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Punching of arbitrary face prismatic loops from hydrogen nanobubbles in copper
When a metal surface is exposed to prolonged irradiation with energetic H−, the ions are expected to penetrate into bulk and dissolve in the matrix. However, the irradiated surfaces exhibit dramatic morphological changes in the form of “blisters” covering the surface exposed to irradiation. Blisteri...
Autores principales: | , , , , , , |
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Lenguaje: | eng |
Publicado: |
2022
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1016/j.actamat.2021.117554 http://cds.cern.ch/record/2852709 |
Sumario: | When a metal surface is exposed to prolonged irradiation with energetic H−, the ions are expected to
penetrate into bulk and dissolve in the matrix. However, the irradiated surfaces exhibit dramatic morphological changes in the form of “blisters” covering the surface exposed to irradiation. Blistering is usually
explained by accumulation of implanted gas in the bubbles near surface. However, the exact mechanism
of continuous growth of a bubble after it reaches the measurable size is still not fully clear. Commonly
such growth is related to prismatic loop punching, which is a short time scale process not easily accessible by experimental techniques. Even atomistic modelling of loop punching in FCC metals is somewhat
cumbersome. Since the void surfaces in these metals yield easily through shear loops, these were debatably suggested to explain the plastic growth of a bubble in copper, without demonstrating the detachment of these loops from the void.
We address the mechanisms of fast bubble growth in Cu which is associated with blistering of Cu surface
exposed to H− irradiation. We observe the emission of a complete prismatic loop enclosed within the
number of shear loops with the Burgers vectors aligned with the gliding direction of the prismatic loop.
We show that the prismatic loops punched from the bubble surface do not need to be smaller than the
bubble cross-section. These simulations capture the general trend of dislocation emission in the condition
of hydrostatic pressure exerted by the accumulated gas on the wall of the bubble. |
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