Spatial heterogeneity as the structure feature for structure–property relationship of metallic glasses

• Published in: Nature communications Vol. 9; no. 1; pp. 3965 - 7
• Main Authors: Zhu, Fan, Song, Shuangxi, Reddy, Kolan Madhav, Hirata, Akihiko, Chen, Mingwei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.09.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 147/137; 147/3; 639/301/1023/1026; 639/301/1023/218; 639/301/1023/303; 639/301/119/1002; Amorphous materials; Crystal defects; Deformation; Dislocations; Feasibility studies; Grain boundaries; Heterogeneity; Humanities and Social Sciences; Mechanical properties; Metallic glasses; Modulus of elasticity; multidisciplinary; Science; Science (multidisciplinary); Solid solutions; Solution strengthening; Spatial heterogeneity; Strain; Strain hardening; Strain relaxation; Time dependence
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-06476-8

The mechanical properties of crystalline materials can be quantitatively described by crystal defects of solute atoms, dislocations, twins, and grain boundaries with the models of solid solution strengthening, Taylor strain hardening and Hall–Petch grain boundary strengthening. However, for metallic glasses, a well-defined structure feature which dominates the mechanical properties of the disordered materials is still missing. Here, we report that nanoscale spatial heterogeneity is the inherent structural feature of metallic glasses. It has an intrinsic correlation with the strength and deformation behavior. The strength and Young’s modulus of metallic glasses can be defined by the function of the square root reciprocal of the characteristic length of the spatial heterogeneity. Moreover, the stretching exponent of time-dependent strain relaxation can be quantitatively described by the characteristic length. Our study provides compelling evidence that the spatial heterogeneity is a feasible structural indicator for portraying mechanical properties of metallic glasses. Directly relating the mechanical properties of metallic glasses to their atomic structure remains a challenge. Here, the authors use high resolution microscopy to show many mechanical properties of metallic glasses depend on a single structural parameter, the characteristic length of spatial heterogeneity.