期刊
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
卷 61, 期 9, 页码 1353-1363出版社
SCIENCE PRESS
DOI: 10.1007/s11431-018-9270-9
关键词
nanocrystalline nanoporous gold; grain-size effect; ligament-size effect; mechanical properties; molecular dynamics
资金
- National Natural Science Foundation of China [11102140, 51575404]
A series of large-scale molecular dynamics (MD) simulations has been performed to study the effects of grain size and ligament diameter on the mechanical properties of nanocrystalline nanoporous gold. Such simulations indicate that the principal deformation mechanism is a combination of grain boundary sliding, grain rotation and dislocation movement. The results of uniaxial tensile tests reveal the presence of a reverse Hall-Petch relation between strength and nominal grain size, rather than the conventional Hall-Petch relationship in the present range of nominal grain size (7.9-52.7 nm). An increase of flow stress may possibly attribute to the lower total proportion of grain boundary sliding and grain rotation in the deformation of samples with larger grain size. The Young's modulus shows a linear relation with the reciprocal of nominal grain size, which depends largely on the volume fraction of grain boundaries and thus decreasing grain size leads to relatively lower Young's modulus. MD simulations on samples with ligament diameter ranging from 4.07 to 8.10 nm are also carried out and results show that the increasing ligament diameter resulted in decreased flow stress and increased Young's modulus.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据