Fracture universality in amorphous nanowires
Fracture universality in amorphous nanowires
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DOI：
10.1016/j.jmps.2023.105210
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发表时间：
2023-04
影响因子：
5.3
通讯作者：
K. Zhao;Yunjiang Wang;P. Cao
中科院分区：
文献类型：
--
作者：
K. Zhao;Yunjiang Wang;P. Cao
结晶纳米线表现出广泛的尺寸依赖性的断裂和失效模式已被广泛研究，但非晶材料的断裂行为及其尺寸依赖性仍然难以捉摸。在这里进行了广泛的原子模拟，以揭示变形和断裂行为在一个广泛的类的非晶纳米线具有不同的尺寸，包括CuZr，CuZrAl，FeP，Si，和韧性Lennard-Jones系统。它被发现，断裂应变Δ f随纳米线长度L增加，但随着直径D，它表现出的线性关系与直径-长度比Δ f Δ D/L，-在这五个不同的玻璃体系中有效的标度律understudied。我们开发了一个理论模型，捕捉在塑性屈服的塑性区的大小和它的重要作用，在管理最终的断裂应变，这表明与模拟数据的协议。考虑到固有的原子级的理想应变，值得注意的是，所有的尺寸相关的断裂应变数据崩溃，标志着广泛的玻璃材料的断裂性质的普遍性。
Crystalline nanowires exhibiting a wide range of size-dependent fracture and failure modes have been extensively studied, yet the fracture behaviors of amorphous materials and their size dependence remain elusive. Here extensive atomistic simulations are performed to reveal the deformation and fracture behaviors in a broad class of amorphous nanowires with varying sizes, including CuZr, CuZrAl, FeP, Si, and a ductile Lennard-Jones system. It is found that the fracture strain ɛ f increases with nanowire length L but decreases with diameter D, which exhibits a linear relationship with the diameter-to-length ratio as ɛ f∝ D/L,—a scaling law valid in these five distinct glassy systems understudied. We develop a theoretical model, capturing the size of plastic zone at plastic yielding and its vital role in governing the final fracture strain, which shows an agreement with the simulation data. By taking into account the intrinsic atomic-level ideal strain, remarkably, all the size-dependent fracture strain data collapse, signifying the universality of fracture nature in a broad range of glassy materials.