Nanoindentation behavior of nanotwinned Cu: Influence of indenter angle on hardness, strain rate sensitivity and activation volume

Choi, In-Chul and Kim, Yong-Jae and Wang, Morris Y and Ramamurty, Upadrasta and Jang, Jae-il (2013) Nanoindentation behavior of nanotwinned Cu: Influence of indenter angle on hardness, strain rate sensitivity and activation volume. In: Acta Materialia, 61 (19). pp. 7313-7323.

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Abstract

The influence of strain on the mechanical properties and deformation kinetic parameters of nanotwinned (at) copper is investigated by a series of nanoindentation experiments, which were performed by employing sharp indenters with five varying centerline-to-face angles (psi). Comparison experiments were also conducted on (1 1 0) single crystalline Cu. Experimental results indicate that, unlike coarsegrained materials, nt-Cu is prone to plastic flow softening with large material pile-up around the indentation impression at high levels of strains. Localized detwinning becomes more significant with decreasing psi, concomitant with reduced strain-rate sensitivity (m) and enhanced activation volume (V*). The m of nt-Cu is found to depend sensitively on psi with a variation of more than a factor of 3, whereas V* exhibits a much less sensitive trend. This paper discusses the validation of the experimental techniques and the implications of various deformation kinetic parameters on the underlying deformation mechanisms of nt-Ca. 2013 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:	Nanotwinned Metals; Nanoindentation; Hardness; Strain-Rate Sensitivity; Activation Volume
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	03 Jan 2014 10:58
Last Modified:	03 Jan 2014 10:58
URI:	http://eprints.iisc.ac.in/id/eprint/48112

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