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Influence of microstructure on intrinsic and extrinsic toughening in an alpha-two titanium aluminide alloy

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Abstract

The toughening mechanisms in the Ti-24A1-11Nb (Ti-24-11) alloy have been identified previously to include crack-tip blunting, bridging, and deflection by the ductileβ phase, while the fracture mechanisms involve the nucleation, growth, and linkage of microcracks with the main crack. By performing appropriate theoretical analyses and critical experiments, the relative contributions of intrinsic and extrinsic toughening mechanisms, including microcrack shielding, crack-tip blunting, bridging, and deflection by theβ phase, to the initiation and crack growth toughness values of the Ti-24-11 alloy have been studied for three microstructures. The results indicate that the microstructure affects not only the amount of toughness enhancement, but also the type of toughening mechanisms present in the Ti-24-11 alloy. The initiation toughness in Ti-24-11 arises from the matrix toughness, crack-tip blunting, and, occasionally, from crack deflection by the ductile phase. As a result, theK IC values increase with the volume fraction of the ductile phase. In contrast, the resistance curve behavior originates from (1) a change of crack-tip singularity, which occurs when the blunted crack extends into the plastic zone, (2) crack bridging by ductile phase and shear ligaments, and (3) microcrack shielding, which occurs mostly at elevated temperatures.

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References

  1. J.M. Larsen, K.A. Williams, S.J. Balsone, and M.A. Stucke: inHigh-Temperature Aluminides and Intermetallics, S.H. Whang, C.T. Liu, D. Pope, and J.O. Stiegler, eds., TMS-AIME, Warrendale, PA, 1990, pp. 521–56.

    Google Scholar 

  2. D.A. Koss, D. Banerjee, D.A. Lukasak, and A.K. Gogia:High- Temperature Aluminides and Intermetallics, S.H. Whang, C.T. Liu, D. Pope, and J.O. Stiegler, eds., TMS-AIME, Warrendale, PA, 1990, pp. 145–96.

    Google Scholar 

  3. D.A. Lukasak and D.A. Koss:Metall. Trans. A, 1990, vol. 21A, pp. 135–43.

    CAS  Google Scholar 

  4. W.Y. Chu, A.W. Thompson, and J.C. Williams:Hydrogen Effects on Material Behavior, N.R. Moody and A.W. Thompson, eds., TMS-AIME, Warrendale, PA, 1990, pp. 543–54.

    Google Scholar 

  5. P.B. Aswath and S. Suresh: Paper presented at TMS Symp. on High-Temperature Aluminides and Intermetallics, S.H. Whang, C.T. Liu, D. Pope, and J.O. Stiegler, organizers, TMS, Fall Meeting, Indianapolis, IN, Oct. 1–5, 1989.

  6. K.S. Chan:Metall. Trans. A, 1990, vol. 21A, pp. 2687–99.

    CAS  Google Scholar 

  7. W.O. Soboyejo, B.A. Abbott, S. Midea, and D.S. Schwartz: McDonnell Douglas Research Laboratories, St. Louis, MO, unpublished research, 1990.

  8. K.S. Chan:Metall. Trans. A, 1991, vol. 22A, pp. 2021–29.

    CAS  Google Scholar 

  9. R.O. Ritchie and R.M. Cannon: Report No. LBL-20656, Lawrence Berkeley Laboratory, University of California, Berkeley, CA, 1985.

  10. L.R.F. Rose:Int. J. Fract., 1986, vol. 31, pp. 233–42.

    Article  CAS  Google Scholar 

  11. S. Suresh:Metall. Trans. A, 1985, vol. 16A, pp. 249–60.

    CAS  Google Scholar 

  12. B. Budiansky, J.C. Amazigo, and A.G. Evans:J. Mech. Phys. Solids, 1988, vol. 36, pp. 167–88.

    Article  Google Scholar 

  13. L.S. Sigl, A.G. Evans, P. Mataga, R.M. McMeeking, and B.J. Dalgleish:Acta Metall., 1988, vol. 36, p. 946.

    Google Scholar 

  14. H.E. Deve, A.G. Evans, G.R. Odette, R. Mehrabian, M.L. Emiliani, and R.J. Hecht:Acta Metall, 1990, vol. 38, pp. 1491–1502.

    Article  CAS  Google Scholar 

  15. S.M.L. Sastry and H.A. Lipsitt:Metall. Trans. A, 1977, vol. 8A, pp. 1543–52.

    CAS  Google Scholar 

  16. H.A. Lipsitt, D. Shechtman, and R.E. Schafrik:Metall. Trans. A, 1980, vol. 11A, pp. 1369–75.

    CAS  Google Scholar 

  17. Y.-W. Kim and F.H. Froes: inHigh-Temperature Aluminides and Intermetallics, S.H. Whang, C.T. Liu, D. Pope, and J.O. Stiegler, eds., TMS-AIME, Warrendale, PA, 1990, pp. 465–92.

    Google Scholar 

  18. W.Y. Chu and A.W. Thompson:Hydrogen Effects on Material Behavior, N.R. Moody and A.W. Thompson, eds., TMS-AIME, Warrendale, PA, 1990, pp. 285–96.

    Google Scholar 

  19. R.O. Ritchie and A.W. Thompson:Metall. Trans. A, 1985, vol. 16A, pp. 233–48.

    CAS  Google Scholar 

  20. K.S. Chan:Metall. Trans. A, 1990, vol. 21A, pp. 69–80.

    CAS  Google Scholar 

  21. J.W. Hutchinson:J. Mech. Phys. Solids, 1968, vol. 16, pp. 13–31.

    Article  Google Scholar 

  22. J.R. Rice and G.R. Rosengren:J. Mech. Phys. Solids, 1968, vol. 16, pp. 1–13.

    Article  Google Scholar 

  23. D.A. Koss and K.S. Chan:Acta Metall., 1980, vol. 28, pp. 1245–52.

    Article  CAS  Google Scholar 

  24. D.A. Koss and K.S. Chan: inDislocation Modeling of Physical Systems, M.F. Ashby, R. Bullough, C.S. Hartley, and J.P. Hirth, eds., Pergamon Press, New York, NY, 1981, pp. 18–22.

    Google Scholar 

  25. R.G. Hoagland and J.D. Embury:J. Am. Ceram. Soc., 1980, vol. 63, pp. 404–10.

    Article  CAS  Google Scholar 

  26. A.G. Evans and K.T. Faber: inFracture in Ceramics Materials, A.G. Evans, ed., Noyes Publications, Park Ridge, NJ, 1984, pp. 109–34.

    Google Scholar 

  27. J.W. Hutchinson:Acta Metall., 1987, vol. 35, pp. 1605–19.

    Article  CAS  Google Scholar 

  28. M. Kachanov:Int. J. Fracture, 1986, vol. 30, pp. R65-R72.

    Article  Google Scholar 

  29. B. Cotterell and J.R. Rice:Int. J. Fracture, 1980, vol. 16, pp. 155–69.

    Article  Google Scholar 

  30. J.R. Rice, W.J. Drugan, and T.L. Sham:Fracture Mechanics: 12th Conf., ASTM STP 700, ASTM, Philadelphia, PA, 1980, pp. 189–221.

    Google Scholar 

  31. K.S. Chan:Metall. Trans. A, 1990, vol. 21A, pp. 81–86.

    CAS  Google Scholar 

  32. K.S. Chan:Metall. Trans. A, 1989, vol. 20A, pp. 155–64.

    CAS  Google Scholar 

  33. K.S. Chan:Acta Metall., 1989, vol. 37, pp. 1217–26.

    Article  CAS  Google Scholar 

  34. D.L. Davidson, K.S. Chan, and R.A. Page: inMicromechanics: Experimental Techniques, W. Sharpe, ed., ASME, New York, NY, 1989, AMD-vol. 102, pp. 73-87.

    Google Scholar 

  35. R.G. Rowe, J.A. Sutliff, and E.F. Koch:MRS Symposia Proceedings, B.G. Girssen, D.E. Polk, and A.I. Taub, eds., MRS, Pittsburgh, PA, 1986, vol. 58, pp. 359-64.

    Google Scholar 

  36. D.P. DeLuca, B.A. Cowles, F.K. Haake, and K.P. Holland:Fatigue and Fracture of Titanium Aluminides, WRDC-TR-89, 4136, 1989.

  37. S. Gittis and D.A. Koss: inHigh Temperature Ordered Intermetallic Alloys III, C.T. Liu, A.I. Taub, N.S. Stoloff, and C.C. Koch, eds., MRS, Pittsburgh, PA, 1989, pp. 561-66.

    Google Scholar 

  38. K.S. Chan:Metall. Trans. A, 1990, vol. 21A, pp. 69–80.

    CAS  Google Scholar 

  39. S. Suresh: inFatigue of Advanced Materials, R.O. Ritchie, B.N. Cox, and R. Dauskardt, eds., Material and Component Engineering Publications, Birmingham, U.K., 1991, in press.

  40. S.J. Balsone: inOxidation of High-Temperature Intermetallics, T. Grobstein and J. Doychak, eds., TMS-AIME, Warrendale, PA, 1988, pp. 219–34.

    Google Scholar 

  41. K.S. Chan: Southwest Research Institute, San Antonio, TX, unpublished research, 1991. $

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Chan, K.S. Influence of microstructure on intrinsic and extrinsic toughening in an alpha-two titanium aluminide alloy. Metall Trans A 23, 183–199 (1992). https://doi.org/10.1007/BF02660864

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