Identification of medium range order defects and their critical effect on spallation of Cu64Zr36 metallic glass

Y Liu and JR Luo and X Huang, JOURNAL OF ALLOYS AND COMPOUNDS, 932, 167591 (2023).

DOI: 10.1016/j.jallcom.2022.167591

The absence of a well-defined structural defect is a longstanding problem, acting as the obstacle for un-derstanding of mechanical behavior in metallic glasses. Here, through a compelling integration of experi-mental and computational technologies containing Synchrotron X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS) as well as atomistic simulations, we present more direct evidences for the existence of medium range order (MRO) defects based on the discontinuity of stiff ico-sahedral network. As revealed by the numerical simulation of spallation process for two Cu64Zr36 metallic glasses with different cooling history, the MRO defects can be used as the efficient predictor of void nu-cleation, as evidenced by the strong correlation between high MRO defects location and subsequent void sites. This observation implies that the initial distribution as well as further generation of MRO defects play a critical role for the mechanical failure process of metallic glasses. It can be also extended to experimental conditions since the atomic packing of metallic glasses in molecular dynamic (MD) simulations is in great agreement with that obtained from reality as characterized by results of X-ray and EXAFS.(c) 2022 Elsevier B.V. All rights reserved.

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