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Heterogeneous dislocation nucleation from surfaces and interfaces as governing plasticity mechanism in nanoscale metals

Jennings, Andrew T. and Greer, Julia R. (2011) Heterogeneous dislocation nucleation from surfaces and interfaces as governing plasticity mechanism in nanoscale metals. Journal of Materials Research, 26 (22). pp. 2803-2814. ISSN 0884-2914. http://resolver.caltech.edu/CaltechAUTHORS:20120312-110102686

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Abstract

We report the results of constant strain rate experiments on electroplated, single crystalline copper pillars with diameters between 75 and 525 nm. At slow strain rates, 10^(−3) s^(−1), pillar diameters with 150 nm and above show a size-dependent strength similar to previous reports. Below 150 nm, we find that the size effect vanishes as the strength transitions to a relatively size-independent regime. Strain rate sensitivity and activation volume are determined from uniaxial compression tests at different strain rates and corroborate a deformation mechanism change. These results are discussed in the framework of recent in situ transmission electron microscopy experiments observing two distinct deformation mechanisms in pillars and thin films on flexible substrates: partial dislocation nucleation from stress concentrations in smaller structures and single arm source operation in larger samples. Models attempting to explain these different size-dependent regimes are discussed in relation to these experiments and existing literature revealing further insights into the likely small-scale deformation mechanisms.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1557/jmr.2011.338 DOIArticle
http://journals.cambridge.org/abstract_S0884291411003384PublisherArticle
ORCID:
AuthorORCID
Greer, Julia R.0000-0002-9675-1508
Additional Information:© 2011 Materials Research Society. Received 10 May 2011; accepted 29 September 2011. The authors gratefully acknowledges the financial support of the National Science Foundation through ATJ’s NSF Graduate Research fellowship and JRG’s CAREER grant (DMR-0748267).
Group:Kavli Nanoscience Institute
Funders:
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
NSF DMR-0748267
Subject Keywords:Defects; Nanoscale; Metal
Record Number:CaltechAUTHORS:20120312-110102686
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20120312-110102686
Official Citation:Andrew T. Jennings and Julia R. Greer (2011). Heterogeneous dislocation nucleation from surfaces and interfaces as governing plasticity mechanism in nanoscale metals. Journal of Materials Research, 26 , pp 2803-2814 doi:10.1557/jmr.2011.338
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29689
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:13 Mar 2012 15:44
Last Modified:11 Sep 2015 01:10

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