In Situ Micromechanical Characterization of Metallic Glass Microwires under Torsional Loading

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

1 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)361-368
Journal / PublicationExperimental Mechanics
Volume59
Issue number3
Online published4 Jan 2019
Publication statusPublished - Mar 2019

Abstract

Small-scale metallic glasses have many applications in microelectromechanical systems (MEMS) and sensors which require good mechanical properties. Bending, tensile and compression properties of metallic glasses at micro/nano-scale have been well investigated previously. In this work, by developing a micro robotic system, we investigated the torsional behavior of Fe-Co based metallic glass microwires inside a scanning electron microscope (SEM). Benefiting from the in situ SEM imaging capability, the fracture behavior of metallic glass microwire has been uncovered clearly. Through the postmortem fractographic analysis, it can be revealed that both spiral stripes and shear bands contributed to the fracture mechanism of the microscale metallic glass. Plastic deformation of the microwires include both homogenous and inhomogeneous plastic strain, which began with the liquid-like region, then a crack formed because of shear bands and propagated along the spiral direction. Although the metallic glass microwire broke in brittle mode, the shear strain was not lower than that of conventional metal wires. Moreover, we found an inverse relationship between the plastic strain and the loading rate.

Research Area(s)

  • Fracture behavior, Metallic glass, Micromechanical testing, Microwire, Torsion