Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-29T14:19:01.403Z Has data issue: false hasContentIssue false
  • English
  • Français

Massive Transformation in High Niobium Containing TiAl-Alloys

Published online by Cambridge University Press:  26 February 2011

A. Bartels ,
S. Bystrzanowski ,
H. Chladil ,
H. Leitner ,
H. Clemens ,
R. Gerling  and
F.-P. Schimansky
A. Bartels
Affiliation:
Materials Science and Technology, TU Hamburg-Harburg, D-21073 Hamburg, Germany
S. Bystrzanowski
Affiliation:
Materials Science and Technology, TU Hamburg-Harburg, D-21073 Hamburg, Germany
H. Chladil
Affiliation:
Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben, Austria
H. Leitner
Affiliation:
Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben, Austria
H. Clemens
Affiliation:
Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben, Austria
R. Gerling
Affiliation:
Institute for Materials Research, GKSS-Research Centre, D-21502 Geesthacht, Germany
F.-P. Schimansky
Affiliation:
Institute for Materials Research, GKSS-Research Centre, D-21502 Geesthacht, Germany
Get access

Abstract

Massive transformation in high Nb bearing γ-TiAl-based alloys, Ti-45Al-7.5Nb and Ti-46Al-9Nb (at.%), and the thermal stability of the resulting microstructure were investigated. Using a quenching dilatometer, a nearly complete massive transformation in Ti-45Al-7.5Nb was found at about 1050°C after annealing at 1305°C for 10min and subsequent cooling with a rate of 55K/s. Higher starting temperatures and higher cooling rates lead to incomplete massive transformation and small transformed areas situated at the grain-boundary triple points of the parent α-grains are observed. By means of EBSD only in one case the same orientation of the close-packed planes of parent α-grains and of massively transformed γM-areas was observed.

The thermal stability of the microstructure of massively transformed Ti-46Al-9Nb sheet material was tested by annealing samples for 1 hour between 400 and 1200°C. Above 800°C a drop of hardness was measured and X-ray diffraction patterns show an increasing separation of (200)γ and (002)γ reflections as expected from a tetragonal γ-TiAl lattice. After annealing at 1100°C α2-phase segregates at grain boundaries and after 1200°C α2-lamellae appear insides the γM-grains parallel to all four {111}γ-planes.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 842: Symposium S – Integrative and Interdisciplinary Aspects of Intermetallics , 2004 , S5.48
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Appel, F., Oehring, M., Wagner, R., Intermetallics, 8, 1283 (2000)Google Scholar
2. Zhang, W.J., Deevi, S.C., Chen, G.L., Intermetallics, 10, 403 (2002)Google Scholar
3. Appel, F., Mat. Sci. Eng. A317, 115 (2001)Google Scholar
4. General Discussion Session of the Symposium on “The Mechanism of the Massive Transformation“, edited by Aaronson, H.I. and Vasudevan, V.K., Metall. Mater. Trans., 33A, 2445 (2002)Google Scholar
5. Hu, D., in Ti-2003, edited by Lütjering, G. and Albrecht, J. (Wiley-VCH Verlag, Weinheim, Germany, 2004) p. 2369 Google Scholar
6. Gerling, R., Clemens, H., Schimansky, F.-P., Advanced Engineering Materials 6, 23 (2004)Google Scholar
7. Gerling, R., Bartels, A., Clemens, H., Kestler, H., Schimansky, F.-P., Intermetallics 12, 275 (2004)Google Scholar