Skip to main content

Micro Fracture Toughness Testing of TiAl Based Alloys with a Fully Lamellar Structure

  • K. Takashima (a1), T. P. Halford (a1), D. Rudinal (a1), Y. Higo (a1) and M. Takeyama (a2)...

A micro-sized testing technique has been applied to investigate the fracture properties of lamellar colonies in a fully lamellar Ti-46Al-5Nb-1W alloy. Micro-sized cantilever specimens with a size ≈ 10 × 10 × 50 μm3 were prepared by focused ion beam machining. Notches with a width of 0.5 μm and a depth of 5 μm were also introduced into the micro-sized specimens by focused ion beam machining. Fracture tests were successfully completed using a mechanical testing machine for micro-sized specimens at room temperature. The fracture toughness (KQ) values obtained were in the range 1.4–7 MPam1/2. Fracture surface observations indicate that these variations are attributable to differences in local lamellar orientations ahead of the notch. These fracture toughness values are also lower than those having been previously reported in conventional samples. This may be due the absence of significant extrinsic toughening mechanisms in these micro-sized specimens. Fracture mechanisms of these alloys are also considered on the micrometer scale. The results obtained in this investigation give important and fundamental information on the development of TiAl based alloys with high fracture toughness.

Hide All
1. Schafrik, R. E., in Proceedings of third International Symposium on Structural Intermetallics (ISSI 3), edited by Hemker, K. J., Dimiduk, D. M., et al. (TMS, Warrendale, PA, 2002), pp.1317.
2. Pather, R., Wisbey, A., Partridge, A., Halford, T., Horspool, D. N., Bowen, P. and Kestler, H., in Proceedings of third International Symposium on Structural Intermetallics (ISSI 3), edited by Hemker, K. J., Dimiduk, D. M., et al. (TMS, Warrendale, PA, 2002), pp.207215.
3. Huang, S. C. and Hall, E. L., Metall. Trans. A., 22A, 427 (1991).
4. Kim, Y., Acta Metall., 40, 1121 (1992).
5. Ritchie, R. O., International Journal of Fracture, 100, 55 (1999).
6. Nakano, T., Kawanaka, T., Yasuda, H. Y. and Umakoshi, Y., Mater. Sci. Eng. A, 194, 43 (1995).
7. Yokoshima, S. and Yamaguchi, M., Acta Mater, 44, 873 (1996).
8. Chan, K. S., Metall. Trans. A, 24A, 569 (1993).
9. Chan, K. S. and Kim, Y. W., Acta Metall., 43, 439 (1995).
10. Higo, Y., Takashima, K., Shimojo, M., Sugiura, S., Pfister, B. and Swain, M. V., in Materials Science of Microelectromechanical Systems (MEMS) Devices II, edited by de Boer, M. P., Heuer, A. H., Jacobs, S. J. and Peeters, E., (Mater. Res. Soc. Proc. 605, Pittsburgh, PA, 2000), pp. 241246.
11. Maekawa, S., Takashima, K., Shimojo, M., Higo, Y., Sugiura, S., Pfister, B. and Swain, M. V., Jpn. J. Appl. Phys., 38, 7194 (1999).
12. Takashima, K., Higo, Y., Sugiura, S. and Shimojo, M., Mat. Trans., 42, 68 (2001).
13. Takashima, K., Shimojo, M., Higo, Y. and Swain, M. V., ASTS STP-1413, 72 (2001).
14. Takashima, K., Koyama, S., Nakai, K. and Higo, Y., in Nano- and Microelectromechanical Systems (NEMS and MEMS) and Molecular Machines, edited by LaVan, D. A., Ayon, A. A., Buchhiet, T. E. and Madou, M. J., (Mater. Res. Soc. Proc. 741, Pittsburgh, PA, 2000), pp. 3540.
15. Okamura, H., Introduction to Linear Fracture Mechanics, (Baifukan, Tokyo, 1976) pp.218 (in Japanese).
16. Chan, K.S., Wang, P., Bhate, N. and Kumar, K. S., Acta Mater., 52, 4601 (2004).
17. Yoo, M. H. and Yoshimi, K., Intermetallics, 8, 1215 (2000).
18. Halford, T.P., Fatigue and Fracture of a High Strength, Fully Lamellar γ-TiAl based Alloy, PhD Thesis, The University of Birmingham, (2003).
19. Rao, K. T. V., Kim, Y. W., Muhlstein, C. L. and Ritchie, R. O., Mat. Sci. Eng. A, 192/193, 474 (1995)
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

MRS Online Proceedings Library (OPL)
  • ISSN: -
  • EISSN: 1946-4274
  • URL: /core/journals/mrs-online-proceedings-library-archive
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 8 *
Loading metrics...

Abstract views

Total abstract views: 69 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st July 2018. This data will be updated every 24 hours.