Open Access Conference Proceedings

Depth sensing indentation allows deriving mechanical properties from the indentation load-displacement data using a micromechanical model developed by Oliver & Pharr (O&P). However, O&P analysis on the indentation unloading curve is developed from a purely elastic contact mechanics (sink-in). The applicability of O&P analysis is limited by the materials pile-up. However, when it does, the contact area is larger than that predicted by elastic contact theory (material sinks-in during purely elastic contact), and both hardness, H, and Young’s modulus, E, are overestimated, because their evaluation depends on the contact area deduced from the load-displacement data. H may be thus overestimated by up to 60 % and E by up to 30 % depending on the extent of pile-up [1,2]. It is therefore important to determine the effect of pile-up on obtained mechanical characteristics of the material by depth sensing indentation. The work experimentally analyses the effect of pile-up on the mechanical characteristics H and E of steel sample with different strain hardening history by Depth Sensing Indentation. Mechanical characteristics are determined by O&P analysis. Pile-up height was measured by atomic force microscopy (AFM). The work experimentally analyses the effect of pile-up on the mechanical characteristics H and E of sample with different strain hardening history by Depth Sensing Indentation. Mechanical characteristics are determined by O&P analysis. Pile-up height was measured by atomic force microscopy (AFM).

Keywords: Berkovich diamond indenter, pile-up, Young’s modulus, hardness, thin steel sheets

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.