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In situ transmission electron microscope study of interface sliding and migration in an ultrafine lamellar structure

Published online by Cambridge University Press:  03 March 2011

L.M. Hsiung ,
J. Zhou  and
T.G. Nieh
L.M. Hsiung*
Affiliation:
Lawrence Livermore National Laboratory, Chemistry and Materials Science Directorate, Livermore, California 94551
J. Zhou
Affiliation:
Lawrence Livermore National Laboratory, Chemistry and Materials Science Directorate, Livermore, California 94551
T.G. Nieh
Affiliation:
The University of Tennessee, Department of Materials Science and Engineering, Knoxville, Tennessee 37996
*
a) Address all correspondence to this author. e-mail: [email protected] This paper was selected as the Outstanding Meeting Paper for the 2005 MRS Spring Meeting Symposium BB Proceedings, Vol. 880E.
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Abstract

The instability of interfaces in an ultrafine TiAl-(γ)/Ti3Al-(α2) lamellar structure by straining at room temperature has been investigated using in situ straining techniques performed in a transmission electron microscope. The purpose of this study was to obtain experimental evidence to support the creep mechanisms based upon the interface sliding in association with a cooperative movement of interfacial dislocations, which was proposed previously to rationalize a nearly linear creep behavior of ultrafine lamellar TiAl alloys. The results reveal that the sliding and migration of lamellar interfaces can take place simultaneously as a result of the cooperative movement of interfacial dislocations, which can lead to an adverse effect in the performance of ultrafine lamellar TiAl alloy.

Keywords

DislocationsGrain boundariesTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 10 , October 2006 , pp. 2453 - 2459
Copyright
Copyright © Materials Research Society 2006

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