Hostname: page-component-5c6d5d7d68-sv6ng Total loading time: 0 Render date: 2024-08-20T03:46:47.821Z Has data issue: false hasContentIssue false

Structural Relaxation by Precipitation in Al-Li I. Growth Kinetics of Precipitates

Published online by Cambridge University Press:  15 February 2011

R. Kamel
Affiliation:
Cairo University, Physics Department, Faculty of Science, Cairo, Egypt.
N. K. Gobran
Affiliation:
Cairo University, Physics Department, Faculty of Science, Cairo, Egypt.
M. M. Danial
Affiliation:
Cairo University, Physics Department, Faculty of Science, Cairo, Egypt.
Get access

Abstract

Changes in electrical resistance measured by the four probe method was adopted as a structure sensitive physical property used to trace changes in the atomic microstructure below and above the δ'-solvus line in the Al-Li binary alloys. The kinetics of the growth and dissolution of δ' phase (Al3Li) and the formation of δ phase (AlLi), below and above δ'-solvus line, during the coarsening process were studied by isochronal and isothermal investigations. The diffusional growth of δ'-phase, below the δ'-solvus line, was found to be activated by 0.24 eV. Interpretation of the results showed that this energy involved two events during the coarsening process. The first event seemed to be a breakdown of the bonding between the vacancy-Lithium pair and the second event involved the transport of Li atoms to Al-particles to coarsen δ'; (Al3Li) particles. Furthermore, the study of the temperature dependence of electrical resistance of the stable phases δ' and δ of Al-Li alloys was found to be accompanied by difference in the temperature coefficient of the electrical resistance and was attributed to the change in structure of the two phases considered.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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. Jensrud, O. and Ryum, N., Mater. Sci. Eng. 64, 229 (1984).CrossRefGoogle Scholar
2. Teoh, N., Toeh, W. and Arags, S., J. Phys. Chem. Solids, 38, 919 (1977).Google Scholar
3. Williams, D.B. and Edington, J.W., Philos. Mag. 30, 1147 (1974).Google Scholar
4. Silcock, J.M., J. Inst. Metals, 88, 357 (19591960).Google Scholar
5. Noble, B. and Thompson, G.E., Metal Sci. J. 5, 114 (1971).Google Scholar
6. Williams, D.B. and Edington, J.W., Acta Metall. 24, 323 (1976).CrossRefGoogle Scholar
7. Baumann, S.F. and Williams, D.B., Acta Metall. 33, 1069 (1985).Google Scholar
8. Williams, D.B. and Edington, J.W., Metal. Sci, J. 9, 529 (1975).Google Scholar
9. Baumann, S.F. and Williams, D.B., Aluminium-Lithium Alloys III, edited by Sanders, T.H. Jr. and Starke, E.A. Jr. (Am. Inst. Min. Engrs., New York, 1984) pp. 1729.Google Scholar
10. Venables, D., Christodoulou, L. and Pickens, J.R., Scr. Metall. 17, 1263 (1983).CrossRefGoogle Scholar