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mqjiang

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应助: 12 (小学生)
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[资源] 【原创】理解金属玻璃中的锯齿状塑性流动

最近，我们结合分子动力学模拟和连续介质力学建模分析，揭示出金属玻璃中的锯齿状流动行为主要取决于内部不可逆原子重排的程度，而这种重排必然是在时间上非均匀的，而与空间上的非均匀行为（或者剪切带）没有直接关联。

本文工作进一步验证了W.H. Jiang在2008年国际塑性上关于非均匀变形的时空特性的猜想图像。相关结果发表在计算材料科学杂志。

Smaller Deborah number inducing more serrated plastic flow of metallic glass
M.Q. Jiang, S.Y. Jiang, Z. Ling , L.H. Dai,*
a State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, PR China
b State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, PR China

a b s t r a c t

Spherical nano-indentations of Cu46Zr54 bulk metallic glass (BMG) model systems were performed using molecular dynamics (MD) computer simulations, focusing specifically on the physical origin of serrated plastic flow. The results demonstrate that there is a direct correlation between macroscopic flow serration and underlying irreversible rearrangement of atoms, which is strongly dependent on the loading (strain) rate and the temperature. The serrated plastic flow is, therefore, determined by the magnitude of such irreversible rearrangement that is inhomogeneous temporally. A imensionless Deborah number is introduced to characterize the effects of strain rate and temperature on serrations. Our simulations are shown to compare favorably with the available experimental observations.

全文下载见：http://www.sciencenet.cn/bbs/showpost.aspx?id=49246

[ Last edited by hslining on 2009-9-12 at 09:07 ]

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