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First principles calculation of the elastic constants of intermetallic compounds: metastable Al3Li

Published online by Cambridge University Press:  31 January 2011

X-Q. Guo ,
R. Podloucky  and
A.J. Freeman
X-Q. Guo
Affiliation:
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208
R. Podloucky
Affiliation:
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208
A.J. Freeman
Affiliation:
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208
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Abstract

We report first principles local density calculations for the metastable Al3Li intermetallic compound with cubic L12 crystal structure using the full-potential linearized augmented plane wave method. From the second derivative of the total energy as a function of volume, and generated tetragonal and trigonal lattice distortions, the elastic constants C11, C12, and C44 were derived yielding C11 = 158 GPa, C12 = 29.4 GPa, and C44 = 57.7 GPa. Because of the very high Young's modulus (E = 141 GPa) compared, for example, to pure Al (E = 66 GPa), it is suggested that Al3Li plays an important role in strengthening the Al–Li alloys. The calculated Young's modulus appears in good agreement with experimental estimates when the experimental values are extrapolated to 0 K. Although the Young's modulus of Al3Li is increased in comparison to Al, the calculated bulk modulus is decreased to a value of 72 GPa as compared to pure Al (82 GPa), in agreement with experiment. As a result, the Poisson ratio is reduced to ŝ = 0.173 as compared to the value 1/3 for an isotropic medium. Because of this and the high Young's modulus, the calculated Debye temperature ΘD at 0 K amounts to 672 K, which is substantially larger than ΘD for Al, which is about 400 K.

Type
Articles
Information
Journal of Materials Research , Volume 6 , Issue 2 , February 1991 , pp. 324 - 329
Copyright
Copyright © Materials Research Society 1991

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References

1Sanders, T. H. Jr. and Starke, E. A. Jr, Aluminum-Lithium Alloys (TMS-AIME, New York, 1981); T. H. Sanders, Jr. and E. A. Starke, Jr., Aluminum-Lithium Alloys II (TMS-AIME, New York, 1984); C. Baker, P. J. Gregson, S. J. Harris, and C. J. Peel, Aluminum-Lithium Alloys III (The Institute of Metals, London, 1986).Google Scholar
2Axon, H. J. and Hume-Rothery, W., Proc. Roy. Soc. (London) A193, 1 (1948); E. D. Levine and E. J. Rapperport, AIME 227, 1024 (1963).Google Scholar
3M¨ller, W., Bubeck, E., and Gerald, V., in Aluminum-Lithium Alloys III, edited by Baker, C., Gregson, P. J., Harris, S. J., and Peel, C. J. (Institute of Metals, London, 1986), p. 435.Google Scholar
4Tamura, M., Mori, T., and Nakamura, T., J. Japan Inst. of Metals 34, 919 (1970); B. Noble and G. E. Thompson, Metals Sci. J. 5, 114 (1971); D. B. Williams and J. W. Edington, Metals Sci. J. 9, 529 (1975); S. F. Baumann and D. B. Williams, Proc. 2nd Int. Conf. Aluminium-Lithium Alloys, 17, edited by T. H. Sanders, Jr. and E. A. Starke, Jr. (TMS-AIME, Warrendale, PA, 1986).CrossRefGoogle Scholar
5Guo, X. Q., Podloucky, R., and Freeman, A. J., Phys. Rev. B 40, 2793 (1989); X. Q. Guo, R. Podloucky, Jian-hua Xu, and A. J. Freeman, Phys. Rev. B 41, 12 432 (1990).CrossRefGoogle Scholar
6Jensrud, O., in Aluminum-Lithium Alloys III, edited by Baker, C., Gregson, P. J., Harris, S. J., and Peel, C. J. (The Institute of Metals, London, 1986), p. 411.Google Scholar
7Chen, Jing and Krakauer, H., Phys. Rev. B 37, 3295 (1988); C. L. Fu and M. H. Yoo, Philos. Mag. Lett. 58, 199 (1988).CrossRefGoogle Scholar
8Hansen, H. J. F. and Freeman, A. J., Phys. Rev. B 30, 561 (1984).Google Scholar
9Hedin, L. and Lundqvist, S., J. Phys. C 4, 2064 (1971).CrossRefGoogle Scholar
10Noble, B., Harris, S. J., and Dinsdale, K., J. Mater. Sci. 17, 461 (1982).CrossRefGoogle Scholar
11Leibfried, G. and Ludwig, W., in Solid State Physics, edited by Seitz, F. and Turnbull, D. (Academic Press, New York, 1961), Vol. 12, p. 276.Google Scholar
12Sutton, P. M., Phys. Rev. 91, 816 (1953).CrossRefGoogle Scholar
13Podloucky, R., Jansen, H. J. F., Guo, X. Q., and Freeman, A. J., Phys. Rev. B 37, 5478 (1988).CrossRefGoogle Scholar
14Sluiter, M., de Fontaine, D., Guo, X. Q., Podloucky, R., and Freeman, A. J., Phys. Rev. B (in press).Google Scholar
15Schlump, W. and Grewe, H., Aluminium 63, 1024 (1987).Google Scholar
16Schreiber, E., Anderson, O. L., and Soga, N., Elastic Constants and Their Measurement (McGraw-Hill, New York, 1973), p. 148.Google Scholar
17Kittel, C., Introduction to Solid State Physics, 5th ed. (Wiley, 1976); J. de Launay, Solid State Physics, edited by F. Seitz and D. Turnbull (Academic Press, New York, 1956), Vol. 2.Google Scholar