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Planar fault energies and dislocation core spreading in B2 NiAl

Published online by Cambridge University Press:  03 March 2011

Diana Farkas  and
Christophe Vailhe
Diana Farkas
Affiliation:
Department of Materials Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0237
Christophe Vailhe
Affiliation:
Department of Materials Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0237
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Abstract

We present computer simulation results for the planar faults involved in core spreading of 〈100〉 and 〈111〉 dislocations. Seven γ surfaces were computed for different crystallographic planes ({110}, {112}, {123}, {210}, {100}, {111}, and {122}). Stable APB's are observed in the {110} and {112} planes, but they are deviated from the exact 1/2a〈111〉 position. No other stable planar fault was observed. The fact that a stable minimum is observed deviated from the 1/2〈111〉 position suggests the possibility of different dissociation reactions for the 〈111〉 screw dislocation in the {110} and {112} planes. The fact that no other stable minima were observed in the γ surfaces indicates that no true core dissociation is expected for the 〈100〉 dislocations. We propose that dislocation core spreading in various planes can be understood in terms of the directions of lowest restoring forces observed for the corresponding γ surfaces.

Type
Articles
Information
Journal of Materials Research , Volume 8 , Issue 12 , December 1993 , pp. 3050 - 3058
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1Baker, I. and Munroe, P., in High Temperature Aluminides and Intermetallics, edited by Whang, S. H., Liu, C. T., Pope, D. P., and Stiegler, J. O. (TMS, Warrrendale, PA, 1990), p. 425.Google Scholar
2Pasianot, R., Farkas, D., and Savino, E. J., J. Phys. Ill 1, 997 (1991).Google Scholar
3Farkas, D., Pasianot, R., Miracle, D. B., and Savino, E. J., in High Temperature Ordered Intermetallic Alloys TV, edited by Johnson, L. A., Pope, D. P., and Stiegler, J. O. (Mater. Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), p. 217.Google Scholar
4Vitek, V., Philos. Mag. 18, 773 (1968).CrossRefGoogle Scholar
5Vitek, V., Crystal Lattice Defects 5, 1 (1974).Google Scholar
6Voter, A. F. and Chen, S. P., in Characterization of Defects in Materials, edited by Siegel, R. W., Weertman, J. R., and Sinclair, R. (Mater. Res. Soc. Symp. Proc. 82, Pittsburgh, PA, 1987), p. 175.Google Scholar
7Norgett, M. J., Perrin, R. C., and Savino, E. J., J. Phys. F2, L73 (1972).CrossRefGoogle Scholar
8Yamaguchi, M., Pope, D. P., and Vitek, V., Philos. Mag. A 43, 1265 (1981).CrossRefGoogle Scholar
9Yamaguchi, M. and Umakoshi, Y., in The Structure and Properties of Crystal Defects, edited by Paidar, V. and Lejček, L. (Elsevier, Amsterdam, 1983), p. 131.Google Scholar
10Parthasarathy, T., Rao, S. I., and Dimiduk, D., Philos. Mag. (1993, in press).Google Scholar
11Tonn, S. C., Zhang, Y., and Crimp, M. A., Mater. Sci. Eng. (1993, in press).Google Scholar
12Kim, J. T. and Gibala, R., in High Temperature Ordered Intermetallic Alloys IV, edited by Johnson, L. A., Pope, D. P., and Stiegler, J. O. (Mater. Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), p. 261.Google Scholar
13Mills, M. J. and Miracle, D. B., Acta Metall. Mater. 41, 85 (1993).CrossRefGoogle Scholar