Superplasticity in electrodeposited nanocrystalline nickel

Prasad, MJNV and Chokshi, AH (2010) Superplasticity in electrodeposited nanocrystalline nickel. In: Acta Materialia, 58 (17). pp. 5724-5736.

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Abstract

Electrodeposited nanocrystalline Ni films were processed with different levels of S, to evaluate the role of S on superplasticity. All the materials exhibited high strain rate superplasticity at a relatively low temperature of 777 K. Microstructural characterization revealed that the S was converted to a Ni3S2 phase which melts at 908 K; no S could be detected at grain boundaries. There was no consistent variation in ductility with S content. Superplasticity was associated with a strain rate sensitivity of similar to 0.8 and an inverse grain size exponent of similar to 1 both of which are unusual observations in superplastic flow of metals. Based on the detailed experiments and analysis, it is concluded that superplasticity in nano-Ni is related to an interface controlled diffusion creep process, and it is not related to the presence of S at grain boundaries or a liquid phase at grain boundaries. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	Acta Materialia
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Nanocrystalline; Nickel; Electrodeposition; Sulfur; Superplasticity
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	26 Oct 2010 07:27
Last Modified:	26 Oct 2010 07:27
URI:	http://eprints.iisc.ac.in/id/eprint/33460

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