Actual indenter tip geometries, material elastoplastic deformation laws and universal hardness

The precise knowledge of materials mechanical properties is always a core issue in every technical application. Through a developed finite elements method (FEM) continuous simulation of the nanoindentation, the applied force course versus the penetration depth is adequately simulated during the loading and unloading phases of this test, and the corresponding material stress ‐ strain curves, as well as the universal hardness, are stepwise defined. Furthermore, the actual tip geometries of various indenters are approached and through equivalent magnitudes described. The results show that the defined material elastoplastic deformation characteristics are independent of the indenter type, as Vickers or Berkovich, since the existing indenter tip form deviations from their ideal geometry are considered. Furthermore, using the developed FEM-based nanoindentation simulation, the influence of the indenter tip geometry on the defined constitutive laws and the universal hardness is sufficiently elucidated. Various materials stress ‐ strain curves and universal hardness courses versus the indentation depth, determined by means of the developed procedure, are presented.