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Interfacial Structures of MoSi2-Mo5Si3 Eutectic Alloys

Published online by Cambridge University Press:  25 February 2011

H. Kung
Affiliation:
Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, MI 48109
H. Chang
Affiliation:
Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, MI 48109
R. Gíbala
Affiliation:
Department of Materials Science and Engineering, The University of Michigan, Ann Arbor, MI 48109
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Abstract

Script lamellar microstructures which occur in certain intermetallic eutectic alloys, such as in the Mo-Si system, may provide desirable mechanical properties. Arc-melted specimens of MoSi2-Mo5Si3 eutectic alloys which exhibit the interlocking lamellar phases were examined in this study. We have observed, by conventional transmission electron microscopy (TEM), an orientation relationship between the MoSi2 and the Mo5Si3 phases, (110)[001]1-2 ‖ (330)[110]5-3, which is consistent with the crystallographic coordinate transformation matrix. High resolution transmission electron microscopy (HRTEM) discloses the interfacial dislocations to be of <100> and 1/2<111> types and the interfaces are regularly faceted. A shear fault which may be consisting of antiphase boundary (APB)-coupled 1/6<331> superpartial dislocations was observed in MoSi2 grain near the interface. Crack propagation paths suggest that the eutectic has a strong, low energy interface which is consistent with the observations of a low index orientation relationship between the two phases and the faceted interfacial structures.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

REFERENCES

1. Tuominen, S.M., J. Less-Common Met. 81, 249 (1981).CrossRefGoogle Scholar
2. Aikin, R.M. Jr, Ceram. Eng. Sci. Proc. 12, 1643 (1991).CrossRefGoogle Scholar
3. Mason, D.P. and Van Aken, D.C., to be published.Google Scholar
4. Ashby, M.F., Blunt, F.J. and Bannister, B., Acta metall. 31, 1847 (1989).CrossRefGoogle Scholar
5. Kung, H., Chang, H. and Gibala, R., to be published.Google Scholar
6. Unal, O., Petrovic, J.J., Carter, D.H. and Mitchell, T.E., J. Amer. Ceram. Soc. 23, 1753 (1990).Google Scholar
7. Umakoshi, Y., Sakagami, T., Hirano, T. and Yamane, T., Acta metall. 38, 909 (1990).CrossRefGoogle Scholar
8. Kung, H., Basu, A. and Ghosh, A.K., to be published.Google Scholar
9. Mitchell, T.E., Castro, R.G. and Chadwick, M.M., Phil Mag., in press.Google Scholar