Formation of self-similar structures on{100}〈00l〉 aluminum single-crystal foils under cyclic tension

We study the relief formed on {100}〈001〉 aluminum single-crystal foils attached to thick aluminum alloy specimens under low-cycle fatigue deformation. The formation of specific surface structures on the aluminum foils is shown to relate to the “foil - specimen” and “aluminum foil - its surface layer” interfaces. Particularly, the formation of longitudinal macroscopic bands on the aluminum foil is explained by periodic distribution of compressive stresses arising at the “foil - specimen” interface. At the interface between the macroscopic bands and tweed structure with spacing ∼2.8 μm a fine tweed substructure of the submicron range is found. The periodic 2D lattices of various scale formed on the foils are self-similar in the linear size range from fractions to hundreds of microns.