A model was developed, for the plastic deformation of nanocrystalline materials, in terms of the evolution of a spatial grid of disclinations which was located at the triple junctions of grains. Plastic deformation took place as the result of the plastic rotation of grains, the mismatch of which caused the nucleation of partial disclinations at the junctions of intergrain boundaries. It was shown that a distinctive feature of the mechanical behavior of nanocrystals was a deviation from the Hall-Petch law, up to a critical grain size of 25nm.

Disclination Mechanism for the Plastic Deformation of Nanocrystalline Materials. G.Zaiichenko, A.M.Glezer: Fizika Tverdogo Tela, 1997, 39[11], 2023-8 (Physics of the Solid State, 1997, 39[11], 1810-4)