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Processing Of Al-Cu-Fe Quasicrystalline Single Grains

Published online by Cambridge University Press:  10 February 2011

T. A. Lograsso  and
A. R. Ross
T. A. Lograsso
Affiliation:
Materials Science and Engineering, Iowa State University, Ames, IA 50011 Ames Laboratory - USDOE, Ames, IA 50011
A. R. Ross
Affiliation:
Ames Laboratory - USDOE, Ames, IA 50011
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Abstract

The phase equilibria of the Al-Cu-Fe quasicrystalline phase (y phase) is complex and conventional crystal growth techniques like the Bridgman and Czochralski methods are not applicable in preparation of large crystals. Large single grains of the y phase been have prepared by either slow cooling or isothermal anneals. In the later technique, arc melted ingots were subjected to either single or multiple heat treatments between 825 and 840°C to encourage grain growth. Following heat treatment, grains of the icosahedral phase are found either as isolated pentagonal-faceted crystals within the ingot or within clusters of intergrown grains. The growth of the large grains is independent of the sample processing history of the sample, is facilitated by the presence of liquid at the growth temperatures and is constrained by the physical dimension of the ingot. The microstructure of both grain types is similar containing a minor quantity (on the order of 5–10 %) of a second phase and a high degree of porosity in the as-grown state. The second phase is usually present as a thin layer between adjacent grains or associated with a pore within a single grain. The grain porosity is distributed throughout the ingot. These defects can be removed through post-growth hot isostatic pressing and anneal treatments.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 553: Symposium LL – Quasicrystals , 1998 , 3
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Gayle, F. W., Shapiro, A. J., Biancaniello, F. S. and Boettinger, W. J., Metall. Trans, 23A, p. 2409 (1992).Google Scholar
2. Gratias, D., Calvayrac, Y., Devaud-Rzepski, J., Faudot, F., Harmelin, M., Quivy, A. and Bancel, P. A., J. of Non-crystalline Solids, 153&54, p. 482 (1993),Google Scholar
3. Bancel, P. A., Phys. Rev. Lett., 63, p. 2741 (1989).Google Scholar
4. Calvayrac, Y., Quivy, A., Bessiere, M., Lefebvre, S., Cornier-Quiquandon, M. and Gratias, D., J. Phys. Paris, 51, p. 417 (1990).Google Scholar
5. Cornier-Quiquandon, M., Quivy, A., Lefebvre, S., Elkaim, E., Heger, G., Katz, A. and Gratias, D., Phys. Rev. B, 44, No. 44, p.2071 (1991).Google Scholar
6. Krakow, W., DiVincenzo, D. P., Bancel, P. A., Cockayne, E. and Elser, V., J. Mater. Res, 8, No. 1, p. 24 (1993).Google Scholar
7. Ishimasa, T. and Mori, M., Phil. Mag. Lett. 62, p. 357 (1990).Google Scholar
8. Lograsso, T. A. and Delaney, D. W., J. Mater. Res, 11, No. 9, p. 2125, (1996).Google Scholar
9. Lograsso, T. A. and Delaney, D. W., in Quasicrystals, edited by Takeuchi, S. and Fujiwara, T., (World Scientific, Singapore 1998), p. 325.Google Scholar
10. German, R. M., Liquid Phase Sintering, Plenum Press, (1985), pp. 164172.Google Scholar