe–22Cr–4.8Al–0.3Y alloy

The displacement of the thermally grown oxide in thermal barrier systems upon temperature cycling

“…The most direct evidence emerges from experiments on thin foils, which elongate upon isothermal oxidation [34,35]. A similar elongation of the TGO occurs, locally, around imperfections (Fig.…”

The non-destructive and nano-microstructural characterization of thermal-barrier coatings

“…The effect of the thermal mismatch alone can give rise to stresses as high as 4 GPa in the TGO at room temperature. [5][6][7] Thus, failures frequently occur during cooling or once ambient temperature is reached. The damage evolution up to the final failure is often related to a complex evolution of the microstructure, where damage during thermo-mechanical cycling initiates at multiple interfacial flaws in the vicinity of the TGO.…”

Evolution of surface morphology of thermo-mechanically cycled NiCoCrAlY bond coats

“…The compressive stresses are caused by a combination of the thermal expansion mismatch between the TGO and the bond coat during the cooling/heating sequence and by the growth strain developing in the TGO during formation of the alumina. The compressive stresses can reach several GPa at ambient conditions [2,30,31]. The TGO strive to relax the compressive stress by deforming out of its plane, deforming the bond coat.…”

“…The growth strain is induced due to the oxidation process when the new alumina is formed [1,30,32,33]. Most of the TGO growth occurs as thickening, but a small part is distributed in the…”