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Strain-Rate Sensitivity (SRS) of Nickel by Instrumented Indentation

  • Jennifer HayEmail author
  • Verena Maier
  • Karsten Durst
  • Mathias Göken
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

For materials which exhibit a power-law relationship between stress and strain rate, it is theoretically possible to evaluate the exponent (m) which governs the relationship by means of instrumented indentation. However, in practice, tests at small strain rates take so long that the results can easily be dominated by thermal drift. A new test method is developed in which several constant strain rates are examined within a single indentation test by switching strain rates as the indenter continues to move into the material. Switching strain rates within a single test overcomes the problem of long testing times by examining large strain rates first and transitioning to smaller strain rates as the test proceeds. The new method is used to test a sample of fine-grained nickel sold by NIST as a standard reference material for Vickers hardness. The strain-rate sensitivity of this sample is measured to be m = 0.021. This value is in good agreement with values obtained by others on fine-grained nickel using both instrumented indentation and uniaxial creep testing.

Keywords

Applied Force Indentation Size Effect Test Strain Rate Thermal Drift Instrument Indentation 
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.

References

  1. 1.
    Lucas BN, Oliver WC (1999) Indentation power-law creep of high-purity indium. Metall Mater Trans A Phys Metall Mater Sci 30(3):601–610CrossRefGoogle Scholar
  2. 2.
    Maier V, Durst K, Mueller J, Backes B, Hoppel H, Göken M (2011) Nanoindentation strain rate jump tests for determining the local strain rate sensitivity in nanocrystalline Ni and ultrafine-grained Al. J Mater Res 26(11):1421–1430CrossRefGoogle Scholar
  3. 3.
    NIST Certificate Standard Reference Material 1896a Vickers Microhardness of Nickel [cited 2011 October 10, 2011]. Available from: http://ts.nist.gov/MeasurementServices/ReferenceMaterials/upload/1896a.pdf
  4. 4.
    Hay JL, Agee P, Herbert EG (2010) Continuous stiffness measurement during instrumented indentation testing. Exp Tech 34(3):86–94CrossRefGoogle Scholar
  5. 5.
    Shen X, Lian JS, Jiang Z, Jiang Q (2008) High strength and high ductility of electrodeposited nanocrystalline Ni with broad grain size distribution. Mater Sci Eng A487:410Google Scholar
  6. 6.
    Dalla Torre F, Van Swygenhoven H, Victoria M (2002) Nanocrystalline electrodeposited Ni: microstructure and tensile properties. Acta Mater 50:3957CrossRefGoogle Scholar
  7. 7.
    Dalla Torre F, Spätig P, Schäublin R, Victoria M (2005) Deformation behavior and microstructure of nanocrystalline electrodeposited and high pressure torsioned nickel. Acta Mater 53:2337CrossRefGoogle Scholar
  8. 8.
    Wang YM, Hamza AV, Ma E (2006) Temperature-dependent strain-rate sensitivity and activation volume in nanocrystalline Ni. Acta Mater 54:2715CrossRefGoogle Scholar

Copyright information

© The Society for Experimental Mechanics 2013

Authors and Affiliations

  • Jennifer Hay
    • 1
    Email author
  • Verena Maier
    • 2
  • Karsten Durst
    • 2
  • Mathias Göken
    • 2
  1. 1.Agilent Technologies, Inc., Nano-Measurements OperationOak RidgeUSA
  2. 2.Department of Materials Science and Engineering Institute 1: General Materials PropertiesUniversity Erlangen-NurembergErlangenGermany

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