It was recalled that generalized planar-fault energy curves had been used to predict partial-dislocation mediated processes in nanocrystalline materials, but their validity had not been evaluated experimentally. Experimental observations were made here of a large number of stacking faults and twins in nanocrystalline Ni, deformed at relatively low stresses in a tensile test. The experimental results indicated that the generalized planar fault energy curves could reasonably explain the formation of stacking faults, but they alone were unable to predict adequately the tendency to deformation twinning.

Predictions for Partial-Dislocation-Mediated Processes in Nanocrystalline Ni by Generalized Planar Fault Energy Curves - an Experimental Evaluation. X.L.Wu, Y.T.Zhu, E.Ma: Applied Physics Letters, 2006, 88[12], 121905 (3pp)