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Importance of dislocation pile-ups on the mechanical properties and the Bauschinger effect in microcantilevers

Published online by Cambridge University Press:  10 March 2015

M.W. Kapp ,
C. Kirchlechner ,
R. Pippan  and
G. Dehm
M.W. Kapp
Affiliation:
Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria; and Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
C. Kirchlechner*
Affiliation:
Max-Planck-Institut für Eisenforschung, Düsseldorf 40237, Germany; and Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria
R. Pippan
Affiliation:
Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
G. Dehm
Affiliation:
Max-Planck-Institut für Eisenforschung, Düsseldorf 40237, Germany; Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria; and Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
*
a)Address all correspondence to this author. e-mail: kirchlechner@mpie.de
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Abstract

Copper microcantilevers were produced by focused ion beam milling and tested in situ using a scanning electron microscope. To provide different interfaces for piling up dislocations, cantilevers were fabricated to be single crystalline, bicrystalline, or single crystalline with a slit in the region of the neutral axis. The aim of the experiment was to study the influence of dislocation pile-ups on (i) strength and (ii) Bauschinger effects in micrometer-sized, focused ion beam milled bending cantilevers. The samples were loaded monotonically for several times under displacement control. Even though the cantilevers exhibited the same nominal strain gradient the strength varied by 34% within the three cantilever geometries. The Bauschinger effect can be promoted and prohibited by the insertion of different interfaces.

Keywords

dislocationCustrength
Type
Articles
Information
Journal of Materials Research , Volume 30 , Issue 6 , 28 March 2015 , pp. 791 - 797
Copyright
Copyright © Materials Research Society 2015 

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