SUMMARY

In this proposed research, oxide scale growth and associated stress and morphological developments during high temperature oxidation are investigated. The objective is to improve the understanding of the mechanisms leading to mechanical failure and their relation with the metallic alloy properties and composition. Two different oxides, alumina and chromia, in two different industrial systems, thermal barrier coatings and solid oxide fuel cell interconnects, are studied. The stress origins and their coupling with the oxide scale growth are reviewed, along with the main influence of metallic alloy composition, particularly of reactive element addition. An innovative treatment of local oxide phase growth coupled with stress generation is developed. This formulation is completed with a comprehensive macroscopic framework including species diffusion in a polycrystalline material, and stress development and relaxation processes. A specific numerical simulation tool is developed allowing for complex analyses. Finally two practical situations in which oxide scale growth and associated stress and morphological developments are critical have been identified and will be simulated and analyzed.