In-situ observation of the initiation of plasticity by nucleation of prismatic dislocation loops

Lee S, Vaid A, Im J, Kim B, Prakash A, Guenole J, Kiener D, Bitzek E, Oh SH (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Book Volume: 11

Article Number: 2367

Journal Issue: 1

DOI: 10.1038/s41467-020-15775-y

Abstract

The elastic-to-plastic transition during the deformation of a dislocation-free nanoscale volume is accompanied by displacement bursts associated with dislocation nucleation. The dislocations that nucleate during the so-called “pop-in” burst take the form of prismatic dislocation loops (PDLs) and exhibit characteristic burst-like emission and plastic recovery. Here, we report the in-situ transmission electron microscopy (TEM) observation of the initial plasticity ensued by burst-like emission of PDLs on nanoindentation of dislocation-free Au nanowires. The in-situ TEM nanoindentation showed that the nucleation and subsequent cross slip of shear loop(s) are the rate-limiting steps. As the indentation size increases, the cross slip of shear loop becomes favored, resulting in a transition from PDLs to open half-loops to helical dislocations. In the present case of nanoindentation of dislocation-free volumes, the PDLs glide out of the indentation stress field while spreading the plastic zone, as opposed to the underlying assumption of the Nix-Gao model.

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Involved external institutions

Pohang University of Science and Technology (POSTECH) Korea, Republic of (KR) Montanuniversität Leoben Austria (AT) Korea Advanced Institute of Science and Technology (KAIST) Korea, Republic of (KR)

How to cite

APA:

Lee, S., Vaid, A., Im, J., Kim, B., Prakash, A., Guenole, J.,... Oh, S.H. (2020). In-situ observation of the initiation of plasticity by nucleation of prismatic dislocation loops. Nature Communications, 11(1). https://doi.org/10.1038/s41467-020-15775-y

MLA:

Lee, Subin, et al. "In-situ observation of the initiation of plasticity by nucleation of prismatic dislocation loops." Nature Communications 11.1 (2020).

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