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Reaction Process of αəγ Massive Transformation in Ti-Rich TiAl Alloy

Published online by Cambridge University Press:  22 February 2011

T. Kumagai ,
E. Abe ,
M. Takeyama  and
M. Nakamura
T. Kumagai
Affiliation:
National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan
E. Abe
Affiliation:
National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan
M. Takeyama
Affiliation:
Department of Metallurgical Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152, Japan
M. Nakamura
Affiliation:
National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan
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Abstract

Reaction sequence of the massive transformation from the high-temperature α-Ti phase to the γ-TiAl phase (αm) in a Ti-48at.% Al alloy has been examined in terms of optical and transmission electron microscopes. Both transformed and untransformed regions were macroscopically observed in the sample quenched from the high-temperature α phase field, when the sample was held there for a extended period of time prior to quenching. The transformed region consists of randomly oriented fine α single phase grains, in which many thermal anti-phase domains (TAPDs), together with a number of stacking faults were observed. In contrast, the untransformed region comprises extremely fine lamellae of the α and α2-Ti3Al phases, and the α plates were found to run through the TAPDs caused by α ə α2 ordering. Subsequent aging at 1273K causes the microstructure change in the untransformed region from α2/γ lamellae to γ/γ lamellae spontaneously and expands the γm region. These observations suggest that the α ə γm transformation proceeds through formation of fine γ plates.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 364: Symposium L – High-Temperature Ordered Intermetallic Alloys–VI , 1994 , 181
Copyright
Copyright © Materials Research Society 1995

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References

1. Kim, Y.W., in Microstructure / Property Relationships in Titanium Aluminides and Alloys, edited by Kim, Y.W. and Boyer, R.R. ( TMS Proc., Warrendale, PA, 1991) pp. 91–103.Google Scholar
2. Takeyama, M., Mater. Sci. and Engn., A152, 269 (1992).Google Scholar
3. Takeyama, M., Kumagai, T., Nakamura, M. and Kikuchi, M., in Structural Intermetallics, edited by Darolia, R. et al. ( TMS Proc., Warrendale, PA, 1993 ) pp. 167–176.Google Scholar
4. Wang, P., Viswanathan, G.B. and Vasudevan, V.K., Metall. Trans. A., 23A, 690 (1992).Google Scholar
5. Wang, P. and Vasudevan, V.K., Scripta Metall. et Mater., 27 , 89 (1992).Google Scholar
6. Jones, S.A. and Kaufman, M.J., Acta metall. mater., 41, 387 (1993).Google Scholar
7. Wang, P. and Vasudevan, V.K., in High-Temperature Ordered Intermetallics, edited by Baker, I. et al. ( MRS Proc. 288, Pittsburgh, PA, 1993 ) pp. 229–236.Google Scholar
8. Kim, Y.W., Acta. Metall. Mater., 40, 1121 (1992).Google Scholar
9. McQuay, P.A. et al., Scripta Metall. Mater., 25, 1689 (1991).Google Scholar
10. Yamabe, Y., Takeyama, M. and Kikuchi, M., Scripta Metall. Mater., 30, 553 (1994).Google Scholar
11. Ramanath, G. and Vasudevan, V.K., in High-Temperature Ordered Intermetallics, edited by Baker, I. et al. ( MRS Proc. 288, Pittsburgh, PA, 1993 ) pp. 223–228.Google Scholar
12. Hall, E.L. and Hung, S.C., Acta Metall. Mater., 38, 539 (1990).Google Scholar
13. Kumagai, T. et al., unpublished results ( National Research Institute for Metals, 1994 ).Google Scholar
14. Kumagai, T. et al., unpublished results (National Research Institute for Metals, 1994 ).Google Scholar
15. Yamabe, Y., Doctoral Thesis, Tokyo Institute of Technology, (1994).Google Scholar