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Microscopic and Quantitative Investigations on PST Ti-Al / Ti Reaction Diffusion Couples

Published online by Cambridge University Press:  11 February 2011

Ling Pan  and
David E. Luzzi
Ling Pan
Affiliation:
Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, U.S.A.
David E. Luzzi
Affiliation:
Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, U.S.A.
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Abstract

Interdiffusion in multi-phase diffusion couples of polycrystalline Ti and polysynthetically twinned (PST) Ti-49.3 at.% Al, with the diffusion direction parallel to the lamellar planes, is investigated in the temperature range 973 – 1173 K. A reaction zone (RZ) of the a2-Ti3Al phase forms between the end materials and exhibits deeper penetration in the a2 lamellae than in the primary g lamellae. The mass balance and the lamellar thickness across the RZ / PST interface are believed to be the major factors that lead to the different behaviors in the penetration depth of the RZ. Direct measurements of the RZ thickness reveal a parabolic growth of the RZ, indicating a diffusion-controlled growth macroscopically. Concentration profiles from the Ti, through the RZ, into the PST g and a2 lamellae are measured by x-ray spectroscopy in a transmission electron microscope. Deviations from a diffusion-controlled composition profile indicate some extent of interface-controlled growth. Plateaus are seen in the concentration profiles in the RZ adjacent to the RZ/PST interface, extending through most of the deeply penetrated well region. The interfacial energy and strain energy are possible reasons for the plateaus. The interdiffusion coefficients are found to be largely independent of composition with a temperature dependence that obeys the Arrhenius relationship.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 753: Symposium BB – Defect Properties and Related Phenomena in Intermetallic Alloys , 2002 , BB4.5
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Froes, F. H. and Suryanarayana, C., in Physical Metallurgy and Processing of Intermetallic Compounds, Stoloff, N. S. and Sikka, V. K., ed., Chapman & Hall, New York, 1996, Chapter 8.Google Scholar
2. Huang, S. C. and Chesnutt, J. C., in Intermetallic Compounds: Vol. 2, Practice, Westbrook, J. H. and Fleischer, R. L., ed., John Wiley & Sons, 1994, Chapter 4.Google Scholar
3. Blackburn, M. J., in The Science, Technology and Application of Titanium, Eds. Jaffee, R. I. and Promisel, N. E., Pergamon, London (1970) 633.Google Scholar
4. Herzig, Chr., Przeorski, T. and Mishin, Y., Intermetallics 7 (1999) 389.Google Scholar
5. Rüsing, J. and Herzig, Chr., Intermetallics 4 (1996) 647.Google Scholar
6. Divinski, S. V., Hisker, F., Bartels, A. and Herzig, Chr., Scripta Mater. 45 (2001) 161.Google Scholar
7. Sprengel, W., Oikawa, N. and Nakajima, H., Intermetallics 4 (1996) 185.Google Scholar
8. Herzig, Chr., Wilger, T., Przeorski, T., Hisker, F., Divinski, S., Intermetallics 9 (2001) 431.Google Scholar
9. Pan, L. and Luzzi, D. E., submitted.Google Scholar
10. Pan, L. and Luzzi, D. E., to be submitted.Google Scholar
11. Cliff, G. and Lorimer, G. W., J. Micros. 103 (1975) 203.Google Scholar