The influence of diameter on the strength and ductility of BCC iron nanowire under axial loading: A reactive molecular dynamics simulation

The paper investigates the influence of diameter on the mechanical behavior of iron nanowires subjected to uniaxial tensile and compressive tests using reactive molecular dynamics simulations. The loading process is conducted quasi-statically and incrementally, in which the nanowire is relaxed after each loading increment to minimize the effects of strain rates. The atomistic model is validated by experimental data. The results highlight that reducing the diameter of the nanowire significantly enhances yield strength and Young's modulus, because of the existence of surface effects, confined dislocation motion, and low structural defect density at the nanoscale. Smaller diameter nanowires exhibited more brittle failures, while larger diameters showed greater ductility. Radial distribution function analysis revealed reduced medium-range orders and increased atomic dispersion with the imposed strain. The results play a crucial role in the optimization of iron nanowire design in advanced engineering applications like nanocomposites and microsensors.