Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study
Uniaxial tension tests were performed for amorphous SiO<sub>2</sub> nanowires using molecular dynamics simulation to probe the size effect on the mechanical properties and plastic deformation by varying the length of nanowires. The simulation results showed that the Young’s modulus of Si...
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MDPI AG
2020-11-01
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| Online Access: | https://www.mdpi.com/1996-1944/13/22/5110 |
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| author | Kun Sun Juan Chen Bingjie Wu Liubing Wang Liang Fang |
| author_facet | Kun Sun Juan Chen Bingjie Wu Liubing Wang Liang Fang |
| author_sort | Kun Sun |
| collection | DOAJ |
| description | Uniaxial tension tests were performed for amorphous SiO<sub>2</sub> nanowires using molecular dynamics simulation to probe the size effect on the mechanical properties and plastic deformation by varying the length of nanowires. The simulation results showed that the Young’s modulus of SiO<sub>2</sub> nanowires increased with the decrease of nanowires length due to its higher surface stress. The corresponding deformation of SiO<sub>2</sub> nanowires during tension exhibited two periods: atomic arrangement at small strain and plastic deformation at large strain. During the atomic arrangement period, the percentage variations of atom number of 2-coordinated silicon and 3-coordinated silicon (PCN2 and PCN3) decreased, while the percentage variations of atom number of 4-coordinated silicon, 5-coordinated silicon (PCN4 and PCN5) and the Si–O bond number (PCB) rose slightly with increasing strain, as the strain was less than 22%. The situation reversed at the plastic deformation period, owing to the numerous breakage of Si–O bonds as the strain grew beyond 22%. The size effect of nanowires radius was considered, finding that the Young’s modulus and fracture stress were higher for the larger nanowire because of fewer dangling bonds and coordinate defeats in the surface area. The elastic deformation occurred at a small strain for the larger nanowire, followed by the massive plastic deformation during tension. A brittle mechanism covers the fracture characteristics, irrespective of the nanowire size. |
| first_indexed | 2024-03-10T14:54:20Z |
| format | Article |
| id | doaj.art-de96be83a71a44db94d81bb455466ec6 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T14:54:20Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
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| series | Materials |
| spelling | doaj.art-de96be83a71a44db94d81bb455466ec62023-11-20T20:44:59ZengMDPI AGMaterials1996-19442020-11-011322511010.3390/ma13225110Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics StudyKun Sun0Juan Chen1Bingjie Wu2Liubing Wang3Liang Fang4State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaSchool of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, ChinaNuclear Power Institute of China, Chengdu 610014, ChinaNuclear Power Institute of China, Chengdu 610014, ChinaState Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, ChinaUniaxial tension tests were performed for amorphous SiO<sub>2</sub> nanowires using molecular dynamics simulation to probe the size effect on the mechanical properties and plastic deformation by varying the length of nanowires. The simulation results showed that the Young’s modulus of SiO<sub>2</sub> nanowires increased with the decrease of nanowires length due to its higher surface stress. The corresponding deformation of SiO<sub>2</sub> nanowires during tension exhibited two periods: atomic arrangement at small strain and plastic deformation at large strain. During the atomic arrangement period, the percentage variations of atom number of 2-coordinated silicon and 3-coordinated silicon (PCN2 and PCN3) decreased, while the percentage variations of atom number of 4-coordinated silicon, 5-coordinated silicon (PCN4 and PCN5) and the Si–O bond number (PCB) rose slightly with increasing strain, as the strain was less than 22%. The situation reversed at the plastic deformation period, owing to the numerous breakage of Si–O bonds as the strain grew beyond 22%. The size effect of nanowires radius was considered, finding that the Young’s modulus and fracture stress were higher for the larger nanowire because of fewer dangling bonds and coordinate defeats in the surface area. The elastic deformation occurred at a small strain for the larger nanowire, followed by the massive plastic deformation during tension. A brittle mechanism covers the fracture characteristics, irrespective of the nanowire size.https://www.mdpi.com/1996-1944/13/22/5110uniaxial tensionamorphous SiO<sub>2</sub> nanowiresmechanical propertiesplastic deformationmolecular dynamics simulation |
| spellingShingle | Kun Sun Juan Chen Bingjie Wu Liubing Wang Liang Fang Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study Materials uniaxial tension amorphous SiO<sub>2</sub> nanowires mechanical properties plastic deformation molecular dynamics simulation |
| title | Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study |
| title_full | Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study |
| title_fullStr | Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study |
| title_full_unstemmed | Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study |
| title_short | Size-Dependent Mechanical Properties of Amorphous SiO<sub>2</sub> Nanowires: A Molecular Dynamics Study |
| title_sort | size dependent mechanical properties of amorphous sio sub 2 sub nanowires a molecular dynamics study |
| topic | uniaxial tension amorphous SiO<sub>2</sub> nanowires mechanical properties plastic deformation molecular dynamics simulation |
| url | https://www.mdpi.com/1996-1944/13/22/5110 |
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