Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Short-range order and its impact on the CrCoNi medium-entropy alloy

Nature volume 581, pages 283–287 (2020)Cite this article

Subjects

Abstract

Traditional metallic alloys are mixtures of elements in which the atoms of minority species tend to be distributed randomly if they are below their solubility limit, or to form secondary phases if they are above it. The concept of multiple-principal-element alloys has recently expanded this view, as these materials are single-phase solid solutions of generally equiatomic mixtures of metallic elements. This group of materials has received much interest owing to their enhanced mechanical properties1,2,3,4,5. They are usually called medium-entropy alloys in ternary systems and high-entropy alloys in quaternary or quinary systems, alluding to their high degree of configurational entropy. However, the question has remained as to how random these solid solutions actually are, with the influence of short-range order being suggested in computational simulations but not seen experimentally6,7. Here we report the observation, using energy-filtered transmission electron microscopy, of structural features attributable to short-range order in the CrCoNi medium-entropy alloy. Increasing amounts of such order give rise to both higher stacking-fault energy and hardness. These findings suggest that the degree of local ordering at the nanometre scale can be tailored through thermomechanical processing, providing a new avenue for tuning the mechanical properties of medium- and high-entropy alloys.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Energy-filtered TEM diffraction patterns, dark-field images formed with diffuse superlattice streaks and the associated high-resolution TEM images.
Fig. 2: Evidence for the three-dimensional structure of the domains and their size distribution.
Fig. 3: Dislocation analysis of both water-quenched and 1,000 °C aged samples.
Fig. 4: Comparison of mechanical properties from nanoindentation and bulk tensile tests.

Similar content being viewed by others

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

References

  1. Yeh, J. W. et al. Nanostructured high-entropy alloys with multiple principal elements: novel alloy design concepts and outcomes. Adv. Eng. Mater. 6, 299–303 (2004).

    Article  CAS  Google Scholar 

  2. Cantor, B., Chang, I. T. H., Knight, P. & Vincent, A. J. B. Microstructural development in equiatomic multicomponent alloys. Mater. Sci. Eng. A 375–377, 213–218 (2004).

    Article  CAS  Google Scholar 

  3. Li, Z., Pradeep, K. G., Deng, Y., Raabe, D. & Tasan, C. C. Metastable high-entropy dual-phase alloys overcome the strength–ductility trade-off. Nature 534, 227–230 (2016).

    Article  ADS  CAS  PubMed  Google Scholar 

  4. Gludovatz, B. et al. A fracture-resistant high-entropy alloy for cryogenic applications. Science 345, 1153–1158 (2014).

    Article  ADS  CAS  PubMed  Google Scholar 

  5. Yang, T. et al. Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys. Science 362, 933–937 (2018).

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Ding, J., Yu, Q., Asta, M. & Ritchie, R. O. Tunable stacking fault energies by tailoring local chemical order in CrCoNi medium-entropy alloys. Proc. Natl Acad. Sci. USA 115, 8919–8924 (2018).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  7. Li, Q.-J., Sheng, H. & Ma, E. Strengthening in multi-principal element alloys with local-chemical-order roughened dislocation pathways. Nat. Commun. 10, 3563 (2019).

    Article  ADS  PubMed  PubMed Central  CAS  Google Scholar 

  8. Zhang, Y. et al. Microstructures and properties of high-entropy alloys. Prog. Mater. Sci. 61, 1–93 (2014).

    Article  CAS  Google Scholar 

  9. Gao, M. C., Yeh, J. W., Liaw, P. K. & Zhang, Y. High-Entropy Alloys: Fundamentals and Applications (Springer International, 2016).

  10. Senkov, O. N., Miracle, D. B., Chaput, K. J. & Couzinie, J. P. Development and exploration of refractory high entropy alloys — a review. J. Mater. Res. 33, 3092–3128 (2018).

    Article  ADS  CAS  Google Scholar 

  11. Miracle, D. B. High entropy alloys as a bold step forward in alloy development. Nat. Commun. 10, 1805 (2019).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  12. George, E. P., Raabe, D. & Ritchie, R. O. High-entropy alloys. Nat. Rev. Mater. 4, 515–534 (2019).

    Article  ADS  CAS  Google Scholar 

  13. Li, Z., Zhao, S., Ritchie, R. O. & Meyers, M. A. Mechanical properties of high-entropy alloys with emphasis on face-centered cubic alloys. Prog. Mater. Sci. 102, 296–345 (2019).

    Article  CAS  Google Scholar 

  14. Gludovatz, B. et al. Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures. Nat. Commun. 7, 10602 (2016).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  15. Zhang, Z. et al. Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy. Nat. Commun. 8, 14390 (2017).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  16. Zaddach, A. J., Niu, C., Koch, C. C. & Irving, D. L. Mechanical properties and stacking fault energies of NiFeCrCoMn high-entropy alloy. J. Miner. Met. Mater. Soc. 65, 1780–1789 (2013).

    Article  CAS  Google Scholar 

  17. Zhang, Y. H., Zhuang, Y., Hu, A., Kai, J. J. & Liu, C. T. The origin of negative stacking fault energies and nano-twin formation in face-centered cubic high entropy alloys. Scr. Mater. 130, 96–99 (2017).

    Article  ADS  CAS  Google Scholar 

  18. Zhao, S., Stocks, G. M. & Zhang, Y. Stacking fault energies of face-centered cubic concentrated solid solution alloys. Acta Mater. 134, 334–345 (2017).

    Article  CAS  Google Scholar 

  19. Niu, C., LaRosa, C. R., Miao, J., Mills, M. J. & Ghazisaeidi, M. Magnetically-driven phase transformation strengthening in high entropy alloys. Nat. Commun. 9, 1363 (2018).

    Article  ADS  PubMed  PubMed Central  CAS  Google Scholar 

  20. Laplanche, G. et al. Reasons for the superior mechanical properties of medium-entropy CrCoNi compared to high-entropy CrMnFeCoNi. Acta Mater. 128, 292–303 (2017).

    Article  CAS  Google Scholar 

  21. Okamoto, N. L. et al. Size effect, critical resolved shear stress, stacking fault energy, and solid solution strengthening in the CrMnFeCoNi high-entropy alloy. Sci. Rep. 6, 35863 (2016).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  22. Smith, T. M. et al. Atomic-scale characterization and modeling of 60° dislocations in a high-entropy alloy. Acta Mater. 110, 352–363 (2016).

    Article  CAS  Google Scholar 

  23. Zhang, F. X. et al. Local structure and short-range order in a NiCoCr solid solution alloy. Phys. Rev. Lett. 118, 205501 (2017).

    Article  ADS  CAS  PubMed  Google Scholar 

  24. Van Tendeloo, G. & Amelinckx, S. The origin of diffuse intensity in electron diffraction patterns. Phase Transit. 67, 101–135 (1998).

    Article  Google Scholar 

  25. Tamm, A., Aabloo, A., Klintenberg, M., Stocks, M. & Caro, A. Atomic-scale properties of Ni-based FCC ternary, and quaternary alloys. Acta Mater. 99, 307–312 (2015).

    Article  CAS  Google Scholar 

  26. Zhang, R. et al. Direct imaging of short-range order and its relationship to deformation in Ti-6Al. Sci. Adv. 5, eaax2799 (2019).

    Article  ADS  PubMed  PubMed Central  Google Scholar 

  27. Laplanche, G. et al. Elastic moduli and thermal expansion coefficients of medium-entropy subsystems of the CrMnFeCoNi high-entropy alloy. J. Alloys Compd. 746, 244–255 (2018).

    Article  CAS  Google Scholar 

  28. Ophus, C., Ciston, J. & Nelson, C. T. Correcting nonlinear drift distortion of scanning probe and scanning transmission electron microscopies from image pairs with orthogonal scan directions. Ultramicroscopy 162, 1–9 (2016).

    Article  CAS  PubMed  Google Scholar 

  29. Gerold, V. & Karnthaler, H. P. On the origin of planar slip in f.c.c. alloys. Acta Metall. 37, 2177–2183 (1989).

    Article  CAS  Google Scholar 

  30. Pekin, T. C., Gammer, C., Ciston, J., Ophus, C. & Minor, A. M. In situ nanobeam electron diffraction strain mapping of planar slip in stainless steel. Scr. Mater. 146, 87–90 (2018).

    Article  CAS  Google Scholar 

  31. Neeraj, T. & Mills, M. J. Short-range order (SRO) and its effect on the primary creep behavior of a Ti-6wt.%Al alloy. Mater. Sci. Eng. A 319–321, 415–419 (2001).

    Article  Google Scholar 

  32. van de Walle, A. & Asta, M. First-principles investigation of perfect and diffuse antiphase boundaries in HCP-based Ti-Al alloys. Metall. Mater. Trans. A 33, 735–741 (2002).

    Article  Google Scholar 

  33. Gouldstone, A. et al. Indentation across size scales and disciplines: recent developments in experimentation and modeling. Acta Mater. 55, 4015–4039 (2007).

    Article  CAS  Google Scholar 

  34. Fisher, J. C. C. On the strength of solid solution alloys. Acta Metall. 2, 9–10 (1954).

    Article  Google Scholar 

  35. Britton, T. B., Dunne, F. P. E. & Wilkinson, A. J. On the mechanistic basis of deformation at the microscale in hexagonal close-packed metals. Proc. R. Soc. A 471, 20140881 (2015).

    Article  ADS  Google Scholar 

  36. Hamdi, F. & Asgari, S. Influence of stacking fault energy and short-range ordering on dynamic recovery and work hardening behavior of copper alloys. Scr. Mater. 62, 693–696 (2010).

    Article  CAS  Google Scholar 

  37. Miracle, D. B. et al. Exploration and development of high entropy alloys for structural applications. Entropy 16, 494–525 (2014).

    Article  ADS  CAS  Google Scholar 

  38. Williams, J. C. & Starke, E. A. Progress in structural materials for aerospace systems. Acta Mater. 51, 5775–5799 (2003).

    Article  CAS  Google Scholar 

  39. Ma, Y. et al. Chemical short-range orders and the induced structural transition in high-entropy alloys. Scr. Mater. 144, 64–68 (2018).

    Article  CAS  Google Scholar 

  40. Singh, P., Smirnov, A. V. & Johnson, D. D. Atomic short-range order and incipient long-range order in high-entropy alloys. Phys. Rev. B 91, 224204 (2015).

    Article  ADS  CAS  Google Scholar 

  41. Lucas, M. S. et al. Absence of long-range chemical ordering in equimolar FeCoCrNi. Appl. Phys. Lett. 100, 251907 (2012).

    Article  ADS  CAS  Google Scholar 

  42. Niu, C. et al. Spin-driven ordering of Cr in the equiatomic high entropy alloy NiFeCrCo. Appl. Phys. Lett. 106, 161906 (2015).

    Article  ADS  CAS  Google Scholar 

  43. Linden, Y., Pinkas, M., Munitz, A. & Meshi, L. Long-period antiphase domains and short-range order in a B2 matrix of the AlCoCrFeNi high-entropy alloy. Scr. Mater. 139, 49–52 (2017).

    Article  CAS  Google Scholar 

  44. Fultz, B. & Howe, J. M. Transmission Electron Microscopy and Diffractometry of Materials (Springer, 2008).

  45. Phillips, P. J., Brandes, M. C., Mills, M. J. & de Graef, M. Diffraction contrast STEM of dislocations: imaging and simulations. Ultramicroscopy 111, 1483–1487 (2011).

    Article  CAS  PubMed  Google Scholar 

  46. Phillips, P. J. et al. Atomic-resolution defect contrast in low angle annular dark-field STEM. Ultramicroscopy 116, 47–55 (2012).

    Article  CAS  Google Scholar 

  47. Cockayne, D. J. H. The weak-beam technique as applied to dissociation measurements. J. Phys. Colloq. 35, C7-141–C7-148 (1974).

    Article  Google Scholar 

  48. Cockayne, D. J. H., Ray, I. L. F. & Whelan, M. J. Investigations of dislocation strain fields using weak beams. Phil. Mag. 20, 1265–1270 (1969).

    Article  ADS  CAS  Google Scholar 

  49. Anderson, P. M., Hirth, J. P. & Lothe, J. Theory of Dislocations (Cambridge Univ. Press, 2017).

  50. Pierce, D. T. et al. The influence of manganese content on the stacking fault and austenite/ε-martensite interfacial energies in Fe–Mn–(Al–Si) steels investigated by experiment and theory. Acta Mater. 68, 238–253 (2014).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was primarily supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under contract no. DE-AC02-05-CH11231 within the Damage-Tolerance in Structural Materials (KC 13) programme. R.Z., S.Z. and Y.C. acknowledge support from the US Office of Naval Research under grant nos. N00014-12-1-0413, N00014-17-1-2283 and N00014-11-1–0886, respectively. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231. X-ray diffraction measurements were made at the Stanford Nano Shared Facilities (SNSF), supported by the National Science Foundation under award ECCS-1542152. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a US Department of Energy Office of Science User Facility operated under contract no. DE-AC02-05CH11231. We thank E. Ma at Johns Hopkins University for providing a 600 °C aged alloy.

Author information

Author notes

  1. These authors contributed equally: Ruopeng Zhang, Shiteng Zhao

Authors and Affiliations

  1. Department of Materials Science and Engineering, University of California, Berkeley, CA, USA

    Ruopeng Zhang, Shiteng Zhao, Yan Chong, Mark Asta, Robert O. Ritchie & Andrew M. Minor

  2. National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

    Ruopeng Zhang, Shiteng Zhao, Yan Chong, Colin Ophus & Andrew M. Minor

  3. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

    Jun Ding, Mark Asta & Robert O. Ritchie

  4. Department of Physics, Stanford University, Stanford, CA, USA

    Tao Jia

Authors
  1. Ruopeng Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Shiteng Zhao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jun Ding
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yan Chong
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Tao Jia
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Colin Ophus
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Mark Asta
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Robert O. Ritchie
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Andrew M. Minor
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

R.Z., S.Z., M.A., R.O.R. and A.M.M. conceived the project.; R.Z. and S.Z. conducted the energy-filtered TEM imaging and dislocation analysis; C.O. and R.Z. developed and optimized the domain recognition algorithm; R.Z. and S.Z. conducted the nanoindentation tests; R.Z., S.Z and Y.C. conducted the tensile tests. J.D. conducted the DFT simulations. T.J. conducted the XRD experiments. R.Z., S.Z., R.O.R., M.A. and A.M.M. prepared the manuscript, which was reviewed and edited by all authors. Project administration, supervision and funding acquisition was performed by R.O.R., M.A. and A.M.M.

Corresponding author

Correspondence to Andrew M. Minor.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature thanks Elena Pereloma, Christopher Woodward and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Energy-filtered TEM diffraction patterns and dark-field images formed with diffuse superlattice streaks.

a–c, Energy-filtered diffraction patterns taken from CrCoNi MEA samples that were water-quenched, aged at 600 °C for one week or aged at 1,000 °C for one week, respectively. The contrast is pseudo-coloured for better visibility. The line plots of intensity show the periodic intensity of the diffuse superlattice streaks. d–f, Energy-filtered dark-field images taken from water-quenched, 600 °C aged and 1,000 °C aged samples, respectively. The aperture positions are marked by the g vectors (labelled arrows). The images of the water-quenched and the 1,000 °C aged samples are the same as in Fig. 1 but are presented again here for comparison with the 600 °C aged sample.

Extended Data Fig. 2 Geometrical phase analysis strain mapping of a 1,000 °C aged sample and a water-quenched sample.

a–d, 1,000 °C aged alloy; e–h, water-quenched sample. a, e, Drift-corrected HRSTEM images of the 1,000 °C aged sample and the water-quenched sample, respectively. The fast Fourier transformed images are shown inset. b–d, Strain maps of a showing nanometre-sized local fluctuations of strain (εxx, normal strain in the x direction; εyy, normal strain in the y direction). f–h, Strain maps of e showing similar but much weaker contrast of local strain.

Extended Data Fig. 3 Results of X-ray diffraction experiments on a water-quenched sample and a 1,000 °C aged sample of the CrCoNi MEA.

The indexed (111) and (200) peaks are marked. The lattice constants a are calculated on the basis of the 2θ angles of the identified peaks..

Extended Data Fig. 4 Diffuse anti-phase boundary (DAPB) energy as a function of successive dislocation slip events from a calculated SRO model.

The data in the inset table represent different states of SRO and the plot is from the state marked blue.

Extended Data Fig. 5 Detailed ‘g·b’ analysis of partial dislocations in the CrCoNi MEA.

a–e, Water-quenched sample; f–j, sample aged at 1,000 °C. a, f, Diffraction references showing the diffraction conditions (g vectors) used for the analysis. b, g, Lower-magnification DC-STEM images of dislocations in the water-quenched and aged samples, respectively. c–e, h–j, Two-beam DC-STEM images of the boxed areas in b and g, respectively; the Burgers vectors of the visible dislocations are noted on the images.

Extended Data Fig. 6 Detailed statistical analysis of the pop-in events.

Pop-in events were observed during nanoindentation tests (see Methods section ‘Nanoindentation experiments’ for details). a, b, Distribution of the pop-in load from water-quenched and 1,000 °C aged samples, respectively. c, d, Distribution of the pop-in depth from water-quenched and 1,000 °C aged samples, respectively. The fitted normal distribution functions are listed in the panels. The results of numerical analysis are summarized in Extended Data Table 1.

Extended Data Fig. 7 Element mapping of the water-quenched and aged CrCoNi samples using EDS.

a–e, Water quenched sample; f–j, sample aged at 1,000 °C. a, f, Reference HAADF (high-angle annular dark field) images showing the regions of interest of a water-quenched sample and a 1,000 °C aged sample, respectively. b–d, g–i, Element mapping of Co, Ni and Cr of the water-quenched sample and the 1,000 °C aged sample, respectively. e, j, Quantitative results of line scans of the water-quenched sample and the 1,000 °C aged sample, respectively. The line scan directions are marked by the dashed lines in a and f.

Extended Data Table 1 Statistical results of SFE measurements and nanoindentation tests
Full size table
Extended Data Table 2 Detailed steps of the Gaussian template fitting process
Full size table

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhang, R., Zhao, S., Ding, J. et al. Short-range order and its impact on the CrCoNi medium-entropy alloy. Nature 581, 283–287 (2020). https://doi.org/10.1038/s41586-020-2275-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41586-020-2275-z

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing