Characterization and Modeling of NbNiTaTiW and NbNiTaTiW-Al Refractory High-Entropy Alloys

  • 283 Accesses


High-entropy alloys (HEAs) represent a new class of material that exhibit unique materials properties and complex microstructure. Little work to date has been done on refractory HEAs (RHEAs), which can loosely be defined as an HEA with the majority of the alloy being refractory metals. In this study, the authors examined two unique RHEA systems: (1) Nb20Ni20Ta20Ti20W20 and (2) Nb18Ni18Ta18Ti18W18Al10. The RHEAs were characterized in the as-cast and heat-treated condition using scanning electron microscopy equipped with energy dispersive spectroscopy to observe the microstructural evolution and elemental segregation and X-ray diffraction to determine the number of phases present and their crystal structure. The RHEA mechanical properties were tested via Vickers hardness measurements. Thermodynamic simulations of the solidification process were performed using a CALPHAD approach involving two basic models: equilibrium lever rule and non-equilibrium Scheil-Gulliver. The simulations were compared with the experimental data.

This is a preview of subscription content, log in to check access.

Access options

Buy single article

Instant unlimited access to the full article PDF.

US$ 39.95

Price includes VAT for USA

Subscribe to journal

Immediate online access to all issues from 2019. Subscription will auto renew annually.

US$ 294

This is the net price. Taxes to be calculated in checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9


  1. 1.

    Zhang Y, Zuo TT, Tang Z, Gao MC, Dahmen KA, Liaw PK, Lu ZP (2014) Progress in Materials Science 61:1–93.

  2. 2.

    Dobbelstein H, Thiele M, Gurevich EL, George EP, Ostendorf A (2016) Physics Procedia 83:624–633.

  3. 3.

    Otto F, Dlouhý A, Pradeep KG, Kuběnová M, Raabe D, Eggeler G, George EP (2016) Acta Mater. 112:40–52.

  4. 4.

    Gorsse S, Miracle DB, Senkov ON (2017) Acta Mater. 135:177–187.

  5. 5.

    Gorsse S, Couzinié J-P, Miracle DB (2018) C. R. Physique 19:721-736.

  6. 6.

    J. W. Yeh, S. K. Chen, S. J. Lin, J. Y. Gan, T. S. Chin, T. T. Shun, C. H. Tsau and S. Y. Chang, Advanced Engineering Materials 2004, vol. 6, pp. 299-303.

  7. 7.

    K. B. Zhang, Z. Y. Fu, J. Y. Zhang, W. M. Wang, H. Wang, Y. C. Wang, Q. J. Zhang and J. Shi, Materials Science and Engineering: A 2009, vol. 508, pp. 214-219.

  8. 8.

    Woei-Ren Wang, Wei-Lin Wang and Jien-Wei Yeh, Journal of Alloys and Compounds 2014, vol. 589, pp. 143-152.

  9. 9.

    Daniel Miracle, Jonathan Miller, Oleg Senkov, Christopher Woodward, Michael Uchic and Jaimie Tiley, Entropy 2014, vol. 16, pp. 494-525.

  10. 10.

    O. N. Senkov and D. B. Miracle, Journal of Alloys and Compounds 2016, vol. 658, pp. 603-607.

  11. 11.

    S. Varalakshmi, M. Kamaraj and B. S. Murty, Journal of Alloys and Compounds 2008, vol. 460, pp. 253-257.

  12. 12.

    Yong Zhang, Jien-Wei Yeh, Jian F. Sun, Jun P. Lin and Ke-Fu Yao, Advances in Materials Science and Engineering 2015, vol. 2015, pp. 1-1.

  13. 13.

    Y. Zhang, S. G. Ma and J. W. Qiao, Metallurgical and Materials Transactions A 2011, vol. 43, pp. 2625-2630.

  14. 14.

    X. Yang and Y. Zhang, Materials Chemistry and Physics 2012, vol. 132, pp. 233-238.

  15. 15.

    B. S. Li, Y. P. Wang, M. X. Ren, C. Yang and H. Z. Fu, Materials Science and Engineering: A 2008, vol. 498, pp. 482-486.

  16. 16.

    K. Y. Tsai, M. H. Tsai and J. W. Yeh, Acta Mater. 2013, vol. 61, pp. 4887-4897.

  17. 17.

    ON Senkov, GB Wilks, DB Miracle, CP Chuang and PK Liaw, Intermetallics 2010, vol. 18, pp. 1758-1765.

  18. 18.

    O. N. Senkov, G. B. Wilks, J. M. Scott and D. B. Miracle, Intermetallics 2011, vol. 19, pp. 698-706.

  19. 19.

    ON Senkov, JM Scott, SV Senkova, DB Miracle and CF Woodward, Journal of alloys and compounds 2011, vol. 509, pp. 6043-6048.

  20. 20.

    RS Mishra, N Kumar and M Komarasamy, Materials Science and Technology 2015, vol. 31, pp. 1259-1263.

  21. 21.

    Daniel B Miracle and Oleg N Senkov, Acta Mater. 2017, vol. 122, pp. 448-511.

  22. 22.

    Soni V, Senkov ON, Gwalani B, Miracle DB, Banerjee R (2018) Sci. Rep. 8:8816

  23. 23.

    O. N. Senkov, S. V. Senkova and C. Woodward, Acta Mater. 2014, vol. 68, pp. 214-228.

  24. 24.

    Erich Scheil, Zeitschrift für Metallkunde 1942, vol. 34, pp. 70-72.

  25. 25.

    GH Gulliver, J. Inst. Met 1913, vol. 9, pp. 120-157.

  26. 26.

    Chuan Zhang, Fan Zhang, Shuanglin Chen and Weisheng Cao, JOM 2012, vol. 64, pp. 839-845.

  27. 27.

    B Zhang, MC Gao, Y Zhang, S Yang and SM Guo, Materials Science and Technology 2015, vol. 31, pp. 1207-1213.

  28. 28.

    B Zhang, MC Gao, Y Zhang and SM Guo, Calphad 2015, vol. 51, pp. 193-201.

  29. 29.

    ON Senkov, JD Miller, DB Miracle, C Woodward (2015) Nat Commun 85:1404

Download references


The authors thank the Forging Industry Association’s FIERF program for partial support of this research. Nathan Ley thanks the AFRL/RWMWS Munitions-Eglin program for partial support of this research. The authors especially thank Dr. Dan Miracle of AFRL AFRL/RX Materials-Dayton for providing his insight and extensive knowledge on the subject of HEAs/CCAs. The authors thank Richard Harris, Dr. Sean Gibbons, and Dr. Rachel Abrahams for their help with characterization as well as for access to facilities and equipment for Nathan Ley at AFRL/RWMWS Munitions-Eglin. The authors acknowledge UNT’s Materials Research Facility (MRF) for providing access to equipment. Stéphane Gorsse thanks Thermo-Calc Software AB for providing the TCHEA databases.

Author information

Correspondence to Nathan A. Ley.

Additional information

Publisher's Note

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

Manuscript submitted November 26, 2018.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ley, N.A., Segovia, S., Gorsse, S. et al. Characterization and Modeling of NbNiTaTiW and NbNiTaTiW-Al Refractory High-Entropy Alloys. Metall and Mat Trans A 50, 4867–4876 (2019) doi:10.1007/s11661-019-05384-w

Download citation