Nucleation and Propagation of Deformation Twin in Polysynthetically Twinned TiAl
L. G. Zhou1, L. M. Hsiung2, Hanchen Huang1
Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
Lawrence Livermore National Laboratory, Chemistry and Materials Science Directorate, P.O. Box 808, L-352, Livermore, CA 94551, USA
Using molecular dynamics simulations,
we study the deformation of polysynthetically twinned
(PST) TiAl at room temperature. The simulation cell
is pre-strained and thermodynamically relaxed to zero
stress, so that no dislocations pre-exist in γ−α2 interfaces. A uniaxial compression is then applied along one
1/6<112] direction. Our results show that interfacial
dislocation pairs nucleate at the γ−α2 interface under
the compression. The glide and agglomeration of these
dislocations lead to the nucleation of deformation twins
from the interface. Based on our studies, twins may nucleate without pre-existing interfacial dislocations. Further we have monitored the propagation of the deformation twin, specifically its interaction with γ−γ and γ−α2
interfaces. The observations show that γ−α2 interfaces
are stronger obstacles to the twin propagation than γ−γ
interfaces are.
Zhou, L. G., Hsiung, L. M., Huang, H. (2004). Nucleation and Propagation of Deformation Twin in Polysynthetically Twinned TiAl. CMES-Computer Modeling in Engineering & Sciences, 6(3), 245–252. https://doi.org/10.3970/cmes.2004.006.245
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