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Planar fault energies and dislocation core spreading in B2 NiAl

Published online by Cambridge University Press:  03 March 2011

Diana Farkas  and
Christophe Vailhe
Diana Farkas
Affiliation:
Department of Materials Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0237
Christophe Vailhe
Affiliation:
Department of Materials Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0237
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Abstract

We present computer simulation results for the planar faults involved in core spreading of 〈100〉 and 〈111〉 dislocations. Seven γ surfaces were computed for different crystallographic planes ({110}, {112}, {123}, {210}, {100}, {111}, and {122}). Stable APB's are observed in the {110} and {112} planes, but they are deviated from the exact 1/2a〈111〉 position. No other stable planar fault was observed. The fact that a stable minimum is observed deviated from the 1/2〈111〉 position suggests the possibility of different dissociation reactions for the 〈111〉 screw dislocation in the {110} and {112} planes. The fact that no other stable minima were observed in the γ surfaces indicates that no true core dissociation is expected for the 〈100〉 dislocations. We propose that dislocation core spreading in various planes can be understood in terms of the directions of lowest restoring forces observed for the corresponding γ surfaces.

Type
Articles
Information
Journal of Materials Research , Volume 8 , Issue 12 , December 1993 , pp. 3050 - 3058
Copyright
Copyright © Materials Research Society 1993

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References

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