Notch sensitivity in nanoscale metallic glass specimens: Insights from continuum simulations

Singh, I and Narasimhan, R (2016) Notch sensitivity in nanoscale metallic glass specimens: Insights from continuum simulations. In: JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, 86 . pp. 53-69.

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Abstract

Recent experiments have shown that nano-sized metallic glass (MG) specimens subjected to tensile loading exhibit increased ductility and work hardening. Failure occurs by necking as opposed to shear banding which is seen in bulk samples. Also, the necking is generally observed at shallow notches present on the specimen surface. In this work, continuum finite element analysis of tensile loading of nano-sized notched MG specimens is conducted using a thermodynamically consistent non-local plasticity model to clearly understand the deformation behavior from a mechanics perspective. It is found that plastic zone size in front of the notch attains a saturation level at the stage when a dominant shear band forms extending across the specimen. This size scales with an intrinsic material length associated with the interaction stress between flow defects. A transition in deformation behavior from quasi-brittle to ductile becomes possible when this critical plastic zone size is larger than the uncracked ligament length. These observations corroborate with atomistic simulations and experimental results. (C) 2015 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copy right for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Metallic glass; Notch sensitivity; Shear band; Brittle-ductile transition; Non-local plasticity model
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	30 Dec 2015 07:31
Last Modified:	30 Dec 2015 07:31
URI:	http://eprints.iisc.ac.in/id/eprint/52932

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