High-temperature oxidation resistance of TiB₂ coatings on molybdenum produced by molten salt electrophoretic deposition

Abstract

TiB₂ coatings can significantly enhance the high-temperature oxidation resistance of molybdenum, which would broaden the application range of molybdenum and alloys thereof. However, traditional methods for preparing TiB₂ coatings have disadvantages such as high equipment costs, complicated processes, and highly toxic gas emissions. This paper proposes an environmentally friendly method, which requires inexpensive equipment and simple processing, for preparing TiB₂ coating on molybdenum via electrophoretic deposition within Na₃AlF₆-based molten salts. The produced TiB₂ layer had an approximate thickness of 60 µm and exhibited high density, outstanding hardness (38.2 GPa) and robust adhesion strength (51 N). Additionally, high-temperature oxidation experiments revealed that, at 900°C, the TiB₂ coating provided effective protection to the molybdenum substrate against oxidation for 3 h. This result indicates that the TiB₂ coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.

Keywords

molten salt electrophoretic deposition / molybdenum / TiB₂ coating / high-temperature oxidation resistance

References

[1] Zhang HA, Gu SY. Preparation and oxidation behavior of MoSi₂–CrSi₂–Si₃N₄ composite coating on Mo substrate. Int. J. Refract. Met. Hard Mater., 2013, 41: 128.

[2] Nyutu EK, Kmetz MA, Suib SL. Formation of MoSi₂–SiO₂ coatings on molybdenum substrates by CVD/MOCVD. Surf. Coat. Technol., 2006, 200(12–13): 3980.

[3] A.V. Abramov, R.R. Alimgulov, A.I. Trubcheninova, et al., Corrosion of molybdenum-based and Ni–Mo alloys in liquid bismuth–lithium alloy, Metals, 13(2023), No. 2, art. No. 366.

[4] Zhang FJ, Liu CH, Chandrasekar S, Li YW, Xu FC. Preparation of sodium molybdate from molybdenum concentrate by microwave roasting and alkali leaching. Int. J. Miner. Metall. Mater., 2024, 31(1): 91.

[5] T. Fu, F.Q. Shen, Y.Y. Zhang, et al., Oxidation protection of high-temperature coatings on the surface of Mo-based alloys—A review, Coatings, 12(2022), No. 2, art. No. 141.

[6] Babinsky K, Weidow J, Knabl W, Lorich A, Leitner H, Primig S. Atom probe study of grain boundary segregation in technically pure molybdenum. Mater. Charact., 2014, 87: 95.

[7] Huang C, Zhang YZ, Vilar R. Microstructure and anti-oxidation behavior of laser clad Ni–20Cr coating on molybdenum surface. Surf. Coat. Technol., 2010, 205(3): 835.

[8] Suzuki RO, Ishikawa M, Ono K. MoSi₂ coating on molybdenum using molten salt. J. Alloy. Compd., 2000, 306(1–2): 285.

[9] K. Amakawa, Y.Q. Wang, J. Kröhnert, R. Schlögl, and A. Trunschke, Acid sites on silica-supported molybdenum oxides probed by ammonia adsorption: Experiment and theory, Mol. Catal., 478(2019), art. No. 110580.

[10] Kruzic JJ, Schneibel JH, Ritchie RO. Fracture and fatigue resistance of Mo–Si–B alloys for ultrahigh-temperature structural applications. Scripta Mater., 2004, 50(4): 459.

[11] C. Jiang, R.D. Mariani, and C.A. Adkins, Ab initio investigation and thermodynamic modeling of the Mo–Ti–Zr system, Materialia, 10(2020), art. No. 100701.

[12] M. Zhao, B.Y. Xu, Y.M. Shao, et al., Microstructure and oxidation mechanism of multiphase Mo–Ti–Si–B alloys at 800°C, Corros. Sci., 187(2021), art. No. 109518.

[13] Zhang YH, Li ZX, Gui YW, Fu HD, Xie JX. Effect of Ti and Ta content on the oxidation resistance of Co–Ni-based superalloys. Int. J. Miner. Metall. Mater., 2024, 31(2): 351.

[14] Zhang HA, Lv JX, Wu YH, Gu SY, Huang Y, Chen Y. Oxidation behavior of (Mo, W)Si₂–Si₃N₄ composite coating on molybdenum substrate at 1600°C. Ceram. Int., 2015, 41(10): 14890.

[15] Huang XX, Sun SC, Lu SD, Li KH, Tu GF, Song JX. Synthesis and characterization of oxidation-resistant TiB₂ coating on molybdenum substrate by chemical vapor deposition. Mater. Lett., 2018, 228: 53.

[16] Huang XX, Sun SC, Tu GF. Investigation of mechanical properties and oxidation resistance of CVD TiB₂ ceramic coating on molybdenum. J. Mater. Res. Technol., 2020, 9(1): 282.

[17] Zhu L, Zhu YS, Ren XR, Zhang P, Qiao JH, Feng PZ. Microstructure, properties and oxidation behavior of MoSi₂–MoB–ZrO₂ coating for Mo substrate using spark plasma sintering. Surf. Coat. Technol., 2019, 375: 773.

[18] Huang XX, Tu GF, Wang SX, Song JX, Liu Y, Wang ZZ. Research progress in preparation and application of TiB₂ coating. Rare Met. Mater. Eng., 2022, 51(3): 1087

[19] Tkadletz M, Schalk N, Mitterer C, Keckes J, Pohler M, Czettl C. Cross-sectional characterization techniques as the basis for knowledge-based design of graded CVD TiN–TiB₂ coatings. Int. J. Refract. Met. Hard Mater., 2018, 71: 280.

[20] Vajdi M, Sadegh Moghanlou F, Ranjbarpour Niari E, Shahedi Asl M, Shokouhimehr M. Heat transfer and pressure drop in a ZrB₂ microchannel heat sink: A numerical approach. Ceram. Int., 2020, 46(2): 1730.

[21] P. Kiryukhantsev-Korneev, A. Sytchenko, Y. Kaplanskii, A. Sheveyko, S. Vorotilo, and E. Levashov, Structure, corrosion resistance, mechanical and tribological properties of ZrB₂ and Zr–B–N coatings, Metals, 11(2021), No. 8, art. No. 1194.

[22] Hao JJ, Li JY, Zou BL, Cai XL, Shi W, Tan Y. Effect of phase composition on the oxidation resistance of ZrB₂–SiC coatings. J. Eur. Ceram. Soc., 2022, 42(5): 2097.

[23] Zhou XJ, Xu JW, Zha YT, et al. . High temperature protection of a novel TiB₂-modified (Nb, Mo, Cr)Si₂ ceramic coating on Nb-based alloy. J. Eur. Ceram. Soc., 2024, 44(7): 4425.

[24] Wang Y, Zhang GH, Chou K. Preparation and oxidation characteristics of ZrC–ZrB₂ composite powders with different proportions. Int. J. Miner. Metall. Mater., 2022, 29(3): 521.

[25] Xu JL, Shi ZN, Qiu ZX. Preparation of TiB₂ inert cathode by electrodeposition process for aluminum electrolysis. J. Northeast. Univ., 2004, 25(9): 873

[26] Yu J, Geng YX, Chen YK, et al. . High-strength and thermally stable TiB₂-modified Al–Mn–Mg–Er–Zr alloy fabricated via selective laser melting. Int. J. Miner. Metall. Mater., 2024, 31(10): 2221.

[27] Pierson HO, Randich E. Titanium diboride coatings and their interaction with the substrates. Thin Solid Films, 1978, 54(1): 119.

[28] Padamata SK, Singh K, Haarberg GM, Saevarsdottir G. Wettable TiB₂ cathode for aluminum electrolysis: A review. J. Sustainable Metall., 2022, 8(2): 613.

[29] Krendelsberger R, Souto MF, Sytchev J, et al. . Texture effects in TiB₂ coatings electrodeposited from a NaCl–KCl–K₂TiF₆–NaF–NaBF₄ melt at 700°C. J. Min. Metall. Sect. B., 2003, 39(1–2): 269.

[30] Makyta M, Daněk V, Haarberg GM, Thonstad J. Electrodeposition of titanium diboride from fused salts. J. Appl. Electrochem., 1996, 26(3): 319.

[31] Fastner U, Steck T, Pascual A, Fafilek G, Nauer GE. Electrochemical deposition of TiB₂ in high temperature molten salts. J. Alloy. Compd., 2008, 452(1): 32.

[32] N. Rybakova, O. Babushkina, W. Artner, and G.E. Nauer, Electrochemical synthesis of TiB₂ layers out of FLiNaK electrolyte in the presence of TaCl₅ additive, J. Electrochem. Soc., 157(2010), No. 12, art. No. D593.

[33] Zhang J, Chu SJ, Jin WL, Cai F, Zhu HM, Xiao SJ. Fabrication of TiB₂ coatings by electrophoretic deposition of synthesized TiB₂ nanoparticles in molten salts. J. Mater. Res. Technol., 2022, 18: 2451.

[34] Pang J, Kou Q, Ge CT, et al. . Electrophoretic deposition of ZrB₂ coatings in NaCl–KCl–AlF₃ melt containing synthesized ZrB₂ nanoparticles. J. Am. Ceram. Soc., 2023, 106(9): 5147.

[35] T. Jiang, J.J. Xu, C.T. Ge, et al., Electrophoretically deposited TiB₂ coatings in NaF–AlF₃ melt for corrosion resistance in liquid zinc, Coatings, 14(2024), No. 8, art. No. 1021.

[36] J.L. Liu, J.J. Xu, C.T. Ge, et al., Stability investigation of TiB₂ coatings in molten zinc fabricated by electrophoretic deposition in molten salts, Metals, 14(2024), No. 9, art. No. 981.

[37] Kou Q, Ge CT, Xu JJ, et al. . Electrophoretic deposition of TiB2 coatings on cemented carbide in molten fluorides. Ceram. Int., 2025, 51(4): 4870.

[38] D.P. Gruber, J. Zalesak, J. Todt, et al., Surface oxidation of nanocrystalline CVD TiB₂ hard coatings revealed by cross-sectional nano-analytics and in situ micro-cantilever testing, Surf. Coat. Technol., 399(2020), art. No. 126181.

[39] Sarkar P, Nicholson PS. Electrophoretic deposition (EPD): Mechanisms, kinetics, and application to ceramics. J. Am. Ceram. Soc., 1996, 79(8): 1987.

[40] Yang SK, Cai WP, Liu GQ, Zeng HB. From nanoparticles to nanoplates: Preferential oriented connection of Ag colloids during electrophoretic deposition. J. Phys. Chem. C, 2009, 113(18): 7692.

[41] Ge CT, Kou Q, Pang J, et al. . Preparation of ZrB₂ coatings by electrophoretic deposition in NaCl–KCl–AlCl₃ molten salts. J. Mater. Res. Technol., 2022, 20: 772.

[42] Chaim R. On the kinetics of liquid-assisted densification during flash sintering of ceramic nanoparticles. Scripta Mater., 2019, 158: 88.

[43] Verkhoturov AD, Egorov FF, Podchernyaeva IA, et al. . Characteristics of coating formation on steel during electric-spark alloying with heterophase TiB₂ + Mo materials in air. Powder Metall. Met. Ceram., 1983, 22(12): 993.

[44] Panich N, Sun Y. Mechanical properties of TiB₂-based nanostructured coatings. Surf. Coat. Technol., 2005, 198(1–3): 14.

[45] Panich N, Sun Y. Effect of substrate rotation on structure, hardness and adhesion of magnetron sputtered TiB2 coating on high speed steel. Thin Solid Films, 2006, 500(1–2): 190.

[46] Murthy TSRC, Sonber JK, Vishwanadh B, et al. . Densification, characterization and oxidation studies of novel TiB₂ + EuB6 compounds. J. Alloy. Compd., 2016, 670: 85.

[47] Opeka MM, Talmy IG, Wuchina EJ, Zaykoski JA, Causey SJ. Mechanical, thermal, and oxidation properties of refractory hafnium and zirconium compounds. J. Eur. Ceram. Soc., 1999, 19(13–14): 2405.

[48] Parthasarathy TA, Rapp RA, Opeka M, Kerans RJ. A model for the oxidation of ZrB₂, HfB₂ and TiB₂. Acta Mater., 2007, 55(17): 5999.

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