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Journal of Materials Science

, Volume 47, Issue 3, pp 1223–1233 | Cite as

Tensile properties and fracture behaviour of an ultrafine grained Ti–47Al–2Cr (at.%) alloy at room and elevated temperatures

  • V. N. NadakuduruEmail author
  • D. L. Zhang
  • B. Gabbitas
  • Y. L. Chiu
Materials in New Zealand

Abstract

An ultrafine grained (UFG) Ti–47Al–2Cr (at.%) alloy has been synthesized using a combination of high energy mechanical milling and hot isostatic pressing (HIP) of a Ti/Al/Cr composite powder compact. The material produced has been tensile tested at room temperature, 700 and 800 °C, respectively, and the microstructure of the as-HIPed material and the microstructure and fracture surfaces of the tensile tested specimens have been examined using X-ray diffractometry, optical microscopy, scanning electron microscopy and transmission electron microscopy. The alloy shows no ductility during tensile testing at room temperature and 700 °C, respectively, but very high ductility (elongation to fracture 70–100%) when tensile tested 800 °C, indicating that its brittle to ductile transition temperature (BDTT) falls within the temperature range of 700–800 °C. The retaining of ultrafine fine equiaxed grain morphology after the large amount of plastic deformation of the specimens tensile tested at 800 °C and the clear morphology of individual grains in the fractured surface indicate that grain boundary sliding is the predominant deformation mechanism of plastic deformation of the UFG TiAl based alloy at 800 °C. Cavitation occurs at locations fairly uniformly distributed throughout the gauge length sections of the specimens tensile tested at 800 °C, again supporting the postulation that grain boundary sliding is the dominant mechanism of the plastic deformation of the UFG TiAl alloys at temperatures above their BDTT. The high ductility of the UFG alloy at 800 °C and its fairly low BDTT indicates that the material a highly favourable precursor for secondary thermomechanical processing.

Keywords

Intergranular Fracture Grain Boundary Slide DBTT True Strain Curve Powder Metallurgy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

The authors would like to thank the Foundation for Research, Science, and Technology (FRST), New Zealand for the financial support to the research work presented in this paper.

References

  1. 1.
    Djanarthany S, Viala JC, Bouix J (2001) Mater Chem Phys 72:301CrossRefGoogle Scholar
  2. 2.
    Morris MA, Leboeuf M (1997) Mater Sci Eng A 239:429CrossRefGoogle Scholar
  3. 3.
    Imayev R, Shagiev M, Salishchev G, Imayev V, Valitov V (1996) Scripta Mater 34:985CrossRefGoogle Scholar
  4. 4.
    Imavey VM, Salishchev GA, Shagiev MR, Kuznetsov AV, Imavey RM, Senkov ON, Froes FH (2001) Mater Sci Eng A 300:263CrossRefGoogle Scholar
  5. 5.
    Haanappel VAC, Clemens H, Stroosnijder MF (2002) Intermetallics 10:293CrossRefGoogle Scholar
  6. 6.
    Rishel LL, Biery NE, Raban R, Gandelsman VZ, Pollock TM, Cramb AW (1998) Intermetallics 6:629CrossRefGoogle Scholar
  7. 7.
    Gerling R, Clemens H, Schimansky FP (2004) Adv Eng Mater 6:23CrossRefGoogle Scholar
  8. 8.
    Hsiung LM, Nieh TG (2004) Mater Sci Eng A 364:1CrossRefGoogle Scholar
  9. 9.
    Wegmann G, Gerling R, Schimansky FP, Clemens H, Bartels A (2002) Intermetallics 10:511CrossRefGoogle Scholar
  10. 10.
    Shagiev MR, Senkov ON, Salishchev GA, Froes FH (2000) J Alloy Compd 313:201CrossRefGoogle Scholar
  11. 11.
    Yang SH, Kim MS, Kim WY, Chiba A (2003) J Metastab Nanocryst Mater 15–16:373CrossRefGoogle Scholar
  12. 12.
    Maziasz PJ, Liu CT (1998) Metall Mater Trans A 29:105CrossRefGoogle Scholar
  13. 13.
    Thomas M, Raviart JL, Popoff F (2005) Intermetallics 13:944CrossRefGoogle Scholar
  14. 14.
    Yu HB, Zhang DL, Chen YY, Cao P, Gabbitas B (2009) J Alloy Compd 474:105CrossRefGoogle Scholar
  15. 15.
    Chen YY, Yu HB, Zhang DL, Chai LH (2009) Mater Sci Eng A 525:166CrossRefGoogle Scholar
  16. 16.
    Bohn R, Klassen T, Bormann R (2001) Intermetallics 9:559CrossRefGoogle Scholar
  17. 17.
    Liu CT, Schneibe JH, Maziasz PJ, Wright JL, Easton DS (1996) Intermetallics 4:429CrossRefGoogle Scholar
  18. 18.
    Kim YW (1995) Mater Sci Eng A 192/193:519CrossRefGoogle Scholar
  19. 19.
    Wu Y, Li XW, Zhou SX, Hwang SK (2007) J Iron Steel Res Int 14:104CrossRefGoogle Scholar
  20. 20.
    Dimiduck DM (1999) Mater Sci Eng A 263:281CrossRefGoogle Scholar
  21. 21.
    Gerling R, Schimansky FP, Clemens H (2003) Wear 249:566Google Scholar
  22. 22.
    Wang GX, Dahms M (1993) J Mater Perform 45:52Google Scholar
  23. 23.
    Beddoes J, Zhao L, Au P, Wallace W (1995) Mater Sci Eng A 192/193:324CrossRefGoogle Scholar
  24. 24.
    Clemens H, Glatz W, Appel F (1996) Scr Mater 35:429CrossRefGoogle Scholar
  25. 25.
    Shagiev MR, Senkov ON, Salishchev GA, Froes FH (2000) J Alloy Compd 313:201CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • V. N. Nadakuduru
    • 1
    Email author
  • D. L. Zhang
    • 1
  • B. Gabbitas
    • 1
  • Y. L. Chiu
    • 2
  1. 1.Waikato Centre for Advanced Materials (WaiCAM), School of EngineeringUniversity of WaikatoHamiltonNew Zealand
  2. 2.School of MetallurgyUniversity of BirminghamBirminghamUK

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