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Atomistic Studies of Jogged Screw Dislocations in γ-TiAl Alloys

Published online by Cambridge University Press:  10 February 2011

K. Y. Chen
Affiliation:
Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
M. Li
Affiliation:
Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
S. J. Zhou
Affiliation:
Applied Theoretical and Computational Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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Abstract

The behavior of jogged screw dislocations in γ-TiAl alloys have been investigated with largescale molecular dynamics (MD) simulations. We find a new mechanism for formation of pinning points in jogged screw dislocations. We also find that the critical height for the jogs in ±[110] directions on the (001) plane to move nonconservatively is between 3r0 and 4r0, where r0 is the nearest neighbor distance of aluminum atoms. Interstitials and vacancies are created during the nonconservative motions of the jogs. In addition, the formations of dislocation dipole and loops around the jogs are also observed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

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