Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-23T12:04:39.714Z Has data issue: false hasContentIssue false
  • English
  • Français

Metastability in high-entropy alloys: A review

Published online by Cambridge University Press:  10 September 2018

Shaolou Wei ,
Feng He  and
Cemal Cem Tasan Open the ORCID record for Cemal Cem Tasan [Opens in a new window]
Shaolou Wei
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,USA
Feng He
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; and State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Cemal Cem Tasan*
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,USA
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Classical alloy design strategies often aim to benefit from metastability. Examples are numerous: metastable transformation- and twinning-induced plasticity steels, cobalt or titanium based alloys, age hardenable aluminum alloys, and severe plastic deformed nanostructured copper. In each of these cases, superior engineering property combinations are achieved by exploring limits of stability. For the case of high-entropy alloys (HEAs), on the other hand, majority of present research efforts focus on exploring compositions that would yield stable single-phase structures. HEA metastability and its effects on microstructure and property development constitute only a relatively small fraction of ongoing work. To help motivate and guide a corresponding shift in HEA research efforts, here in this paper, we provide an overview of the research activities on metastability in HEAs. To this end, we categorize the past research on the topic into two groups based on their focus, namely, compositional and structural stability, and discuss the most relevant and exciting findings.

Keywords

high-entropy alloysmetastabilitymicrostructure
Type
Invited Review
Information
Journal of Materials Research , Volume 33 , Issue 19: Focus Issue: Fundamental Understanding and Applications of High-Entropy Alloys , 14 October 2018 , pp. 2924 - 2937
Copyright
Copyright © Materials Research Society 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

b)

These authors contributed equally to this work.

This section of Journal of Materials Research is reserved for papers that are reviews of literature in a given area.

References

REFERENCES

Cantor, B., Chang, I.T.H., Knight, P., and Vincent, A.J.B.: Microstructural development in equiatomic multicomponent alloys. Mater. Sci. Eng., A 375–377, 213 (2004).CrossRefGoogle Scholar
Yeh, J.W., Chen, S.K., Lin, S.J., Gan, J.Y., Chin, T.S., Shun, T.T., Tsau, C.H., and Chang, S.Y.: Nanostructured high-entropy alloys with multiple principal elements: Novel alloy design concepts and outcomes. Adv. Eng. Mater. 6, 299 (2004).CrossRefGoogle Scholar
Miracle, D.B. and Senkov, O.N.: A critical review of high entropy alloys and related concepts. Acta Mater. 122, 448 (2017).CrossRefGoogle Scholar
Fischer, F.D., Reisner, G., Werner, E., Tanaka, K., Cailletaud, G., and Antretter, T.: A new view on transformation induced plasticity (TRIP). Int. J. Plast. 16, 723 (2000).CrossRefGoogle Scholar
Fine, M.E.: Precipitation hardening of aluminum alloys. Metall. Trans. A 6, 625 (1975).CrossRefGoogle Scholar
Chookajorn, T., Murdoch, H.A., and Schuh, C.A.: Design of stable nanocrystalline alloys. Science 337, 951 (2012).CrossRefGoogle ScholarPubMed
Lu, L., Shen, Y., Chen, X., Qian, L., and Lu, K.: Ultrahigh strength and high electrical conductivity in copper. Science 304, 422 (2004).CrossRefGoogle ScholarPubMed
Cahn, R.W. and Haasen, P.: Physical Metallurgy, Vol. 1 (North-Holland, Amsterdam, 1996).Google Scholar
Ostwald, W.: On chemical energy. J. Am. Chem. Soc. 15, 421 (1893).CrossRefGoogle Scholar
Turnbull, D.: Metastable structures in metallurgy. Metall. Trans. B 12, 217 (1981).CrossRefGoogle Scholar
Senkov, O., Wilks, G., Scott, J., and Miracle, D.: Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys. Intermetallics 19, 698 (2011).CrossRefGoogle Scholar
Takeuchi, A., Amiya, K., Wada, T., Yubuta, K., and Zhang, W.: High-entropy alloys with a hexagonal close-packed structure designed by equi-atomic alloy strategy and binary phase diagrams. JOM 66, 1984 (2014).CrossRefGoogle Scholar
Zhang, Y., Zuo, T.T., Tang, Z., Gao, M.C., Dahmen, K.A., Liaw, P.K., and Lu, Z.P.: Microstructures and properties of high-entropy alloys. Prog. Mater. Sci. 61, 1 (2014).CrossRefGoogle Scholar
Otto, F., Yang, Y., Bei, H., and George, E.P.: Relative effects of enthalpy and entropy on the phase stability of equiatomic high-entropy alloys. Acta Mater. 61, 2628 (2013).CrossRefGoogle Scholar
Tong, C-J., Chen, M-R., Yeh, J-W., Lin, S-J., Chen, S-K., Shun, T-T., and Chang, S-Y.: Mechanical performance of the AlxCoCrCuFeNi high-entropy alloy system with multiprincipal elements. Metall. Mater. Trans. A 36, 1263 (2005).CrossRefGoogle Scholar
Tong, C-J., Chen, Y-L., Yeh, J-W., Lin, S-J., Chen, S-K., Shun, T-T., Tsau, C-H., and Chang, S-Y.: Microstructure characterization of AlxCoCrCuFeNi high-entropy alloy system with multiprincipal elements. Metall. Mater. Trans. A 36, 881 (2005).CrossRefGoogle Scholar
Chen, H-Y., Tsai, C-W., Tung, C-C., Yeh, J-W., Shun, T-T., Yang, C-C., and Chen, S-K.: Effect of the substitution of Co by Mn in Al-Cr-Cu-Fe-Co-Ni high-entropy alloys. Ann. Chim. 31, 6 (2006).Google Scholar
Chen, M-R., Lin, S-J., Yeh, J-W., Chen, S-K., Huang, Y-S., and Tu, C-P.: Microstructure and properties of Al0.5CoCrCuFeNiTix (x = 0–2.0) high-entropy alloys Mater. Trans. 47, 1395 (2006).CrossRefGoogle Scholar
Chen, M-R., Lin, S-J., Yeh, J-W., Chuang, M-H., Chen, S-K., and Huang, Y-S.: Effect of vanadium addition on the microstructure, hardness, and wear resistance of Al0.5CoCrCuFeNi high-entropy alloy. Metall. Mater. Trans. A 37, 1363 (2006).CrossRefGoogle Scholar
Wu, J-M., Lin, S-J., Yeh, J-W., Chen, S-K., Huang, Y-S., and Chen, H-C.: Adhesive wear behavior of AlxCoCrCuFeNi high-entropy alloys as a function of aluminum content. Wear 261, 513 (2006).CrossRefGoogle Scholar
Hsu, U.S., Hung, U.D., Yeh, J.W., Chen, S.K., Huang, Y.S., and Yang, C.C.: Alloying behavior of iron, gold and silver in AlCoCrCuNi-based equimolar high-entropy alloys. Mater. Sci. Eng., A 460–461, 403 (2007).CrossRefGoogle Scholar
Huang, Y-S., Chen, L., Lui, H-W., Cai, M-H., and Yeh, J-W.: Microstructure, hardness, resistivity and thermal stability of sputtered oxide films of AlCoCrCu0.5NiFe high-entropy alloy. Mater. Sci. Eng., A 457, 77 (2007).CrossRefGoogle Scholar
Tung, C-C., Yeh, J-W., Shun, T-t., Chen, S-K., Huang, Y-S., and Chen, H-C.: On the elemental effect of AlCoCrCuFeNi high-entropy alloy system. Mater. Lett. 61, 1 (2007).CrossRefGoogle Scholar
Santodonato, L.J., Zhang, Y., Feygenson, M., Parish, C.M., Gao, M.C., Weber, R.J.K., Neuefeind, J.C., Tang, Z., and Liaw, P.K.: Deviation from high-entropy configurations in the atomic distributions of a multi-principal-element alloy. Nat. Commun. 6, 5964 (2015).CrossRefGoogle ScholarPubMed
Manzoni, A., Daoud, H., Völkl, R., Glatzel, U., and Wanderka, N.: Phase separation in equiatomic AlCoCrFeNi high-entropy alloy. Ultramicroscopy 132, 212 (2013).CrossRefGoogle ScholarPubMed
Munitz, A., Meshi, L., and Kaufman, M.J.: Heat treatments’ effects on the microstructure and mechanical properties of an equiatomic Al–Cr–Fe–Mn–Ni high entropy alloy. Mater. Sci. Eng., A 689, 384 (2017).CrossRefGoogle Scholar
Singh, S., Wanderka, N., Kiefer, K., Siemensmeyer, K., and Banhart, J.: Effect of decomposition of the Cr–Fe–Co rich phase of AlCoCrCuFeNi high entropy alloy on magnetic properties. Ultramicroscopy 111, 619 (2011).CrossRefGoogle ScholarPubMed
Singh, S., Wanderka, N., Murty, B.S., Glatzel, U., and Banhart, J.: Decomposition in multi-component AlCoCrCuFeNi high-entropy alloy. Acta Mater. 59, 182 (2011).CrossRefGoogle Scholar
Xu, X.D., Liu, P., Guo, S., Hirata, A., Fujita, T., Nieh, T.G., Liu, C.T., and Chen, M.W.: Nanoscale phase separation in a fcc-based CoCrCuFeNiAl0.5 high-entropy alloy. Acta Mater. 84, 145 (2015).CrossRefGoogle Scholar
Knipling, K.E., Tharpe, J.L., and Liaw, P.K.: Nanoscale phase separation in Al0.5CoCrFeNi(Cu) high entropy alloys as studied by atom probe tomography. Microsc. Microanal. 23, 726 (2017).CrossRefGoogle Scholar
Otto, F., Dlouhý, A., Somsen, C., Bei, H., Eggeler, G., and George, E.P.: The influences of temperature and microstructure on the tensile properties of a CoCrFeMnNi high-entropy alloy. Acta Mater. 61, 5743 (2013).CrossRefGoogle Scholar
Gludovatz, B., Hohenwarter, A., Catoor, D., Chang, E.H., George, E.P., and Ritchie, R.O.: A fracture-resistant high-entropy alloy for cryogenic applications. Science 345, 1153 (2014).CrossRefGoogle ScholarPubMed
Yeh, J-W., Chen, Y-L., Lin, S-J., and Chen, S-K: High-entropy alloys—A new era of exploitation. Mater. Sci. Forum. 560 (2008).Google Scholar
Zhang, Y., Zhou, Y.J., Lin, J.P., Chen, G.L., and Liaw, P.K.: Solid-solution phase formation rules for multi-component alloys. Adv. Eng. Mater. 10, 534 (2008).CrossRefGoogle Scholar
Yeh, J-W.: Alloy design strategies and future trends in high-entropy alloys. JOM 65, 1759 (2013).CrossRefGoogle Scholar
Pickering, E.J., Muñoz-Moreno, R., Stone, H.J., and Jones, N.G.: Precipitation in the equiatomic high-entropy alloy CrMnFeCoNi. Scr. Mater. 113, 106 (2016).CrossRefGoogle Scholar
Otto, F., Dlouhý, A., Pradeep, K.G., Kuběnová, M., Raabe, D., Eggeler, G., and George, E.P.: Decomposition of the single-phase high-entropy alloy CrMnFeCoNi after prolonged anneals at intermediate temperatures. Acta Mater. 112, 40 (2016).CrossRefGoogle Scholar
He, F., Wang, Z., Wu, Q., Li, J., Wang, J., and Liu, C.T.: Phase separation of metastable CoCrFeNi high entropy alloy at intermediate temperatures. Scr. Mater. 126, 15 (2017).CrossRefGoogle Scholar
Stepanov, N.D., Yurchenko, N.Y., Zherebtsov, S.V., Tikhonovsky, M.A., and Salishchev, G.A.: Aging behavior of the HfNbTaTiZr high entropy alloy. Mater. Lett. 211, 87 (2018).CrossRefGoogle Scholar
Wang, Z., Guo, S., and Liu, C.T.: Phase selection in high-entropy alloys: From nonequilibrium to equilibrium. JOM 66, 1966 (2014).CrossRefGoogle Scholar
Rao, J.C., Diao, H.Y., Ocelík, V., Vainchtein, D., Zhang, C., Kuo, C., Tang, Z., Guo, W., Poplawsky, J.D., Zhou, Y., Liaw, P.K., and De Hosson, J.T.M.: Secondary phases in AlxCoCrFeNi high-entropy alloys: An in situ TEM heating study and thermodynamic appraisal. Acta Mater. 131, 206 (2017).CrossRefGoogle Scholar
Gwalani, B., Soni, V., Choudhuri, D., Lee, M., Hwang, J.Y., Nam, S.J., Ryu, H., Hong, S.H., and Banerjee, R.: Stability of ordered L12 and B2 precipitates in face centered cubic based high entropy alloys—Al0.3CoFeCrNi and Al0.3CuFeCrNi2. Scr. Mater. 123, 130 (2016).CrossRefGoogle Scholar
Zhang, L., Zhou, Y., Jin, X., Du, X., and Li, B.: The microstructure and high-temperature properties of novel nano precipitation-hardened face centered cubic high-entropy superalloys. Scr. Mater. 146, 226 (2018).CrossRefGoogle Scholar
Zhao, Y.L., Yang, T., Zhu, J.H., Chen, D., Yang, Y., Hu, A., Liu, C.T., and Kai, J.J.: Development of high-strength Co-free high-entropy alloys hardened by nanosized precipitates. Scr. Mater. 148, 51 (2018).CrossRefGoogle Scholar
Antonov, S., Detrois, M., and Tin, S.: Design of novel precipitate-strengthened Al–Co–Cr–Fe–Nb–Ni high-entropy superalloys. Metall. Mater. Trans. A 49, 305 (2017).CrossRefGoogle Scholar
Tang, Q., Huang, Y., Cheng, H., Liao, X., Langdon, T.G., and Dai, P.: The effect of grain size on the annealing-induced phase transformation in an Al0·3CoCrFeNi high entropy alloy. Mater. Des. 105, 381 (2016).CrossRefGoogle Scholar
Shun, T-T. and Du, Y-C.: Microstructure and tensile behaviors of FCC Al0.3CoCrFeNi high entropy alloy. J. Alloys Compd. 479, 157 (2009).CrossRefGoogle Scholar
He, F., Wang, Z., Li, Y., Wu, Q., Li, J., Wang, J., and Liu, C.T.: Kinetic ways of tailoring phases in high entropy alloys. Sci. Rep. 6, 34628 (2016).CrossRefGoogle ScholarPubMed
Shun, T-T., Chang, L-Y., and Shiu, M-H.: Microstructure and mechanical properties of multiprincipal component CoCrFeNiMox alloys. Mater. Charact. 70, 63 (2012).CrossRefGoogle Scholar
He, F., Wang, Z., Wang, J., Wu, Q., Chen, D., Han, B., Li, J., Wang, J., and Kai, J.J.: Abnormal γ″–ε phase transformation in the CoCrFeNiNb0.25 high entropy alloy. Scr. Mater. 146, 281 (2018).CrossRefGoogle Scholar
Shun, T-T., Hung, C-H., and Lee, C-F.: The effects of secondary elemental Mo or Ti addition in Al0.3CoCrFeNi high-entropy alloy on age hardening at 700 °C. J. Alloys Compd. 495, 55 (2010).CrossRefGoogle Scholar
Wang, Z., Huang, Y., Wang, J., and Liu, C.: Design of high entropy alloys based on the experience from commercial superalloys. Philos. Mag. Lett. 95, 1 (2015). (ahead-of-print).CrossRefGoogle Scholar
He, J.Y., Wang, H., Huang, H.L., Xu, X.D., Chen, M.W., Wu, Y., Liu, X.J., Nieh, T.G., An, K., and Lu, Z.P.: A precipitation-hardened high-entropy alloy with outstanding tensile properties. Acta Mater. 102, 187 (2016).CrossRefGoogle Scholar
Zhao, Y.L., Yang, T., Tong, Y., Wang, J., Luan, J.H., Jiao, Z.B., Chen, D., Yang, Y., Hu, A., Liu, C.T., and Kai, J.J.: Heterogeneous precipitation behavior and stacking-fault-mediated deformation in a CoCrNi-based medium-entropy alloy. Acta Mater. 138, 72 (2017).CrossRefGoogle Scholar
Ming, K., Bi, X., and Wang, J.: Realizing strength-ductility combination of coarse-grained Al0.2Co1.5CrFeNi1.5Ti0.3 alloy via nano-sized, coherent precipitates. Int. J. Plast. 100, 177 (2018).CrossRefGoogle Scholar
He, J.Y., Wang, H., Wu, Y., Liu, X.J., Mao, H.H., Nieh, T.G., and Lu, Z.P.: Precipitation behavior and its effects on tensile properties of FeCoNiCr high-entropy alloys. Intermetallics 79, 41 (2016).CrossRefGoogle Scholar
Chang, Y-J. and Yeh, A-C.: The formation of cellular precipitate and its effect on the tensile properties of a precipitation strengthened high entropy alloy. Mater. Chem. Phys. 210, 111 (2018).CrossRefGoogle Scholar
Liu, W.H., Lu, Z.P., He, J.Y., Luan, J.H., Wang, Z.J., Liu, B., Liu, Y., Chen, M.W., and Liu, C.T.: Ductile CoCrFeNiMox high entropy alloys strengthened by hard intermetallic phases. Acta Mater. 116, 332 (2016).CrossRefGoogle Scholar
Ming, K., Bi, X., and Wang, J.: Precipitation strengthening of ductile Cr15Fe20Co35Ni20Mo10 alloys. Scr. Mater. 137, 88 (2017).CrossRefGoogle Scholar
Zaddach, A.J., Scattergood, R.O., and Koch, C.C.: Tensile properties of low-stacking fault energy high-entropy alloys. Mater. Sci. Eng., A 636, 373 (2015).CrossRefGoogle Scholar
Zhao, S., Stocks, G.M., and Zhang, Y.: Stacking fault energies of face-centered cubic concentrated solid solution alloys. Acta Mater. 134, 334 (2017).CrossRefGoogle Scholar
Zhang, Y.H., Zhuang, Y., Hu, A., Kai, J.J., and 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 (2017).CrossRefGoogle Scholar
Laplanche, G., Kostka, A., Reinhart, C., Hunfeld, J., Eggeler, G., and George, E.P.: Reasons for the superior mechanical properties of medium-entropy CrCoNi compared to high-entropy CrMnFeCoNi. Acta Mater. 128, 292 (2017).CrossRefGoogle Scholar
Laplanche, G., Kostka, A., Horst, O.M., Eggeler, G., and George, E.P.: Microstructure evolution and critical stress for twinning in the CrMnFeCoNi high-entropy alloy. Acta Mater. 118, 152 (2016).CrossRefGoogle Scholar
Miao, J., Slone, C.E., Smith, T.M., Niu, C., Bei, H., Ghazisaeidi, M., Pharr, G.M., and Mills, M.J.: The evolution of the deformation substructure in a Ni–Co–Cr equiatomic solid solution alloy. Acta Mater. 132, 35 (2017).CrossRefGoogle Scholar
Han, B., Wei, J., Tong, Y., Chen, D., Zhao, Y., Wang, J., He, F., Yang, T., Zhao, C., Shimizu, Y., Inoue, K., Nagai, Y., Hu, A., Liu, C.T., and Kai, J.J.: Composition evolution of gamma prime nanoparticles in the Ti-doped CoFeCrNi high entropy alloy. Scr. Mater. 148, 42 (2018).CrossRefGoogle Scholar
Zhao, Y.Y., Chen, H.W., Lu, Z.P., and Nieh, T.G.: Thermal stability and coarsening of coherent particles in a precipitation-hardened (NiCoFeCr)94Ti2Al4 high-entropy alloy. Acta Mater. 147, 184 (2018).CrossRefGoogle Scholar
Dimiduk, D.M., Thompson, A.W., and Williams, J.C.: The compositional dependence of antiphase-boundary energies and the mechanism of anomalous flow in Ni3Al alloys. Philos. Mag. A 67, 675 (1993).CrossRefGoogle Scholar
Lee, E.H.: A practical guide to pharmaceutical polymorph screening & selection. Asian J. Pharm. Sci. 9, 163 (2014).CrossRefGoogle Scholar
Zhang, F., Wu, Y., Lou, H., Zeng, Z., Prakapenka, V.B., Greenberg, E., Ren, Y., Yan, J., Okasinski, J.S., Liu, X., Liu, Y., Zeng, Q., and Lu, Z.: Polymorphism in a high-entropy alloy. Nat. Commun. 8, 15687 (2017).CrossRefGoogle Scholar
Zhang, F., Zhao, S., Jin, K., Bei, H., Popov, D., Park, C., Neuefeind, J.C., Weber, W.J., and Zhang, Y.: Pressure-induced fcc to hcp phase transition in Ni-based high entropy solid solution alloys. Appl. Phys. Lett. 110, 011902 (2017).CrossRefGoogle Scholar
Ahmad, A.S., Su, Y., Liu, S., Ståhl, K., Wu, Y., Hui, X., Ruett, U., Gutowski, O., Glazyrin, K., and Liermann, H.: Structural stability of high entropy alloys under pressure and temperature. J. Appl. Phys. 121, 235901 (2017).CrossRefGoogle Scholar
Li, G., Xiao, D., Yu, P., Zhang, L., Liaw, P.K., Li, Y., and Liu, R.: Equation of state of an AlCoCrCuFeNi high-entropy alloy. JOM 67, 2310 (2015).CrossRefGoogle Scholar
Huang, E-W., Lin, C-M., Jain, J., Shieh, S.R., Wang, C-P., Chuang, Y-C., Liao, Y-F., Zhang, D-Z., Huang, T., and Lam, T-N.: Irreversible phase transformation in a CoCrFeMnNi high entropy alloy under hydrostatic compression. Mater. Today Commun. 14, 10 (2018).CrossRefGoogle Scholar
Yu, P., Zhang, L., Ning, J., Ma, M., Zhang, X., Li, Y., Liaw, P., Li, G., and Liu, R.: Pressure-induced phase transitions in HoDyYGdTb high-entropy alloy. Mater. Lett. 196, 137 (2017).CrossRefGoogle Scholar
Ma, D., Grabowski, B., Körmann, F., Neugebauer, J., and Raabe, D.: Ab initio thermodynamics of the CoCrFeMnNi high entropy alloy: Importance of entropy contributions beyond the configurational one. Acta Mater. 100, 90 (2015).CrossRefGoogle Scholar
Olson, G. and Cohen, M.: Kinetics of nucleation strain-induced martensitic. Metall. Mater. Trans. A 6, 791 (1975).CrossRefGoogle Scholar
Olson, G. and Cohen, M.: A general mechanism of martensitic nucleation: Part I. General concepts and the FCC → HCP transformation. Metall. Trans. A 7, 1897 (1976).Google Scholar
Olson, G. and Cohen, M.: A general mechanism of martensitic nucleation: Part II. FCC → BCC and other martensitic transformations. Metall. Trans. A 7, 1905 (1976).Google Scholar
Olson, G. and Cohen, M.: A general mechanism of martensitic nucleation: Part III. Kinetics of martensitic nucleation. Metall. Trans. A 7, 1915 (1976).CrossRefGoogle Scholar
Birch, F.: Finite strain isotherm and velocities for single-crystal and polycrystalline NaCl at high pressures and 300 K. J. Geophys. Res.: Solid Earth 83, 1257 (1978).CrossRefGoogle Scholar
Bridgman, P.: The Physics of High Pressure (G. Bell and Sons, London, 1949). Google Scholar. 51 (1980).Google Scholar
Senkov, O.N., Miller, J.D., Miracle, D.B., and Woodward, C.: Accelerated exploration of multi-principal element alloys with solid solution phases. Nat. Commun. 6, 6529 (2015).CrossRefGoogle ScholarPubMed
Tasan, C.C., Deng, Y., Pradeep, K.G., Yao, M.J., Springer, H., and Raabe, D.: Composition dependence of phase stability, deformation mechanisms, and mechanical properties of the CoCrFeMnNi high-entropy alloy system. JOM 66, 1993 (2014).CrossRefGoogle Scholar
Li, G., Xiao, D.H., Yu, P.F., Zhang, L.J., Liaw, P.K., Li, Y.C., and Liu, R.P.: Equation of state of an AlCoCrCuFeNi high-entropy alloy. JOM, 67, 10 (2015).CrossRefGoogle Scholar
Pradeep, K.G., Tasan, C.C., Yao, M.J., Deng, Y., Springer, H., and Raabe, D.: Non-equiatomic high entropy alloys: Approach towards rapid alloy screening and property-oriented design. Mater. Sci. Eng., A 648, 183 (2015).CrossRefGoogle Scholar
Wang, Z., Baker, I., Cai, Z., Chen, S., Poplawsky, J.D., and Guo, W.: The effect of interstitial carbon on the mechanical properties and dislocation substructure evolution in Fe40.4Ni11.3Mn34.8Al7.5Cr6 high entropy alloys. Acta Mater. 120, 228 (2016).CrossRefGoogle Scholar
Li, Z., Tasan, C.C., Springer, H., Gault, B., and Raabe, D.: Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys. Sci. Rep. 7, 40704 (2017).CrossRefGoogle ScholarPubMed
Chen, L.B., Wei, R., Tang, K., Zhang, J., Jiang, F., He, L., and Sun, J.: Heavy carbon alloyed FCC-structured high entropy alloy with excellent combination of strength and ductility. Mater. Sci. Eng., A 716, 150 (2018).CrossRefGoogle Scholar
Wang, Z., Baker, I., Guo, W., and Poplawsky, J.D.: The effect of carbon on the microstructures, mechanical properties, and deformation mechanisms of thermo-mechanically treated Fe40.4Ni11.3Mn34.8Al7.5Cr6 high entropy alloys. Acta Mater. 126, 346 (2017).CrossRefGoogle Scholar
Yao, M.J., Pradeep, K.G., Tasan, C.C., and Raabe, D.: A novel, single phase, non-equiatomic FeMnNiCoCr high-entropy alloy with exceptional phase stability and tensile ductility. Scr. Mater. 72–73, 5 (2014).CrossRefGoogle Scholar
Deng, Y., Tasan, C.C., Pradeep, K.G., Springer, H., Kostka, A., and Raabe, D.: Design of a twinning-induced plasticity high entropy alloy. Acta Mater. 94, 124 (2015).CrossRefGoogle Scholar
Li, Z., Pradeep, K.G., Deng, Y., Raabe, D., and Tasan, C.C.: Metastable high-entropy dual-phase alloys overcome the strength-ductility trade-off. Nature 534, 227 (2016).CrossRefGoogle ScholarPubMed
Li, Z.M., Tasan, C.C., Pradeep, K.G., and Raabe, D.: A TRIP-assisted dual-phase high-entropy alloy: Grain size and phase fraction effects on deformation behavior. Acta Mater. 131, 323 (2017).CrossRefGoogle Scholar
Raabe, D., Tasan, C.C., Springer, H., and Bausch, M.: From high‐entropy alloys to high‐entropy steels. Steel Res. Int. 86, 1127 (2015).CrossRefGoogle Scholar
De Cooman, B.C., Estrin, Y., and Kim, S.K.: Twinning-induced plasticity (TWIP) steels. Acta Mater. 142, 283 (2018).CrossRefGoogle Scholar
Ma, D., Yao, M., Pradeep, K.G., Tasan, C.C., Springer, H., and Raabe, D.: Phase stability of non-equiatomic CoCrFeMnNi high entropy alloys. Acta Mater. 98, 288 (2015).CrossRefGoogle Scholar
Detor, A.J. and Schuh, C.A.: Microstructural evolution during the heat treatment of nanocrystalline alloys. J. Mater. Res. 22, 3233 (2011).CrossRefGoogle Scholar
Stepanov, N., Yurchenko, N.Y., Gridneva, A., Zherebtsov, S., Ivanisenko, Y.V., and Salishchev, G.: Structure and hardness of B2 ordered refractory AlNbTiVZr0.5 high entropy alloy after high-pressure torsion. Mater. Sci. Eng., A 716, 308 (2018).CrossRefGoogle Scholar
Tang, Q.H., Huang, Y., Huang, Y.Y., Liao, X.Z., Langdon, T.G., and Dai, P.Q.: Hardening of an Al0.3CoCrFeNi high entropy alloy via high-pressure torsion and thermal annealing. Mater. Lett. 151, 126 (2015).CrossRefGoogle Scholar
Wani, I.S., Bhattacharjee, T., Sheikh, S., Lu, Y.P., Chatterjee, S., Bhattacharjee, P.P., Guo, S., and Tsuji, N.: Ultrafine-Grained AlCoCrFeNi2.1 eutectic high-entropy alloy. Mater. Res. Lett. 4, 174 (2016).CrossRefGoogle Scholar
Yoshida, S., Bhattacharjee, T., Bai, Y., and 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 (2017).CrossRefGoogle Scholar
Zhang, K.B., Fu, Z.Y., Zhang, J.Y., Shi, J., Wang, W.M., Wang, H., Wang, Y.C., and Zhang, Q.J.: Nanocrystalline CoCrFeNiCuAl high-entropy solid solution synthesized by mechanical alloying. J. Alloys Compd. 485, L31 (2009).CrossRefGoogle Scholar
Jo, Y.H., Jung, S., Choi, W.M., Sohn, S.S., Kim, H.S., Lee, B.J., Kim, N.J., and Lee, S.: Cryogenic strength improvement by utilizing room-temperature deformation twinning in a partially recrystallized VCrMnFeCoNi high-entropy alloy. Nat. Commun. 8, 15719 (2017).CrossRefGoogle Scholar
Schuh, B., Völker, B., Maier-Kiener, V., Todt, J., Li, J., and Hohenwarter, A.: Phase decomposition of a single-phase AlTiVNb high-entropy alloy after severe plastic deformation and annealing. Adv. Eng. Mater. 19, 1600674 (2017).CrossRefGoogle Scholar
Bhattacharjee, T., Wani, I., Sheikh, S., Clark, I., Okawa, T., Guo, S., Bhattacharjee, P., and Tsuji, N.: Simultaneous strength-ductility enhancement of a nano-lamellar AlCoCrFeNi2.1 eutectic high entropy alloy by cryo-rolling and annealing. Sci. Rep. 8, 3276 (2018).CrossRefGoogle ScholarPubMed
Yuan, H., Tsai, M-H., Sha, G., Liu, F., Horita, Z., Zhu, Y., and Wang, J.T.: Atomic-scale homogenization in an fcc-based high-entropy alloy via severe plastic deformation. J. Alloys Compd. 686, 15 (2016).CrossRefGoogle Scholar
Heczel, A., Kawasaki, M., Lábár, J.L., Jang, J-i., Langdon, T.G., and Gubicza, J.: Defect structure and hardness in nanocrystalline CoCrFeMnNi high-entropy alloy processed by high-pressure torsion. J. Alloys Compd. 711, 143 (2017).CrossRefGoogle Scholar
Wu, W., Ni, S., Liu, Y., Liu, B., and Song, M.: Amorphization at twin-twin intersected region in FeCoCrNi high-entropy alloy subjected to high-pressure torsion. Mater. Charact. 127, 111 (2017).CrossRefGoogle Scholar
babu, C.S., Sivaprasad, K., Muthupandi, V., and Szpunar, J.A.: Characterization of nanocrystalline AlCoCrCuNiFeZn high entropy alloy produced by mechanical alloying. Procedia Mater. Sci. 5, 1020 (2014).CrossRefGoogle Scholar
Fu, Z., Chen, W., Xiao, H., Zhou, L., Zhu, D., and Yang, S.: Fabrication and properties of nanocrystalline Co0.5FeNiCrTi0.5 high entropy alloy by MA–SPS technique. Mater. Des. 44, 535 (2013).CrossRefGoogle Scholar
Varalakshmi, S., Kamaraj, M., and Murty, B.S.: Formation and stability of equiatomic and nonequiatomic nanocrystalline CuNiCoZnAlTi high-entropy alloys by mechanical alloying. Metall. Mater. Trans. A 41, 2703 (2010).CrossRefGoogle Scholar
Fu, Z., MacDonald, B.E., Zhang, D., Wu, B., Chen, W., Ivanisenko, J., Hahn, H., and Lavernia, E.J.: Fcc nanostructured TiFeCoNi alloy with multi-scale grains and enhanced plasticity. Scr. Mater. 143, 108 (2018).CrossRefGoogle Scholar
Schuh, B., Mendez-Martin, F., Völker, B., George, E.P., Clemens, H., Pippan, R., and Hohenwarter, A.: Mechanical properties, microstructure and thermal stability of a nanocrystalline CoCrFeMnNi high-entropy alloy after severe plastic deformation. Acta Mater. 96, 258 (2015).CrossRefGoogle Scholar
Schuh, B., Völker, B., Todt, J., Schell, N., Perrière, L., Li, J., Couzinié, J., and Hohenwarter, A.: Thermodynamic instability of a nanocrystalline, single-phase TiZrNbHfTa alloy and its impact on the mechanical properties. Acta Mater. 142, 201 (2018).CrossRefGoogle Scholar
Liu, W.H., Wu, Y., He, J.Y., Nieh, T.G., and Lu, Z.P.: Grain growth and the Hall–Petch relationship in a high-entropy FeCrNiCoMn alloy. Scr. Mater. 68, 526 (2013).CrossRefGoogle Scholar
Bhattacharjee, P.P., Sathiaraj, G.D., Zaid, M., Gatti, J.R., Lee, C., Tsai, C-W., and Yeh, J-W.: Microstructure and texture evolution during annealing of equiatomic CoCrFeMnNi high-entropy alloy. J. Alloys Compd. 587, 544 (2014).CrossRefGoogle Scholar
Wynblatt, P. and Chatain, D.: Anisotropy of segregation at grain boundaries and surfaces. Metall. Mater. Trans. A 37, 2595 (2006).CrossRefGoogle Scholar
MacLean, D.: Grain Boundaries in Metals (Clarendon Press, Oxford, London, 1957).Google Scholar
Zhou, N., Hu, T., Huang, J., and Luo, J.: Stabilization of nanocrystalline alloys at high temperatures via utilizing high-entropy grain boundary complexions. Scr. Mater. 124, 160 (2016).CrossRefGoogle Scholar