@misc{ibanezperez_influence_of_2021, 
author={Ibanez-Perez, J., No, M., Oehring, M., Clemens, H., San Juan, J.},
title={Influence of Nb on Ti diffusion in γ-TiAl intermetallics studied by mechanical spectroscopy},
year={2021},
howpublished = {journal article},
doi = {https://doi.org/10.1016/j.jallcom.2021.158880},
abstract = {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 α2-Ti3Al phase. Internal friction measurements show a relaxation peak P(α2), which is associated with short distance diffusion of Ti atoms in the α2 phase, involving stress-induced rotation of dipoles Al-VTi-Al, whose activation energy is dependent on the Nb content. The increase of the activation energy is quantified as ΔEa(Ti)= 0.037 eV × at% Nb, being attributed to the next-neighbor interaction of Nb atoms with the local configuration of Ti-VTi. 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.},
note = {Online available at: \url{https://doi.org/10.1016/j.jallcom.2021.158880} (DOI). Ibanez-Perez, J.; No, M.; Oehring, M.; Clemens, H.; San Juan, J.: Influence of Nb on Ti diffusion in γ-TiAl intermetallics studied by mechanical spectroscopy. Journal of Alloys and Compounds. 2021. vol. 867, 158880. DOI: 10.1016/j.jallcom.2021.158880}}