Atomic Scale Fluctuations Govern Brittle Fracture and Cavitation Behavior in Metallic Glasses
Atomic Scale Fluctuations Govern Brittle Fracture and Cavitation Behavior in Metallic Glasses
复制标题
DOI：
10.1103/physrevlett.107.215501
复制
发表时间：
2011-11-14
影响因子：
8.6
通讯作者：
Gao, H. J.
中科院分区：
文献类型：
--
作者：
Murali, P.;Guo, T. F.;Gao, H. J.
我们对两种典型金属玻璃（一种是脆性的 (FeP)，另一种是延性的 (CuZr)）的断裂行为进行了原子模拟，结果表明，FeP 玻璃的脆性断裂是由裂纹尖端附近的固有空化机制控制的，而延性 CuZr 玻璃中存在广泛的剪切带。我们表明，局部性质的高度原子尺度空间波动是在脆性金属玻璃中观察到空化行为的主要原因。我们的研究证实了最近在金属玻璃脆性断裂表面上发现的纳米级空腔成核的实验观察结果，并为此类材料中延性与脆性行为的根本原因提供了重要的见解。
We perform atomistic simulations on the fracture behavior of two typical metallic glasses, one brittle (FeP) and the other ductile (CuZr), and show that brittle fracture in the FeP glass is governed by an intrinsic cavitation mechanism near crack tips in contrast to extensive shear banding in the ductile CuZr glass. We show that a high degree of atomic scale spatial fluctuations in the local properties is the main reason for the observed cavitation behavior in the brittle metallic glass. Our study corroborates with recent experimental observations of nanoscale cavity nucleation found on the brittle fracture surfaces of metallic glasses and provides important insights into the root cause of the ductile versus brittle behavior in such materials.