Investigation of Elasto-Plastic Deformation Behavior of Haynes242 Alloy Subjected to Nanoscale Loads Through Indentation Experiments

  • B. Sridhar  Babu
  • A. Kumaraswamy
  • B. Anjaneya  Prasad
Technical Paper
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Abstract

The deformation behavior of Haynes242 alloy subjected to nanoscale loads was investigated through nanoindentation experiments with strain rates varying from 0.05 to 0.20 s−1 and an indentation depth of 2000 nm. The strain rate jump tests have been carried out to examine the strain rate sensitivity on mechanical properties at ambient temperature. Strain rate sensitivity measured from these tests was observed to be 0.112 indicating its influence on mechanical properties. Elastic properties such as indentation hardness and Young’s modulus decreased with increase in indentation depth at different strain rates representing strong indentation size effect (ISE). It was observed that, the hardness at nanoscale loads increased with increasing strain rate, however, the influence of strain rate on Young’s modulus is not predominant. The ISE was also studied through Nix and Gao model. The H2 versus 1/h for Haynes242 exhibited a better linear relationship, which is in agreement with the behavior of Ti-6Al-4V. The study of plastic behaviour revealed that, strain rates had no predominant effect on strain hardening exponent, however, it had a significant influence on yield stress.

Keywords

Nanoindentation Strain-rate Indentation size effect Young’s modulus Haynes242 

List of symbols

Aproj

Projected area (nm2)

b

Burgers vector (nm)

D

Damage variable

E*

Reduced Young’s modulus (GPa)

E

Young’s modulus of sample from nanoindentation (GPa)

Eu

Young’s modulus of undamaged material (GPa)

H

Hardness (GPa)

H0

Nanoindentation hardness for a large indentation depth (GPa)

h

Indentation depth (nm)

h*

Characteristic length (nm)

hc

Indenter contact depth (nm)

m

Strain rate sensitivity

P

Indentation load (mN)

Pmax

Maximum indentation load (mN)

S

Slope of the unloading curve

\( \nu_{s} \)

Poisson’s ratio of the specimen

\( \nu_{i} \)

Poisson’s ratio of the indenter

σ

Flow stress in the presence of a strain gradient (MPa)

σo

Flow stress in the absence of strain gradient (MPa)

ρs

Density of statistically stored dislocations

μ

Shear modulus (GPa)

θ

Angle between indenter surface and plane of specimen surface

\( \chi \)

Strain gradient

l^

Intrinsic material length scale (µm)

γ

Indenter geometry constant

\( \dot{\varepsilon} \)

Indentation strain rate

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Notes

Acknowledgments

The authors are grateful to the Vice Chancellor, DIAT (DU), Pune for granting permission to publish this paper. The help provided by technical staff at CMTI, Bangalore to use the facilities for conducting nanoindentation experiments cannot be ignored in this work.

References

  1. 1.
    Pingli MAO, Yan XIN, Ke HAN, and Weiguo JIANG, Acta Metall Sin 22 (2009) 365.CrossRefGoogle Scholar
  2. 2.
    Geng S J, Zhu J H, and Lu Z G, Solid State Ion 177 (2006) 559.CrossRefGoogle Scholar
  3. 3.
    Wei Q, Cheng S, Ramesh K T, and Ma E, Mat Sci Eng A 381 (2004) 71.CrossRefGoogle Scholar
  4. 4.
    Schwaiger R, Moser B, Dao M, Chollacoop N, and Suresh S, Acta Mater 51 (2003) 5159.CrossRefGoogle Scholar
  5. 5.
    Wang W, Jiang C B, and Lu K, Acta Mater 51 (2003) 6169.CrossRefGoogle Scholar
  6. 6.
    Ohmura T, Tsuzaki K, and Yin F, Mater Trans 46 (2005) 2026.CrossRefGoogle Scholar
  7. 7.
    Deng X, Chawla N, Chawla K K, and Koopman M, Acta Mater 52 (2004) 4291.CrossRefGoogle Scholar
  8. 8.
    Trelewicz J R, and Schuh C A, Scr Mater 61 (2009) 1056.CrossRefGoogle Scholar
  9. 9.
    Li R, Riester L, Watkins T R, Blau P J, and Shih A J, Mater Sci Eng 472 (2008) 115.CrossRefGoogle Scholar
  10. 10.
    Maa Z S, Zhou Y C, Long S G, and Luc C, Int J Plast 34 (2012) 1.CrossRefGoogle Scholar
  11. 11.
    Huanga Y, Zhang F, Hwang K C, Nix W D, Pharrd G M, and Feng G, J Mech Phys Solids 54 (2006) 1668.CrossRefGoogle Scholar
  12. 12.
    Zhang M, Li F, Yuan Z, Li J, and Wang S, Mater Des 49 (2013) 705.CrossRefGoogle Scholar
  13. 13.
    Zhanga M, Li F, Chen B, and Wang S, Mater Sci Eng A 535 (2012) 170.CrossRefGoogle Scholar
  14. 14.
    Cai J, Li F, Liu T, and Chen B, Mater Charact 62 (2011) 287.CrossRefGoogle Scholar
  15. 15.
    Zhang T-Y, Xu W-H, and Zhao M-H, Acta Mater 52 (2004) 57.CrossRefGoogle Scholar
  16. 16.
    Oliver W C, and Pharr G M, J Mater Res 7 (1992) 1564.CrossRefGoogle Scholar
  17. 17.
    Nix WD, and Gao H, J Mech Phys Solids 46 (1998) 411.CrossRefGoogle Scholar
  18. 18.
    Maier V, Durst K, Mueller J, Backes B, Hoppel H W, and Goken M, J Mater Res 26 (2011) 1421.CrossRefGoogle Scholar

Copyright information

© The Indian Institute of Metals - IIM 2015

Authors and Affiliations

  • B. Sridhar  Babu
    • 1
  • A. Kumaraswamy
    • 2
  • B. Anjaneya  Prasad
    • 3
  1. 1.Department of Mechanical EngineeringCMRITHyderabadIndia
  2. 2.Department of Mechanical EngineeringDefence Institute of Advanced Technology (DU)PuneIndia
  3. 3.Department of Mechanical EngineeringJawaharlal Nehru Technological UniversityHyderabadIndia

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