The stresses and distortions caused by formation of a thermally grown alumina: comparison between measurements and simulations

Abstract The formation of α-Al2O3 upon thermal oxidation of Al containing alloys is accompanied by growth stresses and distortions. Experiments that demonstrate and measure these phenomena have been devised. A model that predicts the distortions and the stresses has been developed, which incorporates new oxide formation on grain boundaries within the α-Al2O3, as well as redistribution of the induced stresses by plastic deformation. In this study, a quantitative comparison is made between measurements and predictions by analyzing oxide formation around a surface groove in an FeCrAlY substrate. The changes in the shape of the groove caused by cyclic oxidation are characterized and the stresses induced in the oxide that forms around the groove are measured using piezospectroscopy. Simulations are conducted using the independently known thermo-mechanical properties of the alloy and the α-Al2O3. Direct comparisons between the measurements and simulations are used to validate the model.