Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals
| Autor: | Hojun Lim, Alexander P. Moore, Shuh Rong Chen, J. Matthew D. Lane, Corbett Chandler. Battaile, Jay Carroll |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Multidisciplinary Materials science Condensed matter physics lcsh:R Tantalum chemistry.chemical_element lcsh:Medicine 02 engineering and technology Strain rate Plasticity 021001 nanoscience & nanotechnology 01 natural sciences Article Deformation mechanism chemistry Lattice (order) 0103 physical sciences lcsh:Q Crystallite 0210 nano-technology Anisotropy lcsh:Science Single crystal |
| Zdroj: | Scientific Reports Scientific Reports, Vol 8, Iss 1, Pp 1-6 (2018) |
| ISSN: | 2045-2322 |
| Popis: | Deformation mechanisms in bcc metals, especially in dynamic regimes, show unusual complexity, which complicates their use in high-reliability applications. Here, we employ novel, high-velocity cylinder impact experiments to explore plastic anisotropy in single crystal specimens under high-rate loading. The bcc tantalum single crystals exhibit unusually high deformation localization and strong plastic anisotropy when compared to polycrystalline samples. Several impact orientations - [100], [110], [111] and [$$\bar{1}49$$ 1 ¯ 49 ] - are characterized over a range of impact velocities to examine orientation-dependent mechanical behavior versus strain rate. Moreover, the anisotropy and localized plastic strain seen in the recovered cylinders exhibit strong axial symmetries which differed according to lattice orientation. Two-, three-, and four-fold symmetries are observed. We propose a simple crystallographic argument, based on the Schmid law, to understand the observed symmetries. These tests are the first to explore the role of single-crystal orientation in Taylor impact tests and they clearly demonstrate the importance of crystallography in high strain rate and temperature deformation regimes. These results provide critical data to allow dramatically improved high-rate crystal plasticity models and will spur renewed interest in the role of crystallography to deformation in dynamics regimes. |
| Databáze: | OpenAIRE |
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