Correlation of nanoindentation measurements of nickel made using geometrically different indenter tips

Nanoindentation is a widely used technique to measure the mechanical properties of coatings and thin films whose thickness ranges from nanometers to micrometers. Measurement of mechanical properties like hardness and modulus of elasticity of the sample being indented depends on the geometry of the indenter. A change in tip geometry is an added characterization advantage for reliability in design of structural components for mechanical systems. Different kinds of stresses imposed by geometrically different indenters give an indication of material behavior when multiple stresses act on a surface. Tip calibration and analytical simulations of these experiments have been performed using the finite element method. Hardness and modulus values differ for geometrically different indenters. In this paper, an attempt is made to correlate hardness values obtained using three indenters of different geometries and to understand deformation mechanisms of nickel in nanoindentation. The results are examined on the basis of geometrically necessary deformation mechanisms theory [Nix WD, Gao H. J Mech Phys Solids 1998;46:411].