People | Locations | Statistics |
---|---|---|
Naji, M. |
| |
Motta, Antonella |
| |
Aletan, Dirar |
| |
Mohamed, Tarek |
| |
Ertürk, Emre |
| |
Taccardi, Nicola |
| |
Kononenko, Denys |
| |
Petrov, R. H. | Madrid |
|
Alshaaer, Mazen | Brussels |
|
Bih, L. |
| |
Casati, R. |
| |
Muller, Hermance |
| |
Kočí, Jan | Prague |
|
Šuljagić, Marija |
| |
Kalteremidou, Kalliopi-Artemi | Brussels |
|
Azam, Siraj |
| |
Ospanova, Alyiya |
| |
Blanpain, Bart |
| |
Ali, M. A. |
| |
Popa, V. |
| |
Rančić, M. |
| |
Ollier, Nadège |
| |
Azevedo, Nuno Monteiro |
| |
Landes, Michael |
| |
Rignanese, Gian-Marco |
|
No, Maria L.
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (2/2 displayed)
Places of action
Organizations | Location | People |
---|
article
Influence of Nb on Ti diffusion in γ-TiAl intermetallics studied by mechanical spectroscopy
Abstract
<p>The development of intermetallic titanium aluminides has been driven by the aeronautic and aerospace industries because of the excellent mechanical properties and low density of γ-TiAl based alloys. Up to now, several generations of γ-TiAl based alloys were developed with increasing complexity of the alloy systems. Nb is one of the most important alloying elements in γ-TiAl alloys and although it is considered as a slow diffuser, its influence has not been fully quantified yet. In this work we demonstrate, through mechanical spectroscopy measurements conducted on several γ-TiAl based alloys with different Nb content, that Nb impedes the diffusion of Ti atoms in the α<sub>2</sub>-Ti<sub>3</sub>Al phase. Internal friction measurements show a relaxation peak P(α<sub>2</sub>), which is associated with short distance diffusion of Ti atoms in the α<sub>2</sub> phase, involving stress-induced rotation of dipoles Al-V<sub>Ti</sub>-Al, whose activation energy is dependent on the Nb content. The increase of the activation energy is quantified as ΔE<sub>a</sub>(Ti)= 0.037 eV × at% Nb, being attributed to the next-neighbor interaction of Nb atoms with the local configuration of Ti-V<sub>Ti</sub>. This mechanism also produces a further broadening of the relaxation peak, which is attributed to the near-next-neighbor interactions for high Nb contents. Finally, an atomic model for the mechanism responsible for this relaxation is proposed allowing to explain the observed experimental behavior.</p>