Study of nanometer-scaled lamellar microstructure in a Ti-45Al-7.5Nb alloy - Experiments and modeling

Author(s)
Franz Dieter Fischer, Thomas Waitz, Christina Scheu, Limei Cha, Gerhard Dehm, Thomas Antretter, Helmut J. Clemens
Abstract

Quenching of Ti-45 at%Al-7.5 at%Nb from the single alpha-phase region to room temperature followed by aging below the eutectoid temperature leads to the precipitation of ultra-fine gamma-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 gamma-TiAl lamellae within the alpha(2)-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.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Montanuniversität Leoben, Ludwig-Maximilians-Universität München
Journal
Intermetallics
Volume
18
Pages
509-517
No. of pages
9
ISSN
0966-9795
DOI
https://doi.org/10.1016/j.intermet.2009.09.012
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/study-of-nanometerscaled-lamellar-microstructure-in-a-ti45al75nb-alloy--experiments-and-modeling(cddbb733-c560-4b76-bb62-ac4c21e5892b).html