|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale IV
||Uniaxial Deformation of Nanotwinned Nanopillars/Nanotubes in Body-centered Cubic Tungsten
||Shuozhi Xu, Thomas G. Payne, Jacob K. Startt, Chaitanya S. Deo, David L. McDowell
|On-Site Speaker (Planned)
Compared with face-centered cubic metals, atomistic modeling of nanotwinned nanopillars in body-centered cubic (BCC) systems have been less heavily explored, owing in part to their more complex dislocation phenomena and a lack of reliable interatomic potentials for BCC systems. In this work, the fault energies predicted by two semi-empirical interatomic potentials in BCC tungsten (W) are first benchmarked against density functional theory calculations. Then, the more accurate potential is employed in molecular dynamics simulations of uniaxial loading of nanotwinned nanopillars/nanotubes in BCC W with different cross sectional shapes/sizes, twin boundary spacing, and wall thickness. A single crystal, nanotwinned crystals, and single crystalline nanopillars/nanotubes are also studied for perspective. Analyses of the stress-strain response and defect nucleation reveal a strong tension-compression asymmetry and weak pillar size and wall thickness dependence of the yield strength. The twin boundary spacing is found to affect the yield strength weakly and strongly under tensile and compressive loading, respectively.
||Planned: Supplemental Proceedings volume