A Method for Studying the Nano-Scale Stress-Strain Response of a Material by Nanoindentation

Abstract

A method was developed using nanoindentation with a spherical indenter to probe the elastic stress-strain response of a given material quantitatively at the nanoscale. To account for the fact that the realistic indenter tip shape is not strictly spherical down at the nanoscale, this method comprises a procedure to calibrate the indentation strain based on the elastic indentation stress-strain data of a reference sample with known elastic modulus. One of the advantages of the nanoindentation-based approach is that it also enables qualitative assessment of the subsequent elastic-to-plastic transition and post yield behavior of the material. An aluminum alloy tested by the present method was shown capable of exhibiting a significantly greater strength to resist initial plastic deformation than in the case of tensile testing of bulk samples.