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.

  • Review Article
  • Published:

High-entropy alloys

Abstract

Alloying has long been used to confer desirable properties to materials. Typically, it involves the addition of relatively small amounts of secondary elements to a primary element. For the past decade and a half, however, a new alloying strategy that involves the combination of multiple principal elements in high concentrations to create new materials called high-entropy alloys has been in vogue. The multi-dimensional compositional space that can be tackled with this approach is practically limitless, and only tiny regions have been investigated so far. Nevertheless, a few high-entropy alloys have already been shown to possess exceptional properties, exceeding those of conventional alloys, and other outstanding high-entropy alloys are likely to be discovered in the future. Here, we review recent progress in understanding the salient features of high-entropy alloys. Model alloys whose behaviour has been carefully investigated are highlighted and their fundamental properties and underlying elementary mechanisms discussed. We also address the vast compositional space that remains to be explored and outline fruitful ways to identify regions within this space where high-entropy alloys with potentially interesting properties may be lurking.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Fig. 1: Possible mixing reactions for three alloying elements.
Fig. 2: Damage-tolerant properties of the Cantor CrMnFeCoNi alloy.
Fig. 3: Tuning the stacking-fault energy and the phases in a set of non-equimolar derivatives of the Cantor alloy.
Fig. 4: A mechanistic approach to the design of high-entropy alloys.
Fig. 5: Mechanical properties of the dual-phase, high-entropy, transformation-induced plasticity alloy Fe50Mn30Co10Cr10.
Fig. 6: Role of local chemical ordering on the stacking-fault energy calculated by density functional theory for solid-solution CrCoNi alloys.

Similar content being viewed by others

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).

    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, 213–218 (2004).

    Google Scholar 

  3. Cantor, B. Multicomponent and high entropy alloys. Entropy 16, 4749–4768 (2014).

    Google Scholar 

  4. Miracle, D. B. & Senkov, O. N. A critical review of high entropy alloys and related concepts. Acta Mater. 122, 448–511 (2017).

    CAS  Google Scholar 

  5. Huang, P. K., Yeh, J. W., Shun, T. T. & Chen, S. K. Multi-principal-element alloys with improved oxidation and wear resistance for thermal spray coating. Adv. Eng. Mater. 6, 74–78 (2004).

    CAS  Google Scholar 

  6. Tong, C. J. et al. Microstructure characterization of AlxCoCrCuFeNi high-entropy alloy system with multi-principal elements. Metall. Mater. Trans. A Phys. Metall. Mater. Sci. 36, 881–893 (2005).

    Google Scholar 

  7. Zhou, Y. J., Zhang, Y., Wang, Y. L. & Chen, G. L. Solid solution alloys of AlCoCrFeNiTix with excellent room-temperature mechanical properties. Appl. Phys. Lett. 90, 181904 (2007).

    Google Scholar 

  8. Wang, F. J. & Zhang, Y. Effect of Co addition on crystal structure and mechanical properties of Ti0.5CrFeNiAlCo high entropy alloy. Mater. Sci. Eng. A 496, 214–216 (2008).

    Google Scholar 

  9. Shun, T. T., Hung, C. H. & Lee, C. F. Formation of ordered/disordered nanoparticles in FCC high entropy alloys. J. Alloys. Compd. 493, 105–109 (2010).

    CAS  Google Scholar 

  10. Singh, S., Wanderka, N., Murty, B. S., Glatzel, U. & Banhart, J. Decomposition in multi-component AlCoCrCuFeNi high-entropy alloy. Acta Mater. 59, 182–190 (2011).

    CAS  Google Scholar 

  11. Yardley, V. & Povstugar, V. et al. On local phase equilibria and appearance of nanoparticles in the microstructure of single-crystal Ni-base superalloys. Adv. Eng. Mater. 18, 1556–1567 (2016).

    CAS  Google Scholar 

  12. Zhang, C., Zhang, F., Chen, S. & Cao, W. Computational thermodynamics aided high-entropy alloy design. JOM 64, 839–845 (2012).

    CAS  Google Scholar 

  13. Zhang, F. et al. An understanding of high entropy alloys from phase diagram calculations. CALPHAD 45, 1–10 (2014).

    Google Scholar 

  14. Gao, M. C. et al. Thermodynamics of concentrated solid solution alloys. Curr. Opin. Sol. State Mater. Sci. 21, 238–251 (2017).

    CAS  Google Scholar 

  15. Mao, H. H., Chen, H. L. & Chen, Q. TCHEA1: a thermodynamic database not limited for “high entropy” alloys. J. Phase Equilibria Diffus. 38, 353–368 (2017).

    CAS  Google Scholar 

  16. Gorsse, S. & Tancret, F. Current and emerging practices of CALPHAD toward the development of high entropy alloys and complex concentrated alloys. J. Mater. Res. 33, 2899–2923 (2018).

    CAS  Google Scholar 

  17. Gorsse, S. & Senkov, O. N. About the reliability of CALPHAD predictions in multicomponent systems. Entropy 20, 899 (2018).

    CAS  Google Scholar 

  18. Abu-Odeh, A. et al. Efficient exploration of the high entropy alloy composition-phase space. Acta Mater. 152, 41–57 (2018).

    CAS  Google Scholar 

  19. Chen, H. L., Mao, H. H. & Chen, Q. Database development and CALPHAD calculations for high entropy alloys: challenges, strategies, and tips. Mater. Chem. Phys. 210, 279–290 (2018).

    CAS  Google Scholar 

  20. Borkar, T. et al. A combinatorial assessment of AlxCrCuFeNi2 (0 < x < 1.5) complex concentrated alloys: microstructure, microhardness, and magnetic properties. Acta Mater. 116, 63–76 (2016).

    CAS  Google Scholar 

  21. Borkar, T. & Chaudhary, V. et al. A combinatorial approach for assessing the magnetic properties of high entropy alloys: role of Cr in AlCoxCr1-xFeNi. Adv. Eng. Mater. 19, 1700048 (2017).

    Google Scholar 

  22. Kauffmann, A. et al. Combinatorial exploration of the high entropy alloy system Co-Cr-Fe-Mn-Ni. Surf. Coat. Technol. 325, 174–180 (2017).

    CAS  Google Scholar 

  23. Li, Y. J., Kostka, A., Savan, A., Stein, H. S. & Ludwig, A. Accelerated atomic-scale exploration of phase evolution in compositionally complex materials. Mater. Horizons. 5, 86–92 (2018).

    CAS  Google Scholar 

  24. Li, Y. J., Kostka, A., Savan, A. & Ludwig, A. Atomic-scale investigation of fast oxidation kinetics of nanocrystalline CrMnFeCoNi alloy thin films. J. Alloys. Compd. 766, 1080–1085 (2018).

    CAS  Google Scholar 

  25. Otto, F. et al. The influences of temperature and microstructure on the tensile properties of a CoCrFeMnNi high-entropy alloy. Acta Mater. 61, 5743–5755 (2013).

    CAS  Google Scholar 

  26. Deng, Y. et al. Design of a twinning-induced plasticity high entropy alloy. Acta Mater. 94, 124–133 (2015).

    CAS  Google Scholar 

  27. Li, Z. & Raabe, D. Strong and ductile non-equiatomic high-entropy alloys: design, processing, microstructure, and mechanical properties. JOM 69, 2099–2106 (2017).

    CAS  Google Scholar 

  28. Jo, Y. H. et al. Cryogenic strength improvement by utilizing room-temperature deformation twinning in a partially recrystallized VCrMnFeCoNi high-entropy alloy. Nat. Commun. 8, 15719 (2017).

    CAS  Google Scholar 

  29. 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).

    CAS  Google Scholar 

  30. Li, Z., Körmann, F., Grabowski, B., Neugebauer, J. & Raabe, D. Ab initio assisted design of quinary dual-phase high-entropy alloys with transformation-induced plasticity. Acta Mater. 136, 262–270 (2017).

    CAS  Google Scholar 

  31. Huang, H. L. et al. Phase-transformation ductilization of brittle high-entropy alloys via metastability engineering. Adv. Mater. 29, 1701678 (2017).

    Google Scholar 

  32. Otto, F., Yang, Y., Bei, H. & George, E. P. Relative effects of enthalpy and entropy on the phase stability of equiatomic high-entropy alloys. Acta Mater. 61, 2628–2638 (2013).

    CAS  Google Scholar 

  33. Poletti, M. G. & Battezzati, L. Electronic and thermodynamic criteria for the occurrence of high-entropy alloys in metallics systems. Acta Mater. 75, 297–306 (2014).

    CAS  Google Scholar 

  34. Ma, D., Grabowski, B., Körmann, F., Neugebauer, J. & Raabe, D. Ab initio thermodynamics of the CoCrFeMnNi high entropy alloy: importance of entropy contributions beyond the configurational one. Acta Mater. 100, 90–97 (2015).

    CAS  Google Scholar 

  35. Schön, C. G., Duong, T., Wang, Y. & Arróyave, R. Probing the entropy hypothesis in highly concentrated alloys. Acta Mater. 148, 263–279 (2018).

    Google Scholar 

  36. Schuh, B. et al. Mechanical properties, microstructure and thermal stability of a nanocrystalline CoCrFeMnNi high-entropy alloy after severe plastic deformation. Acta Mater. 96, 258–268 (2015).

    CAS  Google Scholar 

  37. Pickering, E. J., Munoz-Moreno, R., Stone, H. J. & Jones, N. G. Precipitation in the equiatomic high-entropy alloy CrMnFeCoNi. Scr. Mater. 113, 106–109 (2016).

    CAS  Google Scholar 

  38. Otto, F. et al. Decomposition of the single-phase high-entropy alloy CrMnFeCoNi after prolonged anneals at intermediate temperatures. Acta Mater. 112, 40–52 (2016).

    CAS  Google Scholar 

  39. Schuh, B. et al. Thermodynamic instability of a nanocrystalline, single-phase TiZrNbHfTa alloy and its impact on the mechanical properties. Acta Mater. 142, 201–212 (2018).

    CAS  Google Scholar 

  40. Stepanov, N. D., Yurchenko, N. Yu., Zherebtsov, S. V., Tikhonovsky, M. A. & Salishchev, G. A. Aging behavior of the HfNbTaTiZr high entropy alloy. Mater. Lett. 211, 87–90 (2018).

    CAS  Google Scholar 

  41. Ma, D. et al. Phase stability of non-equiatomic CoCrFeMnNi high entropy alloys. Acta Mater. 98, 288–296 (2015).

    CAS  Google Scholar 

  42. Tian, F. et al. Structural stability of NiCoFeCrAl high-entropy alloy from ab initio theory. Phys. Rev. B 88, 085128 (2013).

    Google Scholar 

  43. van de Walle, A. & Asta, M. Self-driven lattice-model Monte Carlo simulations of alloy thermodynamic properties and phase diagrams. Model. Simul. Mat. Sci. Eng. 10, 521–538 (2002).

    Google Scholar 

  44. Senkov, O. N., Miller, J. D., Miracle, D. B. & Woodward, C. Accelerated exploration of multi-principal element alloys for structural applications. CALPHAD 50, 32–48 (2015).

    CAS  Google Scholar 

  45. Senkov, O. N. et al. CALPHAD-aided development of quaternary multi-principal element refractory alloys based on NbTiZr. J. Alloys. Compd. 783, 729–742 (2019).

    CAS  Google Scholar 

  46. Yeh, J. W. Alloy design strategies and future trends in high-entropy alloys. JOM 65, 1759–1771 (2013).

    CAS  Google Scholar 

  47. Tsai, M. H. & Yeh, J. W. High-entropy alloys: a critical review. Mater. Res. Lett. 2, 107–123 (2014).

    Google Scholar 

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

    Google Scholar 

  49. Troparevsky, M. C., Morris, J. R., Kent, P. R. C., Lupini, A. R. & Stocks, G. M. Criteria for predicting the formation of single-phase high-entropy alloys. Phys. Rev. X 5, 011041 (2015).

    Google Scholar 

  50. Troparevsky, M. C. et al. Beyond atomic sizes and Hume-Rothery rules: understanding and predicting high-entropy alloys. JOM 67, 2350–2363 (2015).

    CAS  Google Scholar 

  51. King, D. J. M., Middleburgh, S. C., McGregor, A. G. & Cortie, M. B. Predicting the formation and stability of single phase high-entropy alloys. Acta Mater. 104, 172–179 (2016).

    CAS  Google Scholar 

  52. Pickering, E. J. & Jones, N. G. High-entropy alloys: a critical assessment of their founding principles and future prospects. Int. Mater. Rev. 61, 183–202 (2016).

    CAS  Google Scholar 

  53. Gali, A. & George, E. P. Tensile properties of high- and medium-entropy alloys. Intermetallics 39, 74–78 (2013).

    CAS  Google Scholar 

  54. Tsai, K. Y., Tsai, M. H. & Yeh, J. W. Sluggish diffusion in Co–Cr–Fe–Mn–Ni high-entropy alloys. Acta Mater. 61, 4887–4897 (2013).

    CAS  Google Scholar 

  55. Liu, W. H., Wu, Y., He, J. Y., Nieh, T. G. & Lu, Z. P. Grain growth and the Hall-Petch relationship in a high-entropy FeCrNiCoMn alloy. Scr. Mater. 68, 526–529 (2013).

    CAS  Google Scholar 

  56. He, J. Y. et al. Steady state flow of the FeCoNiCrMn high entropy alloy at elevated temperatures. Intermetallics 55, 9–14 (2014).

    CAS  Google Scholar 

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

    CAS  Google Scholar 

  58. Otto, F., Hanold, N. L. & George, E. P. Microstructural evolution after thermomechanical processing in an equiatomic single-phase CoCrFeMnNi high-entropy alloy with special focus on twin boundaries. Intermetallics 54, 39–48 (2014).

    CAS  Google Scholar 

  59. Wu, Z., Bei, H., Pharr, G. M. & George, E. P. Temperature dependence of the mechanical properties of equiatomic solid solution alloys with face-centered cubic crystal structures. Acta Mater. 81, 428–441 (2014).

    CAS  Google Scholar 

  60. Haglund, A., Koehler, M., Catoor, D., George, E. P. & Keppens, V. Polycrystalline elastic moduli of a high-entropy alloy at cryogenic temperatures. Intermetallics 58, 62–64 (2015).

    CAS  Google Scholar 

  61. Laplanche, G. et al. Temperature dependencies of the elastic moduli and thermal expansion coefficient of an equiatomic, single-phase CoCrFeMnNi high-entropy alloy. J. Alloys. Compd. 623, 348–353 (2015).

    CAS  Google Scholar 

  62. Laurent-Brocq, M. et al. Insights into the phase diagram of the CrMnFeCoNi high entropy alloy. Acta Mater. 88, 355–365 (2015).

    CAS  Google Scholar 

  63. Laplanche, G., Horst, O., Otto, F., Eggeler, G. & George, E. P. Microstructural evolution of a CoCrFeMnNi high-entropy alloy after swaging and annealing. J. Alloys. Compd. 647, 548–557 (2015).

    CAS  Google Scholar 

  64. Laplanche, G., Kostka, A., Horst, O. M., Eggeler, G. & George, E. P. Microstructure evolution and critical stress for twinning in the CrMnFeCoNi high-entropy alloy. Acta Mater. 118, 152–163 (2016).

    CAS  Google Scholar 

  65. Bracq, G. et al. The fcc solid solution stability in the Co-Cr-Fe-Mn-Ni multi-component system. Acta Mater. 128, 327–336 (2017).

    CAS  Google Scholar 

  66. Laplanche, G., Bonneville, J., Varvenne, C., Curtin, W. A. & George, E. P. Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy. Acta Mater. 143, 257–264 (2018).

    CAS  Google Scholar 

  67. Laplanche, G. et al. Phase stability and kinetics of σ-phase precipitation in CrMnFeCoNi high-entropy alloys. Acta Mater. 161, 338–351 (2018).

    CAS  Google Scholar 

  68. Haas, S. et al. Entropy determination of single-phase high entropy alloys with different crystal structures over a wide temperature range. Entropy 20, 654 (2018).

    Google Scholar 

  69. Senkov, O. N., Wilks, G. B., Miracle, D. B., Chuang, C. P. & Liaw, P. K. Refractory high-entropy alloys. Intermetallics 18, 1758–1765 (2010).

    CAS  Google Scholar 

  70. Senkov, O. N. & Woodward, C. F. Microstructure and properties of a refractory NbCrMo0.5Ta0.5TiZr alloy. Mater. Sci. Eng. A 529, 311–320 (2011).

    CAS  Google Scholar 

  71. Senkov, O. N., Wilks, G. B., Scott, J. M. & Miracle, D. B. Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys. Intermetallics 19, 698–706 (2011).

    CAS  Google Scholar 

  72. Senkov, O. N., Scott, J. M., Senkova, S. V., Miracle, D. B. & Woodward, C. F. Microstructure and room temperature properties of a high-entropy TaNbHfZrTi alloy. J. Alloys. Compd. 509, 6043–6048 (2011).

    CAS  Google Scholar 

  73. Senkov, O. N. et al. Microstructure and elevated temperature properties of a refractory TaNbHfZrTi alloy. J. Mater. Sci. 47, 4062–4074 (2012).

    CAS  Google Scholar 

  74. Senkov, O. N., Senkova, S. V. & Woodward, C. Effect of aluminum on the microstructure and properties of two refractory high-entropy alloys. Acta Mater. 68, 214–228 (2014).

    CAS  Google Scholar 

  75. Senkov, O. N. & Semiatin, S. L. Microstructure and properties of a refractory high-entropy alloy after cold working. J. Alloys. Compd. 649, 1110–1123 (2015).

    CAS  Google Scholar 

  76. Juan, C. C. et al. Enhanced mechanical properties of HfMoTaTiZr and HfMoNbTaTiZr refractory high-entropy alloys. Intermetallics 62, 76–83 (2015).

    CAS  Google Scholar 

  77. Couzinié, J. P. et al. On the room temperature deformation mechanisms of a TiZrHfNbTa refractory high-entropy alloy. Mater. Sci. Eng. A 645, 255–263 (2015).

    Google Scholar 

  78. Sheikh, S. et al. Alloy design for intrinsically ductile refractory high-entropy alloys. J. Appl. Phys. 120, 164902 (2016).

    Google Scholar 

  79. Takeuchi, A., Amiya, K., Wada, T., Yubuta, K. & Zhang, W. High-entropy alloys with a hexagonal close-packed structure designed by equi-atomic alloy strategy and binary phase diagrams. JOM 66, 1984–1992 (2014).

    CAS  Google Scholar 

  80. Feuerbacher, M., Heidelmann, M. & Thomas, C. Hexagonal high-entropy alloys. Mater. Res. Lett. 3, 1–6 (2015).

    Google Scholar 

  81. Zhao, Y. J. et al. A hexagonal close-packed high-entropy alloy: the effect of entropy. Mater. Des. 96, 10–15 (2016).

    CAS  Google Scholar 

  82. Soler, R. et al. Microstructural and mechanical characterization of an equiatomic YGdTbDyHo high entropy alloy with hexagonal close-packed structure. Acta Mater. 156, 86–96 (2018).

    CAS  Google Scholar 

  83. Qiao, J. W. et al. Rare-earth high entropy alloys with hexagonal close-packed structure. J. Appl. Phys. 124, 195101 (2018).

    Google Scholar 

  84. Lilensten, L. et al. New structure in refractory high-entropy alloys. Mater. Lett. 132, 123–125 (2014).

    CAS  Google Scholar 

  85. Bhattacharjee, P. P. et al. Microstructure and texture evolution during annealing of equiatomic CoCrFeMnNi high-entropy alloy. J. Alloys. Compd. 587, 544–552 (2014).

    CAS  Google Scholar 

  86. Salishchev, G. A. et al. Effect of Mn and V on structure and mechanical properties of high-entropy alloys based on CoCrFeNi system. J. Alloys. Compd. 591, 11–21 (2014).

    CAS  Google Scholar 

  87. Stepanov, N. D. et al. High temperature deformation behavior and dynamic recrystallization in CoCrFeMnNi high entropy alloy. Mater. Sci. Eng. A 636, 188–195 (2015).

    CAS  Google Scholar 

  88. 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, 8819–8924 (2018).

    Google Scholar 

  89. Tracy, C. L. et al. High pressure synthesis of a hexagonal close-packed phase of the high-entropy alloy CrMnFeCoNi. Nat. Commun. 8, 15634 (2017).

    CAS  Google Scholar 

  90. Zhang, F. et al. Polymorphism in a high-entropy alloy. Nat. Commun. 8, 15687 (2017).

    CAS  Google Scholar 

  91. 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).

    CAS  Google Scholar 

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

    CAS  Google Scholar 

  93. Smith, T. M. et al. Atomic-scale characterization and modeling of 60° dislocations in a high-entropy alloy. Acta Mater. 110, 352–362 (2016).

    CAS  Google Scholar 

  94. Zhang, Z. J. et al. Nanoscale origins of the damage tolerance of the high-entropy alloy CrMnFeCoNi. Nat. Commun. 6, 10143 (2015).

    CAS  Google Scholar 

  95. Meyers, M. A., Vöhringer, O. & Lubarda, V. A. The onset of twinning in metals: a constitutive description. Acta Mater. 49, 4025–4039 (2001).

    CAS  Google Scholar 

  96. Abuzaid, W. & Sehitoglu, H. Critical resolved shear stress for slip and twin nucleation in single crystalline FeNiCoCrMn high entropy alloy. Mater. Char. 129, 288–299 (2017).

    CAS  Google Scholar 

  97. Kireeva, I. V., Chumlyakov, Yu. I., Pobedennaya, Z. V., Kuksgausen, I. V. & Karaman, I. Orientation dependence of twinning in single crystalline CoCrFeMnNi high-entropy alloy. Mater. Sci. Eng. A 707, 176–181 (2017).

    Google Scholar 

  98. Wu, Y., Bönisch, M., Alkan, S., Abuzaid, W. & Sehitoglu, H. Experimental determination of latent hardening coefficients in FeMnNiCoCr. Int. J. Plastic. 105, 239–260 (2018).

    CAS  Google Scholar 

  99. Kireeva, I. V., Chumlyakov, Yu. I., Pobedennaya, Z. V., Vyrodova, A. V. & Karaman, I. Twinning in [001]-oriented single crystals of CoCrFeMnNi high-entropy alloy at tensile deformation. Mater. Sci. Eng. A 713, 253–259 (2018).

    CAS  Google Scholar 

  100. Bönisch, M., Wu, Y. & Sehitoglu, H. Hardening by slip-twin and twin-twin interactions in FeMnNiCoCr. Acta Mater. 153, 391–403 (2018).

    Google Scholar 

  101. Stepanov, N. et al. Effect of cryo-deformation on structure and properties of CoCrFeNiMn high-entropy alloy. Intermetallics 59, 8–17 (2015).

    CAS  Google Scholar 

  102. Patriarca, L., Ojha, A., Sehitoglu, H. & Chumlyakov, Y. I. Slip nucleation in single crystal FeNiCoCrMn high entropy alloy. Scr. Mater. 112, 54–57 (2016).

    CAS  Google Scholar 

  103. Koppenaal, T. J. & Fine, M. E. Solid solution strengthening in alpha Cu-Al single crystals. Trans. Metall. Soc. AIME 224, 347–353 (1962).

    CAS  Google Scholar 

  104. Basinski, Z. S., Foxall, R. A. & Pascual, R. Stress equivalence of solution hardening. Scr. Metall. 6, 807–814 (1972).

    CAS  Google Scholar 

  105. Traub, H., Neuhäuser, H. & Schwink, Ch. Investigation of yield region of concentrated Cu-Ge and Cu-Zn single crystals. 1. Critical resolved shear-stress, slip line formation and true strain rate. Acta Metall. 25, 437–446 (1977).

    CAS  Google Scholar 

  106. Butt, M. Z. & Feltham, P. Solid-solution hardening. Acta Metall. 26, 167–173 (1978).

    CAS  Google Scholar 

  107. Wille, Th. & Schwink, Ch. Precision measurements of critical resolved shear-stress in CuMn alloys. Acta Metall. 34, 1059–1069 (1986).

    CAS  Google Scholar 

  108. Wille, Th, Gieseke, W. & Schwink, Ch Quantitative analysis of solution hardening in selected copper alloys. Acta Metall. 35, 2679–2693 (1987).

    CAS  Google Scholar 

  109. Varvenne, C., Aitor, L. & Curtin, W. A. Theory of strengthening in fcc high entropy alloys. Acta Mater. 118, 164–176 (2016).

    CAS  Google Scholar 

  110. Varvenne, C., Leyson, G. P. M., Ghazisaeidi, M. & Curtin, W. A. Solute strengthening in random alloys. Acta Mater. 124, 660–683 (2017).

    CAS  Google Scholar 

  111. Haasen, P. Plastic deformation of nickel single crystals at low temperatures. Philos. Mag. 3, 384–418 (1958).

    CAS  Google Scholar 

  112. Okamoto, N. L., Yuge, K., Tanaka, K., Inui, H. & George, E. P. Atomic displacement in the CrMnFeCoNi high-entropy alloy – a scaling factor to predict solid solution strengthening. AIP Adv. 6, 125008 (2016).

    Google Scholar 

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

    CAS  Google Scholar 

  114. Zhao, Y. L. et al. Heterogeneous precipitation behavior and stacking-fault-mediated deformation in a CoCrNi-based medium-entropy alloy. Acta Mater. 138, 72–82 (2017).

    CAS  Google Scholar 

  115. Sohn, S. S. et al. Ultrastrong medium-entropy single-phase alloys designed via severe lattice distortion. Adv. Mater. 31, 1807142 (2019).

    Google Scholar 

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

    CAS  Google Scholar 

  117. 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).

    CAS  Google Scholar 

  118. Yang, M. et al. Dynamically reinforced heterogeneous grain structure prolongs ductility in a medium-entropy alloy with gigapascal yield strength. Proc. Natl. Acad. Sci. USA 115, 7224–7229 (2018).

    CAS  Google Scholar 

  119. Slone, C. E., Miao, J., George, E. P. & Mills, M. J. Achieving ultra-high strength and ductility in equiatomic CrCoNi with partially recrystallized microstructures. Acta Mater. 165, 497–507 (2019).

    Google Scholar 

  120. Tasan, C. C. et al. Composition dependence of phase stability, deformation mechanisms, and mechanical properties of the CoCrFeMnNi high-entropy alloy system. JOM 66, 1993–2001 (2014).

    CAS  Google Scholar 

  121. Wang, M., Li, Z. & Raabe, D. In-situ SEM observation of phase transformation and twinning mechanisms in an interstitial high-entropy alloy. Acta Mater. 147, 236–246 (2018).

    CAS  Google Scholar 

  122. Li, Z., Tasan, C. C., Springer, H., Gault, B. & Raabe, D. Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys. Sci. Rep. 7, 40704 (2017).

    CAS  Google Scholar 

  123. Pradeep, K. G. et al. Non-equiatomic high entropy alloys: approach towards rapid alloy screening and property-oriented design. Mater. Sci. Eng. A 648, 183–192 (2015).

    CAS  Google Scholar 

  124. Lu, W., Liebscher, C. H., Dehm, G., Raabe, D. & Li, Z. Bidirectional transformation enables hierarchical nanolaminate dual-phase high-entropy alloys. Adv. Mater. 30, 1804727 (2018).

    Google Scholar 

  125. Su, J., Raabe, D. & Li, Z. Hierarchical microstructure design to tune the mechanical behavior of an interstitial TRIP-TWIP high-entropy alloy. Acta Mater. 163, 40–54 (2019).

    CAS  Google Scholar 

  126. Dirras, G. et al. Elastic and plastic properties of as-cast equimolar TiHfZrTaNb high-entropy alloy. Mater. Sci. Eng. A 654, 30–38 (2016).

    CAS  Google Scholar 

  127. Song, H., Tian, F. & Wang, D. Thermodynamic properties of refractory high entropy alloys. J. Alloys. Compd. 682, 773–777 (2016).

    CAS  Google Scholar 

  128. Couzinié, J. P. et al. Microstructure of a near-equimolar refractory high-entropy alloy. Mater. Lett. 126, 285–287 (2014).

    Google Scholar 

  129. Lin, C.-M., Juan, C.-C., Chang, C.-H., Tsai, C.-W. & Yeh, J.-W. Effect of Al addition on mechanical properties and microstructure of refractory AlxHfNbTaTiZr alloys. J. Alloys. Compd. 624, 100–107 (2015).

    CAS  Google Scholar 

  130. Dirras, G. et al. Microstructural investigation of plastically deformed Ti20Zr20Hf20Nb20Ta20 high entropy alloy by X-ray diffraction and transmission electron microscopy. Mater. Char. 108, 1–7 (2015).

    CAS  Google Scholar 

  131. Juan, C.-C. et al. Simultaneously increasing the strength and ductility of a refractory high-entropy alloy via grain refining. Mater. Lett. 184, 200–203 (2016).

    CAS  Google Scholar 

  132. Lilensten, L. et al. Design and tensile properties of a bcc Ti-rich high-entropy alloy with transformation-induced plasticity. Mater. Res. Lett. 5, 110–116 (2017).

    CAS  Google Scholar 

  133. Lei, Z. et al. Enhanced strength and ductility in a high-entropy alloy via ordered oxygen complexes. Nature 563, 546–550 (2018).

    CAS  Google Scholar 

  134. Li, Z., Ludwig, A., Savan, A., Springer, H. & Raabe, D. Combinatorial metallurgical synthesis and processing of high-entropy alloys. J. Mater. Res. 33, 3156–3169 (2018).

    CAS  Google Scholar 

  135. Holdren, J. P. Materials Genome Initiative for Global Competitiveness (National Science and Technology Council, Washington, 2011).

  136. Kennedy, K., Stefansky, T., Dvy, G., Zackay, V. F. & Parker, E. R. Rapid method for determining ternary-alloy phase diagrams. J. Appl. Phys. 36, 3808–3810 (1965).

    CAS  Google Scholar 

  137. Hanak, J. J. The “multiple-sample concept” in materials research: synthesis, compositional analysis, and testing of entire multicomponent systems. J. Mater. Sci. 5, 964–971 (1970).

    CAS  Google Scholar 

  138. Xiang, X.-D. et al. A combinatorial approach to materials discovery. Science 268, 1738–1740 (1995).

    CAS  Google Scholar 

  139. Specht, E. D. et al. Rapid structural and chemical characterization of ternary phase diagrams using synchrotron radiation. J. Mater. Res. 18, 2522–2527 (2003).

    CAS  Google Scholar 

  140. Collins, P. C., Banerjee, R., Banerjee, S. & Fraser, H. L. Laser deposition of compositionally graded titanium-vanadium and titanium-molybdenum alloys. Mater. Sci. Eng. A 352, 118–128 (2003).

    Google Scholar 

  141. Rar, A. et al. PVD synthesis and high-throughput property characterization of Ni-Fe-Cr alloy libraries. Meas. Sci. Technol. A 16, 46–53 (2005).

    CAS  Google Scholar 

  142. Wilson, P., Field, R. & Kaufman, M. The use of diffusion multiples to examine the compositional dependence of phase stability and hardness of the Co–Cr–Fe–Mn–Ni high entropy alloy system. Intermetallics 75, 15–24 (2016).

    CAS  Google Scholar 

  143. Springer, H. & Raabe, D. Rapid alloy prototyping: compositional and thermo-mechanical high throughput bulk combinatorial design of structural materials based on the example of 30Mn−1.2 C–xAl triplex steels. Acta Mater. 60, 4950–4959 (2012).

    CAS  Google Scholar 

  144. Zhao, J.-C., Zheng, X. & Cahill, D. G. High-throughput diffusion multiples. Mater. Today 8, 28–37 (2005).

    CAS  Google Scholar 

  145. Zhao, J.-C. Combinatorial approaches as effective tools in the study of phase diagrams and composition–structure–property relationships. Prog. Mater. Sci. 51, 557–631 (2006).

    Google Scholar 

  146. Knoll, H. et al. Combinatorial alloy design by laser additive manufacturing. Steel Res. Int. 88, 1600416 (2017).

    Google Scholar 

  147. Mertens, R., Sun, Z. M., Music, D. & Schneider, J. M. Effect of the composition on the structure of Cr-Al-C investigated by combinatorial thin film synthesis and ab initio calculations. Adv. Eng. Mater. 6, 903–907 (2004).

    CAS  Google Scholar 

  148. Ludwig, A., Zarnetta, R., Hamann, S., Savan, A. & Thienhaus, S. Development of multifunctional thin films using high-throughput experimentation methods. Int. J. Mater. Res. 99, 1144–1149 (2008).

    CAS  Google Scholar 

  149. Dobbelstein, H., Gurevich, E. L., George, E. P., Ostendorf, A. & Laplanche, G. Laser metal deposition of compositionally graded TiZrNbTa refractory high-entropy alloys using elemental powder blends. Addit. Manuf. 25, 252–262 (2019).

    CAS  Google Scholar 

  150. Bleck, W., Raabe, D., Tasan, C. C., Springer, H. & Bausch, M. From high-entropy alloys to high-entropy steels. J. Steel Res. Int. 86 1127–1138 (2015).

  151. Raabe, D. et al. Ab initio-guided design of twinning-induced plasticity steels. MRS Bull. 41, 320–325 (2016).

    CAS  Google Scholar 

  152. Christian, J. W. & Mahajan, S. Deformation twinning. Prog. Mater. Sci. 39, 1–157 (1995).

    Google Scholar 

  153. Steinmetz, D. R. et al. Revealing the strain-hardening behavior of twinning-induced plasticity steels: theory, simulations, experiments. Acta Mater. 6, 494–510 (2013).

    Google Scholar 

  154. Venables, J. A. Deformation Twinning (Gordon & Breach, NY, 1964).

  155. Friedel, J. Dislocations (Pergamon Press, Oxford, 1965).

  156. Mahajan, S. Twin-slip and twin-twin interactions in Mo-35 at.% Re alloy. Philos. Mag. 23, 781–794 (1971).

    CAS  Google Scholar 

  157. Mahajan, S. & Chin, G. Y. Formation of deformation twins in FCC crystals. Acta Metall. 21, 1353–1363 (1973).

    CAS  Google Scholar 

  158. Gutierrez-Urrutia, I. & Raabe, D. Multistage strain hardening through dislocation substructure and twinning in a high strength and ductile weight-reduced Fe-Mn-Al-C steel. Acta Mater. 60, 5791–5802 (2012).

    CAS  Google Scholar 

  159. Huang, S. et al. Temperature dependent stacking fault energy of FeCrCoNiMn high entropy alloy. Scr. Mater. 108, 44–47 (2015).

    CAS  Google Scholar 

  160. Li, Z. & Raabe, D. Influence of compositional inhomogeneity on mechanical behavior of an interstitial dual-phase high-entropy alloy. Mater. Chem. Phys. 210, 29–36 (2018).

    CAS  Google Scholar 

  161. Li, Z., Tasan, C. C., Pradeep, K. G. & Raabe, D. A. TRIP-assisted dual-phase high-entropy alloy: grain size and phase fraction effects on deformation behavior. Acta Mater. 131, 323–335 (2017).

    CAS  Google Scholar 

  162. Basu, S., Li, Z., Pradeep, K. G. & Raabe, D. Strain rate sensitivity of a TRIP-assisted dual-phase high-entropy alloy. Front. Mater. 5, 30 (2018).

    Google Scholar 

  163. Nene, S. S. et al. Enhanced strength and ductility in a friction stir processing engineered dual phase high entropy alloy. Sci. Rep. 7, 16167 (2017).

    CAS  Google Scholar 

  164. Luo, H., Li, Z. & Raabe, D. Hydrogen enhances strength and ductility of an equiatomic high-entropy alloy. Sci. Rep. 7, 9892 (2017).

    Google Scholar 

  165. Luo, H. et al. Beating hydrogen with its own weapon: nano-twin gradients enhance embrittlement resistance of a high-entropy alloy. Mater. Today 21, 1003–1009 (2018).

    CAS  Google Scholar 

  166. Kozelj, K. et al. Discovery of a superconducting high-entropy alloy. Phys. Rev. Lett. 113, 107001 (2014).

    CAS  Google Scholar 

  167. Vrtnik, S. et al. Superconductivity in thermally annealed Ta-Nb-Hf-Zr-Ti high-entropy alloys. J. Alloys. Compd. 695, 3530–3540 (2017).

    CAS  Google Scholar 

  168. Rost, C. M. et al. Entropy-stabilized oxides. Nat. Commun. 6, 8485 (2015).

    CAS  Google Scholar 

  169. Berardan, D., Franger, S., Meena, A. K. & Dragoe, N. Room temperature lithium superionic conductivity in high entropy oxides. J. Mater. Chem. A 4, 9536–9541 (2016).

    CAS  Google Scholar 

  170. Berardan, D., Franger, S., Dragoe, D., Meena, A. K. & Dragoe, N. Colossal dielectric constant in high entropy oxides. Phys. Status Solidi Rapid Res. Lett. 10, 328–333 (2016).

    CAS  Google Scholar 

  171. Berardan, D., Meena, A. K., Franger, S., Herrero, C. & Dragoe, N. Controlled Jahn-Teller distortion in (MgCoNiCuZn)O-based high entropy oxides. J. Alloys. Compd. 704, 693–700 (2017).

    CAS  Google Scholar 

  172. Sarkar, A. et al. High entropy oxides for reversible energy storage. Nat. Commun. 9, 3400 (2018).

    Google Scholar 

  173. Anand, G., Wynn, A. P., Handley, C. M. & Freeman, C. L. Phase stability and distortion in high-entropy oxides. Acta Mater. 146, 119–125 (2018).

    CAS  Google Scholar 

  174. Jiang, S. et al. A new class of high-entropy perovskite oxides. Scr. Mater. 142, 116–120 (2018).

    CAS  Google Scholar 

  175. Malinovskis, P. et al. Synthesis and characterization of multicomponent (CrNbTaTiW)C films for increased hardness and corrosion resistance. Mater. Des. 149, 51–62 (2018).

    CAS  Google Scholar 

  176. Zhou, J. et al. High-entropy carbide: a novel class of multicomponent ceramics. Ceram. Int. 44, 22014–22018 (2018).

    CAS  Google Scholar 

  177. Dusza, J. et al. Microstructure of (Hf-Ta-Zr-Nb)C high-entropy carbide at micro and nano/atomic level. J. Eur. Ceram. Soc. 38, 4303–4307 (2018).

    CAS  Google Scholar 

  178. Harrington, T. J. et al. Phase stability and mechanical properties of novel high entropy transition metal carbides. Acta Mater. 166, 271–280 (2019).

    CAS  Google Scholar 

  179. Feng, L., Fahrenholtz, W. G., Hilmas, G. E. & Zhou, Y. Synthesis of single-phase high-entropy carbide powders. Scr. Mater. 162, 90–93 (2019).

    CAS  Google Scholar 

  180. Demirskyi, D. et al. High-temperature flexural strength performance of ternary high-entropy carbide consolidated via spark plasma sintering of TaC, ZrC and NbC. Scr. Mater. 164, 12–16 (2019).

    CAS  Google Scholar 

  181. Hsieh, T. H., Hsu, C. H., Wu, C. Y., Kao, J. Y. & Hsu, C. Y. Effects of deposition parameters on the structure and mechanical properties of high-entropy alloy nitride films. Curr. Appl. Phys. 18, 512–518 (2018).

    Google Scholar 

  182. Mayrhofer, P. H., Kirnbauer, A., Ertelthaler, Ph. & Koller, C. M. High-entropy ceramic thin films: a case study on transition metal diborides. Scr. Mater. 149, 93–97 (2018).

    CAS  Google Scholar 

  183. Tallarita, G., Licheri, R., Garroni, S., Orru, R. & Cao, G. Novel processing route for the fabrication of bulk high-entropy metal diborides. Scr. Mater. 158, 100–104 (2019).

    CAS  Google Scholar 

  184. Li, Q.-L. Sheng, H. & Ma, E. Strengthening in multi-principal element alloys with local-chemical-order roughened dislocation pathways. Preprint at arXiv https://arxiv.org/abs/1904.07681 (2019).

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

    CAS  Google Scholar 

  186. Su, J., Wu, X., Raabe, D. & Li, Z. Deformation-driven bidirectional transformation promotes bulk nanostructure formation in a metastable interstitial high entropy alloy. Acta Mater. 167, 23–39 (2019).

    CAS  Google Scholar 

  187. Wegst, U. G. K., Bai, H., Saiz, E., Tomsia, A. P. & Ritchie, R. O. Bioinspired structural materials. Nat. Mater. 14, 23–36 (2015).

    CAS  Google Scholar 

  188. Kireeva, I. et al. Mechanisms of plastic deformation in [111]-oriented single crystals of FeNiMnCrCo high entropy alloy. AIP Conf. Proc. 1783, 020090 (2016).

    Google Scholar 

Download references

Acknowledgements

This study was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, through the Materials Science and Technology Division at the Oak Ridge National Laboratory (E.P.G.) and the Materials Sciences Division at the Lawrence Berkeley National Laboratory (R.O.R.). D.R. was supported by the European Research Council (ERC) through the 7th Framework Programme (FP7/2007–2013) ERC Advanced Grant SMARMET (grant agreement 290998) and through the German Research Foundation (DFG) through the Priority Programme ‘Compositionally Complex Alloys – High Entropy Alloys (CCA-HEA)’ (special priority programme (SPP) no. 2006).

Author information

Authors and Affiliations

Authors

Contributions

The authors contributed equally to all aspects of the article.

Corresponding author

Correspondence to Easo P. George.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note

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

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

George, E.P., Raabe, D. & Ritchie, R.O. High-entropy alloys. Nat Rev Mater 4, 515–534 (2019). https://doi.org/10.1038/s41578-019-0121-4

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41578-019-0121-4

This article is cited by

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