Hostname: page-component-77c89778f8-gq7q9 Total loading time: 0 Render date: 2024-07-19T05:20:03.076Z Has data issue: false hasContentIssue false

Deformation-induced α2 ↔ γ phase transformation in a Ti–48Al–2Cr alloy

Published online by Cambridge University Press:  31 January 2011

J. X. Zhang
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
H. Q. Ye
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
Get access

Abstract

The structure of γ–α2 interfaces in deformed Ti–48Al–2Cr alloy was analyzed by high-resolution transmission electron microscopy (HREM) and image simulations. Growth of γ–TiAl plate in α2–Ti3Al phase was found to be a result of a ledge mechanism consisting of Shockley partial dislocations on alternate (0001)α2 planes. The height of the ledges was always a multiple of two (0001)α2 planes. The γ → α2 phase transformation was also an interface-related process. Large ledges of six close packed planes (111)γ high were often observed at the γ–α2 interface. Every large ledge consisted of six Shockley partial dislocations that originated from the γ–a2 interfacial lattice misfit. The movement of these partial dislocations accomplished the transformation of γ → α2 phase. Comparing the experimental and simulated HREM image, it was found that atomic reordering appears during the deformation-induced γ↔α2 transformation.

Type
Articles
Copyright
Copyright © Materials Research Society 2000

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. Sastry, S.M.L and Lipsitt, H.A., Metall. Trans. A 8, 299 (1977).CrossRefGoogle Scholar
2. Vasudevan, V.K., Court, S.A., Kurath, P., and Fraser, H.L., Scripta Metall. 23, 907 (1989).CrossRefGoogle Scholar
3. Kim, Y.W., J. Metals 41, 24 (1989).Google Scholar
4. Singh, S.R. and Howe, J.M., Philos. Mag. A 66, 739 (1992).CrossRefGoogle Scholar
5. Singh, S.R. and Howe, J.M., Philos. Mag. Lett. 62, 233 (1992).CrossRefGoogle Scholar
6. Yang, Y.S., Wu, S.K., and Wang, J.Y., Philos. Mag. A 67, 463 (1993).CrossRefGoogle Scholar
7. Wang, J.G., Zhang, L.C., Chen, G.L., Ye, H.Q., and Nieth, T.G., Mater. Sci. Eng. A 239–240, 287 (1997).Google Scholar
8. Gao, Y., Zhu, J., Shen, H., and Wang, Y., Scripta Metall. Mater. 28, 651 (1993).CrossRefGoogle Scholar
9. Feng, C.R., Michel, D.J., and Crowe, C.R., Scripta Metall. 23, 241 (1989).CrossRefGoogle Scholar
10. Feng, C.R., Michel, D.J., and Crowe, C.R., Mater. Sci. Eng. A 145, 257 (1991).CrossRefGoogle Scholar
11. Zhang, Y.G., Ticheaar, F.D., Schapink, F.W., Xu, Q., and Chen, C.Q., Scripta Metall. Mater. 32, 981 (1995).CrossRefGoogle Scholar
12. Yang, Y.S. and Wu, S.K., Scripta Metall. Mater. 24, 1801 (1990).CrossRefGoogle Scholar
13. Zhao, L. and Tangri, K., Acta Metall. Mater. 39, 2209 (1991).CrossRefGoogle Scholar
14. Mahon, G.J. and Howe, J.M., Metall. Trans. A 21A, 1655 (1990).CrossRefGoogle Scholar