Size effects on the fracture behavior of amorphous silica nanowires
C Zhang and FL Duan and QS Liu, COMPUTATIONAL MATERIALS SCIENCE, 99, 138-144 (2015).
Size effects on deformation behavior and fracture mechanism of amorphous silica nanowires (NWs) were studied by molecular dynamics simulation with reactive force field ReaxFF. We analyzed the evolution of voids during the tension deformation, and focused on the role of voids played in the fracture process of amorphous silica NWs. Our study shows that the smaller diameter NWs damage only from localized necking and the small growth of voids has no effect on its fracture behavior. While for the larger diameter NWs, there exists growth and coalescence of void inside the NWs and crack propagation on the surface of NWs. It is the combined action of these two mechanisms that leads to the final fracture. The evolution of the size of biggest void (BV) displays three distinct regions, which are corresponding to the different deformation stages of NWs. The voids begin to grow significantly after the yielding point, and the size of BV in the fracture stage increases much more quickly owing to the coalescence of voids. Moreover, the critical radius of BV at the start point of fracture stage increases from 2.6 angstrom to 3.8 angstrom with the increase of diameter of amorphous silica NWs. (C) 2014 Elsevier B.V. All rights reserved.
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