Porosity dependence of mechanical properties of titanium nanofoams.

CONTEXT

This study employs molecular dynamics (MD) simulations to investigate the mechanical properties and deformation mechanisms of titanium (Ti) nanofoam under uniaxial tensile loading. The effects of porosity (ranging from 20 to 50%), strain rate (from 5 × 10⁸ to 5 × 10⁹ s⁻), and temperature (from 300 to 900 K) on the tensile response are systematically examined. The results reveal that increasing porosity significantly reduces the ultimate tensile strength (UTS) and elastic modulus, while intensifying localized shear strain and stress concentration. These conditions facilitate the formation of amorphous phases and grain structures, and substantially influence dislocation behavior. Furthermore, higher strain rates are found to enhance strength by increasing both UTS and elastic modulus. In contrast, elevated temperatures induce phase transformations that improve ductility but compromise strength. Overall, this work provides valuable insights into tailoring the mechanical performance of Ti nanofoams, with implications for their use in biomedical, structural, and functional applications.

METHODS

The simulations were performed using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) package. The results were analyzed using the Open Visualization Tool (OVITO). Structural analysis was conducted using common neighbor analysis (CNA) and polyhedral template matching (PTM), while dislocation behavior was studied with dislocation analysis (DXA). Surface meshes for volume and surface computations were generated using the construct surface mesh method.