Mechanical behaviour of rapidly solidified aluminium with multiple twinned nanograins: A molecular dynamics simulation study
| Autor: | Xiao-Gang Zhao, Rang-su Liu, Zhen Wang, Zean Tian, Fenglong Wang, Li-Xia Liu, Zhao-Yang Hou |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
General Computer Science General Physics and Astronomy chemistry.chemical_element 02 engineering and technology General Chemistry Flow stress 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Nanocrystalline material Grain size 0104 chemical sciences Computational Mathematics Grain growth Deformation mechanism chemistry Mechanics of Materials Aluminium General Materials Science Composite material Deformation (engineering) 0210 nano-technology Crystal twinning |
| Zdroj: | Computational Materials Science. 156:1-6 |
| ISSN: | 0927-0256 |
| DOI: | 10.1016/j.commatsci.2018.09.036 |
| Popis: | The mechanical behaviour of rapidly solidified aluminium with multiple twinned nanograins is investigated by a large-scale molecular dynamics simulation. The nanocrystalline structures with mean grain sizes ranging from 3.1 nm to 24.4 nm are prepared by quenching liquid at appropriate cooling rates. It is found that the mechanical properties of rapidly solidified aluminium with multiple twinned nanograins are dependent on its grain size. The flow stress displays inverse Hall-Petch relationship in the present grain-size range. The multiple twinned nanocrystalline aluminium with large and small grain sizes respectively displays different deformation mechanisms during the uniaxial tensile processes. For that with large grain size, the dominated deformation mechanism is twin boundary migration, though co-existing with dislocation activities. And the morphologies of multiple twinned nanograins remain nearly unchanged during the deformation process. For that with small grain size, the deformation is governed by the softening mechanisms of grain growth and detwinning. The grain boundary migration and grain rotation are found in the grain growth process. And the morphologies of multiple twinned nanograins gradually transform into parallel twins or monocrystal. |
| Databáze: | OpenAIRE |
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