Metallurgical and Materials Transactions A

, Volume 39, Issue 10, pp 2340–2350 | Cite as

Tensile Properties of Ni-Based Superalloy 720Li: Temperature and Strain Rate Effects

  • K. GopinathEmail author
  • A.K. Gogia
  • S.V. Kamat
  • R. Balamuralikrishnan
  • U. Ramamurty


Tensile properties, deformation, and fracture behavior of a wrought nickel-base superalloy 720Li have been studied in standard solutionized and two-stage-aged condition in the temperature range of 25 °C to 750 °C. Effect of strain rate on tensile behavior was assessed at 25 °C, 400 °C, and 750 °C at five strain rates that range between 10−5 s−1 and 10−1 s−1. The yield strength and ultimate tensile strength of the alloy remained unaffected by temperature until about 600 °C and 500 °C, respectively, typical of superalloys strengthened by fine and coherent intermetallic Ni3Al-based precipitates. The flow stress of the alloy was found to be insensitive to the strain rates studied at 25 °C and 400 °C. However, at 750 °C, the flow stresses showed strain rate sensitivity at strain rates <10−3 s−1. The strain hardening behavior at 25 °C and 400 °C were similar. At 750 °C, stain hardening was observed only at strain rates >10−3 s−1, and at lower strain rates, tensile instability was seen to set in immediately after yielding. The alloy exhibited ductile dimple fracture at all the temperatures and strain rates studied. Microstructural investigations indicate that in regimes where flow stresses are insensitive to strain rate, deformation occurs through heterogeneous planar slip, whereas in strain rate sensitive regimes, thermally activated diffusion processes promote homogeneous deformation.


Strain Hardening Flow Stress Ultimate Tensile Strength High Strain Rate Stack Fault Energy 
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.



The authors thank the Defence Research and Development Organisation for permitting and supporting this research. The alloy for the study was provided by the Gas Turbine Research Establishment, Bangalore. Specimens were prepared and tested at Aeronautical Materials Testing Laboratory, Hyderabad, and all metallurgical characterization was carried out at the Defence Metallurgical Research Laboratory, Hyderabad. The authors gratefully acknowledge the cooperation, support, and encouragement received from these organizations.


  1. 1.
    S.J. Hessel, W. Voice, A.W. James, S.A. Blackham, C.J. Small, and M.R. Winstone: USP No. 6132527, 2000Google Scholar
  2. 2.
    R.J. Smith, G.J. Lewis, D.H. Yates: Aircraft Engineering and Aerospace Technol., 2001, vol. 73, pp. 138–46CrossRefGoogle Scholar
  3. 3.
    K. Steffens and H. Wilhelm: engineering_news/ 11773.pdf
  4. 4.
    D. Helm and O. Roder: Superalloys, 2000, T.M. Pollock, R.D. Kissinger, R.R. Bowman, K.A. Green, M. McLean, S.L. Olson, and J.J. Schirra, eds., TMS, Warrendale, PA, 2000, pp. 487–93Google Scholar
  5. 5.
    D.J. Bryant and G. McIntosh: Superalloys, 1996, R.D. Kissinger, D.J. Deye, D.L. Anton, A.D. Cetel, M.V. Nathal, T.M. Pollock, and D.A. Woodford, eds., TMS, Warrendale, PA, 1996, pp. 713–22Google Scholar
  6. 6.
    M. Marchionni, G.A. Osinkolu, G. Onofrio: Int. J. Fatigue, 2002, vol. 24, pp. 1261–67CrossRefGoogle Scholar
  7. 7.
    J. Albrecht: Mater. Sci. Eng., 1999, vol. A263, pp. 176–86Google Scholar
  8. 8.
    W.J. Evans, J.P. Jones, S. Williams: Int. J. Fatigue, 2005, vol. 27, pp. 1473–84CrossRefGoogle Scholar
  9. 9.
    G. Onofrio, G.A. Osinkolu, M. Marchionni: Int. J. Fatigue, 2001, vol. 23, pp. 887–95CrossRefGoogle Scholar
  10. 10.
    ASTM E 8M-04: Standard Test Methods for Tension Testing of Metallic Materials [Metric], Annual Book of ASTM Standards, Sec. 3, vol. 03.01, ASTM International, West Conshohocken, PA, 2005, pp. 86–109Google Scholar
  11. 11.
    ASTM E 21-03a: Standard Test Methods for Elevate Temperature Tension Tests of Metallic Materials, Annual Book of ASTM Standards, Sec. 3, vol. 03.01, ASTM International, West Conshohocken, PA, 2005, pp. 150–57Google Scholar
  12. 12.
    M.P. Jackson, R.C. Reed: Mater. Sci. Eng., 1999, vol. A259, pp. 85–97Google Scholar
  13. 13.
    J.M. Robinson, M.P. Shaw: Int. Mater. Rev., 1994, vol. 39 (3), pp. 113–22Google Scholar
  14. 14.
    G.E. Dieter: Mechanical Metallurgy, SI Metric Edition, McGraw-Hill Book Co., London, 1988, pp. 283–89Google Scholar
  15. 15.
    A. Ghosh: in ASM Handbook, vol. 14A, Metal Working: Bulk Forming, S.L. Semiatin, ed., ASM, Metals Park, OH, pp. 563–86Google Scholar
  16. 16.
    A. Kelly, R.B. Nicholson: Progr. Mater. Sci., 1963, vol. 10, pp. 151–391CrossRefGoogle Scholar
  17. 17.
    K. Luke, H. Mecking: The Inhomogenity of Plastic Deformation, ASM, Metals Park, OH, 1973, pp. 223–49Google Scholar
  18. 18.
    R.E. Reedhill and R. Abbaschian: Physical Metallurgy Principles, 3rd ed., Brooks/Cole Publication, 1994, pp. 181–83Google Scholar
  19. 19.
    D.C. Ludwigson: Metall. Trans., 1971, vol. 2, pp. 2825–28CrossRefGoogle Scholar
  20. 20.
    M. Benyoucef, B. Décamps, A. Coujou, N. Clément: Phil. Mag. A, 1995, vol. 71, pp. 907–23CrossRefGoogle Scholar
  21. 21.
    W.R. Johnson, C.R. Barrett, W.D. Nix: Metall. Trans., 1972, vol. 3, pp. 963–69CrossRefGoogle Scholar
  22. 22.
    F.E. Sczerzenie, S.O. Mancuso, P.W. Keefe, G.E. Maurer, and W.J. Boesch: Udimet Alloy 720, TR-88-002, Special Metals Corporation, New Hartford, NY, 1988Google Scholar
  23. 23.
    T.A. Parthasarathy, S.I. Rao, and D.M. Dimiduk: Superalloys, 2004, K.A. Green, T.M. Pollock, H. Hirada, T.E. Howson, R.C. Reed, J.J. Schirra, and S. Walston, eds., TMS, Warrendale, PA, 2004, pp. 887–96Google Scholar
  24. 24.
    P. Beardmore, R.G. Davies, T.L. Johnston: Trans. TMS-AIME, 1969, vol. 245, pp. 1537–45Google Scholar
  25. 25.
    D.L. Anton: in Intermetallic Compounds, vol. 2, Practice, J.H. Westbrook and R.L. Fleischer, eds., John Wiley & Sons Ltd., New York, NY, 1994, pp. 3–15Google Scholar
  26. 26.
    S.M. Copley, B.H. Kear: Trans. TMS-AIME, 1967, vol. 239, pp. 977–84Google Scholar
  27. 27.
    C.T. Liu and D.P. Pope: in Intermetallic Compounds, vol. 2, Practice, J.H. Westbrook and R.L. Fleischer, eds., John Wiley & Sons Ltd., New York, NY, 1994, pp. 17–51Google Scholar
  28. 28.
    P.H. Thornton, R.G. Davies, T.L. Johnston: Metall. Trans., 1970, vol. 1, pp. 207–18Google Scholar
  29. 29.
    S.M. Copley, B.H. Kear: Trans. TMS-AIME, 1967, vol. 239, pp. 984–92Google Scholar
  30. 30.
    G.R. Leverant, B.H. Kear: Metall. Trans., 1970, vol. 1, pp. 491–98Google Scholar
  31. 31.
    D. Mukherji, F. Jiao, W. Chen, R.P. Wahi: Acta Metall. Mater., 1991, vol. 39, pp. 1515–24CrossRefGoogle Scholar
  32. 32.
    M.N. Menon, W.H. Reimann: Metall. Trans. A, 1975, vol. 6A, pp. 1075–85Google Scholar
  33. 33.
    S. Sinharoy, P. Virro-Nic, W.W. Milligan: Metall. Mater. Trans. A, 2001, vol. 32A, pp. 2021–32CrossRefGoogle Scholar
  34. 34.
    G.R. Leverant, M. Gell, S.W. Hopkins: Mater. Sci. Eng., 1971, vol. 8, pp. 125–33CrossRefGoogle Scholar
  35. 35.
    G.R. Leverant, B.H. Kear: Metall. Trans., 1970, vol. 1, pp. 491–98Google Scholar
  36. 36.
    B.H. Kear, G.R. Leverant, J.M. Oblak: Trans. ASM, 1969, vol. 62, pp. 639–50Google Scholar
  37. 37.
    G.B. Viswanathan, P.M. Sarosi, D.H. Whitis, M.J. Mills: Mater. Sci. Eng. A, 2005, vols. 400–401, pp. 489–95Google Scholar
  38. 38.
    W.W. Milligan, S.D. Antolovich: Metall. Trans. A, 1991, vol. 22A, pp. 2309–17Google Scholar
  39. 39.
    S.S. Ezz, P.B. Hirsch: Phil. Mag. A, 1994, vol. 69, pp. 105–27CrossRefGoogle Scholar
  40. 40.
    E. Nembach, K. Suzuki, M. Ichhara, S. Takeuchi: Phil. Mag. A, 1985, vol. 51, pp. 607–18CrossRefGoogle Scholar
  41. 41.
    J.W. Martin: Micromechanisms in Particle Hardened Alloys, Cambridge University Press, New York, NY, 1980, pp. 99–114Google Scholar
  42. 42.
    M. Goto, D.M. Knowles: Eng. Fr. Mech., 1998, vol. 60, pp. 1–18CrossRefGoogle Scholar
  43. 43.
    H.C. Rogers: Ductility, ASM, Metals Park, OH, 1968, pp. 31–61Google Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2008

Authors and Affiliations

  • K. Gopinath
    • 1
    Email author
  • A.K. Gogia
    • 1
  • S.V. Kamat
    • 2
  • R. Balamuralikrishnan
    • 2
  • U. Ramamurty
    • 3
  1. 1.Project Office (Materials), DRDOHyderabadIndia
  2. 2.Defence Metallurgical Research Laboratory, DRDOHyderabadIndia
  3. 3.Department of Materials EngineeringIndian Institute of ScienceBangaloreIndia

Personalised recommendations