A finite element model of grain boundary sliding for nanostructured metals
Efforts to characterize and understand the mechanical behavior of nanocrystals have unveiled some unique features of deformation that are not commonly observed in polycrystals. In this work, we propose a continuum model describing the competing deformation mechanisms believed to determine the effect...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2004
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| Summary: | Efforts to characterize and understand the mechanical behavior of nanocrystals have unveiled some unique features of deformation that are not commonly observed in polycrystals. In this work, we propose a continuum model describing the competing deformation mechanisms believed to determine the effective response of nanocrystalline materials. The model is based on explicitly accounting for grain-boundary deformation including sliding and other accomodation mechanisms, as well as for the interaction among neighboring grains. The results obtained reproduce the inverse trend in the grain-size dependency of the macroscopic yield stress predicted by atomistic simulations. The numerically predicted grain-size dependency of the yield stress shows a linear relation with the inverse square root of the grain size, a phenomenon identified as the inverse Hall-Petch effect, in agreement with the behavior predicted by recent atomistic descriptions and experimental characterizations. Copyright © 2004 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. |
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