The tensile tests of BCC Fe nanowires were simulated through molecular dynamics methods. The temperature and strain rate effects on the mechanical properties as well as the orientation-dependent plastic deformation mechanism were analyzed. For [001]-oriented BCC Fe nanowires, as the temperature increased, the yield stress and Young's modulus decreased. While the yield stress and Young's modulus increased as the strain rate increased. With the increase of temperature, when the temperature was less than 400 K, the twin propagation stress decreased dramatically, and then tended to reach a saturation value at higher temperatures. Under different temperatures and strain rates, the [001]-oriented Fe nanowires all deformed by twinning. The oscillation stage in the stress-strain curve corresponds to the process from the nucleation of the twin to the reorientation of the nanowire. For [110]-oriented Fe nanowires, the plastic deformation is dominated by dislocation slip. The independent events such as the nucleation, slip, and annihilation of dislocations are the causes of the unsteady fluctuations in the stress-strain curve. The Fe nanowires eventually undergo shear damage along the dominant slip surface.

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A dual-phase nanostructured amorphous/crystalline model is an effective method to improve the mechanical properties of Mg alloys. However, the fundamental strengthening mechanism related to the interaction between basal/prismatic (BP) and amorphous phase in the dual-phase Mg alloys is still unclear. Here, the effects of the size and spacing of amorphous nanopillars on the mechanical properties and the BP interface migration behavior of the bicrystalline Mg alloys are investigated by the molecular dynamics simulation method. The results show that due to the attraction of amorphous nanopillar to interfacial dislocations, the introduction of amorphous nanopillar reduces the yield stress of the bicrystalline Mg alloys, and the yield stress decreases with the increase of the amorphous nanopillar radius. The results indicate that the amorphous nanopillar has an obvious blocking effect on the migration of the BP interface, and the larger the radius of amorphous nanopillars (or the smaller the spacing of amorphous nanopillars), the more obvious the strengthening effect. In addition, the migration mechanism of the BP interface in the bicrystalline Mg alloys is analyzed in detail.

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