Effect of carbonate additive on the microstructure and corrosion resistance of plasma electrolytic oxidation coating on Mg-9Li-3Al alloy

Abstract

Carbonate was added to the silicate system electrolyte to improve the corrosion resistance of the plasma electrolytic oxidation coating on Mg-9Li-3Al (wt%, LA93) alloy. The influences of carbonate on the morphology, structure, and phase composition of the coating were investigated by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. The corrosion resistance of the coating was evaluated by electrochemical experiment, hydrogen evolution, and immersion test. The results showed that the addition of carbonate resulted in a denser coating with increased hardness, and the corrosion-resistant Li₂CO₃ phase was formed. Electrochemical experiments showed that compared with the coating without carbonate, the corrosion potential of the carbonate coating positively shifted (24 mV), and the corrosion current density was reduced by approximately an order of magnitude. The coating with carbonate addition possessed a high corrosion resistance and long-term protection capability.

Keywords

Mg-Li alloy / plasma electrolytic oxidation / corrosion resistance / carbonate

References

[1] J.H. Wang, L. Xu, R.Z. Wu, D. An, Z. Wei, J.X. Wang, J. Feng, J.H. Zhang, L.G. Hou, and M.D. Liu, Simultaneous achievement of high electromagnetic shielding effectiveness (X-band) and strength in Mg-Li-Zn-Gd/MWCNTs composite, J. Alloys Compd., 882(2021), art. No. 160524.

[2] A. Mehrabi, R. Mahmudi, and H. Miura, Superplasticity in a multi-directionally forged Mg-Li-Zn alloy, Mater. Sci. Eng. A, 765(2019), art. No. 138274.

[3] S.Y. Jin, H.Y. Liu, R.Z. Wu, F. Zhong, L.G. Hou, and J.H. Zhang, Combination effects of Yb addition and cryogenic-rolling on microstructure and mechanical properties of LA141 alloy, Mater. Sci. Eng. A, 788(2020), art. No. 139611.

[4] Wang JH, Xu L, Wu RZ, Feng J, Zhang JH, Hou LG, Zhang ML. Enhanced electromagnetic interference shielding in a duplex-phase Mg-9Li-3Al-1Zn alloy processed by accumulative roll bonding. Acta Metall. Sinica Engl. Lett., 2020, 33(4): 490.

[5] Y.Q. He, C.Q. Peng, Y. Feng, R.C. Wang, and J.F. Zhong, Effects of alloying elements on the microstructure and corrosion behavior of Mg-Li-Al-Y alloys, J. Alloys Compd., 834(2020), art. No. 154344.

[6] Orlov D, Ralston KD, Birbilis N, Estrin Y. Enhanced corrosion resistance of Mg alloy ZK60 after processing by integrated extrusion and equal channel angular pressing. Acta Mater., 2011, 59(15): 6176.

[7] L.Y. Wang, X.M. Xiao, E.Y. Liu, S.R. Yu, X.L. Yin, J. Wang, G. Zhu, Q. Li, and J. Li, Fabrication of superhydrophobic needle-like Ca-P coating with anti-fouling and anti-corrosion properties on AZ31 magnesium alloy, Colloids Surf. A, 620(2021), art. No. 126568.

[8] B.T. da Fonseca, E. D’Elia, J.M. Siqueira Júnior, S.M. Oliveira, K.L. Castro, and E.S. Ribeiro, Study of the characteristics and properties of the SiO₂/TiO₂/Nb₂O₅ material obtained by the sol-gel process, Sci. Rep., 11(2021), No. 1, art. No. 1106.

[9] Huang CA, Lin CK, Yeh YH. The corrosion and wear resistances of magnesium alloy (LZ91) electroplated with copper and followed by 1 μm-thick chromium deposits. Thin Solid Films, 2011, 519(15): 4774.

[10] Zhang JM, Wang K, Duan X, Zhang Y, Cai H, Wang ZH. Effect of hydrothermal treatment time on microstructure and corrosion behavior of micro-arc oxidation/layered double hydroxide composite coatings on LA103Z Mg-Li alloy in 3.5 wt.% NaCl solution. J. Mater. Eng. Perform., 2020, 29(6): 4032.

[11] Qian BY, Miao W, Qiu M, Gao F, Hu DH, Sun JF, Wu RZ, Krit B, Betsofen S. Influence of voltage on the corrosion and wear resistance of micro-arc oxidation coating on Mg-8Li-2Ca alloy. Acta Metall. Sinica Engl. Lett., 2019, 32(2): 194.

[12] Apelfeld A, Krit B, Ludin V, Morozova N, Vladimirov B, Wu RZ. The characterization of plasma electrolytic oxidation coatings on AZ41 magnesium alloy. Surf. Coat. Technol., 2017, 322, 127.

[13] An LY, Ma Y, Liu YP, Sun L, Wang S, Wang ZY. Effects of additives, voltage and their interactions on PEO coatings formed on magnesium alloys. Surf. Coat. Technol., 2018, 354, 226.

[14] Li ZJ, Ren QH, Wang XX, Kuang Q, Ji DB, Yuan RX, Jing XY. Effect of phosphate additive on the morphology and anti-corrosion performance of plasma electrolytic oxidation coatings on magnesium-lithium alloy. Corros. Sci., 2019, 157, 295.

[15] M. Mohedano, P. Pérez, E. Matykina, B. Pillado, G. Garcés, and R. Arrabal, PEO coating with Ce-sealing for corrosion protection of LPSO Mg-Y-Zn alloy, Surf. Coat. Technol., 383(2020), art. No. 125253.

[16] Li ZJ, Yuan Y, Sun PP, Jing XY. Ceramic coatings of LA141 alloy formed by plasma electrolytic oxidation for corrosion protection. ACS Appl. Mater. Interfaces, 2011, 3(9): 3682.

[17] Wang XB, Tian XB, Gong CZ, Yang SQ. Effect of Na₂CO₃ on energy consumption of micro-arc oxidation of magnesium alloy. Rare Met. Mater. Eng., 2012, 41(S1): 187

[18] Li CQ, Tong ZP, He YB, Huang HP, Dong Y, Zhang P. Comparison on corrosion resistance and surface film of pure Mg and Mg-14Li alloy. Trans. Nonferrous Met. Soc. China, 2020, 30(9): 2413.

[19] S. Tang, T.Z. Xin, W.Q. Xu, D. Miskovic, C.Q. Li, N. Birbilis, and M. Ferry, The composition-dependent oxidation film formation in Mg-Li-Al alloys, Corros. Sci., 187(2021), art. No. 109508.

[20] Xu WQ, Birbilis N, Sha G, Wang Y, Daniels JE, Xiao Y, Ferry M. A high-specific-strength and corrosion-resistant magnesium alloy. Nat. Mater., 2015, 14(12): 1229.

[21] Yan Y, Qiu Y, Gharbi O, Birbilis N, Nakashima PNH. Characterisation of Li in the surface film of a corrosion resistant Mg-Li(-Al-Y-Zr) alloy. Appl. Surf. Sci., 2019, 494, 1066.

[22] Li CQ, He YB, Huang HP. Effect of lithium content on the mechanical and corrosion behaviors of HCP binary Mg-Li alloys. J. Magnes. Alloys, 2021, 9(2): 569.

[23] Yang JJ, Lu XP, Blawert C, Di SC, Zheludkevich ML. Microstructure and corrosion behavior of Ca/P coatings prepared on magnesium by plasma electrolytic oxidation. Surf. Coat. Technol., 2017, 319, 359.

[24] Duan HP, Du KQ, Yan CW, Wang FH. Electrochemical corrosion behavior of composite coatings of sealed MAO film on magnesium alloy AZ91D. Electrochim. Acta, 2006, 51(14): 2898.

[25] Yin B, Peng ZJ, Liang J, Jin KJ, Zhu SY, Yang J, Qiao ZH. Tribological behavior and mechanism of self-lubricating wear-resistant composite coatings fabricated by one-step plasma electrolytic oxidation. Tribol. Int., 2016, 97, 97.

[26] J. da Silva Rodrigues, L. Marasca Antonini, A.A. da Cunha Bastos, J. Zhou, and C. de Fraga Malfatti, Corrosion resistance and tribological behavior of ZK30 magnesium alloy coated by plasma electrolytic oxidation, Surf. Coat. Technol., 410(2021), art. No. 126983.

[27] E. Wierzbicka, B. Vaghefinazari, S.V. Lamaka, M.L. Zheludkevich, M. Mohedano, L. Moreno, P. Visser, A. Rodriguez, J. Velasco, R. Arrabal, and E. Matykina, Flash-PEO as an alternative to chromate conversion coatings for corrosion protection of Mg alloy, Corros. Sci., 180(2021), art. No. 109189.

[28] Xia QX, Zhang DJ, Li DQ, Jiang ZH, Yao ZP. Preparation of the plasma electrolytic oxidation coating on Mg-Li alloy and its thermal control performance. Surf. Coat. Technol., 2019, 369, 252.

[29] L. Liu, S.R. Yu, E.Y. Liu, Y. Zhao, B.Y. Wang, Y.F. Niu, K. Zhang, G. Zhu, and Q. Li, Preparation and characterization of micro-arc oxidation coating on hollow glass microspheres/Mg alloy degradable composite, Mater. Chem. Phys., 271(2021), art. No. 124935.

[30] Wang XB, Tian XB, Gong CZ, Yang SQ. Na₂CO₃-induced gas evolution reaction and morphology modulation on magnesium alloy during micro-arc oxidation. J. Inorg. Mater., 2011, 26(7): 721.

[31] Chang CY, Yang SY, Chan JCC. Solubility product of amorphous magnesium carbonate. J. Chin. Chem. Soc., 2021, 68(3): 476.

[32] Wang L, Shinohara T, Zhang BP. XPS study of the surface chemistry on AZ31 and AZ91 magnesium alloys in dilute NaCl solution. Appl. Surf. Sci., 2010, 256(20): 5807.

[33] Qian K, Li WZ, Lu XP, Han XX, Jin Y, Zhang T, Wang FH. Effect of phosphate-based sealing treatment on the corrosion performance of a PEO coated AZ91D Mg alloy. J. Magnes. Alloys, 2020, 8(4): 1328.

[34] Pardo A, Merino S, Merino MC, Barroso I, Mohedano M, Arrabal R, Viejo F. Corrosion behaviour of silicon-carbide-particle reinforced AZ92 magnesium alloy. Corros. Sci., 2009, 51(4): 841.

[35] Yao HB, Li Y, Wee ATS. Passivity behavior of melt-spun Mg-Y Alloys. Electrochim. Acta, 2003, 48(28): 4197.

[36] Lee SJ, Do LHT. Effects of copper additive on micro-arc oxidation coating of LZ91 magnesium-lithium alloy. Surf. Coat. Technol., 2016, 307, 781.

[37] X.M. Zhang, G.S. Wu, X. Peng, L.M. Li, H.Q. Feng, B. Gao, K.F. Huo, and P.K. Chu, Mitigation of corrosion on magnesium alloy by predesigned surface corrosion, Sci. Rep., 5(2015), art. No. 17399.

[38] Yerokhin AL, Snizhko LO, Gurevina NL, Leyland A, Pilkington A, Matthews A. Spatial characteristics of discharge phenomena in plasma electrolytic oxidation of aluminium alloy. Surf. Coat. Technol., 2004, 177–178, 779.

[39] Mortezanejad E, Atapour M, Salimijazi H, Alhaji A, Hakimizad A. Wear and corrosion behavior of aluminate- and phosphate-based plasma electrolytic oxidation coatings with polytetrafluoroethylene nanoparticles on AZ80 Mg alloy. J. Mater. Eng. Perform., 2021, 30(6): 4030.

[40] L. Prince, M.A. Rousseau, X. Noirfalise, L. Dangreau, L.B. Coelho, and M.G. Olivier, Inhibitive effect of sodium carbonate on corrosion of AZ31 magnesium alloy in NaCl solution, Corros. Sci., 179(2021), art. No. 109131.

[41] Hou LF, Raveggi M, Chen XB, Xu WQ, Laws KJ, Wei YH, Ferry M, Birbilis N. Investigating the passivity and dissolution of a corrosion resistant Mg-33at.%Li alloy in aqueous chloride using online ICP-MS. J. Electrochem. Soc., 2016, 163(6): C324.