Indentation and impression fatigue of aluminum processed by equal channel angular extrusion

Severely deformed aluminum was produced by the ECAE process. The as-processed Al was in a non-equilibrium state with a high dislocation density and displayed unusual mechanical behavior. The near-surface deformation of the as-ECAE processed aluminum was characterized by using micro-indentation technique. The micro-indentation using a Vickers indenter was used to study the effect of the ECAE process on the ECAE deformed Al. The micro-indentation with spherical indenters was used to assess the relation between the indentation stress and indentation strain from the viewpoint of dislocation plasticity. The fatigue behavior of the annealed and the as-ECAE deformed Al was evaluated by using indentation fatigue technique with a flat-end indenter.