Oxidation and Mechanical Behavior of Nb-Ti-(Cr)-(Al) Refractory Multi-principal Element Alloys at 1000 °C
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Abstract
Abstract The oxidation and mechanical behavior at 1000 °C of five single-phase body-centered cubic (BCC) Nb-Ti-(Cr)-(Al) Refractory Multi-Principal Element Alloys (RMPEAs), with low density of ~ 6.5 g cm −3 and intrinsic room-temperature ductility, was systematically investigated. Isothermal oxidation tests conducted in air for up to 100 h revealed a strongly composition-dependent response. The binary NbTi alloy exhibited near-linear oxidation kinetics and an extensive internal reaction zone (IRZ). Conversely, Cr- and Al-containing alloys demonstrated reduced mass gain, narrowed IRZ and altered kinetic regimes, attributed to the formation of chemically complex oxide scales. Although Cr and Al additions reduced both mass gain and IRZ, oxide-scale spallation persisted across all compositions. Compression tests at 1000 °C confirmed that all alloys retained ductile behavior, with Cr-containing compositions exhibiting superior yield strength. Among the evaluated alloys, Nb 3 Ti 3 Cr 1 Al 1 achieved the most favorable balance between oxidation resistance (mass gain of 14.4 mg cm −2 after 100 h of exposure) and mechanical stability (yield strength 229.0 MPa at 1000 °C). The combined addition of Cr and Al to the equimolar NbTi alloy improves oxidation resistance and mechanical performance, advancing the development of lightweight RMPEAs for high-temperature structural applications.
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References (95)
Show source-provided references
1. V. Soni, O.N. Senkov, B. Gwalani, D.B. Miracle, and R. Banerjee, Microstructural Design for Improving Ductility of an Initially Brittle Refractory High Entropy Alloy, Sci. Rep., 2018, 8(1), p 1–10. https://doi.org/10.1038/s41598-018-27144-310.1038/s41598-018-27144-3 ↗
2. H.W. Yao, J.W. Qiao, J.A. Hawk, H.F. Zhou, M.W. Chen, and M.C. Gao, Mechanical Properties of Refractory High-Entropy Alloys: Experiments and Modeling, J. Alloys Compd., 2017, 696, p 1139–1150. https://doi.org/10.1016/j.jallcom.2016.11.18810.1016/j.jallcom.2016.11.188 ↗
3. B. Cantor, I.T.H. Chang, P. Knight, and A.J.B. Vincent, Microstructural Development in Equiatomic Multicomponent Alloys, Mater. Sci. Eng. A, 2004, 375–377, p 213–218. https://doi.org/10.1016/j.msea.2003.10.25710.1016/j.msea.2003.10.257 ↗
4. J.W. Yeh, S.K. Chen, S.J. Lin, J.Y. Gan, T.S. Chin, T.T. Shun et al., Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes, Adv. Eng. Mater., 2004, 6(5), p 299–303. https://doi.org/10.1002/adem.20030056710.1002/adem.200300567 ↗
5. N. Birbilis, S. Choudhary, J.R. Scully, and M.L. Taheri, A Perspective on Corrosion of Multi-Principal Element Alloys, npj Mater. Degrad., 2021 https://doi.org/10.1038/s41529-021-00163-810.1038/s41529-021-00163-8 ↗
6. O.N. Senkov, G.B. Wilks, D.B. Miracle, C.P. Chuang, and P.K. Liaw, Refractory High-Entropy Alloys, Intermetallics, 2010, 18(9), p 1758–1765. https://doi.org/10.1016/j.intermet.2010.05.01410.1016/j.intermet.2010.05.014 ↗
7. C.H. Chang, M.S. Titus, and J.W. Yeh, Oxidation Behavior between 700 and 1300 °C of Refractory TiZrNbHfTa High-Entropy Alloys Containing Aluminum, Adv. Eng. Mater., 2018, 20(6), p 1700948. https://doi.org/10.1002/adem.20170094810.1002/adem.201700948 ↗
8. S. Sheikh, M.K. Bijaksana, A. Motallebzadeh, S. Shafeie, A. Lozinko, L. Gan et al., Accelerated Oxidation in Ductile Refractory High-Entropy Alloys, Intermetallics, 2018, 97, p 58–66. https://doi.org/10.1016/j.intermet.2018.04.00110.1016/j.intermet.2018.04.001 ↗
9. K.C. Lo, A.C. Yeh, and H. Murakami, Microstructural Investigation of Oxidized Complex Refractory High Entropy Alloys, Mater. Trans., 2018, 59(4), p 556–562. https://doi.org/10.2320/matertrans.MJ20161110.2320/matertrans.MJ201611 ↗
10. C.M. Liu, H.M. Wang, S.Q. Zhang, H.B. Tang, and A.L. Zhang, Microstructure and Oxidation Behavior of New Refractory High Entropy Alloys, J. Alloys Compd., 2014, 583, p 162–169. https://doi.org/10.1016/j.jallcom.2013.08.10210.1016/j.jallcom.2013.08.102 ↗
11. W.M. Pasini, A. Polkowska, R. Nowak, G. Bruzda, A. Kudyba, D. Górniewicz et al., Boron Enhanced Complex Concentrated Silicides : A Bridge between Lightweight, Oxidation-Resistant Refractory Metal Silicides and Refractory Complex Concentrated Alloys, Next Materials, 2024, 3, p 100052. https://doi.org/10.1016/j.nxmate.2023.10005210.1016/j.nxmate.2023.100052 ↗
12. W.M. Pasini, A. Polkowska, R. Nowak, G. Bruzda, A. Kudyba, M. Jawańska et al., Boron Enhanced Complex Concentrated Silicides: New Pathway for Designing and Optimizing Ultra-High Temperature Intermetallic Composite Materials, J. Mater. Res. Technol., 2023, 27, p 6182–6191. https://doi.org/10.1016/j.jmrt.2023.11.05610.1016/j.jmrt.2023.11.056 ↗
13. W.M. Pasini, A. Polkowska, Ł Boroń, M. Podsiadło, E. Rząd, G. Bruzda et al., Synthesis of Complex Concentrated Silicide Coatings via Reactive Melt-Infiltration: Exploring Interfacial Phenomena between Si-B Melt and MoNbTaW High-Entropy Alloy, Surf. Coat. Technol., 2024, 494, p 131401. https://doi.org/10.1016/j.surfcoat.2024.13140110.1016/j.surfcoat.2024.131401 ↗
14. W.M. Pasini, S.H. Borges, F. Kateusz, E. Rząd, N. Chaia, N.A. Mariano et al., Synthesis, Microstructure, Growth Kinetics and Oxidation Performance of Complex Concentrated Silicide Coatings on Nb7Ti7Al1Cr1 via Hot-Dip Siliconizing, Open Ceram., 2025, 23, p 100810. https://doi.org/10.1016/j.oceram.2025.10081010.1016/j.oceram.2025.100810 ↗
15. N. Chaia, P.L. Cury, G. Rodrigues, G.C. Coelho, and C.A. Nunes, Aluminide and Silicide Diffusion Coatings by Pack Cementation for Nb-Ti-Al Alloy, Surf. Coat. Technol., 2020, 389, p 125675. https://doi.org/10.1016/j.surfcoat.2020.12567510.1016/j.surfcoat.2020.125675 ↗
16. T.M. Butler and K.J. Chaput, Native Oxidation Resistance of Al20Nb30Ta10Ti30Zr10 Refractory Complex Concentrated Alloy (RCCA), J. Alloys Compd., 2019, 787, p 606–617. https://doi.org/10.1016/j.jallcom.2019.02.12810.1016/j.jallcom.2019.02.128 ↗
17. O.N. Senkov, S.V. Senkova, D.M. Dimiduk, C. Woodward, and D.B. Miracle, Oxidation Behavior of a Refractory NbCrMo0.5Ta0.5TiZr Alloy, J. Mater. Sci., 2012, 47(18), p 6522–6534. https://doi.org/10.1007/s10853-012-6582-010.1007/s10853-012-6582-0 ↗
18. T.M. Butler, K.J. Chaput, J.R. Dietrich, and O.N. Senkov, High Temperature Oxidation Behaviors of Equimolar NbTiZrV and NbTiZrCr Refractory Complex Concentrated Alloys (RCCAs), J. Alloys Compd., 2017, 729, p 1004–1019. https://doi.org/10.1016/j.jallcom.2017.09.16410.1016/j.jallcom.2017.09.164 ↗
19. C. Zhu, X. Li, Z. Ma, Y. Qiao, and Z. Zhang, The Oxidation Behavior of Ti1.5NbVAlx Lightweight Medium-Entropy Alloys in Dry Air at 800 °C, Mater. Today Commun., 2024, 38, p 108156. https://doi.org/10.1016/j.mtcomm.2024.10815610.1016/j.mtcomm.2024.108156 ↗
20. S. Lu, X. Li, X. Liang, W. Shao, W. Yang, and J. Chen, Effect of Al Content on the Oxidation Behavior of Refractory High-Entropy Alloy AlMo0.5NbTa0.5TiZr at Elevated Temperatures, Int. J. Refract. Met. Hard Mater., 2022, 105, p 105812. https://doi.org/10.1016/j.ijrmhm.2022.10581210.1016/j.ijrmhm.2022.105812 ↗
21. S. Lu, X. Li, X. Liang, J. He, W. Shao, K. Li et al., Effect of Y Additions on the Oxidation Behavior of Vacuum Arc Melted Refractory High-Entropy Alloy AlMo0.5NbTa0.5TiZr at Elevated Temperatures, Vacuum, 2022, 201, p 111069. https://doi.org/10.1016/j.vacuum.2022.11106910.1016/j.vacuum.2022.111069 ↗
22. S. Schellert, B. Gorr, H.J. Christ, C. Pritzel, S. Laube, A. Kauffmann et al., The Effect of Al on the Formation of a CrTaO4 Layer in Refractory High Entropy Alloys Ta-Mo-Cr-Ti-xAl, Oxid. Met., 2021, 96(3–4), p 333–345. https://doi.org/10.1007/s11085-021-10046-710.1007/s11085-021-10046-7 ↗
23. M.P. Brady, P.F. Tortorelli, and L.R. Walker, Correlation of Alloy Microstructure with Oxidation Behavior in Chromia-Forming Intermetallic-Reinforced Cr Alloys, Mater. High Temp., 2000, 17(2), p 235–241. https://doi.org/10.1179/mht.2000.17.2.00910.1179/mht.2000.17.2.009 ↗
24. M.P. Brady, P.F. Tortorelli, E.A. Payzant, and L.R. Walker, Oxidation Behavior of Cr2N, CrNbN, and CrTaN Phase Mixtures Formed on Nitrided Cr and Laves-Reinforced Cr Alloys, Oxid. Met., 2004, 61(5–6), p 379–401. https://doi.org/10.1023/B:OXID.0000032330.95411.ec10.1023/B:OXID.0000032330.95411.ec ↗
25. K.C. Lo, Y.J. Chang, H. Murakami, J.W. Yeh, and A.C. Yeh, An Oxidation Resistant Refractory High Entropy Alloy Protected by CrTaO4-Based Oxide, Sci. Rep., 2019, 9(1), p 1–12. https://doi.org/10.1038/s41598-019-43819-x10.1038/s41598-019-43819-x ↗
26. O.N. Senkov, D.B. Miracle, K.J. Chaput, and J.P. Couzinie, Development and Exploration of Refractory High Entropy Alloys: A Review, J. Mater. Res., 2018, 33(19), p 3092–3128. https://doi.org/10.1557/jmr.2018.15310.1557/jmr.2018.153 ↗
27. S. Wang, M. Wu, D. Shu, G. Zhu, D. Wang, and B. Sun, Mechanical Instability and Tensile Properties of TiZrHfNbTa High Entropy Alloy at Cryogenic Temperatures, Acta Mater., 2020, 201, p 517–527. https://doi.org/10.1016/j.actamat.2020.10.04410.1016/j.actamat.2020.10.044 ↗
28. O.N. Senkov, B. Crossman, S.I. Rao, J.P. Couzinie, D.B. Miracle, T.M. Butler et al., Mechanical Properties of an Al10Nb20Ta15Ti30V5Zr20 A2/B2 Refractory Superalloy and its Constituent Phases, Acta Mater., 2023, 254, p 119017. https://doi.org/10.1016/j.actamat.2023.11901710.1016/j.actamat.2023.119017 ↗
29. O.N. Senkov, S. Gorsse, D.B. Miracle, S.I. Rao, and T.M. Butler, Correlations to Improve High-Temperature Strength and Room Temperature Ductility of Refractory Complex Concentrated Alloys, Mater. Des., 2024, 239, p 112762. https://doi.org/10.1016/j.matdes.2024.11276210.1016/j.matdes.2024.112762 ↗
30. B. Gorr, F. Müller, S. Schellert, H.J. Christ, H. Chen, A. Kauffmann et al., A New Strategy to Intrinsically Protect Refractory Metal Based Alloys at Ultra High Temperatures, Corros. Sci., 2020, 166, p 108475. https://doi.org/10.1016/j.corsci.2020.10847510.1016/j.corsci.2020.108475 ↗
31. H. Chen, A. Kauffmann, S. Seils, T. Boll, C.H. Liebscher, I. Harding et al., Crystallographic Ordering in a Series of Al-Containing Refractory High Entropy Alloys Ta-Nb-Mo-Cr-Ti-Al, Acta Mater., 2019, 176, p 123–133. https://doi.org/10.1016/j.actamat.2019.07.00110.1016/j.actamat.2019.07.001 ↗
32. S. Laube, A. Kauffmann, S. Schellert, S. Seils, A.S. Tirunilai, C. Greiner et al., Formation and Thermal Stability of Two-Phase Microstructures in Al-Containing Refractory Compositionally Complex Alloys, Sci. Technol. Adv. Mater., 2022, 23(1), p 692–706. https://doi.org/10.1080/14686996.2022.213211810.1080/14686996.2022.2132118 ↗
33. K. Khanchych, C. Tang, C. Schroer, B. Schäfer, J. Jung, M. Dürrschnabel et al., CALPHAD-Guided Prediction and Interpretation of Phase Formation in Ta-Mo-Cr-Ti-Al Refractory High-Entropy Alloys, Adv. Eng. Mater., 2025, 27(24), p 2500527. https://doi.org/10.1002/adem.20250052710.1002/adem.202500527 ↗
34. T. Wang, C. Wang, J. Li, W. Wang, L. Chai, and J. Luo, Oxidation Resistance, Corrosion Behavior and Grinding Performance of Laser-Deposited TaMoCrTiAl Refractory High-Entropy Coating, Int. J. Refract. Met. Hard Mater., 2024, 123, p 106771. https://doi.org/10.1016/j.ijrmhm.2024.10677110.1016/j.ijrmhm.2024.106771 ↗
35. S. Schellert, M. Weber, H.J. Christ, C. Wiktor, B. Butz, M.C. Galetz et al., Formation of Rutile (Cr,Ta,Ti)O2 Oxides during Oxidation of Refractory High Entropy Alloys in Ta-Mo-Cr-Ti-Al System, Corros. Sci., 2023, 211, p 110885. https://doi.org/10.1016/j.corsci.2022.11088510.1016/j.corsci.2022.110885 ↗
36. C. Tang, B. Schäfer, C. Schroer, and B. Gorr, Improved Oxidation Behavior of M-20Cr-20Ta (M: Ni, Fe, Co) Ternary Alloys by Formation of Complex Cr-Ta-Based Oxides, Corros. Sci., 2025, 249, p 112847. https://doi.org/10.1016/j.corsci.2025.11284710.1016/j.corsci.2025.112847 ↗
37. S. Schellert, B. Gorr, S. Laube, A. Kauffmann, M. Heilmaier, and H.J. Christ, Oxidation Mechanism of Refractory High Entropy Alloys Ta-Mo-Cr-Ti-Al with Varying Ta Content, Corros. Sci., 2021, 192, p 109861. https://doi.org/10.1016/j.corsci.2021.10986110.1016/j.corsci.2021.109861 ↗
38. P.R. Subramanian, M.G. Mendiratta, and D.M. Dimiduk, The Development of Nb-Based Advanced Intermetallic Alloys for Structural Applications, JOM, 1996, 48(1), p 33–38. https://doi.org/10.1007/BF0322136010.1007/BF03221360 ↗
39. K.S. Chan and D.L. Davidson, Improving the Fracture Toughness of Constituent Phases and Nb-Based In-Situ Composites by a Computational Alloy Design Approach, Metall. Mater. Trans. A, 2003, 34(9), p 1833–1849. https://doi.org/10.1007/s11661-003-0149-210.1007/s11661-003-0149-2 ↗
40. P. Tsakiropoulos, Alloys for Application at Ultra-High Temperatures: Nb-Silicide In Situ Composites: Challenges, Breakthroughs and Opportunities, Prog. Mater. Sci., 2022, 123, p 100714. https://doi.org/10.1016/j.pmatsci.2020.10071410.1016/j.pmatsci.2020.100714 ↗
41. K. Zelenitsas and P. Tsakiropoulos, Effect of Al, Cr and Ta Additions on the Oxidation Behaviour of Nb-Ti-Si In Situ Composites at 800 °C, Mater. Sci. Eng. A, 2006, 416(1–2), p 269–280. https://doi.org/10.1016/j.msea.2005.10.01710.1016/j.msea.2005.10.017 ↗
42. V. Bhardwaj, Q. Zhou, F. Zhang, W. Han, Y. Du, K. Hua et al., Effect of Al Addition on the Microstructure, Mechanical and Wear Properties of TiZrNbHf Refractory High Entropy Alloys, Tribol. Int., 2021, 160, p 107031. https://doi.org/10.1016/j.triboint.2021.10703110.1016/j.triboint.2021.107031 ↗
43. K. Zhang and Z. Fu, Effects of Annealing Treatment on Phase Composition and Microstructure of CoCrFeNiTiAlx High-Entropy Alloys, Intermetallics, 2012, 22, p 24–32. https://doi.org/10.1016/j.intermet.2011.10.01010.1016/j.intermet.2011.10.010 ↗
44. M. Ogura, T. Fukushima, R. Zeller, and P.H. Dederichs, Structure of the High-Entropy Alloy AlxCrFeCoNi: fcc Versus bcc, J. Alloys Compd., 2017, 715, p 454–459. https://doi.org/10.1016/j.jallcom.2017.04.31810.1016/j.jallcom.2017.04.318 ↗
45. H. Chen, A. Kauffmann, B. Gorr, D. Schliephake, C. Seemüller, J.N. Wagner et al., Microstructure and Mechanical Properties at Elevated Temperatures of a New Al-Containing Refractory High-Entropy Alloy Nb-Mo-Cr-Ti-Al, J. Alloys Compd., 2016, 661, p 206–215. https://doi.org/10.1016/j.jallcom.2015.11.05010.1016/j.jallcom.2015.11.050 ↗
46. O.N. Senkov, S.V. Senkova, D.B. Miracle, and C. Woodward, Mechanical Properties of Low-Density, Refractory Multi-Principal Element Alloys of the Cr-Nb-Ti-V-Zr system, Mater. Sci. Eng. A, 2013, 565, p 51–62. https://doi.org/10.1016/j.msea.2012.12.01810.1016/j.msea.2012.12.018 ↗
47. L. Mengis, A.S. Ulrich, P. Watermeyer, C.H. Liebscher, and M.C. Galetz, Oxidation Behaviour and Related Microstructural Changes of Two β0–Phase Containing TiAl Alloys Between 600 and 900 °C, Corros. Sci., 2021, 178, p 109085. https://doi.org/10.1016/j.corsci.2020.10908510.1016/j.corsci.2020.109085 ↗
48. O. Genc and R. Unal, Development of Gamma Titanium Aluminide (γ-TiAl) Alloys: A Review, J. Alloys Compd., 2022, 929, p 167262. https://doi.org/10.1016/j.jallcom.2022.16726210.1016/j.jallcom.2022.167262 ↗
49. T.M. Pollock and S. Tin, Nickel-Based Superalloys for Advanced Turbine Engines: Chemistry, Microstructure, and Properties, J. Propul. Power, 2006, 22(2), p 361–374. https://doi.org/10.2514/1.1823910.2514/1.18239 ↗
50. M. Perrut, P. Caron, M. Thomas, and A. Couret, High Temperature Materials for Aerospace Applications: Ni-Based Superalloys and γ-TiAl Alloys, C. R. Phys., 2018, 19(8), p 657–671. https://doi.org/10.1016/j.crhy.2018.10.00210.1016/j.crhy.2018.10.002 ↗
51. W.C. Lin, Y.W. Lien, L.E. Moreau, H. Murakami, K.C. Lo, S. Gorsse et al., High-Temperature Oxidation of NbTi-Bearing Refractory Medium- and High-Entropy Alloys, Materials, 2024, 17(18), p 4579. https://doi.org/10.3390/ma1718457910.3390/ma17184579 ↗
52. N. Yurchenko, E. Panina, D. Moskovskikh, D. Kapustin, M. Zhilina, L. Shekhawat et al., Strength and Oxidation Resistance of Laves Phase-Containing Refractory Nb-Ti-Zr-Cr Alloys: Effect of Chemical Complexity, Scr. Mater., 2024, 243, p 115978. https://doi.org/10.1016/j.scriptamat.2024.11597810.1016/j.scriptamat.2024.115978 ↗
53. S.C. Parida, N.K. Gupta, K. Krishnan, G.A. Rama Rao, and B.K. Sen, High-Temperature Oxidation of β-NbTi Alloys, Metall. Mater. Trans. A, 2008, 39(9), p 2020–2025. https://doi.org/10.1007/s11661-008-9548-810.1007/s11661-008-9548-8 ↗
54. S.H. Borges, W.M. Pasini, I. Dainezi, V.D.L. Vilela, W. Polkowski, N. Chaia et al., Effects of Chromium and Aluminum Additions on High-Entropy Alloys of the NbTiCrAl System: Development and Characterization, Mater. Res., 2025, 28, p e20250105. https://doi.org/10.1590/1980-5373-MR-2025-010510.1590/1980-5373-MR-2025-0105 ↗
55. DIN 50106:2023-02, Testing of metallic materials: Compression test at room temperature, Deutsches Institut für Normung (DIN), Berlin, 2023. Available at: https://www.dinmedia.de/de/norm/din-50106/360374267 (accessed 11 Dec 2025).
56. N. Birks, G.H. Meier, and F.S. Pettit, Oxidation of pure metals, Introduction to the High Temperature Oxidation of Metals. Cambridge University Press, 2006, p 75–10010.1017/CBO9781139163903.006 ↗
57. I. Dainezi, B. Gleeson, and C.A. Della Rovere, Failure Analysis of TiNbCr Multi-Principal Element Alloy: Temperature-Dependent Oxidation and Internal Degradation in Oxygen Atmospheres, Eng. Fail. Anal., 2025, 175, p 109573. https://doi.org/10.1016/j.engfailanal.2025.10957310.1016/j.engfailanal.2025.109573 ↗
58. N.J. Welch, M.J. Quintana, T.M. Butler, and P.C. Collins, High-Temperature Oxidation Behavior of TaTiCr, Ta4Ti3Cr, Ta2TiCr, and Ta4TiCr3 Concentrated Refractory Alloys, J. Alloys Compd., 2023, 941(7), p 169000. https://doi.org/10.1016/j.jallcom.2023.16900010.1016/j.jallcom.2023.169000 ↗
59. C. Tang, A. Radi, M. Dürrschnabel, U. Jäntsch, M. Klimenkov, A. Kauffmann et al., Design of Lightweight high Temperature Structural Materials Based on Ti-Mo-Ta-Cr-Al Refractory Compositionally Complex Alloys, Part II: High Temperature Oxidation Behavior, J. Alloys Metall. Syst., 2025, 12, p 100217. https://doi.org/10.1016/j.jalmes.2025.10021710.1016/j.jalmes.2025.100217 ↗
60. N.J. Welch, M.J. Quintana, S.J. Kuhr, T.M. Butler, and P.C. Collins, Intermediate and High-Temperature Oxidation Behavior of an Equiatomic TaTiCr RCCA from 800 to 1400 °C, Int. J. Refract. Met. Hard Mater., 2024, 118, p 106437. https://doi.org/10.1016/j.ijrmhm.2023.10643710.1016/j.ijrmhm.2023.106437 ↗
61. F. Müller, B. Gorr, H.J. Christ, J. Müller, B. Butz, H. Chen et al., On the Oxidation Mechanism of Refractory High Entropy Alloys, Corros. Sci., 2019, 159, p 108161. https://doi.org/10.1016/j.corsci.2019.10816110.1016/j.corsci.2019.108161 ↗
62. K.C. Lo, H. Murakami, U. Glatzel, J.W. Yeh, S. Gorsse, and A.C. Yeh, Elemental Effects on the Oxidation of Refractory Compositionally Complex Alloys, Int. J. Refract. Met. Hard Mater., 2022, 108, p 105918. https://doi.org/10.1016/j.ijrmhm.2022.10591810.1016/j.ijrmhm.2022.105918 ↗
63. M.E. Dahshan, J. Stringer, and D.P. Whittle, The Oxidation of Cobalt-Chromium-Carbon Alloys, Anti-Corros. Man., 1975, 22(9), p 10–14. https://doi.org/10.1108/eb00699010.1108/eb006990 ↗
64. K.P. Lillerud and P. Kofstad, On High Temperature Oxidation of Chromium: I . Oxidation of Annealed, Thermally Etched Chromium at 800-1100 °C, J. Electrochem. Soc., 1980, 127(11), p 2397. https://doi.org/10.1149/1.212947810.1149/1.2129478 ↗
65. I. Dainezi, B. Gleeson, S.H. Borges, N.A. Mariano, G.S. Vacchi, and C.A.D. Rovere, Insights into Early Stages of Oxidation Behavior of an Equiatomic TiNbCr Multi-Principal Element Alloy: Microstructural Aspects and Anisothermal Oxidation testing in Air, J. Mater. Res. Technol., 2026, 41, p 6855–6865. https://doi.org/10.1016/j.jmrt.2026.02.20810.1016/j.jmrt.2026.02.208 ↗
66. Y.K. Cao, Y. Liu, B. Liu, W.D. Zhang, J.W. Wang, and M. Du, Effects of Al and Mo on High Temperature Oxidation Behavior of Refractory High Entropy Alloys, Trans. Nonferrous Met. Soc. China, 2019, 29(7), p 1476–1483. https://doi.org/10.1016/S1003-6326(19)65054-510.1016/S1003-6326(19)65054-5 ↗
67. T.M. Butler, O.N. Senkov, T.I. Daboiku, M.A. Velez, H.E. Schroader, L.G. Ware et al., Oxidation Behaviors of CrNb, CrNbTi, and CrNbTaTi Concentrated Refractory Alloys, Intermetallics, 2022, 140, p 107374. https://doi.org/10.1016/j.intermet.2021.10737410.1016/j.intermet.2021.107374 ↗
68. H. Asteman and M. Spiegel, A Comparison of the Oxidation Behaviours of Al2O3 Formers and Cr2O3 Formers at 700 °C–Oxide Solid Solutions Acting as a Template for Nucleation, Corros. Sci., 2008, 50(6), p 1734–1743. https://doi.org/10.1016/j.corsci.2007.12.01210.1016/j.corsci.2007.12.012 ↗
69. H. Shi, A. Jianu, R. Fetzer, D.V. Szabó, S. Schlabach, A. Weisenburger et al., Compatibility and Microstructure Evolution of Al-Cr-Fe-Ni High Entropy Model Alloys Exposed to Oxygen-Containing Molten Lead, Corros. Sci., 2021, 189, p 109593. https://doi.org/10.1016/j.corsci.2021.10959310.1016/j.corsci.2021.109593 ↗
70. P. Zhao, H. Zhao, J. Yu, H. Zhang, H. Gao, and Q. Chen, Crystal Structure and Properties of Al2O3-Cr2O3 Solid Solutions with Different Cr2O3 Contents, Ceram. Int., 2018, 44(2), p 1356–1361. https://doi.org/10.1016/j.ceramint.2017.08.19510.1016/j.ceramint.2017.08.195 ↗
71. B. Gorr, F. Müller, M. Azim, H.J. Christ, T. Müller, H. Chen et al., High-Temperature Oxidation Behavior of Refractory High-Entropy Alloys: Effect of Alloy Composition, Oxid. Met., 2017, 88(3–4), p 339–349. https://doi.org/10.1007/s11085-016-9696-y10.1007/s11085-016-9696-y ↗
72. P. Zhang, Y. Li, Z. Chen, J. Zhang, and B. Shen, Oxidation Response of a Vacuum Arc Melted NbZrTiCrAl Refractory High Entropy Alloy at 800-1200 °C, Vacuum, 2019, 162, p 20–27. https://doi.org/10.1016/j.vacuum.2019.01.02610.1016/j.vacuum.2019.01.026 ↗
73. T. Yuan, L. Soule, B. Zhao, J. Zou, J. Yang, M. Liu et al., Recent Advances in Titanium Niobium Oxide Anodes for High-Power Lithium-Ion Batteries, Energy Fuels, 2020, 34(11), p 13321–13334. https://doi.org/10.1021/acs.energyfuels.0c0273210.1021/acs.energyfuels.0c02732 ↗
74. R.D. Shannon, Revised Effective Ionic Radii and Systematic Studies of Interatomic Distances in Halides and Chalcogenides, Acta Crystallogr. Sect. A, 1976, 32(5), p 751–767. https://doi.org/10.1107/S056773947600155110.1107/S0567739476001551 ↗
75. S. Lou, X. Cheng, J. Gao, Q. Li, L. Wang, Y. Cao et al., Pseudocapacitive Li+ Intercalation in Porous Ti2Nb10O29 Nanospheres Enables Ultra-Fast Lithium Storage, Energy Storage Mater., 2018, 11, p 57–66. https://doi.org/10.1016/j.ensm.2017.09.01210.1016/j.ensm.2017.09.012 ↗
76. R. Muruganantham, M.C. Lin, P.K. Wang, B.K. Chang, and W.R. Liu, Highly Effective Al-Doped Titanium Niobate Porous Anode Material for Rechargeable High-Rate Li-Ion Storage Performance, J. Taiwan Inst. Chem. Eng., 2022, 131, p 104187. https://doi.org/10.1016/j.jtice.2021.10418710.1016/j.jtice.2021.104187 ↗
77. M. Guo, L. Xu, Y. Zhao, S. Deng, Z. Li, and S. Wei, High Temperature Oxidation Behavior and Mechanism of MoNbVTa0.5Crx Refractory High Entropy Alloys, Corros. Sci., 2025, 245, p 112672. https://doi.org/10.1016/j.corsci.2024.11267210.1016/j.corsci.2024.112672 ↗
78. I. Dainezi, B. Gleeson, B.R. Buzatti, AMdeS. Malafaia, and C.A. Della Rovere, TiNbCr Multi-Principal Element Alloy Oxidation Behavior in Air at 800-1000 °C, High Temp. Corros. Mater., 2024, 101(4), p 789–810. https://doi.org/10.1007/s11085-024-10246-x10.1007/s11085-024-10246-x ↗
79. O.N. Senkov, J. Gild, and T.M. Butler, Microstructure, Mechanical Properties and Oxidation Behavior of NbTaTi and NbTaZr Refractory Alloys, J. Alloys Compd., 2021, 862, p 158003. https://doi.org/10.1016/j.jallcom.2020.15800310.1016/j.jallcom.2020.158003 ↗
80. C.Y. Liu, Z.L. Ma, H.Y. Li, Z.Q. Xu, and X.W. Cheng, Designing NbTiTa-Cr/Al Refractory Complex Concentrated Alloys with Balanced Strength-Ductility-Oxidation Resistance Properties: Insights into Oxidation Mechanisms, Int. J. Refract. Metals Hard Mater., 2023, 115, p 106308. https://doi.org/10.1016/j.ijrmhm.2023.10630810.1016/j.ijrmhm.2023.106308 ↗
81. T.M. Butler, O.N. Senkov, M.A. Velez, and T.I. Daboiku, Microstructures and Mechanical Properties of CrNb, CrNbTi, and CrNbTaTi Concentrated Refractory Alloys, Intermetallics, 2021, 138, p 107323.10.1016/j.intermet.2021.107323 ↗
82. A. Roy, P. Sreeramagiri, T. Babuska, B. Krick, P.K. Ray, and G. Balasubramanian, Lattice Distortion as an Estimator of Solid Solution Strengthening in High-Entropy Alloys, Mater Charact, 2021, 172, p 110877. https://doi.org/10.1016/j.matchar.2021.11087710.1016/j.matchar.2021.110877 ↗
83. J.H. Yan, M.J. Li, K. Li, J.W. Qiu, and Y. Guo, Effects of Cr Content on Microstructure and Mechanical Properties of WMoNbTiCr High-Entropy Alloys, J. Mater. Eng. Perform., 2020, 29(4), p 2125–2133. https://doi.org/10.1007/s11665-020-04744-710.1007/s11665-020-04744-7 ↗
84. X.J. Gao, L. Wang, N.N. Guo, L.S. Luo, G.M. Zhu, C.C. Shi et al., Microstructure Characteristics and Mechanical Properties of Hf0.5Mo0.5NbTiZr Refractory High Entropy Alloy with Cr Addition, Int. J. Refract. Metals Hard Mater., 2021, 95, p 105405. https://doi.org/10.1016/j.ijrmhm.2020.10540510.1016/j.ijrmhm.2020.105405 ↗
85. F. Wang, T. Yang, Y. Zhong, L. Li, and T. Yuan, Design Crystallographic Ordering in NbTa0.5TiAlx Refractory High Entropy Alloys with Strength-Plasticity Synergy, J. Mater. Res. Technol., 2023, 27, p 8386–8402. https://doi.org/10.1016/j.jmrt.2023.11.25410.1016/j.jmrt.2023.11.254 ↗
86. S. Ge, H. Fu, L. Zhang, H. Mao, H. Li, A. Wang et al., Effects of Al Addition on the Microstructures and Properties of MoNbTaTiV Refractory High Entropy Alloy, Mater. Sci. Eng. A, 2020, 784, p 139275. https://doi.org/10.1016/j.msea.2020.13927510.1016/j.msea.2020.139275 ↗
87. Z.H. Sun, J. Zhang, G.X. Xin, L. Xie, L.C. Yang, and Q. Peng, Tensile Mechanical Properties of CoCrFeNiTiAl High Entropy Alloy via Molecular Dynamics Simulations, Intermetallics, 2022, 142, p 107444. https://doi.org/10.1016/j.intermet.2021.10744410.1016/j.intermet.2021.107444 ↗
88. G.E.P. Box, J.S. Hunter, and W.G. Hunter, Statistics for Experimenters: Design, Innovation, and Discovery, 2nd ed. Wiley-Interscience, 2005, p 633
89. D.C. Montgomery, Design and Analysis of Experiments, 8th ed. Wiley, 2012, p 752
90. A. Fitzner, D.G.L. Prakash, J.Q. Da Fonseca, M. Thomas, S.Y. Zhang, J. Kelleher et al., The Effect of Aluminium on Twinning in Binary Alpha-Titanium, Acta Mater., 2016, 103, p 341–351. https://doi.org/10.1016/j.actamat.2015.09.04810.1016/j.actamat.2015.09.048 ↗
91. Y. Xiao, W. Kuang, Y. Xu, L. Wu, W. Gong, J. Qian et al., Microstructure and Oxidation Behavior of the CrMoNbTaV High-Entropy Alloy, J. Mater. Res., 2019, 34(2), p 301–308. https://doi.org/10.1557/jmr.2018.34010.1557/jmr.2018.340 ↗
92. O.A. Waseem, U. Auyeskhan, H.M. Lee, and H.J. Ryu, A Combinatorial Approach for the Synthesis and Analysis of AlxCryMozNbTiZr High-Entropy Alloys: Oxidation Behavior, J. Mater. Res., 2018, 33(19), p 3226–3234. https://doi.org/10.1557/jmr.2018.24110.1557/jmr.2018.241 ↗
93. B. Gorr, M. Azim, H.J. Christ, T. Mueller, D. Schliephake, and M. Heilmaier, Phase Equilibria, Microstructure, and High Temperature Oxidation Resistance of Novel Refractory High-Entropy Alloys, J. Alloys Compd., 2015, 624(5), p 270–278. https://doi.org/10.1016/j.jallcom.2014.11.01210.1016/j.jallcom.2014.11.012 ↗
94. B. Gorr, F. Mueller, H.J. Christ, T. Mueller, H. Chen, A. Kauffmann et al., High Temperature Oxidation Behavior of an Equimolar Refractory Metal-Based Alloy 20Nb20Mo20Cr20Ti20Al with and without Si Addition, J. Alloys Compd., 2016, 688(11), p 468–477. https://doi.org/10.1016/j.jallcom.2016.07.21910.1016/j.jallcom.2016.07.219 ↗
95. S. Gorsse, D.B. Miracle, and O.N. Senkov, Mapping the World of Complex Concentrated Alloys, Acta Mater., 2017, 135, p 177–187. https://doi.org/10.1016/j.actamat.2017.06.02710.1016/j.actamat.2017.06.027 ↗