Abstract
Two pyramidal indenters, one nearly sharp and one worn, were used to investigate contact deformation and nanohardness of a gold film. By superposing area functions of the two indenters on the Berkovich pyramidal relationship, the bluntness distances, hbs of the indenters could be estimated; hb values were 8.19 and 40.08 nm for the NEW and OLD indenters, respectively. Nanoindentations on a gold film produced different data from the two indenters; the peak indentation loads of the OLD indenter were higher than those of the NEW one at corresponding indentation depths because the blunt or OLD indenter caused more severe contact deformations at higher loads. Nanohardness trend analyzed from raw nanoindentation curves of the NEW indenter seemed to be lower than that of the OLD indenter. In order to compensate the apex blunting, the raw nanoindentation curves of each indenter shifted along the indentation depth axis by the amount of the bluntness distance. Conclusively, nearly overlapping nanohardness trends could be obtained regardless of the indenter from the shifted nanoindentation curves. The nanohardness values recalculated were consistent within 0.45% at deep indentation regime where all indenters acted as the perfect Berkovich pyramid.
