An analysis of dislocation nucleation under an idealized nano-indenter was presented which was based upon a variational boundary integral formulation of the Peierls–Nabarro dislocation model. By solving the embryonic dislocation profiles, corresponding to the relative displacements between the 2 adjacent atomic layers along the slip plane, the critical conditions for athermal dislocation nucleation were determined; as well as the activation energies required to thermally activate embryonic dislocations from their stable to unstable saddle-point configurations. The effect of the size of the indenter upon the energetics of dislocation nucleation was quantitatively characterized. The result was compared with a simplified analysis which was based upon the application of the Rice model for dislocation nucleation at a crack tip.

Energetics of Dislocation Nucleation under a Nano-Indenter. C.Zhang, G.Xu: Materials Science and Engineering A, 2005, 400-401, 471-5