Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T01:39:08.695Z Has data issue: false hasContentIssue false

The Effect of Aluminum on the Formation of Orthorhombic Plates in the Nb-Ti-Al Ternary System

Published online by Cambridge University Press:  15 February 2011

D. T. Hoelzer
Affiliation:
Dept. of Materials Science and Engineering, University of Florida, Gainesville, FL 32611 *NYS College of Ceramics, Alfred University, Alfred, NY 14802
F. Ebrahimi
Affiliation:
Dept. of Materials Science and Engineering, University of Florida, Gainesville, FL 32611 *NYS College of Ceramics, Alfred University, Alfred, NY 14802
Get access

Abstract

Transmission electron microscopy (TEM) was used to study the phase transformation in an alloy containing 33Ti-27Nb-40Al (at.%). The results showed that the BCC β phase was present at high temperatures, which ordered to the B2 phase, and finally was martensitically transformed to a plate microstructure during quenching. The plates possessed an orthorhombic crystal structure and a substructure that consisted of both coarse and fine anti-phase domain boundaries (APDBs). These APDBs were consistent with three sublattices that were derived from the inherited site occupancy of the B2 matrix and a subsequent disorder to order transition. The CBED analysis of the plates showed that the site occupancy of this orthorhombic phase was consistent with the Al2NbTi stoichiometry with Al occupying the 8g, Nb the 4c1, and Ti the 4c2 Wyckoff sites.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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. Banerjee, D., Gogia, A.K., Nandi, T.K., and Joshi, V.A., Acta Metall., 36, (1988), 871.Google Scholar
2. Kestner-Weykamp, H.T., Ward, C.H., Broderick, T.F., and Kaufman, M.J., Scripta Metall., 23, (1989), 1697.Google Scholar
3. Mozer, B., Bendersky, L.A., and Boettinger, W.J., Scripta Metall., 24, (1990), 2363.Google Scholar
4. Bendersky, L.A., Boettinger, W.J., and Roytburd, A., Acta Metall. Mater., 39, 8, (1991), 1959.Google Scholar
5. Muraleedharan, K., Nandy, W.J., Banerjee, D., and Lele, S., Metall. Trans. A, 23A, (1992), 417.Google Scholar
6. Bendersky, L.A. and Boettinger, W.J., Acta Metall. Mater., 42, 7, (1994), 2337.Google Scholar
7. Muraleedharan, K., Nandy, T.K., Banerjee, D., Intermetallics, 3, (1995), 187.Google Scholar
8. Hoelzer, D.T. and Ebrahimi, F., in High Temperature Niobium Alloys, ed. by Stephens, J.J. and Ahmal, I., TMS-AIME, Warrendale, PA, (1990), 105.Google Scholar
9. Hoelzer, D.T., Ph.D. Dissertation, Univ. of Florida, (1996).Google Scholar
10. Tanner, L.E., Peiton, A.R., and Gronsky, R., J. Phys. Colloq. C4, 43, (1982), 169.Google Scholar
11. Wayman, C.M., Introduction to the Crystallography of Martensitic Transformation, MacMillan, New York, (1964).Google Scholar
12. Jepson, K.S., Brown, A.R.G., and Gray, J.A., in The Science, Technology and Application of Titanium, ed. by Jaffee, R.J. and Promisel, N.E., Pergamon Press, London, (1970), 677.Google Scholar
13. International Tables for Crystallography, ed. by Hahn, T., Reidel, D., Dordrecht, A, (1987).Google Scholar
14. Banerjee, D., Nandy, T.K., and Gogia, A.K., Scripta Met., 21, (1987), 597.Google Scholar
15. Kohmoto, H., Shyue, J., Aindow, M., and Fraser, H.L., Scripta Met., 29, (1993), 1271.Google Scholar