Mechanical instability in non-uniform atomic structure: Application to amorphous metal
Mechanical instability in non-uniform atomic structure: Application to amorphous metal
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DOI：
10.1016/j.msea.2006.03.158
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发表时间：
2007-07
期刊：
影响因子：
6.4
通讯作者：
Y. Umeno;T. Kitamura;M. Tagawa
中科院分区：
文献类型：
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作者：
Y. Umeno;T. Kitamura;M. Tagawa
由于非晶态材料因其突出的功能而备受关注，在原子尺度上揭示非晶态金属的变形具有重要意义。本文对非晶模型的拉伸变形进行了原子学模拟，并分析了局部力学不稳定性，以阐明非晶结构的变形机制。导致应力急剧下降的不稳定性与局域内原子的不稳定运动有关。发生不稳定原子运动的区域的大小与总应力减小的大小相对应。在大应力降低失稳时，失稳初期的变形向周围扩展，在应力应变关系中产生滞后环。这揭示了非晶态结构塑性的微观机制。
It is important to reveal the deformation of amorphous metal in the atomistic scale level as materials with non-crystal structure have been attracting attention with their prominent functions. In this paper atomistic simulations of tensile deformation of an amorphous model are conducted and local mechanical instability is analyzed to clarify the deformation mechanism of the amorphous structure. Instability causing sharp stress drop is associated with unstable motion of atoms within local region. The size of the region where the unstable atomic motion occurs corresponds to the magnitude of total stress decrease. At instability with large stress decrease the deformation at the onset of the instability propagates to surrounding region, which gives rise to a hysteresis loop in the stress–strain relation. This manifests the microscopic mechanism of the plasticity of amorphous structure.