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Hydride structures in Ti-aluminides subjected to high temperature and hydrogen pressure charging conditions

Published online by Cambridge University Press:  31 January 2011

D. Legzdina ,
I.M. Robertson  and
H.K. Birnbaum
D. Legzdina
Affiliation:
Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801
I.M. Robertson
Affiliation:
Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801
H.K. Birnbaum
Affiliation:
Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801
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Abstract

The distribution and chemistry of hydrides produced in single and dual phase alloys with a composition near TiAl have been investigated by using a combination of TEM and x-ray diffraction techniques. The alloys were exposed at 650 °C to 13.8 MPa of gaseous H2 for 100 h. In the single-phase gamma alloy, large hydrides preferentially nucleated on the grain boundaries and matrix dislocations and a population of small hydrides was distributed throughout the matrix. X-ray and electron diffraction patterns from these hydrides indicated that they have an fcc structure with a lattice parameter of 0.45 nm. EDAX analysis of the hydrides showed that they were enriched in Ti. The hydrides were mostly removed by vacuum annealing at 800 °C for 24 h. On dissolution of the hydrides, the chemistry of hydride-free regions of the grain boundary returned to the matrix composition, suggesting that Ti segregation accompanied the hydride formation rather than Ti enrichment causing the formation of the hydride. The hydrogen content in the two-phase (γ-α2) alloy was approximately three times that of the single phase alloy, which was presumably a consequence of the presence of the α2-Ti3Al phase in the two-phase alloy. The hydrides in the two-phase material were shown by x-ray diffraction to have an fcc structure and were removed on annealing in vacuum at 800 °C for 24 h.

Type
Articles
Information
Journal of Materials Research , Volume 6 , Issue 6 , June 1991 , pp. 1230 - 1237
Copyright
Copyright © Materials Research Society 1991

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References

1.Kim, Young Won, Journal of Metals 41, 24 (1989).Google Scholar
2.Lipsitt, H., in High Temperature Ordered Intermetallic Alloys, edited by Koch, C. C., Liu, C. T., and Stoloff, N. S. (Mater. Res. Soc, 1985), p. 351.Google Scholar
3.Chu, W. Y., Thompson, A. W., and Williams, J. C., to be published in the Proc. 3rd NASP Workshop Conf. (Scottsdale, 1990).Google Scholar
4.Holbrook, J. H., Cialone, H. J., and Majumdar, B. S., to be published in the Proc. 3rd NASP Workshop Conf. (Scottsdale, 1990).Google Scholar
5.Rudman, P. S., Reilly, J. J., and Wiswall, R. H., J. Less-Common Mater. 58, 231 (1978).CrossRefGoogle Scholar
6.Xiao, H., Robertson, I. M., and Birnbaum, H. K. (to be published).Google Scholar
7.Shih, D. S., Scarr, G. K., and Wasielewski, G. E., Scripta Metall. 23, 973 (1989).CrossRefGoogle Scholar
8.Fritzemeier, L. G., Jacinto, M. A., and Schnittgrund, G. D., to be published in the Proc. 3rd NASP Workshop Conf. (Scottsdale, 1990).Google Scholar
9.Sheinker, A. A. and El-Soudani, S. M., to be published in the Proc. 3rd NASP Workshop Conf. (Scottsdale, 1990).Google Scholar
10.Mateczyk, D. and Rhodes, C., Scripta Metall. 24, 1369 (1990).CrossRefGoogle Scholar
11.Majumdar, B. S., to be published in the Proc. 3rd NASP Workshop Conf. (Scottsdale, 1990).Google Scholar
12.Boyd, J. D., in The Science, Technology and Application of Ti, edited by Jaffee, R. I. and Promisel, N. E. (Pergamon Press, Oxford, England, 1970), p. 545.CrossRefGoogle Scholar
13.Mueller, W. M., in Metal Hydrides, edited by Mueller, W. M., Blackledge, J. P., and Libowitz, G. G. (Academic Press, New York, 1986).Google Scholar
14.Stalinski, B. and Bieganski, Z., Acad. Pol. Sci. Sen. Sci. Chim. 8, 243 (1960).Google Scholar
15.Stalinski, B. and Bieganski, Z., Acad. Pol. Sci. Sen. Sci. Chim. 10, 247 (1962).Google Scholar
16.Aoki, K., Yanagitani, A., and Masumoto, T., Phys. Lett. 52, 2122 (1988).Google Scholar
17.Aoki, K., Yamamoto, T., and Masumoto, T., Scripta Metall. 21, 27 (1987).CrossRefGoogle Scholar
18.Yeh, X. L., Samwer, K., and Johnson, W. L., Appl. Phys. Lett. 42, 242 (1983).CrossRefGoogle Scholar
19.Blackburn, M. J., in The Science, Technology and Application of Ti, edited by Jaffee, R. I. and Promisel, N. E. (Pergamon Press, Oxford, England, 1970), p. 633.CrossRefGoogle Scholar
20.Xiao, H., Robertson, I. M., and Birnbaum, H. K. (unpublished work).Google Scholar