1. A thermodynamical model for the nucleation of mechanical twins in TiAl
- Author
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Fischer, F.D., Appel, F., and Clemens, H.
- Subjects
- *
DEFORMATIONS (Mechanics) , *INTERMETALLIC compounds , *SHEAR (Mechanics) , *THERMODYNAMICS , *TITANIUM alloys - Abstract
Mechanical twinning has long been recognized as an important deformation mechanism in many intermetallics including γ(TiAl) based alloys. The generation of a twin can be triggered by dislocations at grain boundaries. The reduction of the stored strain energy in relation to a configuration without any twins can be shown by applying an established transformation criterion, considering twinning as a transformation shearing process. In addition, the application of a thermodynamical extremal principle allows one to predict a distinct twin nucleus in good agreement with experimental observations. The concept is rather general and can be adapted to any initial eigenstress field produced by dislocations present at misfitting interfaces. [Copyright &y& Elsevier]
- Published
- 2003
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