Quantification of first contact detection errors on hardness and indentation size effect measurements

A new method is proposed for the quantification of macroscopic hardness and indentation size effect. This method is based on the simultaneous treatment of several nanoindentation loading curves which are located according to the gap between their shape and the one predicted by the Bernhardt law. By applying this method on stainless steel loading curves, it is shown that hardness error can be reduced by a factor of 2 compared with usual treatment methods. It is shown that only the simultaneous treatment of all the curves enables the good prediction of pile-up in the material.

Graphical AbstractFigure optionsDownload high-quality image (331 K)Download as PowerPoint slideHighlights
► Macrohardness and indentation size effect are quantified using a new treatment method.
► One hundred experimental loading curves are treated simultaneously.
► The zero position is dealt with a new definition of the curve location.
► Macrohardness error is divided by two compared to usual methods.
► Treating the curves separately leads to misidentification of the indentation size effect.