ANALYSIS OF VICKERS INDENTATION

Indentation tests have for a long time been a standard method for material characterization as they provide an easy, inexpensive, non-destructive and objective method of evaluating basic properties from small volumes of materials. Besides hardness, recently also aspects of, for example, toughness and residual stresses have been advantageously investigated by indentation. Sharp indentation tests such as Vickers, Berkovich and Knoop lack however a solid mechanical foundation. The present paper aims mainly to explore the theoretical foundation for the commonly used Vickers test. The investigated types of constitutive behavior include isotropic linear elasticity and plasticity. The influence of large elastoplastic deformations was also assessed. Extensive computation was required, based on the finite element method. In addition, the analysis was compared with depth-sensing indentation experiments. The results put forward explanations of hardness formulae for many standard materials such as metals, as well as the stress and deformation analysis relating to the Vickers indentation test.