Indentation velocity effect on martens hardness measurement

The indentation test in the micro- and nanorange is analysed for practical indentation velocities in the range between (2 ⋯ 60 nm/s). This is one decisive peculiarity when measuring coated samples with a coating thickness d 1 μm/s. The influence of the indentation velocity vind for coated samples yields the largest relative changes of Martens Hardness ΔHM for ductile materials with small coating thickness and for brittle materials with large coating thickness. In order to assure comparable measurement results of HM in the draft standard ISO/CD 14577-4 should be stipulated a range of indentation velocity vind = (10 ⋯ 20) nm/s. The investigation of the effect of the indentation velocity on coated samples should be continued in the direction to reveal further influence quantities, like the indentation velocity in different parts of the indentation process. For the macro range a sensitivity to final velocity of indentation has been confirmed, but only for high hardness level