Electronic structure based design of thin film metallic glasses with superior fracture toughness
Electronic structure based design of thin film metallic glasses with superior fracture toughness
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DOI：
10.1016/j.matdes.2019.108327
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发表时间：
2020-01-15
影响因子：
8.4
通讯作者：
Schneider, Jochen M.
中科院分区：
文献类型：
--
作者：
Evertz, Simon;Kirchlechner, Ines;Schneider, Jochen M.
高断裂韧性对于金属玻璃作为结构材料的应用是至关重要的，以避免材料以脆性方式发生灾难性失效。金属玻璃中断裂韧性的一个指纹是杂化键的分数，其受合金化Pd 57.4 Al 23.5 Y 7.8 M 11.3（M = Fe、Ni、Co、Cu、Os、Ir、Pt和Au）的影响。它示出，实验断裂韧性数据相关的杂化键的比例与本地化的债券在费米能级。因此，在费米能级的本地化的债券定量地利用作为断裂韧性的措施。基于从头计算，杂化键的最小分数被确定为Pd57.4Al23.5Y7.8Ni11.3。根据费米能级的晶体轨道重叠布居与断裂韧性成比例的假设，首次定量预测了Pd 57.4Al 23.5Y 7.8Ni 11.3的约95 +/- 20 MPa.m（0.5）的值。与此预测一致，在微机械梁弯曲实验Pd57.4Al23.5Y7.8Ni11.3薄膜显示出显着的塑性和裂纹扩展的情况下。(c)2018作者爱思唯尔有限公司出版
High fracture toughness is crucial for the application of metallic glasses as structural materials to avoid catastrophic failure of the material in a brittle manner. One fingerprint for fracture toughness in metallic glasses is the fraction of hybridized bonds, which is affected by alloying Pd57.4Al23.5Y7.8M11.3 with M = Fe, Ni, Co, Cu, Os, Ir, Pt, and Au. It is shown that experimental fracture toughness data is correlated to the fraction of hybridized bonds which scale with the localized bonds at the Fermi level. Thus, the localized bonds at the Fermi level are utilized quantitatively as a measure for fracture toughness. Based on ab initio calculations, the minimum fraction of hybridized bonds was identified for Pd57.4Al23.5Y7.8Ni11.3. According to the ansatz that the crystal orbital overlap population at the Fermi level scales with fracture toughness, for Pd57.4Al23.5Y7.8Ni11.3 a value of around 95 +/- 20 MPa.m(0.5) is predicted quantitatively for the first time. Consistent with this prediction, in micro-mechanical beam bending experiments Pd57.4Al23.5Y7.8Ni11.3 thin films show pronounced plasticity and absence of crack growth. (c) 2018 The Authors. Published by Elsevier Ltd.