Correlation between band propagation property and the nature of serrations in the Portevin-Le Chatelier effect

Sarmah, Ritupan and Ananthakrishna, G (2015) Correlation between band propagation property and the nature of serrations in the Portevin-Le Chatelier effect. In: ACTA MATERIALIA, 91 . pp. 192-201.

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Abstract

We investigate the correlation between the band propagation property and the nature and amplitude of serrations in the Portevin-Le Chatelier effect within the framework of the Ananthakrishna model. Several significant results emerge. First, we find that spatial and temporal correlations continuously increase with strain rate from type C to type A bands. Consequently, the nature of the bands also changes continuously from type C to A bands, and so do the changes in the associated serrations. Second, even the smallest extent of propagation induces small amplitude serrations. The spatial extent of band propagation is directly correlated with the duration of small amplitude serrations, a result that is consistent with recent experiments. This correspondence allows one to estimate the spatial extent of band propagation by just measuring the temporal stretch of small amplitude serrations. Therefore, this should be of practical value when only stress versus strain is recorded. Third, the average stress drop magnitude of the small amplitude serrations induced by the propagating bands remains small and nearly constant with strain rate. As a consequence, the fully propagating type A bands are in a state of criticality. We rationalize the increasing levels of spatial and temporal correlations found with increasing strain rates. Lastly, the model also predicts several band morphologies seen in experiments including the Luders-like propagating band. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	ACTA MATERIALIA
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:	Portevin-Le Chatelier effect; Plastic instability; Band types; Small amplitude serrations; Dynamical approach
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	15 Jun 2015 05:01
Last Modified:	15 Jun 2015 05:01
URI:	http://eprints.iisc.ac.in/id/eprint/51631

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