The unique ability of grain boundaries to act as effective sinks for radiation damage plays a significant role in nanocrystalline materials due to their large interfacial area per unit volume. Leveraging this mechanism in the design of tungsten as a plasma-facing material provides a potential pathway for enhancing its radiation tolerance under fusion-relevant conditions. In this study, we explore the impact of defect microstructures on the mechanical behavior of helium ion implanted nanocrystalline tungsten through nanoindentation. Softening was apparent across all implantation temperatures and attributed to bubble/cavity loaded grain boundaries suppressing the activation barrier for the onset of plasticity via grain boundary mediated dislocation nucleation. An increase in fluence placed cavity induced grain boundary softening in competition with hardening from intragranular defect loop damage, thus signaling a new transition in the mechanical behavior of helium implanted nanocrystalline tungsten.
Cunningham, W. Streit, et al. "Softening due to Grain Boundary Cavity Formation and its Competition with Hardening in Helium Implanted Nanocrystalline Tungsten." Scientific Reports, vol. 8, no. 1, Feb. 2018. https://doi.org/10.1038/s41598-018-20990-1
Cunningham, W. Streit, Gentile, Jonathan M., El-Atwani, Osman, Taylor, Chase N., Efe, Mert, Maloy, Stuart A., & Trelewicz, Jason R. (2018). Softening due to Grain Boundary Cavity Formation and its Competition with Hardening in Helium Implanted Nanocrystalline Tungsten. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-20990-1
Cunningham, W. Streit, Gentile, Jonathan M., El-Atwani, Osman, et al., "Softening due to Grain Boundary Cavity Formation and its Competition with Hardening in Helium Implanted Nanocrystalline Tungsten," Scientific Reports 8, no. 1 (2018), https://doi.org/10.1038/s41598-018-20990-1
@article{osti_1423975,
author = {Cunningham, W. Streit and Gentile, Jonathan M. and El-Atwani, Osman and Taylor, Chase N. and Efe, Mert and Maloy, Stuart A. and Trelewicz, Jason R.},
title = {Softening due to Grain Boundary Cavity Formation and its Competition with Hardening in Helium Implanted Nanocrystalline Tungsten},
annote = {The unique ability of grain boundaries to act as effective sinks for radiation damage plays a significant role in nanocrystalline materials due to their large interfacial area per unit volume. Leveraging this mechanism in the design of tungsten as a plasma-facing material provides a potential pathway for enhancing its radiation tolerance under fusion-relevant conditions. In this study, we explore the impact of defect microstructures on the mechanical behavior of helium ion implanted nanocrystalline tungsten through nanoindentation. Softening was apparent across all implantation temperatures and attributed to bubble/cavity loaded grain boundaries suppressing the activation barrier for the onset of plasticity via grain boundary mediated dislocation nucleation. An increase in fluence placed cavity induced grain boundary softening in competition with hardening from intragranular defect loop damage, thus signaling a new transition in the mechanical behavior of helium implanted nanocrystalline tungsten.},
doi = {10.1038/s41598-018-20990-1},
url = {https://www.osti.gov/biblio/1423975},
journal = {Scientific Reports},
issn = {ISSN 2045-2322},
number = {1},
volume = {8},
place = {United States},
publisher = {Nature Publishing Group},
year = {2018},
month = {02}}
Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12https://doi.org/10.1016/j.nimb.2010.02.091