Understanding the behaviour of inert gases in metals, e.g. He and Kr in Zr, is important in order to predict changes in material properties as a result of exposure to a core environment. Experiments[1,2,3] have shown that high concentrations of gases lead to a high density of small bubbles in some core components, that self-organise into a stable, long-lived super lattice under certain core conditions. This could provide a useful means to sequester the gases away from grain boundaries, reducing their effect on mechanical properties. Despite its potential utility, the phenomenon is not completely understood.
In this work we apply the phase field approach (using the MOOSE framework developed at the Idaho National Laboratory), to the phenomenon of bubble lattice formation, and investigate the relative importance of the various formation mechanisms that have been proposed, such as the anisotropic diffusion of atomic defects, and elastic interactions between voids and bubbles.
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