title: Hardness variation with indenter sharpness in an Au thin-film.
abstract: The effects of the indenter shape on hardness were studied from thin-film nanoindentations. Two Berkovich indenters with different operating histories were prepared and their morphologies were measured with an atomic force microscope. The curvature radii of both indenters that were measured through an image analysis were 58.8 nm and 732.2 nm, respectively. The nanoindentations were carried out on a 1.2 microm-thick Au thin-film with a Nanoindenter XP system with both indenters. Various nanoindentation data with indenter exchanges were surveyed, and they showed that the peak indentation loads under the blunter indenter were higher than those of the sharper indenter at the same indentation depths. The indenter sharpness parameter was used to correct the raw nanoindentation curves. The corrected curves overlapped well and the resulting hardness values were consistent regardless of the indenter sharpness. The intrinsic hardness values of the Au thin-film from both indenters agreed with each other, with only a 0.6% difference. This means the indenter sharpness was properly corrected and that the sharpness must be considered when the contact properties are measured at shallow indentations.
authors.affiliation: Division of Industrial Metrology, Korea Research Institute of Standards and Science, Daejeon 305-340, Republic of Korea.
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Lee
authors.forename: Yong-Il
authors.initials: YI
authors.lastname: Kim
authors.forename: Jun-Hee
authors.initials: JH
authors.lastname: Hahn