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Size effects of micrometer-scaled metals—the search continues for materials containing real microstructures

Published online by Cambridge University Press:  09 April 2017

A. H. W. Ngan ,
X. X. Chen ,
P. S. S. Leung ,
R. Gu  and
K. F. Gan
A. H. W. Ngan*
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China
X. X. Chen
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China Ove Arup & Partners Hong Kong Ltd, Hong Kong, People's Republic of China
P. S. S. Leung
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China Ove Arup & Partners Hong Kong Ltd, Hong Kong, People's Republic of China
R. Gu
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China Public Testing & Analysis Center, South University of Science and Technology of China, Shenzhen 518055, People's Republic of China
K. F. Gan
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China
*
Address all correspondence to A. H. W. Ngan at hwngan@hku.hk
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Abstract

Recent observations on strength and deformation of small metals containing microstructures, including dislocation patterns, grain boundaries, and second-phase precipitates are reviewed. These microstructures impose an internal length scale that may interplay with the extrinsic length scale due to the specimen size to affect strength and deformation in an intricate manner. For micro-crystals containing pre-existing dislocations, Taylor work-hardening may dictate the dependence of strength on specimen size. The presence of grain boundaries in a small specimen may lead to effects far from the conventional Hall–Petch behavior. Precipitate–dislocation interactions in a small specimen may lead to an interesting weakest-size behavior.

Type
Prospective Articles
Information
MRS Communications , Volume 7 , Issue 2 , June 2017 , pp. 131 - 140
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Copyright
Copyright © Materials Research Society 2017 

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