Development and characterization of a high-Cr-content Co–Ni–Al–V–Ta–Cr superalloy: Microstructure, mechanical properties and oxidation resistance

Abstract

Enhancing the oxidation resistance of Co-based superalloys by adding a high content of Cr, while simultaneously ensuring the stability of the γ/γ′ phases, presents a significant challenge. This study evaluated the alloying potential of Co–30Ni–10Al–5V–4Ta using the CALPHAD method, revealing promising characteristics. The developed Co–30Ni–10Al–5V–4Ta–12Cr alloy characterized by high Cr content and γ/γ′ two-phase structure, demonstrating high γ′ solvus temperature of 1139°C, low density of 8.48 g/cm³, minimal γ/γ′ lattice misfit of +0.28%, high compressive yield strength of 651 MPa at 800°C, and excellent oxidation resistance with a weight gain of 6.5 mg/cm³ after 200 h at 1000°C. Examination of the oxidation behavior at 1000°C revealed an oxide layer consisting of a porous outer CoO, NiO, and V₃O₄ (CNV) oxide and a denser inner mixed oxide layer comprising CoO, NiO, and V₃O₄ (CNV) oxide, Al₂O₃, Cr₂O₃, CoO, and NiO (CNAC) oxide, and TaO₂, CoO, and NiO (CNT) oxide.

Keywords

Co-based superalloys / compressive yield strength / γ′ solvus temperature / γ′ phase stability / oxidation behavior

References

[1] Reed R, Broder HL, Jenkins G, Spivack E, Janal MN. Oral health promotion among older persons and their care providers in a nursing home facility. Gerodontology. 2006, 23273.

[2] Pollock TM, Tin S. Nickel-based superalloys for advanced turbine engines: Chemistry, microstructure and properties. J. Propuls. Power. 2006, 222361.

[3] Sato J, Omori T, Oikawa K, Ohnuma I, Kainuma R, Ishida K. Cobalt-base high-temperature alloys. Science. 2006, 312577090.

[4] Makineni SK, Nithin B, Chattopadhyay K. A new tungsten-free γ–γ′ Co–Al–Mo–Nb-based superalloy. Scripta Mater.. 2015, 9836.

[5] Chen YC, Wang CP, Ruan JJet al. . High-strength Co–Al–V-base superalloys strengthened by γ′-Co₃(Al, V) with high solvus temperature. Acta Mater.. 2019, 17062.

[6] Makineni SK, Nithin B, Chattopadhyay K. Synthesis of a new tungsten-free γ–γ′ cobalt-based superalloy by tuning alloying additions. Acta Mater.. 2015, 8585.

[7] Makineni SK, Samanta A, Rojhirunsakool Tet al. . A new class of high strength high temperature Cobalt based γ–γ′ Co–Mo–Al alloys stabilized with Ta addition. Acta Mater.. 2015, 9729.

[8] C.P. Wang, X. Chen, Y.C. Chen, et al., Accelerated design of high γ′ solvus temperature and yield strength cobalt-based superalloy based on machine learning and phase diagram, Front. Mater., 9(2022), art. No. 882955.

[9] Liu XJ, Wei ZB, Lu Y, Han JJ, Shi RP, Wang CP. Progress on the diffusion kinetics of novel Co-based and Nb–Si-based superalloys. Acta Metall Sin. 2023, 598969

[10] Reed RC. The Superalloys: Fundamentals and Applications. 2006, London, Cambridge University Press.

[11] Ruan JJ, Liu XJ, Yang SYet al. . Novel Co–Ti–V-base superalloys reinforced by L1₂-ordered γ′ phase. Intermetallics. 2018, 92126.

[12] Im HJ, Makineni SK, Gault B, Stein F, Raabe D, Choi PP. Elemental partitioning and site-occupancy in γ/γ′ forming Co–Ti–Mo and Co–Ti–Cr alloys. Scripta Mater.. 2018, 154159.

[13] Li LL, Wang CP, Yang SYet al. . Phase equilibria in Co–Ti–Re ternary system. Rare Met.. 2023, 4282736.

[14] Reyes Tirado FL, Perrin Toinin J, Dunand DC. γ+γ′ microstructures in the Co–Ta–V and Co–Nb–V ternary systems. Acta Mater.. 2018, 151137.

[15] Nyshadham C, Oses C, Hansen JE, Takeuchi I, Curtarolo S, Hart GLW. A computational high-throughput search for new ternary superalloys. Acta Mater.. 2017, 122438.

[16] Y.H. Chen, C.P. Wang, C. Zhang, C. Yang, J.J. Han, and X.J. Liu, Theoretical investigation of effects of transition elements on phase stabilities and elastic properties of the γ′ phase in Co–V–Ta superalloys, Front. Mater., 9(2022), art. No. 885608.

[17] Chinen H, Sato J, Omori Tet al. . New ternary compound Co₃(Ge, W) with L1₂ structure. Scripta Mater.. 2007, 562141.

[18] Chinen H, Omori T, Oikawa K, Ohnuma I, Kainuma R, Ishida K. Phase equilibria and ternary intermetallic compound with L12 structure in Co–W–Ga system. J. Phase Equilib. Diffus.. 2009, 306587.

[19] W.D. Li, L.F. Li, S. Antonov, F. Lu, and Q. Feng, Effects of Cr and Al/W ratio on the microstructural stability, oxidation property and γ′ phase nano-hardness of multi-component Co–Ni-base superalloys, J. Alloy. Compd., 826(2020), art. No. 154182.

[20] Yan HY, Vorontsov VA, Dye D. Alloying effects in polycrystalline γ′ strengthened Co–Al–W base alloys. Intermetallics. 2014, 4844.

[21] Klein L, Shen Y, Killian MS, Virtanen S. Effect of B and Cr on the high temperature oxidation behaviour of novel γ/γ′-strengthened Co-base superalloys. Corros. Sci.. 2011, 5392713.

[22] Y.H. Chen, F. Xue, C.H. Wang, et al,, Effect of Cr on the microstructure and oxidation properties of Co–Al–W superalloys studied by in situ environmental TEM, Corros. Sci., 161(2019), art. No. 108179.

[23] M. Weiser, R.J. Chater, B.A. Shollock, and S. Virtanen, Transport mechanisms during the high-temperature oxidation of ternary γ/γ′ Co-base model alloys, npjMater. Degrad., 3(2019), art. No. 33.

[24] Povstugar I, Zenk CH, Li Ret al. . Elemental partitioning, lattice misfit and creep behaviour of Cr containing γ′ strengthened Co base superalloys. Mater. Sci. Technol.. 2016, 323220.

[25] X.L. Zhuang, S. Lu, L.F. Li, and Q. Feng, Microstructures and properties of a novel γ′-strengthened multi-component CoNi-based wrought superalloy designed by CALPHAD method, Mater. Sci. Eng. A, 780(2020), art. No. 139219.

[26] W.D. Li, L.F. Li, S. Antonov, and Q. Feng, Effective design of a Co–Ni–Al–W–Ta–Ti alloy with high γ′ solvus temperature and microstructural stability using combined CALPHAD and experimental approaches, Mater. Des., 180(2019), art. No. 107912.

[27] B. Xu, H.Q. Yin, X. Jiang, et al., CALPHAD design and high-throughput search of novel Ni-based superalloys that are reinforced by γ′ + γ″, Mater. Today Commun., 30(2022), art. No. 103164.

[28] Wang CP, Yang P, Liang YHet al. . Phase equilibria in Ni–Ti–Ta ternary system. Trans. Nonferrous Met. Soc. China. 2022, 3241178.

[29] C.P. Wang, K.Y. Chen, H. Ren, et al., Thermodynamic description of the binary Al–V and ternary Al-Cr-V systems, Calphad, 82(2023), art. No. 102579.

[30] Smith JF. Phase Diagrams of Binary Vanadium Alloys. 1989, State of Ohio, ASM International

[31] Pavlů J, Vřešt’ál J, Šob M. Re-modeling of Laves phases in the Cr–Nb and Cr–Ta systems using first-principles results. Calphad. 2009, 331179.

[32] Nagender Naidu SV, Sriramamurthy AM, Rao PR. The Cr–W (Chromium-Tungsten) system. Bull. Alloy Phase Diagr.. 1984, 53289.

[33] Wang CP, Liu XJ, Kainuma R, Takaku Y, Ohnuma I, Ishida K. Formation of core-type macroscopic morphologies in Cu–Fe base alloys with liquid miscibility gap. Metall. Mater. Trans. A. 2004, 3541243.

[34] C.P. Wang, X.J. Liu, I. Ohnuma, R. Kainuma, and K. Ishida, Phase equilibria in Fe–Cu–X (X: Co, Cr, Si, V) ternary systems, J. Phase Equilib., 23(2002), No. 3, art. No. 236.

[35] Wang CP, Liu XJ, Ohnuma I, Kainuma R, Ishida K. Thermodynamic database of the phase diagrams in Cu–Fe base ternary systems. J. Phase Equilib. Diffus.. 2004, 254320.

[36] Shi RP, Wang CP, Wheeler D, Liu XJ, Wang Y. Formation mechanisms of self-organized core/shell and core/shell/corona microstructures in liquid droplets of immiscible alloys. Acta Mater.. 2013, 6141229.

[37] Wang CP, Liu XJ, Ohnuma I, Kainuma R, Ishida K. Formation of immiscible alloy powders with egg-type microstructure. Science. 2002, 2975583990.

[38] Chen YC, Wang CP, Ruan JJet al. . Development of low-density γ/γ′ Co–Al–Ta-based superalloys with high solvus temperature. Acta Mater.. 2020, 188652.

[39] Omori T, Oikawa K, Sato Jet al. . Partition behavior of alloying elements and phase transformation temperatures in Co–Al–W-base quaternary systems. Intermetallics. 2013, 32274.

[40] Shinagawa K, Omori T, Sato Jet al. . Phase equilibria and microstructure on γ′ phase in Co–Ni–Al–W system. Mater. Trans.. 2008, 4961474.

[41] S.S. Qu, Y.J. Li, M.L. He, et al., Microstructural evolution and compression property of a novel γ′-strengthened directionally solidified CoNi-base superalloy, Mater. Sci. Eng. A, 761(2019), art. No. 138034.

[42] B. Ohl, L. Owen, H. Stone, and D.C. Dunand, Microstructure and mechanical properties of L1₂-strengthened Co–Ni–Fe-based superalloys, Mater. Sci. Eng. A, 884(2023), art. No. 145276.

[43] Hisazawa H, Terada Y, Takeyama M. Morphology evolution of γ′ precipitates during isothermal exposure in wrought Ni-based superalloy Inconel X-750. Mater. Trans.. 2017, 585817.

[44] Saenarjhan N, Kiatwisarnkij N, Korthamniwet Wet al. . Development of morphology and lattice misfit in modified Ni-base superalloy with Al, Co and Ni additions. Mater. Test.. 2023, 6581179.

[45] H. Mughrabi, The importance of sign and magnitude of γ/γ′ lattice misfit in superalloys—with special reference to the new γ′-hardened cobalt-base superalloys, Acta Mater., (81)2014, p. 21.

[46] Pandey P, Makineni SK, Samanta Aet al. . Elemental site occupancy in the L1₂ A₃B ordered intermetallic phase in Co-based superalloys and its influence on the microstructure. Acta Mater.. 2019, 163140.

[47] Nithin B, Samanta A, Makineni SKet al. . Effect of Cr addition on γ–γ′ cobalt-based Co–Mo–Al–Ta class of superalloys: A combined experimental and computational study. J. Mater. Sci.. 2017, 521811036.

[48] L.L. Li, C.P. Wang, Y.C. Chen, et al., Effect of Re on microstructure and mechanical properties of γ/γ′ Co–Ti-based superalloys, Intermetallics, 115(2019), art. No. 106612.

[49] Zenk CH, Povstugar I, Li Ret al. . A novel type of Co–Ti–Cr-base γ/γ′ superalloys with low mass density. Acta Mater.. 2017, 135244.

[50] Tirado FLR. Tungsten-free Cobalt-based Superalloys with Gamma Prime Precipitates. 2019, Boston, Northwestern University

[51] Reyes Tirado FL, Taylor S, Dunand DC. Effect of Al, Ti and Cr additions on the γ–γ′ microstructure of W-free Co–Ta–V-based superalloys. Acta Mater.. 2019, 17244.

[52] C.H. Pei, Q.S. Ma, Q.Z. Gao, et al., A critical review on oxidation behavior of Co-based superalloys, Chin. J. Aeronaut., 38(2025), No. 3, art. No. 103380.

[53] Birks N, Meier GH, Pettit FS. Introduction to the High Temperature Oxidation of Metals. 20062nd eds.London, Cambridge University Press.

[54] Bouhanek K, Oquab D, Pieraggi B. High temperature oxidation of single-crystal Ni-base superalloys. Mater. Sci. Forum. 1997, 251–25433.

[55] J.Q. Shi, T.B. Zhang, B. Sun, B. Wang, X.H. Zhang, and L. Song, Isothermal oxidation and TGO growth behavior of NiCo–CrAlY–YSZ thermal barrier coatings on a Ni-based superalloy, J. Alloy. CompdL, 844(2020), art. No. 156093.

[56] Akhtar A, Hegde S, Reed RC. The oxidation of single-crystal nickel-based superalloys. JOM. 2006, 58137.

[57] Chen M, Hallstedt B, Gauckler LJ. Thermodynamic assessment of the Co–O system. J. Phase Equilib.. 2003, 243212.

[58] Suzuki A, DeNolf GC, Pollock TM. Flow stress anomalies in γ/γ′ two-phase Co-Al-W-base alloys. Scripta Mater.. 2007, 565385.

[59] Sims CT, Stoloff NS, Hagel WC. Superalloys II: High-temperature Materials for Aerospace and Industrial Power. 1987, New York, Hoboken, Wiley

[60] Suzuki A, Pollock TM. High-temperature strength and deformation of γ/γ′ two-phase Co–Al–W-base alloys. Acta Mater.. 2008, 5661288.

RIGHTS & PERMISSIONS

University of Science and Technology Beijing