Abstract
Quenching of Ti-45 at%Al-7.5 at%Nb from the single α-phase region to room temperature followed by aging below the eutectoid temperature leads to the precipitation of ultra-fine γ-TiAl lamellae. In addition to an extensive experimental program, reported by Cha et al. in Intermetallics 16 (2008) 868-875, in this work a micromechanical and thermodynamical model is presented for the formation of γ-TiAl lamellae within the α2-Ti3Al parent phase. A global transformation condition allows to predict a thickness to length ratio in accordance with experimental observations. Furthermore, a local transformation condition offers the basis for a kinetic law. The modeling concept can be applied to similar problems of combined diffusive and displacive phase transformations.
Original language | English |
---|---|
Pages (from-to) | 509-517 |
Number of pages | 9 |
Journal | Intermetallics |
Volume | 18 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2010 |
Externally published | Yes |
Keywords
- A. Titanium aluminides
- B. Phase transformation
- C. Thermal treatment
- D. Microstructure
- E. Modeling