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Journal of Materials Science

, Volume 45, Issue 17, pp 4790–4795 | Cite as

Effect of grain size on strain rate sensitivity of cryomilled Al–Mg alloy

  • Byungmin Ahn
  • Rahul Mitra
  • Enrique J. Lavernia
  • Steven R. Nutt
Ultrafine Grained Materials

Abstract

Al–Mg alloy powder was cryomilled to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic forging. The consolidation resulted in a bulk material with ultrafine grains of about 250 nm, and the material exhibited enhanced strength compared to conventionally processed Al–Mg alloy. The hardness of as-cryomilled powder, the forged ultrafine-grained (UFG) material, and the conventional coarse-grained (CG) alloy were measured by nanoindentation using various loading rates, and the results were compared with strain rate sensitivity (SRS) from uniaxial compression tests. Negative SRS was observed in the cryomilled NC powder and the forged UFG material, while the conventional alloy was relatively insensitive to strain rate. The dependence on loading rate was stronger in the NC powders than in the UFG material.

Keywords

Strain Rate Sensitivity Select Area Diffraction Pattern Dynamic Strain Aging Processing Control Agent Negative Strain Rate Sensitivity 
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

Research was sponsored by U.S. Army Research Laboratory (ARL) and was accomplished under Cooperative Agreement W911NF-08-2-0028. The views and conclusions made in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of ARL or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation hereon. The authors are grateful to JEOL USA, Inc. for providing access to the SM-09010 cross-section polisher, to Scott Sitzman (Oxford Instruments America, Inc.) for his effort on EBSD analysis, to Prof. Andrea Hodge (University of Southern California) for her permission to use the nanoindenter, and to Prof. Kwang Ho Kim (National Core Research Center for Hybrid Materials Solution, Busan, Korea) for valuable technical discussions. The authors also gratefully acknowledge A. Piers Newbery previously of University of California, Davis, for his assistance.

References

  1. 1.
    Gleiter H (1989) Prog Mater Sci 33:223CrossRefGoogle Scholar
  2. 2.
    Kumar KS, Van Swygenhoven H, Suresh S (2003) Acta Mater 51:5743CrossRefGoogle Scholar
  3. 3.
    Zhou F, Lee J, Dallek S, Lavernia EJ (2001) J Mater Res 16:3451CrossRefADSGoogle Scholar
  4. 4.
    Witkin DB, Lavernia EJ (2006) Prog Mater Sci 51:1CrossRefGoogle Scholar
  5. 5.
    Schwaiger R, Moser B, Dao M, Chollacoop N, Suresh S (2003) Acta Mater 51:5159CrossRefGoogle Scholar
  6. 6.
    Wei Q, Cheng S, Ramesh KT, Ma E (2004) Mater Sci Eng A 381:71CrossRefGoogle Scholar
  7. 7.
    Han BQ, Huang JY, Zhu YT, Lavernia EJ (2006) Scripta Mater 54:1175CrossRefGoogle Scholar
  8. 8.
    Han BQ, Huang J, Zhu YT, Lavernia EJ (2006) Adv Eng Mater 8:945CrossRefGoogle Scholar
  9. 9.
    Wei Q (2007) J Mater Sci 42:1709. doi: 10.1007/s10853-006-0700-9 CrossRefADSGoogle Scholar
  10. 10.
    Wang YM, Hodge AM, Bythrow PM, Barbee TW Jr, Hamza AV (2006) Appl Phys Lett 89:081903CrossRefADSGoogle Scholar
  11. 11.
    Cavaliere P (2008) Physica B 403:569CrossRefADSGoogle Scholar
  12. 12.
    Masumura RA, Hazzledine PM, Pande CS (1998) Acta Mater 46:4527CrossRefGoogle Scholar
  13. 13.
    Hayes RW, Witkin D, Zhou F, Lavernia EJ (2004) Acta Mater 52:4259CrossRefGoogle Scholar
  14. 14.
    Qian T, Marx M, Schűler K, Hockauf M, Vehoff H (2010) Acta Mater 58:2112CrossRefGoogle Scholar
  15. 15.
    Newbery AP, Ahn B, Hayes RW, Pao PS, Nutt SR, Lavernia EJ (2008) Metall Mater Trans A 39A:2193CrossRefADSGoogle Scholar
  16. 16.
    Ahn B, Newbery AP, Lavernia EJ, Nutt SR (2007) Mater Sci Eng A 463:61CrossRefGoogle Scholar
  17. 17.
    Li Y, Liu W, Ortalan V, Li WF, Zhang Z, Vogt R, Browning ND, Lavernia EJ, Schoenung JM (2010) Acta Mater 58:1732CrossRefGoogle Scholar
  18. 18.
    Dregia SA, Wynblatt P (1991) Acta Metall Mater 39(5):771CrossRefGoogle Scholar
  19. 19.
    Hondros ED, Seah MP (1977) Inter Mater Rev 22:262Google Scholar
  20. 20.
    McLean D (1957) Grain boundaries in metals. Clarendon Press, Oxford, p 116Google Scholar
  21. 21.
    Fan GJ, Wang GY, Choo H, Liaw PK, Park YS, Han BQ, Lavernia EJ (2005) Scripta Mater 52:929CrossRefGoogle Scholar
  22. 22.
    Li JCM (1963) Trans Met Soc AIME 227:239Google Scholar
  23. 23.
    Yamakov V, Wolf D, Philpot SR, Mukherjee AK, Gleiter H (2002) Nat Mater 1:1CrossRefGoogle Scholar
  24. 24.
    Conrad H (1964) J Metals 16(7):582Google Scholar
  25. 25.
    Lothe J (1962) Acta Metall 10:663CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Byungmin Ahn
    • 1
  • Rahul Mitra
    • 2
  • Enrique J. Lavernia
    • 3
  • Steven R. Nutt
    • 1
  1. 1.Department of Chemical Engineering and Materials ScienceUniversity of Southern CaliforniaLos AngelesUSA
  2. 2.Department of Metallurgical and Materials EngineeringIndian Institute of TechnologyKharagpurIndia
  3. 3.Department of Chemical Engineering and Materials ScienceUniversity of CaliforniaDavisUSA

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