Evolution of microstructures during creep in TiAl-base intermetallics with a different Nb content

0440417 - ÚFM 2015 RIV GB eng C - Conference Paper (international conference)
Dlouhý, Antonín - Orlová, Alena - Kuchařová, Květa
Evolution of microstructures during creep in TiAl-base intermetallics with a different Nb content.
15th International Conference on the Strength of Materials (ICSMA-15). Bristol: IOP Publishing, 2010 - (Skrotzki, W.; Oertel, C.; Biermann, H.; Heilmaier, M.), Art. No. 012091. Journal of Physics: Conference Series, 240. ISSN 1742-6588.
[ICSMA 15 - International Conference on the Strength of Materials /15./. Dresden (DE), 16.08.2009-21.08.2009]
R&D Projects: GA ČR GA106/07/0762; GA AV ČR 1QS200410502
Institutional research plan: CEZ:AV0Z20410507
Keywords : intermetallics * creep * TiAl
Subject RIV: JG - Metallurgy
http://iopscience.iop.org/1742-6596/240/1

An evolution of microstructure has been investigated with increasing compression creep strain in intermetallic alloys Ti-48Al-2Cr-2Nb-1B (alloy Nb2) and Ti-46Al-7Nb-0.6Cr-0.2Ni-0.1Si (alloy Nb7) loaded to 350 MPa at 973 K. Scanning electron microscopy and transmission electron microscopy analysis focused on individual deformation modes and on the phase stability of the alloys. Dislocation densities and deformation twinning characteristics were systematically evaluated for strains up to 0.38. Results of these quantitative studies showed that the evolution of total and non-zero c -component dislocation densities with strain was similar for all the investigated materials in spite of relevant differences in the initial gamma/alpha 2 microstructures. However, the spacing between deformation twins seemed to scale with the creep strength of the two alloys. These results are discussed in terms of the fundamental deformation modes and their contributions to the strain accumulation kinetics during high temperature creep in TiAl-base intermetallics with a different Nb content.
Permanent Link: http://hdl.handle.net/11104/0243538