• Citation: Y. Oh, S. Sung, J.-i. Jang, W.-S. Ko, and H.N. Han (2024), "Integrated experimental and computational study on the effect of hydrogen in mechanical responses of pure tungsten", Acta Materialia 280, 120341. DOI: 10.1016/j.actamat.2024.120341.
    Abstract: Hydrogen irradiation profoundly changes the microstructure and morphological characteristics of tungsten, ultimately resulting in the modifications to its mechanical properties. Unfortunately, the specific mechanisms through which hydrogen irradiation influences the mechanical behavior of tungsten have not been clearly elucidated. Therefore, this study aims to further improve the understanding of the impact of hydrogen irradiation on the mechanical responses and its microstructure dependence in tungsten by employing two advanced techniques: nano-indentation experiments and Molecular dynamics (MD) simulations. The experimental findings revealed that deuterium (D) exposure decreased the maximum shear stress required for the incipient plasticity and led to the occurrence of multiple pop-ins. Particularly noteworthy was the most remarkable change in mechanical behaviors observed prominently in the recrystallized tungsten after D exposure. The microstructure dependence of irradiation-induced change in mechanical responses was investigated by two series of MD simulation, indentation and dislocation glide simulation, focusing on the independent effects of each irradiation-induced defect type (interstitial, substitutional, vacancy, vacancy-hydrogen (Vac-H) cluster, void-hydrogen (Vo-H) cluster) on dislocation activities. Based on the MD simulations, it was eventually revealed that Vo-H clusters were the most influential agent affecting dislocation activities. They not only lowered the pop-in stress by heterogeneous dislocation nucleation but also caused strain serration by a continuous pinning/unpinning process during dislocation glide. Consequently, we concluded that the dominant presence of d-induced Vo-H clusters facilitated the onset of plastic yielding and led to multiple pop-in phenomena in recrystallized tungsten, whereas inserted hydrogen caused minimal change in mechanical responses by interacting with pre-existing dislocation in cold-rolled tungsten.

    Related Models:
  • LAMMPS pair_style meam (2024--Oh-Y--W-H--LAMMPS--ipr1)
    See Computed Properties
    Notes: These files were provided by Won-Seok Ko on June 2, 2026. The README.md file contains usage notes, element ordering, reference structures, and recommended cutoff values.
    File(s):
  • Citation: D.R. Mason, D. Nguyen-Manh, V.W. Lindblad, F.G. Granberg, and M.Y. Lavrentiev (2023), "An empirical potential for simulating hydrogen isotope retention in highly irradiated tungsten", Journal of Physics: Condensed Matter 35(49), 495901. DOI: 10.1088/1361-648x/acf25f.
    Abstract: We describe the parameterization of a tungsten-hydrogen empirical potential designed for use with large-scale molecular dynamics simulations of highly irradiated tungsten containing hydrogen isotope atoms, and report test results. Particular attention has been paid to getting good elastic properties, including the relaxation volumes of small defect clusters, and to the interaction energy between hydrogen isotopes and typical irradiation-induced defects in tungsten. We conclude that the energy ordering of defects changes with the ratio of H atoms to point defects, indicating that this potential is suitable for exploring mechanisms of trap mutation, including vacancy loop to plate-like void transformations.

    Notes: Notes from Daniel R. Mason: This potential was designed to combine the good W-W properties of 2017--Mason-D-R-Nguyen-Manh-D-Becquart-C-S--W, with the good W-H properties of Wang et al JPCM 29:435401 (2017), and is intended for use studying hydrogen isotope retention in radiation damaged tungsten. The binding energies of H to point defects are very similar to those in Wang et al 2017, and the formation energies of larger defect clusters very similar to 2017--Mason-D-R-Nguyen-Manh-D-Becquart-C-S--W. The main improvements over Wang et al are a) better relaxation volumes of H-decorated defects and b) better binding of H to surface.

  • LAMMPS pair_style eam/alloy (2023--Mason-D-R--W-H--LAMMPS--ipr1)
    See Computed Properties
    Notes: These files were provided by Daniel R. Mason on September 26, 2023.
    File(s):
Date Created: October 5, 2010 | Last updated: June 04, 2026