Torsional Behavior of Carbon-Doped Ferrous Nanowires: Atomic-Scale Insights from MD Simulations

TL;DR

This paper uses molecular dynamics simulations to explore how carbon doping, temperature, and size affect the torsional mechanical properties of iron nanowires, providing insights for their application in nanoengineering.

Contribution

It introduces a detailed atomic-scale analysis of FeC nanowires' torsional behavior considering multiple variables, which was previously unexplored.

Findings

Increasing carbon content weakens grain boundaries and reduces shear stress.

Higher temperatures induce phase transitions from elastic to plastic deformation.

Larger cross-sections increase shear stress resistance due to outer layer strengthening.

Abstract

This study investigates the torsional mechanical properties of pristine iron (Fe) and carbon-doped iron (FeC) nanowires with [001] orientation through molecular dynamics simulations utilizing the Modified Embedded Atom Method (MEAM) potential developed by Liyanage et al. for accurately modeling Fe-C interactions in body-centered cubic structures. Systematic analysis across carbon concentrations (0 - 10%), temperatures (1 - 900 K), and cross-sectional dimensions 10a, 13a, 15a, ( where a = 2.81 Angstrom represents the lattice constant ) within the LAMMPS environment reveals that increasing carbon content weakens grain boundaries, reducing the maximum shear stress required to reach the critical torsional angle, while higher temperatures promote phase transitions from elastic to plastic deformation due to enhanced atomic vibrations, and larger cross-sections exhibit higher shear stress resistance attributed to strengthening effects from the outer atomic layers. By elucidating these interrelationships between carbon content, temperature, and dimensional factors, this work provides fundamental insights into the mechanical behavior of FeC nanowires under torsional loading conditions, offering valuable guidance for their potential applications in nanoelectromechanical systems, nanorobotic actuators, and advanced structural materials where precise control of mechanical properties is essential.