Quantitative In Situ Analysis of Deformation in Sliding Metals: Effect of Initial Strain State

Mahato, Anirban and Sundaram, Narayan K and Yeung, Ho and Lukitsch, Michael and Sachdev, Anil K and Chandrasekar, Srinivasan (2015) Quantitative In Situ Analysis of Deformation in Sliding Metals: Effect of Initial Strain State. In: TRIBOLOGY LETTERS, 60 (3).

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Abstract

Using in situ, high-speed imaging of a hard wedge sliding against pure aluminum, and image analysis by particle image velocimetry, the deformation field in sliding is mapped at high resolution. This model system is representative of asperity contacts on engineered surfaces and die-workpiece contacts in deformation and machining processes. It is shown that large, uniform plastic strains of 1-5 can be imposed at the Al surface, up to depths of 500 mu m, under suitable sliding conditions. The spatial strain and strain rate distributions are significantly influenced by the initial deformation state of the Al, e.g., extent of work hardening, and sliding incidence angle. Uniform straining occurs only under conditions of steady laminar flow in the metal. Large pre-strains and higher sliding angles promote breakdown in laminar flow due to surface fold formation or flow localization in the form of shear bands, thus imposing limits on uniform straining by sliding. Avoidance of unsteady sliding conditions, and selection of parameters like sliding angle, thus provides a way to control the deformation field. Key characteristics of the sliding deformation such as strain and strain rate, laminar flow, folding and prow formation are well predicted by finite element simulation. The deformation field provides a quantitative basis for interpreting wear particle formation. Implications for engineering functionally graded surfaces, sliding wear and ductile failure in metals are discussed.

Item Type:	Journal Article
Publication:	TRIBOLOGY LETTERS
Publisher:	SPRINGER/PLENUM PUBLISHERS
Additional Information:	Copy right for this article belongs to the SPRINGER/PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013 USA
Keywords:	Metals; Sliding; High-speed imaging; Large strain deformation; Wear
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	06 Jan 2016 06:10
Last Modified:	06 Jan 2016 06:10
URI:	http://eprints.iisc.ac.in/id/eprint/53047

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