Deconvolution of hardness from data obtained from nanoindentation of roughsurfaces

Variation of hardness with penetration in nanoindentation of a rough surfac e is a compound effect of variation in asperity geometry with penetration, designated geometric effect, and genuine property gradients with depth as m ay exist in a near-surface zone. We simulate indentation of a rough surface numerically to elucidate the geometric effects and validate it by some mod el "macro" experiments. Finally, we formulate a general framework to deconv olute genuine property variation by normalizing the measured hardness with the geometric effect.