The graph shows snapshots obtained from molecular dynamics simulations of Ni nanowires. The system was under 0.05% ps-1 strain rate in the  crystallographic direction. At this low strain rate the system is able to practically reach equilibrium condition between two successive strain applications. In the middle panels we can see lattice-planes starting to slip. These deformations in the structure appear when dislocations start to move through the crystal. This results in twin formation and other shear processes that are present in plastic deformations of crystals. With strain greater than 50% we can note that the plastic deformation leads to a necking in the system. This culminates with the failure of the nanowire when strain exceeds 91%. We can note that in this case, the cross sectional area of the neck goes to nearly zero when the system fails, characterizing what is called superplasticity.
This graph was submitted by Paulo Sérgio Branicio, Department of Physics, Universidade Federal de São Carlos, SP, Brazil.