Skip to main content
SpringerLink
Log in

High strain-rate superplasticity in a fine-grained PM 7475 Al Alloy

  • Published:
Metals and Materials Aims and scope Submit manuscript

Abstract

Superplastic behavior of powder-metallurgy (PM) processed 7475 +0.7Zr Al alloy having a fine grain size of 2 um was investigated. Strain-rate-change tests were conducted at elevated temperatures to examine the strain rate-stress relations. The deformation behavior was analyzed by assuming the presence of threshold stress for grain boundary sliding. After the threshold-stress compensation, the plastic flow was found to correlated well with lattice self-diffusion in pure aluminum. A maximum tensile elongation of up to 1000% was observed at a very high strain rate near l0-1s-1 and 515°C. A deformation map was constructed to identify the dominant deformation mechanism for the PM alloy. It was the grain boundary sliding controlled by lattice diffusion in aluminum. Evidence of short fiber or whisker-like formation were observed on the fractured samples over a wide range of temperature.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. K. Higashi, H. Imamura, T. Ito and S. Tanimura,Superplasticity in Aerospace II (eds., T. R. McNelley and H. C. Heikkenen), p. 251, The Minerals, Metals & Materials Society (1990).

  2. T. G. Nieh, G. A. Henshall and J. Wadsworth,Scripta metall. 18, 1040 (1984).

    Google Scholar 

  3. T. R. Bieler, T. G. Nieh, J. Wadsworth and A. K. Mukherjee,Scripta metall. 22, 81 (1988).

    Article  CAS  Google Scholar 

  4. T. G. Nieh, J. Wadsworth and T. Imai,Scripta metall. 26, 703 (1992).

    Article  CAS  Google Scholar 

  5. M. Mabuchi, K. Higashi and T. G. Langdon,Acta metall. mater. 42, 1793 (1994).

    Google Scholar 

  6. R. S. Mishra, T. R. Bieler and A. K. Mukherjee,Acta metall. mater. 43, 3275 (1995).

    Article  Google Scholar 

  7. K. Higashi,Mater. Sci. Eng. A166, 109 (1993).

    CAS  Google Scholar 

  8. K. Higashi, T. Okada, T. Mukai and S. Tanimura,Scripta metall. 25, 2053 (1991).

    Article  CAS  Google Scholar 

  9. T. Imai, M. Mabuchi, Y. Tozawa and M. Yamada,J. Mater. Sci. Lett. 9, 255 (1990).

    Article  CAS  Google Scholar 

  10. M. Mabuchi and K. Higashi,Mater. Sci. Eng. A179, 625 (1994).

    Google Scholar 

  11. H. J. Forst and M. F. Ashby, inDeformation-Mechanism Maps, p. 21, Pergamon Press (1982).

  12. D. H. Shin, K. T. Park and E. J. Lavernia,Mater. Sci. Eng. A20l, 118 (1995).

    Google Scholar 

  13. D. H. Shin, K. S. Kum, D. W. Kim and S. W. Nam,Metall. Trans. 12A, 2729 (1990).

    Google Scholar 

  14. W. J. Kim, E. Taleff and O.D. Sherby,Scripta metall. 32, 1625 (1995).

    Article  Google Scholar 

  15. O. A. Ruano, J. Wadsworth and O. D. Sherby,.J. Mater. Sci. 20, 3735 (1985).

    Article  ADS  CAS  Google Scholar 

  16. F. A. Mohamed, K. T. Park and E. J. Lavernia,Mater. Sci. Eng. A150, 21 (1992).

    CAS  Google Scholar 

  17. E. Orowan,Dislocation in Metals (ed., M. Cohen), p. 1954, AIME, New York (1956).

    Google Scholar 

  18. E. Arzt and M. F. Ashby,Scripta metall. 16, 1285 (1982).

    Article  Google Scholar 

  19. E. Arzt and J. Rosler,Acta metall. 36, 1053 (1988).

    Article  CAS  Google Scholar 

  20. J. Rosler and E. Arzt,Acta metall. 38, 671 (1990).

    Article  Google Scholar 

  21. R. S. Mishra, T. K. Nandy and G. W. Greenwood,Phil. Mag. A69, 1097 (1994).

    ADS  Google Scholar 

  22. G. S. Murty and M. J. Koczak,Mater. Sci. Eng. 100, 37 (1988).

    Article  CAS  Google Scholar 

  23. E. W. Hart,Acte metall. 15, 351 (1969).

    Article  Google Scholar 

  24. W. D. Cao, X. P. Lu and H. Conrad,Acta metall. 44, 697 (1996).

    CAS  Google Scholar 

  25. R. Z. Valiev, Y. V. Gertsman and O. A. Kaibysev,Metallofizika. 8, 72 (1986).

    CAS  Google Scholar 

  26. M. Mabuchi and K. Higashi,Scripta matall. 34, 1893 (1996).

    Article  CAS  Google Scholar 

  27. J. Koike, M. Mabuchi and K. Higashi,Acta metall. mater. 43, 199 (1995).

    CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Metallurgy and Materials Science, Hong-Ik University, 72-1 Sangsu-dong, Mapo-ku, 121-791, Seoul, Korea

    Woo-Jin Kim & Jong-Kab Kim

Authors
  1. Woo-Jin Kim
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jong-Kab Kim
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kim, WJ., Kim, JK. High strain-rate superplasticity in a fine-grained PM 7475 Al Alloy. Metals and Materials 4, 1133–1141 (1998). https://doi.org/10.1007/BF03025987

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF03025987

Key words

Search

Navigation