Nanoscopic Hardness Measurement by Atomic Force Microscope

Atomic force microscopes (AFMs) can be used for atomic-scale imaging and nanofabrication. Taking advantage of this we developed a nanoindentation technique. Hardness measurements were carried out on cementite-spheroidized S 25 C carbon steel (Vickers hardness H v ,= 128) and 400°C-tempered SNCM 439 low alloy steel (H v = 414), using a cantilever with a three-sided pyramidal diamond tip. The depth of indentations created was between 14 and 330 nm. The difference in hardness between S 25 C and SNCM 439 steels was detected in the nanoscopic region. From these results, it was concluded that nanoindentation was realized with AFM.