The unique deformation behavior of nanocrystalline materials was considered to be caused by suppression of conventional lattice dislocation slip (which dominates in coarse-grained materials) and effective action of alternative deformation mechanisms occurring through motion of grain boundary defects. A significant role of grain boundary sliding in deformation processes in nanocrystalline materials was shown in models and was revealed experimentally.

Grain Boundary Sliding in Nanomaterials at Elevated Temperatures. A.V.Sergueeva, N.A.Mara, A.K.Mukherjee: Journal of Materials Science, 2007, 42[5], 1433-8