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On the new structural phases in Al65Cu20Cr15 quasicrystalline alloy

Published online by Cambridge University Press:  03 March 2011

Varsha Khare
Affiliation:
Department of Physics, Banaras Hindu University, Varanasi-221005, India
N.P. Lalla
Affiliation:
Department of Physics, Banaras Hindu University, Varanasi-221005, India
R.S. Tiwari
Affiliation:
Department of Physics, Banaras Hindu University, Varanasi-221005, India
O.N. Srivastava
Affiliation:
Department of Physics, Banaras Hindu University, Varanasi-221005, India
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Abstract

The quasicrystalline (qc) alloy Al65Cu20Cr15, unlike its Ru- and Fe-bearing counterparts like Al65Cu20Ru15 and Al65Cu20Fe15, is a metastable phase. This qc alloy has been shown to possess several structural variants and curious structural characteristics. We have investigated the qc alloy Al65Cu20Cr15 with special reference to the possible occurrence of new structural variants. TEM exploration of the as-quenched qc alloy has indeed revealed the existence of several new phases. These are (i) body-centered cubic (bcc) (a = 12.60 Å, disordered) and simple cubic (s.c.) (a = 12.60 Å, ordered), which are the 1/1 approximants of the primitive icosahedral phase (i phase); (ii) a twice order-induced modulated cubic phase (bcc, a = 25.20 Å) which has been shown to correspond to 1/1 approximant of the ordered i phase [i.e., face-centered icosahedral (FCI)]; and (iii) real crystalline bcc (a = 8.90 Å) and face-centered cubic (fcc) (a = 17.98 Å) phases possessing a specific orientation relationship with the icosahedral matrix phase. Tentative structural models showing the interrelationships between the bcc/fcc phases have been outlined.

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Articles
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1Shechtman, D., Blech, I., Gratias, D., and Cahn, J. W., Phys. Rev. Lett. 53, 1951 (1984).CrossRefGoogle Scholar
2Poon, S. J., Drehman, A. J., and Lawless, K. R., Phys. Rev. Lett. 55, 2324 (1985).CrossRefGoogle Scholar
3Ramachandrarao, P. and Sastry, G. V. S., Pramana 25, L225 (1985).CrossRefGoogle Scholar
4Dubost, B., Lang, J. M., Tanaka, M., Sainfort, P., and Audier, M., Nature (London) 324, 48 (1986).CrossRefGoogle Scholar
5Tsai, A. P., Inoue, A., and Masumoto, T., J. Mater. Sci. Lett. 6, 1403 (1987).CrossRefGoogle Scholar
6Tsai, A. P., Inoue, A., and Masumoto, T., J. Mater. Sci. Lett. 7, 322 (1988).CrossRefGoogle Scholar
7Ebalard, S. and Spaepen, F., J. Mater. Res. 5, 62 (1990).CrossRefGoogle Scholar
8Elser, V., Phys. Rev. B 32, 4892 (1985).CrossRefGoogle Scholar
9Mukhopadhyay, N. K., Ishihara, K. N., Ranganathan, S., and Chattopadhyay, K., Acta Metall. Mater. 39, 1151 (1991).CrossRefGoogle Scholar
10Shield, J. E., Chumbley, L. S., McCallum, R. W., and Goldman, A. I., J. Mater. Res. 8, 44 (1993).CrossRefGoogle Scholar
11Selke, H., Vogg, U., and Ryder, P. L., Philos. Mag. B65, 421 (1992).CrossRefGoogle Scholar
12Liu, W., Koster, U., Muller, F., and Rosenberg, M., Phys. Status Solidi 132, 17 (1992).CrossRefGoogle Scholar
13Liu, W. and Koster, U., Mater. Sci. Eng. A1, 55 (1992).Google Scholar
14Hu, J. J. and Ryder, P. L., Philos. Mag. B68, 389 (1993).CrossRefGoogle Scholar
15Copper, M. and Robinson, K., Acta Crystallogr. 20, 614 (1966).CrossRefGoogle Scholar
16Guyot, P. and Audier, M., Philos. Mag. B52, L15 (1985).CrossRefGoogle Scholar
17Bendersky, L., Cahn, J. W., and Gratias, D., Philos. Mag. B60, 837 (1989).CrossRefGoogle Scholar
18Lalla, N. P., Tiwari, R. S., and Srivastava, O. N., J. Mater. Res. 7, 53 (1992).CrossRefGoogle Scholar
19Fung, K. K. and Zhou, Y. Q., Philos. Mag. B54, L27 (1986).CrossRefGoogle Scholar