Icosahedron-forming ability of MgZn alloys studied by molecular dynamics simulations
| Autor: | Zean Tian, Yongchao Liang, Xiao-Tian Guo, Rang-su Liu, Quan Xie, Tinghong Gao, Yunfei Mo |
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| Rok vydání: | 2017 |
| Předmět: |
Amorphous metal
Materials science Chemical substance Icosahedral symmetry Mechanical Engineering Metals and Alloys 02 engineering and technology 021001 nanoscience & nanotechnology Critical value 01 natural sciences law.invention Crystallography Molecular dynamics Cooling rate Sphere packing Magazine Mechanics of Materials law 0103 physical sciences Materials Chemistry 010306 general physics 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 700:61-66 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2017.01.046 |
| Popis: | A molecular dynamics simulation is performed to investigate the icosahedron in Mg x Zn (100- x ) alloys during solidification at the cooling rate of 1 × 10 11 K/s. It is found that with x increase the icosahedron-forming ability (IFA) of Mg x Zn (100 -x ) increases first, and then decrease as x > 50; and Mg 90 Zn 10 can crystallize at this cooling rate. Consistent with the geometry, the smaller Zn atoms are usually at the centre of icosahedra, and the maximal fraction of Mg atoms in neighbours of Zn-centred icosahedra is just the critical value with which such icosahedra get the highest packing density. Further analysis reveals that the stronger IFA of Zn-rich alloys is closely related to the forming ability of GE9IS-ICOs (clusters composed of more than 8 icosahedra that are interconnected by IS-linkages) that still grow at low temperatures where all other smaller icosahedral clusters stop grow. |
| Databáze: | OpenAIRE |
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