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Characterization of superdislocation dissociations in Al66Ti25Cr9 with transmission electron microscopy observations and image simulations

Published online by Cambridge University Press:  31 January 2011

Mukul Kumar  and
K. J. Hemker
Mukul Kumar
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218–2686
K. J. Hemker
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218–2686
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Abstract

The nature of dissociated superlattice dislocation cores in Al66Ti25Cr9, deformed at room temperature, has been characterized by weak-beam transmission electron microscopy (TEM) and comparison of experimental images with computer-simulated images. The displacement fields associated with narrowly dissociated APB- and SISF-dissociated ‹110› superdislocations were calculated to account for the asymmetry in dislocation contrast and led to a better understanding of the formation of images. Such calculations are a powerful aid, when coupled with image simulations, in distinguishing the “real” intensity peaks from the supplementary peaks that can be generated under experimental imaging conditions. While both APB- and SISF-dissociated superdislocations were identified, the vast majority of superdislocations were determined to be APB-dissociated. Corrected values of the fault energies (γAPB and γSISF ) have been measured for this alloy. These energies and the observed dissociations are shown to be self-consistent.

Type
Articles
Information
Journal of Materials Research , Volume 13 , Issue 3 , March 1998 , pp. 610 - 624
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1.Dislocations in Solids, edited by Nabarro, F. R. N. and Duesbery, M. S. (North-Holland, Amsterdam, 1996), Vol. 10.Google Scholar
2.Yamaguchi, M., Paidar, V., Pope, D. P., and Vitek, V., Philos. Mag. A 45, 867 (1982).CrossRefGoogle Scholar
3.Paidar, V., Yamaguchi, M., Pope, D. P., and Vitek, V., Philos. Mag. A 45, 883 (1982).CrossRefGoogle Scholar
4.Kumar, K. S., Int. Metals Rev. 35, 293 (1990).CrossRefGoogle Scholar
5.Vasudevan, V. K., Wheeler, R., and Fraser, H. L., in High Temperature Ordered Intermetallic Alloys III, edited by Liu, C. T., Taub, A. I., Stoloff, N. S., and Koch, C. C. (Mater. Res. Soc. Symp. Proc. 133, Pittsburgh, PA, 1989), p. 705.Google Scholar
6.Turner, C. D., Powers, W. O., and Wert, J. A., Acta Metall. 37, 2635 (1989).CrossRefGoogle Scholar
7.Powers, W. O. and Wert, J. A., Metall. Trans. A 21, 145 (1990).CrossRefGoogle Scholar
8.George, E. P., Horton, J. A., Porter, W. D., and Schneibel, J. H., J. Mater. Res. 5, 1639 (1990).CrossRefGoogle Scholar
9.Hu, G., Chen, S., Wu, X., and Chen, X., J. Mater. Res. 6, 957 (1991).CrossRefGoogle Scholar
10.Morris, D. G. and Lerf, R., Acta Metall. Mater. 39, 2419 (1991).Google Scholar
11.Morris, D. G., J. Mater. Res. 7, 303 (1992).CrossRefGoogle Scholar
12.Inui, H., Luzzi, D. E., Porter, W. D., Pope, D. P., Vitek, V., and Yamaguchi, M., Philos. Mag. A 65, 245 (1992).CrossRefGoogle Scholar
13.Zhang, S., Milligan, W. W., and Mikkola, D. E., Scripta Metall. Mater. 27, 1073 (1992); Philos. Mag. A 71, 523 (1995).CrossRefGoogle Scholar
14.Wu, X., Rong, Y., Chen, S., and Hu, G., Scripta Metall. Mater. 28, 1519 (1993).CrossRefGoogle Scholar
15.Wu, Z. L., Pope, D. P., and Vitek, V., Philos. Mag. A 70, 159 (1994)CrossRefGoogle Scholar
Wu, Z. L., Pope, D. P., and Vitek, V., Philos. Mag., 70, p. 171 (1994).CrossRefGoogle Scholar
16.Morris, D. G., Lerf, R., and Leboeuf, M., Acta Metall. Mater. 43, 2825 (1995).CrossRefGoogle Scholar
17.Edington, J. W., Practical Electron Microscopy in Materials Science (Van Nostrand, New York, 1976).Google Scholar
18.Veyssière, P. and Morris, D. G., Philos. Mag. A 67, 491 (1993).CrossRefGoogle Scholar
19.Wilkens, M. and Hornbogen, E., Phys. Status Solidi 4, 557 (1964).CrossRefGoogle Scholar
20.Cockayne, D. J. H., Ray, I. L. F., and Whelan, M. J., Philos. Mag. A 20, 1265 (1969).CrossRefGoogle Scholar
21.Hug, G., Loiseau, A., and Veyssière, P., Philos. Mag. A 57, 499 (1988).CrossRefGoogle Scholar
22.Korner, A., Philos. Mag. A 58, 507 (1988).CrossRefGoogle Scholar
23.Baluc, N., Karnthaler, H. P., and Mills, M. J., Philos. Mag. A 64, 137 (1991).CrossRefGoogle Scholar
24.Veyssière, P., ISIJ Int. 31, 1028 (1991).CrossRefGoogle Scholar
25.Stobbs, W. M. and Sworn, C. H., Philos. Mag. 24, 1365 (1971).CrossRefGoogle Scholar
26.Humphreys, C. J., Drummond, R. A., Hart-Davis, A., and Butler, E. P., Philos. Mag. 35, 1543 (1977).CrossRefGoogle Scholar
27.Hemker, K. J. and Mills, M. J., Philos. Mag. A 68, 305 (1993).CrossRefGoogle Scholar
28.Baluc, N. and Schäublin, R., Philos. Mag. A 74, 113 (1996).CrossRefGoogle Scholar
29.Hemker, K. J., Philos. Mag. A 76 (1) (1997).CrossRefGoogle Scholar
30.Schäublin, R. and Stadelmann, P., Mater. Sci. Eng. A164, 373 (1993).CrossRefGoogle Scholar
31.Head, A. K., Humble, P., Clarebrough, L. M., Morton, A. J., and Forwood, G. T., Computed Electron Micrographs and Defect Identification (North-Holland, Amsterdam, 1973).Google Scholar
32.Hirsch, P. B., Howie, A., Nicholson, R. B., Pashley, D. W., and Whelan, M. J., Electron Microscopy of Thin Crystals (Butterworths, London, 1965).Google Scholar
33.Schäublin, R., Meng, X., and Stobbs, W. M., Inst. Phys. Conf. Ser. 147, 91 (1995).Google Scholar
34.Stadelmann, P., Ultramicroscopy 21, 131 (1987).CrossRefGoogle Scholar
35.Weickenmeier, A. and Kohl, H., Acta Crystallogr. A 47, 590 (1991).CrossRefGoogle Scholar
36.Cockayne, D. J. H., Z. Natur. A 27, 452 (1972).CrossRefGoogle Scholar
37.Stroh, A. N., Philos. Mag. 3, 625 (1958).CrossRefGoogle Scholar
38.Baluc, N., Schäublin, R., and Hemker, K. J., Philos. Mag. Lett. 64, 327 (1991).CrossRefGoogle Scholar
39.Paidar, V., Pope, D. P., and Yamaguchi, M., Scripta Metall. 15, 1029 (1981).CrossRefGoogle Scholar
40.Morris, D. G., Scripta Metall. 25, 713 (1991); 26, 733 (1992).CrossRefGoogle Scholar
41.Yoo, M. H. and Fu, C. L., ISIJ Int. 31, 1049 (1991).CrossRefGoogle Scholar