Comparison of different hardness definitions usable for micro- and nanoindentation

In order to describe the hardness of substrates and layers, different defin itions are used which consider the plastic or the elastic-plastic behavior of the material. For a chosen spectrum of substrate and layer materials the absolute hardness values according to these definitions are compared with each other. Moreover, relationships between the hardness values are derived . For the investigation of differences in the accuracy of the various hardn ess definitions the variance coefficients of different hardnesses were dete rmined.