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Atom location by channeling enhanced microanalysis study of site distributions of alloying elements in titanium aluminides

Published online by Cambridge University Press:  31 January 2011

Y. L. Hao
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110015, People's Republic of China
R. Yang*
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110015, People's Republic of China
Y. Y. Cui
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110015, People's Republic of China
D. Li
Affiliation:
Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110015, People's Republic of China
*
a)Address all correspondence to this author.
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Abstract

The original equation of Spence and Taftø for quantitative determination of site occupancy using atom location by channeling enhanced microanalysis method has been extended to take into account both delocalization effect and the influence of point defects (antisite atomic distribution and vacancies). The outcome of this treatment suggests that, for crystals free of antisite defects, the accuracy of site occupancy is influenced by delocalization effect but is independent of both thermal and structural vacancies. For crystals free of structural vacancies, the accuracy of site occupancy is influenced by both delocalization effect and antisite defects, but is independent of thermal vacancies. The delocalization effect was shown to vary with channeling strength at a given channeling condition. For a binary ordered phase in which at least one of the host elements exhibits weak delocalization effect (as is the case for many transition-metal aluminides), a tangent-line method for obtaining the value of k (a parameter necessary for the calculation of site occupancy) was proposed, allowing the determination of the delocalization correction factor for the other host element. Application of this method to estimating the delocalization effect of Al in Ti3Al and TiAl under axial and planar channeling conditions, respectively, was demonstrated.

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Articles
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1.Spence, J.C.H and Taftø, J., J. Microsc. 130, 147 (1983).CrossRefGoogle Scholar
2.Otten, M.T. and Buseck, P.R., Ultramicroscopy 23, 151 (1987).CrossRefGoogle Scholar
3.Ma, Y. and Gjønnes, J., J. Mater. Res. 7, 2049 (1992).CrossRefGoogle Scholar
4.Hao, Y.L., Xu, D.S., Cui, Y.Y., Yang, R., and Li, D., Acta Mater. 47, 1129 (1999).CrossRefGoogle Scholar
5.Hao, Y.L., Yang, R., Cui, Y.Y., and Li, D., J. Mater. Sci. Technol. 15, 536 (1999).Google Scholar
6.Pennycook, S.J., Ultramicroscopy 26, 239 (1988).CrossRefGoogle Scholar
7.Rossouw, C.J., Forwood, C.T., Gibson, M.A., and Miller, P.R., Philos. Mag. A 74, 57 (1996).CrossRefGoogle Scholar
8.Shindo, D., Hirabayashi, M., Kawabata, T., and Kikuchi, M., J. Electron Microsc. 35, 409 (1986).Google Scholar
9.Matsumura, S., Morimura, T. and, Oki, K., Mater. Trans. Jpn. Inst. Met. 32, 905 (1991).Google Scholar
10.Horita, Z., Matsumura, S., and Baba, T., Ultramicroscopy 58, 327 (1995).CrossRefGoogle Scholar
11.Anderson, I.M., Acta Mater. 45, 3897 (1997).CrossRefGoogle Scholar
12.Hao, Y.L., Yang, R., Cui, Y.Y., and Li, D., Scripta Mater. 41, 1305 (2000).CrossRefGoogle Scholar
13.Anderson, I.M., Duncan, A.J., and Bentley, J., Intermetallics 7, 1017 (1999).CrossRefGoogle Scholar
14.Horita, Z., Ultramicroscopy 66, 1 (1996).CrossRefGoogle Scholar
15.Yang, R. and Hao, Y.L., Scripta Mater. 41, 341 (1999).CrossRefGoogle Scholar
16.Hao, Y.L., Yang, R., Cui, Y.Y. and Li, D.Acta Mater. 48, 1313 (2000).CrossRefGoogle Scholar
17.Rossouw, C.J., Forwood, C.T., Gibson, M.A., and Miller, P.R., Philos. Mag. A 74, 77 (1996).CrossRefGoogle Scholar
18.Shirai, Y., Murakami, T., Ogawa, N., and Yamaguchi, M., Intermetallics 4, 31 (1996).CrossRefGoogle Scholar
19.Wüschum, R., Kümmerle, E.A., Badura-Greven, K., Seeger, K., Herzig, C., and Schaefer, H-E., J. Appl. Phys. 80, 724 (1996).CrossRefGoogle Scholar