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The Role of Twinning in Brittle Fracture Of Ti-Aluminides

  • M. H. Yoo (a1), C. L. Fu (a1) and J. K. Lee (a1)

Abstract

The important roles of (111)[112] twinning in cleavage fracture of single-phase γ-TiAl and TiAl3 are assessed on the basis of theoretically calculated elastic constants, shear fault energies, and cleavage energies. The importance of elastic anisotropy in both homogeneous twin nucleation theory and dislocation models for twin nucleation is emphasized. The twin-slip conjugate relationship makes an important contribution to the strain compatibility for localized plasticity at a crack tip of Mode-I type. The intrinsic brittleness of these aluminides is attributed to a combined effect of the low mobility of slip and twin dislocations and the relatively low cleavage strength. The effect of the resolved normal stress on the twin plane is to enhance twinning activity at a (110) crack tip, leading to transformation toughening of shear type.

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1. Christian, J. W. and Laughlan, D. E., Acta Metall. 36, 1617 (1988).
2. Yoo, M. H., Fu, C. L., and Lee, J. K., High-Temperature Ordered Intermetallic Alloys III, ed. Liu, C. T., Taub, A. J., Stoloff, N. S., and Koch, C. C., MRS Symp. Proc. Vol. 133, MRS Publication, Pittsburgh, PA, 1989, p. 189.
3. Yamaguchi, M., Nishitani, S. R., and Shirai, Y., High-Temperature Aluminides and Intermerallics, Proc. of Symp. 1989 TMS Fall Meeting, Indianapolis, IN.
4. Yoo, M. H., Fu, C. L., and Lee, J. K., Revue de Physique Appliquee (in press).
5. Lipsitt, H. A., Shechtman, D., and Schafrik, R. E., Metall. Trans. 6A, 1991 (1975).
6. Yamaguchi, M., Shirai, Y., and Umakoshi, Y., Dispersion Strengthened Aluminum Alloys, ed. Kim, Y. W. and Griffith, W. M., TMS Symp. Proc., Materials Park, OH, 1988, p. 721.
7. Greenberg, B. F., Anisimov, V. I., and Gornostirev, Y. N., Scr. Metall. 22, 859 (1988).
8. Court, S. A., Vasudevan, V. K., and Fraser, H. L., Philos. Mag. A61, 141 (1990).
9. Fu, C. L. and Yoo, M. H., Alloy Phase Stability and Design, ed. Stocks, G. M., Pope, D. P., and Giamei, A. F., MRS Symp. Proc. Vol. 186, MRS Publication, Pittsburgh, PA 1990 (in press).
10. Yamaguchi, M., High-Temperature Ordered Intermetallic Compounds II, ed. Stoloff, N. S., Koch, C. C., Liu, C. T., and Izumi, O., MRS Symp. Proc.Vol. 81, MRS Publication, Pittsburgh, PA 1986, p. 275.
11. Yoo, M. H., J. Mater. Res. 4, 50 (1988).
12. Hanamura, T., Uemori, R., and Tanino, M., J. Mater. Res. 3, 656 (1988).
13. Hug, G. and Veyssiére, P., Electron Microscopy and Fracture Research of Materials, Intl. Symp., Dresden, 1989 (in press).
14. Fu, C. L. and Yoo, M. H., Philos. Mag. Lett. 62, 159 (1990).
15. Fu, C. L., J. Mater. Res. 5, 971 (1990).
16. Fu, C. L. and Yoo, M. H., High-Temperature Ordered Intermetallic Alloys III, ed. Liu, C. T., Taub, A. J., Stoloff, N. S., and Koch, C. C., MRS Symp. Proc. Vol. 133, MRS Publication, Pittsburgh, PA, 1989, p. 81.
17. Eshelby, J. D., Prog. Sol. Mech. 2, 89 (1961).
18. Johnson, W. C. and Cahn, J. W., Acta Metall. 32, 1925 (1984).
19. Lee, J. K. and Yoo, M. H., Metall. Trans. 21A, 2521 (1990).
20. Yoo, M. H., Takasugi, T., Hanada, S., and Izumi, O., Mater. Trans. Jpn. Inst. Metall. 31, 435 (1990).
21. Sih, G. C., Paris, P. C., and Irwin, G. R., Int. J. Fracture Mech. 1, 189 (1965).
22. The Role of Twinning in Fracture of Metals and Alloys, a collection of five papers presented at TMS Symposium, Metall. Trans. 12A (1981), pp. 365418.
23. Yamaguchi, M., Umakoshi, Y., and Yamane, T., Dislocations in Solids, Yamada Science Foundation, University of Tokyo Press, Tokyo, Japan, 1985, p. 77.
24. Kawabata, T., Takezono, Y., Kanai, T., and Izumi, O., Acta Metall. 36, 9163 (1988).
25. Soboyejo, W. O., Aswath, P. B., and Deffeyes, J. E., J. Mater. Sci. Eng. (in press).
26. Kohlhoff, S. and Schmauder, S., Atomistic Modelling in Materials -Beyond Pair Potentials, ed. Vitek, V. and Srolovitz, D. J., Plenum Press, NY, 1989, p. 411.
27. Liu, Y., Takasugi, T., Izumi, O., and Takahashi, T., Acta Metall. 36, 2959 (1988).
28. Yoo, M. H. and Fu, C. L., to be published.

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