本文以分子動力學模擬來探討尺寸的改變對金屬與金屬玻璃奈米線機械性質的影響。金屬奈米線我們選用面心立方的銅以[001]方向做軸向拉伸與壓縮，而金屬玻璃奈米線我們選用銅鋯鈦三元合金來做[001]方向的軸向拉伸與壓縮。而為了減少熱震動對微觀結果的擾動與影響，我們將系統溫度維持在接近絕對0度下進行，以釐清尺寸對結構與機械性質影響。
在金屬銅奈米線中我們發現無論是在平衡、拉伸以及壓縮，其表層原子與內部原子之應力、楊氏模數、以及能量變化上具有不同的表現。由於不同尺寸下的金屬銅奈米線表面原子所佔系統原子比例與奈米線尺寸呈非線性關係，而使得上述物理性質也與奈米線尺寸呈現非線性關係。
我們在金屬玻璃奈米線的拉伸與壓縮試驗中發現奈米尺寸下金屬玻璃是以延性的方式形變而非巨觀下以脆性破裂的方式形變，尺寸的改變不僅改變了金屬玻璃機械性質，同時還改變了其變形方式。

In this study, we use molecular dynamics simulation to investigate the impact of size effect on the mechanical properties of metal and metallic glass nanowires. We select face-centered cubic copper nanowire to simulate the axial tensile and compression on [001] direction. For metallic glass, we selected Cu-Zr-Ti ternary alloy to do the axial tension and compression on [001] direction. In order to reduce the impact of thermal vibration on atomic level simulations, we maintain the system temperature near 0 K to clarify the size effect of the structure and mechanical properties.
We found by simulation of copper nanowires that, stress, Young’s modulus, and potential energy behave differently in surficial atoms and interior ones under equilibration, tension, and compression tests. The fact that proportion of surficial atoms in copper nanowires doesn’t increase with nanowire diameter also leads to nonlinearity between the above physical behaviors and nanowire diameter.
On the other hand, with tension and compression tests of metallic glass nanowires, we found that in nanoscale, ductile deformation is the dominant mechanism, while brittle deformation is the bulk counterpart. In general, we found that size difference in metal glass nanowire not only affects mechanical properties, but also the way it deforms

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