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Effect of Coherency Stresses on the Stability of Lamellar (α2+γ) Titanium Aluminides

Published online by Cambridge University Press:  15 February 2011

F. Appel ,
U. Christoph ,
U. Lorenz  and
D R. Wagner
F. Appel
Affiliation:
Institute for Materials Research, GKSS Research Centre, Max-Planck-Str., D-21502 Geesthacht, Germany.
U. Christoph
Affiliation:
Institute for Materials Research, GKSS Research Centre, Max-Planck-Str., D-21502 Geesthacht, Germany.
U. Lorenz
Affiliation:
Institute for Materials Research, GKSS Research Centre, Max-Planck-Str., D-21502 Geesthacht, Germany.
D R. Wagner
Affiliation:
Institute for Materials Research, GKSS Research Centre, Max-Planck-Str., D-21502 Geesthacht, Germany.
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Abstract

Two phase titanium aluminides with a lamellar microstructure of the intermetallic phases α2(Ti3Al) and γ (TiAl) are being developed for high temperature structural applications. Due to differences in lattice parameters and crystal structure, coherency stresses and mismatch structures occur at various types of semicoherent interfaces present in the material. The implications of these structural features on the stability of lamellar microstructures were studied by TEM in situ heating experiments. The investigations revealed that the lamellar interfaces serve as sources for perfect and twinning dislocations. The results will be discussed with respect to the observed degradation of the strength properties of the two phase alloys in the intended service temperature range of 900- 1000 K.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 404: Symposium J – In Situ Electron and Tunneling Microscopy of Dynamic Processes , 1995 , 211
Copyright
Copyright © Materials Research Society 1996

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References

1. Shechtman, D., Blackburn, M. J. and Lipsitt, H. A., Metall. Trans., 5, 1373 (1974).Google Scholar
2. Kim, Y.-W. and Dimiduk, D. M., J OM, 43, 40 (1991).Google Scholar
3. McCullough, C., Valencia, J. J., Levi, C. G., and Mehrabian, R., Acta metall. mater., 37, 1321 (1989).Google Scholar
4. Sastry, S. L. M. and Lipsitt, H. A., Metall. Trans. A, 8, 299 (1997).Google Scholar
5. Inui, H., Nakamura, A., Oh, M. H., and Yamaguchi, M., Ultramicroscopy, 39, 268 (1991).Google Scholar
6. Mahon, G. J. and Howe, J. M., Metall. Trans. A, 8, 299 (1990).Google Scholar
7. Zhao, L. and Tangri, K., Phil. Mag. A, 64, 361 (1991).Google Scholar
8. Singh, S. R. and Howe, J. M., Phil. Mag. Lett. 65, 233 (1992).Google Scholar
9. Kad, B. K. and Hazzledine, P. M., Phil. Mag. Lett. 66, 133 (1992).Google Scholar
10. Appel, F., Beaven, P. A. and Wagner, R., Acta metall. mater. 41, 1721 (1993).Google Scholar
11. Appel, F., Christoph, U. and Wagner, R., in Interface Control of Electrical, Chemical, and Mechanical Properties, edited by Muraka, S. P., Rose, K., Ohmi, T., and Seidel, T. (Mater. Res. Soc. Proc. 318, Pittsburgh, PA 1994), p. 691.Google Scholar
12. Appel, F. and Wagner, R., in Twinning in Advanced Materials, edited by Yoo, M. H. and Wuttig, M. (TMS, Warrendale, PA 1994) p. 317.Google Scholar
13. Appel, F., Sparka, U. and Wagner, R., in High-Temperature Ordered Intermetallic Alloys VI, edited by Horton, J., Baker, I., Hanada, S., Noebe, R. D., and Schwartz, D. S. (Mater. Res. Soc. proc. 364, Pittsburgh PA, 1995) p. 623.Google Scholar
14. Appel, F., Christoph, U. and Wagner, R., Phil. Mag. A, 72, 341 (1995).Google Scholar
15. Appel, F. and Wagner, R., to be published in Mater. Sci. Eng.Google Scholar