Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-06T08:31:01.818Z Has data issue: false hasContentIssue false

The Effect of Fe-Addition to Al-10Ti Alloy on Superplasticity at High-Strain Rates

Published online by Cambridge University Press:  10 February 2011

D. Kum
Affiliation:
Korea Institute of Science and Technology, P.O. Box 131, Seoul 130-650, KOREA, [email protected]
W. J. Kim
Affiliation:
Hong-ik University, 72-1 Mapo-ku, Sangsu-dong, Seoul 121-791, KOREA
Get access

Abstract

Ultra-fine microstructure consisting of equiaxed Al-grains and aluminide particulate was produced by powder metallurgy process using gas-atomized powders of Al-10wt%Ti-2wt%Fe alloy. High strain rate superplasticity (HSRS) has been investigated at 873-923K and strain rates higher than 10−3s−1 in tension, and total elongation up to 500% was observed at the strain-rate of 10−1s−1. The strain rate vs. flow stress behavior exhibits the typical aspect of HSRS such as the increase of strain-rate sensitivity exponent with increase in strain-rate and an apparent activation energy higher than that for lattice diffusion in aluminum. The concept of threshold stress has been incorporated to illustrate the HSRS behavior, where the stress exponent of 3 describes the experimental data. The determined threshold stress showed strong temperature dependency as in the case of a similarly processed Al-10wt%Ti alloy, which exhibited the stress exponent of 2 in the same testing conditions. Solute drag mechanism has been postulated for the Al-Ti-Fe alloy.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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

1. Murty, G.S., Koczak, M.J. and Frazier, W.E., Scripta Metall. 21, 141 (1987).10.1016/0036-9748(87)90424-8Google Scholar
2. Kum, Dongwha and Kim, Hyeseung, Mater. Sci. Forum 170–172, 543 (1994).10.4028/www.scientific.net/MSF.170-172.543Google Scholar
3. Nieh, T. G., Henshall, G. A. and Wadsworth, J., Scripta metall. 18, 1040 (1984).Google Scholar
4. Bieler, T. R., Nieh, T. G., Wadsworth, J. and Mukherjee, A. K., Scripta metall. 22, 81 (1988).10.1016/S0036-9748(88)80310-7Google Scholar
5. Nieh, T. G. and Wadsworth, J., Mater. Sci. Engr. A 147, 129 (1991).10.1016/0921-5093(91)90839-FGoogle Scholar
6. Kum, Dongwha and Frommeyer, G., Met. Mater. 3, 239 (1997).10.1007/BF03025930Google Scholar
7. Kum, Dongwha, Mater. Sci. Forum, 243–245, 287 (1997).Google Scholar
8. Massalski, T. B., in Binary Alloy Phase Diagrams (2nd edition), (ASM International 1990), p. 147.Google Scholar
9. Kim, H., Kim, W. and Kum, D., Mater. Sci. Forum, 304–306, 321 (1999).10.4028/www.scientific.net/MSF.304-306.321Google Scholar
10. Lin, R.J. and Sherby, O.D., Res. Mechanica 2, 251 (1981).Google Scholar
11. Mohamed, F.A., J. Mater. Sci., 18, 582 (1983).10.1007/BF00560647Google Scholar
12. Bieler, T.R. and Mukherjee, A.K., Mater. Sci. Engr. A 128, 171 (1990).10.1016/0921-5093(90)90225-RGoogle Scholar
13. Cannon, W.R. and Sherby, O.D., Metall. Trans. 1, 1030 (1970).Google Scholar
14. Kim, W. J. and Kum, D. W., Metal Trans. JIM, in press.Google Scholar