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Deformation and Fracture Behavior of Tial

Published online by Cambridge University Press:  28 February 2011

C. L. Fu
Affiliation:
Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6114
M. H. Yoo
Affiliation:
Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6114
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Abstract

First-principles total-energy calculations of the elastic constants, shear fault energies, and cleavage energies of TiAl are presented. We find a large elastic shear anisotropy along the [011] direction, and high APB energies due to the strong cohesion between Ti and Al layers. Shear faults of SISF, SESF, and twin boundary are predicted to be prevalent due to their low energies. The anomalous temperature dependence of flow stress is explained by the cross-slip pinning and fault dragging mechanisms. The intrinsic brittleness of TiAl is discussed in terms of the low mobility of 1/2[110] dislocations.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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