Increased time-dependent room temperature plasticity in metallic glass nanopillars and its size-dependency

Yoo, Byung-Gil and Kim, Ju-Young and Kim, Yong-Jae and Choi, In-Chul and Shim, Sanghoon and Tsui, Ting Y. and Bei, Hongbin and Ramamurty, Upadrasta and Jang, Jae-il (2012) Increased time-dependent room temperature plasticity in metallic glass nanopillars and its size-dependency. In: INTERNATIONAL JOURNAL OF PLASTICITY, 37 . pp. 108-118.

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Abstract

Room temperature, uniaxial compression creep experiments were performed on micro-/nano-sized pillars (having diameters in the range of 250-2000 nm) of a Zr-based bulk metallic glass (BMG) to investigate the influence of sample size on the time-dependent plastic deformation behavior in amorphous alloys. Experimental results reveal that plastic deformation indeed occurs at ambient temperature and at stresses that are well below the nominal quasi-static yield stress. At a given stress, higher total strains accrue in the smaller specimens. In all cases, plastic deformation was found to be devoid of shear bands, i.e., it occurs in homogeneous manner. The stress exponent obtained from the slope of the linear relation between strain rate and applied stress also shows a strong size effect, which is rationalized in terms of the amount of free volume created during deformation and the surface-to-volume ratio of the pillar. (C) 2012 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	INTERNATIONAL JOURNAL OF PLASTICITY
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copy right for this article belongs to Pergahon_Elsevier Science England.
Keywords:	Metallic glass;Time-dependent plasticity;Nanomechanical properties;Size effect;Nanopillar
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	04 Oct 2012 12:30
Last Modified:	04 Oct 2012 12:30
URI:	http://eprints.iisc.ac.in/id/eprint/45073

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