Large-scale Atomistic Simulations of Helium-3 Bubble Growth in Complex Palladium Alloys

Published

May 21, 2016

Author(s)

Lucas M. Hale, Jonathan Zimmerman, Bryan Wong

Abstract

Palladium is an attractive material for hydrogen and hydrogen-isotope storage applications due to its properties of large storage density and high diffusion of lattice hydrogen. When considering tritium storage, the material's structural and mechanical integrity is threatened by both the embrittlement effect of hydrogen, and the creation and evolution of additional crystal defects (e.g. dislocations, stacking faults) caused by the formation and growth of helium-3 bubbles. Using recently developed inter-atomic potentials for the palladium- silver- hydrogen system, we perform large-scale atomistic simulations to examine the defect-mediated mechanisms that govern helium bubble growth. Our simulations show the evolution of a distribution of material defects, and we compare the material behavior displayed with expectations from experiment and theory. We also present density functional theory calculations to characterize ideal tensile and shear strengths for these materials, which enable the understanding of how and why our developed potentials either meet or confound these expectations.

Citation

Journal of Chemical Physics

Volume

144

Issue

19

Pub Type

Journals

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DOI Link

Keywords

metal hydrides, tritium, helium bubbles, aging

Citation

Hale, L. , Zimmerman, J. and Wong, B. (2016), Large-scale Atomistic Simulations of Helium-3 Bubble Growth in Complex Palladium Alloys, Journal of Chemical Physics, [online], https://doi.org/10.1063/1.4948789 (Accessed December 13, 2024)