Deformation of anodic aluminum oxide nano-honeycombs during nanoindentation

Anodic aluminum oxide with a nano-honeycomb structure is subjected to nanoindentation along the axial direction of the honeycomb. The load–displacement behavior is discontinuous with periodic strain excursions. Top-view and cross-sectional microscopic examination reveals a localized mode of deformation with very clear-cut elastoplastic boundaries. A crack system that is self-similar with respect to the indent size is also found, and this is thought to correspond to the discontinuous load–displacement behavior. A simple column model is proposed to explain certain features of the deformation microstructure.