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Shear deformation in TiAl: Atomic dynamic and static simulations

Published online by Cambridge University Press:  31 January 2011

Y.L. Liu ,
S.Q. Wang  and
H.Q. Ye
Y.L. Liu*
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China; and Graduate University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
S.Q. Wang
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
H.Q. Ye
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China; and Electron Microscope Lab, Peking University, Beijing 100871, People’s Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The dynamic shear deformation process and the related stacking fault transitions in TiAl have been systematically investigated using both the molecular dynamics and ab initio methods. The details of the dislocation initiation and microstructural evolution are presented, and the concomitant potential energy variation and the radial distribution functions have been analyzed. The results show, interestingly, that some deformation-induced hexagonal close-packed (hcp) structures are metastable, and that a higher velocity field promotes more hcp segments. The phenomena are interpreted based on ab initio calculations of the detailed energy variation at the different fault transition stages, i.e., superlattice intrinsic stacking fault (SISF) → TWIN, SISF → hcp, and hcp → TWIN. The intrinsic factor that governs the deformation process is discussed. The results promote new understanding of the stress-induced interfaces and dislocation behaviors in experimental observations.

Keywords

DislocationsMicrostructureSimulation
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 6 , June 2007 , pp. 1685 - 1693
Copyright
Copyright © Materials Research Society2007

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References

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