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Effects of hydrogen on the microstructure and microchemistry of Ti3Al – Nb intermetallics at high temperatures and high pressures

Published online by Cambridge University Press:  31 January 2011

H. Z. Xiao ,
I. M. Robertson  and
H. K. Birnbaum
H. Z. Xiao
Affiliation:
Materials Research Laboratory and Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
I. M. Robertson
Affiliation:
Materials Research Laboratory and Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
H. K. Birnbaum
Affiliation:
Materials Research Laboratory and Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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Abstract

The microstructural and microchemical changes produced in a Ti–25Al–10Nb–3V–1Mo alloy (at. %) by charging at high temperatures in high pressures of hydrogen gas have been studied using transmission electron microscopy (TEM) and x-ray methods. Hydrides incorporating all of the substitutional solutes that formed during charging have a face-centered cubic (fcc) structure and exhibit either a plate or fine-grained morphology. With increasing hydrogen content, the size of the hydrides decreases and their microchemistry changes as they approach the stable binary hydride, TiH2. Rejection of substitutional solute elements from the hydride produces changes in the microchemistry, and consequently in the crystal structure, of the surrounding matrix. In alloys containing 50 at. % H, this solute redistribution results in the formation of an orthohombic substitutional solid solution phase containing increased levels of Nb. The driving force of this redistribution of solutes is the reduction in the chemical potential of the system as the amount of the most stable hydride, TiH2, forms. The hydrides reverted to a solid solution on annealing in vacuum at 1073 K, and the original microchemistry of the alloy was restored. Reversion from the hydride structure to the original α2 ordered DO19 structure proceeds via a disordered HCP phase.

Type
Articles
Information
Journal of Materials Research , Volume 11 , Issue 9 , September 1996 , pp. 2186 - 2197
Copyright
Copyright © Materials Research Society 1996

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References

REFERENCES

1.Fleischer, R. L., Dimiduk, D. M., and Lipsett, H. A., Annu. Rev. Mater. Sci. 19, 231 (1989).CrossRefGoogle Scholar
2.Dimiduk, D. M., Miracle, D.B., Kim, Y-W., and Mendiratta, M.G., ISIJ Int. 31, 1223 (1991).CrossRefGoogle Scholar
3.Dimiduk, D., Miracle, D. B., and Ward, C. H., Mater. Sci. Technol. 8, 367 (1992).CrossRefGoogle Scholar
4.Rudman, P. S., Reilly, J. J., and Wiswall, R. H., Ber Bunsenges Phys. Chem. 81, 76 (1977).CrossRefGoogle Scholar
5.Xiao, H. Z., Robertson, I.M., and Birnbaum, H. K., unpublished work.Google Scholar
6.Shih, D. S., Scarr, G. K., and Wasielewski, G. E., Scripta Metall. 23, 973 (1989).CrossRefGoogle Scholar
7.Schwartz, D. S., Yelon, W. B., Berliner, R. B., Lederich, R. J., and Sastry, S. M. L., Acta Metall. 39, 2799 (1991).CrossRefGoogle Scholar
8.Gao, M., Boodey, J. B., and Wei, R. P., Scripta Metall. 24, 2135 (1990).CrossRefGoogle Scholar
9.Chan, K. S., Metall. Trans. 24A, 1095 (1993).CrossRefGoogle Scholar
10.Chu, W. Y. and Thompson, A. W., Metall. Trans. 22A, 71 (1991).CrossRefGoogle Scholar
11.Koss, D. A., Banerjee, D., and Luksasak, D. A., High Temperature Aluminides and Intermetallics, edited by Whang, S-H., Liu, C. T., Pope, D., and Steigler, J. O. (TMS, Warrendale, PA, 1989), p. 1989.Google Scholar
12.Shih, D. S., Huang, S-C., Scarr, G. K., Jang, H., and Chestnutt, J.C., Microstructure/Property Relationships in Titanium Aluminides and Titanium Alloys, edited by Kim, Y. and Boyers, R. R. (TMS, Warrendale, PA, 1991), p. 135.Google Scholar
13.Chan, K. S., Metall. Trans. 21A, 2687 (1990).CrossRefGoogle Scholar
14.Chan, K. S., Metall. Trans. 23A, 183 (1992).CrossRefGoogle Scholar
15.Thompson, A. W., Chu, W., and Williams, J.C., Metall. Trans. 21A, 641 (1990).Google Scholar
16.Thomson, A. W. and Pollack, T. M., ISIJ Int. 31, 1139 (1991).CrossRefGoogle Scholar
17.Chan, K. S., Metall. Trans. 23A, 497 (1992).CrossRefGoogle Scholar
18.Fritzemeier, L. G. and Jacinto, M. A. (1990), private communication.Google Scholar
19.Majumdar, B. S., Cialone, H. J., and Holbrook, J. H., Proc. 3th NASP Hydrogen-Materials Interactions Workshop (NASA, Scottsdale, AZ, 1989).Google Scholar
20.Muraleedharan, K., Gogia, A. K., Nandy, T. K., Banerjee, D., and Lele, S., Metall. Trans. 23A, 401 (1992).CrossRefGoogle Scholar
21.Boyd, J. D., Trans. ASM 62, 977 (1969).Google Scholar
22.Legzdina, D., Robertson, I. M., and Birnbaum, H. K., J. Mater. Res. 6, 1230 (1991).CrossRefGoogle Scholar
23.Legzdina, D., Robertson, I.M., and Birnbaum, H. K., Scripta Metall. Mater. 26, 1737 (1992).CrossRefGoogle Scholar
24.Buschow, K. H. J., Bouten, C. P., and Miedema, A. R., Rep. Prog. Phys. 45, 937 (1982).CrossRefGoogle Scholar
25.Aoki, K., Yamamoto, T., Satoh, Y., Fukamichi, K., and Mat-sumoto, T., Acta Metall. 35, 2465 (1987).CrossRefGoogle Scholar
26.Libowitz, G. C., The Solid State Chemistry of Binary Metal Hydrides (W.A. Benjamin, Inc., New York, 1965).Google Scholar
27.Mueller, W. M., Blackledge, J. P., and Libowitz, G. C., Metal Hydrides (Academic Press, London, 1968).Google Scholar