Nano-indentation was simulated by the motion of statistically distributed discrete dislocations on slip-bands parallel to the free surface. No dislocation emission from sources was permitted in the simulations, and it was shown that - even under these highly simplified conditions - it was possible to obtain an indentation size-effect. The degree of decrease in the hardness with increasing indentation depth was shown to be affected mainly by the number of pre-existing dislocations in the model material and by the lattice friction stress. It was shown that the hardness was much higher than that of a solid which contained dislocation sources.

Discrete Dislocation Simulation of Nano-Indentation - the Effect of Statistically Distributed Dislocations. H.G.M.Kreuzer, R.Pippan: Materials Science and Engineering A, 2005, 400-401, 460-2