Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10620287 | Acta Materialia | 2013 | 9 Pages |
Abstract
Instrumented nanoindentation was conducted on a FeCoCrMnNi high-entropy alloy with a single face-centered cubic structure to characterize the nature of incipient plasticity. Experiments were carried out over loading rates of 25-2500 μN sâ1 and at temperatures ranging from 22 to 150 °C. The maximum shear stress required to initiate plasticity was found to be within 1/15 to 1/10 of the shear modulus and relatively insensitive to grain orientation. However, it was strongly dependent upon the temperature, indicating a thermally activated process. Using a statistical model developed previously, both the activation volume and activation energy were evaluated and further compared with existing dislocation nucleation models. A mechanism consisting of a heterogeneous dislocation nucleation process with vacancy-like defects (â¼3 atoms) as the rate-limiting nuclei appeared to be dominant.
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Authors
C. Zhu, Z.P. Lu, T.G. Nieh,