Inverse Grain-Size Effect on Twinning in Nanocrystalline Ni
Open Access
- 10 July 2008
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 101 (2), 025503
- https://doi.org/10.1103/physrevlett.101.025503
Abstract
A long-standing controversy exists between molecular dynamics simulations and experiments on the twinning propensity of nanocrystalline (NC) face-centered-cubic metals. For example, three-dimensional molecular dynamics simulations rarely observed twins in NC Ni, whereas experiments readily observed them. Here this discrepancy is resolved by experimental observation of an inverse grain-size effect on twinning. Specifically, decreasing the grain size first promotes twinning in NC Ni and then hinders twinning due to the inverse grain-size effect. Interestingly, no inverse grain-size effect exists on stacking fault formation. These observations are explained by generalized planar fault energies and grain-size effect on partial emissions.Keywords
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