Hostname: page-component-7bb8b95d7b-5mhkq Total loading time: 0 Render date: 2024-09-20T05:14:43.523Z Has data issue: false hasContentIssue false
  • English
  • Français

Microstructure and Property Change of Ti-49Al Induced by Hydrogen Charging

Published online by Cambridge University Press:  21 March 2011

E. Abe ,
K.W. Gao  and
M. Nakamura
E. Abe
Affiliation:
National Research Institute for Metals, 1–2–1 Sengen, Tsukuba 305–0047, JAPAN
K.W. Gao
Affiliation:
University of Science & Technology Beijing, Beijing, 100083, P.R. China.
M. Nakamura
Affiliation:
National Research Institute for Metals, 1–2–1 Sengen, Tsukuba 305–0047, JAPAN
Get access

Abstract

We have investigated an effect of hydrogen gas-charging on the microstructure and the mechanical property of a Ti-49at.%Al alloy. After hydrogen-charging performed under an atmospheric pressure of hydrogen gas at 1023K for 3 hours, the alloy with γ-single phase has become completely brittle, while this hydrogen-induced embrittlement is suppressed for that with (γ+α2) two-phase microstructure composed of lath-precipitates in the γ matrix. A significant microstructural change was found to occur for the two-phase alloy (approximately 340ppm hydrogen in the alloy); a thin amorphous layers with a few nm thickness appear at the preexisting γ/α2 interfaces in the lath-precipitates after hydrogen-charging. In-situ TEM observation confirmed that the amorphous region transforms to a nano-crystalline state after heating to 1000K at which the hydrogen could be removed (degassed), indicating that the amorphous phase is not a binary Ti-Al phase but a ternary Ti-Al-H one. This, in turn, suggests that the γ/α2 interface in the lath packets act as the most preferential sites for hydrogen storage. Therefore, the scavenging is expected to occur effectively for the microstructure composed of γ-α2 fine lamellae in which a large number of γ/α2 interfaces exist. It is worthwhile mentioning that the fine-scale of the lamellae makes it possible to have a large number of interfaces for a given volume of the α2 phase.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 646 , 2000 , N7.3.1
Copyright
Copyright © Materials Research Society 2001

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. Kawabata, T., Tadano, M. and Izumi, O., Scripta. metall., 22, 1725 (1988).Google Scholar
2. Nakamura, M., Hashimoto, K. and Tsujimoto, T., J. Mater. Res., 68, 8 (1993).Google Scholar
3. Kumagai, T., Abe, E., Kimura, T. and Nakamura, M., Scripta. mater., 34, 235 (1996).Google Scholar
4. Gao, K.W. and Nakamura, M., Scripta. mater., 43, 135 (2000).Google Scholar
5. Abe, E., Gao, K.W. and Nakamura, M., Scripta. mater., 42, 1113 (2000).Google Scholar
6. Kaufman, M.J., Konitzer, D.G., Shull, R.D. and Fraser, H.L., Scripta. metall., 20, 103 (1986)Google Scholar
7. Vasudevan, V.K., Stucke, M.A., Court, S.A. and Fraser, H.L., Philos. Mag. Lett., 59, 299 (1989).Google Scholar
8. Uemori, R., Hanamura, T. and Morikawa, H., Scripta. metall. mater., 26, 969 (1992).Google Scholar
9. Onodera, H., Abe, T. and Tsujimoto, T., Current Advances in Materials and Processes, 6, 627 (1993).Google Scholar
10. Abe, E., Onuma, M. and Nakamura, M., Acta. mater., 47, 3607 (1999).Google Scholar
11. Li, K., Pollock, T.M., Thompson, A.W. and De Graef, M., Scripta. metall. mater., 32, 1009 (1995).Google Scholar