Abstract
Isothermal molecular dynamics is used to study the correlation between the spatial distribution of internal stress and mechanical deformation of a 6.7-nm-diameter Al nanowire with axis subjected to an external uniaxial stress. In the case of a tensile load, the internal stress distribution is found to result from interplay between structure and morphology.
As a general rule, yielding nucleates where the internal stress gradient is the highest. If the Al wire is interfaced with a harder material-Ni in this study-the highest gradients occur at the interface, where a characteristic interfacial stress pattern is induced.
Remarkably, compressive and tensile yield strengths are found to be unaffected by the hard/soft interfaces. The structure of the stress-strain relationship is found to correlate with identified discrete plastic events.
These may be complex, involving interactions between partial dislocations, stacking faults, Surfaces and interfaces, internal stress localization and release.