Volume 26, Issue 6 (November 1998)
Vickers Hardness Indentations Measured with Atomic Force Microscopy
Vickers hardness indentations on a steel gage block (-900 HV) with diagonals between 3.4 and 44 µm have been measured with a calibrated atomic force microscope (AFM) and with an opticalbased method. From the AFM images the diagonals were measured from hard copies of diagonal profiles and automatically by image analysis. The combined standard uncertainty for the 3.4-µm diagonals was 10% for the optical-based and only 2.4% for the profile-based measurements (68% confidence level). Indentations with diagonals between 10 and 44 µm had concave shapes, in contrast to the 3.4-µm indentations. We show that optical-based measurements were not made at the level of the background plane, but higher on the indentation ridges.