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Journal of Materials Science

, Volume 42, Issue 3, pp 889–900 | Cite as

Analysis of dislocation mechanisms around indentations through slip step observations

  • K. A. Nibur
  • F. Akasheh
  • D. F. BahrEmail author
Article

Abstract

Atomic force microscopy has been used to study slip step patterns, which form around indentations in FCC alloys. These patterns form in a consistent and repeatable manner. From these observations it has been determined that slip steps increase in height only in the outer region of the plastic zone leading to the cessation of their growth as the plastic zone expands outward. Electron backscatter diffraction techniques are used to map grain orientation and the effect of different surface orientations as well as different tip geometries on slip step behavior is explored. Changes in resolved shear stress on different slip planes can be observed qualitatively from changes in the slip step patterns as surface orientation and tip geometry are varied. Pile up is shown to form above the regions with the largest amounts of strain downward into the bulk. Changes in slip step patterns can be predicted based on changes in resolved shear stress. Discreet dislocation dynamics simulations have been performed to support these observations.

Keywords

Plastic Zone Slip System Slip Plane Resolve Shear Stress Surface Orientation 
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

Funding was provided by the United States Department of Energy and Sandia National Laboratories through the Presidential Early Career Award for Scientists and Engineers program under contract DE-AC04-94AL85000. The authors wish to thank Prof. H.M. Zbib of Washington State University for assistance with the dislocation dynamics simulations and Dr. B.P. Somerday of Sandia National Laboratories for helpful discussions.

References

  1. 1.
    McInteer WA, Thompson AW, Bernstein IM (1980) Acta Metall 28:887CrossRefGoogle Scholar
  2. 2.
    Gerberich WW, Harvey SE, Kramer DE, Hoehn JW (1998) Acta Mater 46:5007CrossRefGoogle Scholar
  3. 3.
    Nibur KA, Bahr DF (2003) Scripta Mater 49:1055CrossRefGoogle Scholar
  4. 4.
    Carrasco E, Gonzalez MA, Rodriguez de la Fuente O, Rojo JM (2004) Surf Sci 572:467CrossRefGoogle Scholar
  5. 5.
    Kadjik SE, Broese Van Groenou A (1989) Acta Metall 37:2625CrossRefGoogle Scholar
  6. 6.
    Tromas C, Girard JC, Audrier V, Woirgard J (1999) J Mater Sci 34:5337CrossRefGoogle Scholar
  7. 7.
    Gaillard Y, Tromas C, Woirgard J (2003) Phil Mag Lett 83:553CrossRefGoogle Scholar
  8. 8.
    Gaillard Y, Tromas C, Woirgard J (2003) Acta Mater 51:1059CrossRefGoogle Scholar
  9. 9.
    Stelmashenko NA, Walls MG, Brown LM, Milman YUV (1993) Acta Metall Mater 41:2855CrossRefGoogle Scholar
  10. 10.
    Woodcock CL, Bahr DF (2000) Scripta Mater 43:783CrossRefGoogle Scholar
  11. 11.
    Johnson KL (1985) Contact mechanics, Cambridge University Press, 50, pp 171–176Google Scholar
  12. 12.
    Samuels LE, Mulhearn TO (1957) J Mech Phys Sol 5:125CrossRefGoogle Scholar
  13. 13.
    Nibur KA (2005) PhD Thesis. Washington State UniversityGoogle Scholar
  14. 14.
    Zielinski W, Huang H, Gerberich WW (1993) J Mater Res 8:1300CrossRefGoogle Scholar
  15. 15.
    Hu SM (1975) J Appl Phys 46:1470CrossRefGoogle Scholar
  16. 16.
    Zbib HM, Diaz de la Rubia T (2002) Int J Plasticity 18:1133CrossRefGoogle Scholar
  17. 17.
    Stelmashenko NA, Walls MG, Brown LM, Milman YuV (1993) Acta Metall Mater 41:2855CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  1. 1.Mechanical and Materials EngineeringWashington State UniversityPullmanUSA

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