Published online by Cambridge University Press: 15 February 2011
The steady-state creep response of multilayered polycrystalline materials subjected to cyclic variations in temperature is analyzed. The approach presented here is capable of predicting the evolution of curvature, the thermal stresses, and the dominant deformation mechanisms at any through-thickness location of each layer for prescribed layer geometries and thermo-mechanical properties of the constituent layers. The Al-Al2O3 model system is considered, where the dominant relaxation mechanism in Al is studied as the layer thickness is systematically varied. Creep due to grain boundary diffusion is found to become more significant in thin layers with a three-dimensional equiaxed grain structure. The effects of columnar grain structure in Al thin films on the thermal cycling response are also discussed.