Cavitation-Induced Fracture Causes Nanocorrugations in Brittle Metallic Glasses.
Cavitation-Induced Fracture Causes Nanocorrugations in Brittle Metallic Glasses.
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DOI：
10.1103/physrevlett.117.044302
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发表时间：
2016-07
影响因子：
8.6
通讯作者：
I. Singh;R. Narasimhan;U. Ramamurty
中科院分区：
文献类型：
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作者：
I. Singh;R. Narasimhan;U. Ramamurty
脆性金属玻璃呈现出一种独特而耐人寻味的周期性纳米磨损断口形态，其间距和幅度都在几十纳米量级。我们通过连续介质模拟表明，由于缺口尖端前的本征原子密度涨落，它们在多个弱区内自发和同时发生空化而失效。然后，动态裂纹扩展将沿着连接不断增长的空腔的弯曲但狭窄的剪切带发生。这一机制几乎不涉及耗散，也解释了纳米压痕的形成。
Brittle metallic glasses exhibit a unique and intriguing fracture morphology of periodic nanocorrugations whose spacing and amplitude are of the order of tens of nanometers. We show through continuum simulations that they fail by spontaneous and simultaneous cavitation within multiple weak zones arising due to intrinsic atomic density fluctuations ahead of a notch tip. Dynamic crack growth would then occur along curved but narrowly confined shear bands that link the growing cavities. This mechanism involves little dissipation and also explains the formation of nanocorrugations.