Advertisement

Sub-grain Plastic Strain Localization in CoCrNi Medium Entropy Alloy at Cryogenic Temperatures

  • Wael AbuzaidEmail author
  • Luca Patriarca
Conference paper
Part of the Structural Integrity book series (STIN, volume 8)

Abstract

High and medium entropy alloys are currently attracting significant research interest due to their potential to achieve superior mechanical properties compared to traditional alloys systems. The CoCrNi alloy has been of particular interest owing to the simple single phase structure, superior fracture toughness, and exceptional strength and ductility at cryogenic temperatures. Previous works have been primarily focused on identifying the operative microstructural mechanisms responsible for improved ductility. The activation of deformation twining at low deformation temperatures and high strains has been identified as a primary source for the improved ductility. However, detailed quantitative analysis focused on the deformation heterogeneities in the vicinity of grain boundaries, in particular at cryogenic temperatures, remains limited. Strain heterogeneities across grain boundaries reveal the micro-mechanisms responsible for the alloy strengthening and fracture properties, thus their measurements is of fundamental importance. The current work is dedicated to study the local strain accumulation in the vicinity of grains boundaries of plastically deforming CoCrNi. High resolution digital image correlation was used to measure and quantify the deformation heterogeneities at room temperature (298 K) and cryogenic temperature (77 K). The work aims to further elucidate the role of grain boundaries in improving the strength and ductility at cryogenic deformation temperatures.

Keywords

Medium entropy alloy Strain localization Cryogenic temperatures 

Notes

Acknowledgements

The corresponding author would like to acknowledge the financial support from the American University of Sharjah through the Office of Research (EFRG18-MSE-CEN-22).

References

  1. 1.
    Miracle, D.B., Senkov, O.N.: A critical review of high entropy alloys and related concepts. Acta Mater. 122, 448–511 (2017)CrossRefGoogle Scholar
  2. 2.
    Zhang, Z., et al.: High-entropy alloy CrMnFeCoNi. Nat. Commun. 6, 1–6 (2015)Google Scholar
  3. 3.
    Slone, C.E., Chakraborty, S., Miao, J., George, E.P., Mills, M.J., Niezgoda, S.R.: Influence of deformation induced nanoscale twinning and FCC-HCP transformation on hardening and texture development in medium-entropy CrCoNi alloy. Acta Mater. 158, 38–52 (2018)CrossRefGoogle Scholar
  4. 4.
    Gludovatz, B., George, E.P., Ritchie, R.O.: Processing, microstructure and mechanical properties of the CrMnFeCoNi high-entropy alloy. 67(10), 2262–2270 (2015)Google Scholar
  5. 5.
    Uzer, B., et al.: On the mechanical response and microstructure evolution of NiCoCr single crystalline medium entropy alloys. Mater. Res. Lett. 6(8), 442–449 (2018)CrossRefGoogle Scholar
  6. 6.
    Dan Sathiaraj, G., et al.: Effect of annealing on the microstructure and texture of cold rolled CrCoNi medium-entropy alloy. Intermetallics 101, 87–98 (2018)CrossRefGoogle Scholar
  7. 7.
    Yoshida, S., Bhattacharjee, T., Bai, Y., Tsuji, N.: Friction stress and Hall-Petch relationship in CoCrNi equi-atomic medium entropy alloy processed by severe plastic deformation and subsequent annealing. Scr. Mater. 134, 33–36 (2017)CrossRefGoogle Scholar
  8. 8.
    Moravcik, I., et al.: Mechanical and microstructural characterization of powder metallurgy CoCrNi medium entropy alloy. Mater. Sci. Eng., A 701, 370–380 (2017)CrossRefGoogle Scholar
  9. 9.
    Laplanche, G., Kostka, A., Reinhart, C., Hunfeld, J., Eggeler, G., George, E.P.: Reasons for the superior mechanical properties of medium-entropy CrCoNi compared to high-entropy CrMnFeCoNi. Acta Mater. 128, 292–303 (2017)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.American University of SharjahSharjahUAE
  2. 2.Politecnico di MilanoMilanItaly

Personalised recommendations