Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-25T15:42:32.753Z Has data issue: false hasContentIssue false
  • English
  • Français

Analysis of Weak-Beam Contrast from SESF/SISF Fault Pairs Associated with ½ <112] Superdislocations in TiAl

Published online by Cambridge University Press:  10 February 2011

Mukul Kumar ,
S. Sriram ,
Adam J. Schwartz  and
Vijay K. Vasudevan
Mukul Kumar
Affiliation:
Lawrence Livermore National Laboratory, Univ. of California, L-370, Livermore, CA 94550
S. Sriram
Affiliation:
Novellus Systems, Inc., 3970 N First St., San Jose, CA 95134
Adam J. Schwartz
Affiliation:
Lawrence Livermore National Laboratory, Univ. of California, L-370, Livermore, CA 94550
Vijay K. Vasudevan
Affiliation:
Dept. of Materials Science & Engineering, Univ. of Cincinnati, Cincinnati, OH 45221–0012
Get access

Abstract

The diffraction contrast from dissociated ½<112] superdislocations in γ-TiAl intermetallic alloy cannot always be analyzed using conventional rules of diffraction contrast. In particular, the configuration involving three similar Shockley partials on adjacent planes has often been ruled out due to the absence of fringes indicating the presence of stacking faults. In order to determine the dissociated configuration, weak-beam transmission electron microscope observations of edge-oriented ½<112] superdislocations have been correlated with computer simulated images. Dissociation of these superdislocations into three similar ⅙<112] partial dislocations bounding a superlattice extrinsic and intrinsic stacking fault pair has been consequently determined from these analyses. It has been found that diffraction contrast alone cannot distinguish between the various configurations that lead to the formation of the fault pair, but the formation of an antiphase boundary or complex stacking fault linked dissociation or locking by stair rod dislocations can be ruled out.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 552: Symposium KK – High-Temperature Ordered Intermetallic Alloys VIII , 1998 , KK8.19.1
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Greenberg, B. A., 1970, Phys. Stat. Sol., 42, 459; 1973, Phys. Stat. Sol. (b), 55, 59.CrossRefGoogle Scholar
2. Greenberg, B. A., Antonova, O. V., Indenbaum, V. N., Karkina, L. E., Notkin, A. B., Ponomarev, M. V., and Smirnov, L. V., 1991a, Acta Metall. Mater., 39, 233; 1991b, ibid., 39, 243.CrossRefGoogle Scholar
3. Hug, G., Loiseau, A., and Lasalmonie, A., 1986, Phil. Mag. A, 54, 47.CrossRefGoogle Scholar
4. Hug, G., Loiseau, A. and, Veyssière, P., 1988, Phil. Mag. A, 57, 499.CrossRefGoogle Scholar
5. Greenberg, B. A., Antonova, O. V., Karkina, L. E., Notkin, A. B., and Ponomarev, M. V., 1992a, Acta Metall. Mater., 40, 815; 1992b, ibid., 40, 823.CrossRefGoogle Scholar
6. Hemker, K. J., Viguier, B., and Mills, M. J., 1993, Mater. Sci. Engg., A164, 391.CrossRefGoogle Scholar
7. Inkson, B. J., and Humphreys, C. J., 1995, Phil. Mag. Lett., 71, 307.CrossRefGoogle Scholar
8. Stucke, M., Vasudevan, V. K., and Dimiduk, D. M., 1995, Mater. Sci. Engg., A192/193, 111.CrossRefGoogle Scholar
9. Jiao, S., Bird, N., Hirsch, P. B., and Taylor, G., 1998, Phil. Mag. A, in press.Google Scholar
10. Mills, M. J., Wiezorek, J. M. K., and Fraser, H. L., 1997, Mat. Res. Soc. Symp. Proc., 466, 131.CrossRefGoogle Scholar
11. Tunstall, W. J., and Goodhew, P. J., 1966, Phil. Mag., 13, 1260.CrossRefGoogle Scholar
12. Gallagher, P. C. J., Washburn, J., and Thomas, G., 1966, Phys. Stat. Sol., 15, K93.CrossRefGoogle Scholar
13. Gallagher, P. C. J., 1966, Phys. Stat. Sol., 16, 95.CrossRefGoogle Scholar
14. Carter, C. B., 1980, Phys. Stat. Sol. (a), 61, 579.CrossRefGoogle Scholar
15. Schdiublin, R., and Stadelmann, P., 1993, Mater. Sci. Engg., A164, 373.CrossRefGoogle Scholar
16. Tanaka, K., Ichitsubo, T., Inui, H., Yamaguchi, M., and Koiwa, M., 1996, Phil. Mag. Lett., 73, 71.CrossRefGoogle Scholar
17. Head, A. K., Humble, P., Clarebrough, L. M., Morton, A. J., and Forwood, G. T., 1973, Computed Electron Micrographs and Defect Identification, North-Holland, Amsterdam.Google Scholar
18. Viguier, B., and Hemker, K. J., 1996, Phil. Mag. A, 73, 575.CrossRefGoogle Scholar
19. Wilkens, M., and Hornbogen, E., 1964, Phys. Stat. Sol., 4, 557.CrossRefGoogle Scholar
20. Baluc, N., Karnthaler, H. P., and Mills, M. J., 1991, Phil. Mag. A, 64, 137.CrossRefGoogle Scholar
21. Veyssiire, P., 1991, ISIJ Inter., 31, 1028.CrossRefGoogle Scholar
22. Zhang, S., Milligan, W. W., and Mikkola, D. E., 1992, Scripta Metall., 27, 1073; 1995, Phil. Mag. A, 71, 523.CrossRefGoogle Scholar
23. Hemker, K. J., and Mills, M. J., 1993, Phil. Mag. A, 68, 305.CrossRefGoogle Scholar
24. Veyssière, P., and Morris, D. G., 1993, Phil. Mag. A, 67, 491.CrossRefGoogle Scholar
25. Kumar, M., and Hemker, K. J., 1998, J. Mater. Res., 13, 610.CrossRefGoogle Scholar
26. Hazzledine, P. M., Karnthaler, H. P., and Wintner, E., 1975, Phil. Mag., 32, 81.CrossRefGoogle Scholar
27. Morton, A. J., 1981, Phil. Mag. A, 44, 1099.CrossRefGoogle Scholar
28. Inkson, B. J., 1998, Phil. Mag. A, 77, 715.CrossRefGoogle Scholar