What activates the Mg surface—A comparison of Mg dissolution mechanisms

doi:10.1016/j.jmst.2020.03.060

Abstract

Abstract:

Several mechanisms have been proposed to interpret the widely reported phenomenon of Mg corrosion that the hydrogen evolution rate increases with increasing anodic potential or anodic current density. This paper critically analyzed the two main mechanisms, (1) “the incomplete film univalent Mg ⁺ ion mechanism” and (2) “the enhanced catalytic activity mechanism”, aiming to clarify the current understanding of the Mg corrosion mechanism and to provide a profound insight into the Mg characteristic electrochemical behavior, anodic polarization accelerating both hydrogen evolution and Mg dissolution. It is expected that the deepened fundamental understanding from this comprehensive mechanistic review will provide a basis of practical applications for Mg alloys and open up a new way to the control of corrosion of Mg alloys in practice.

Key words: Magnesium, Negative difference effect (NDE), Corrosion, Hydrogen evolution, Anodic dissolution

Jufeng Huang, Guang-Ling Song, Andrej Atrens, Matthew Dargusch. What activates the Mg surface—A comparison of Mg dissolution mechanisms[J]. J. Mater. Sci. Technol., 2020, 57: 204-220.

Figures/Tables 11

Fig. 1. Timeline of the development of Mg dissolution mechanism [12,17,[32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44]].

Fig. 2. Schematic illustration of various NDE or Mg dissolution models [12,40,41,43,60,62,63].

Table 1 Proposed Mg corrosion and NDE mechanisms.

Mechanism	Key points	Supporting experiments	Opposing observations
(1) Partially protective surface film	The surface film increasingly disrupted with increasing current density or potential.	The Mg(OH)₂ and MgO on the Mg surface detected [64].	The corrosion potential too positive in a neutral or acidic solution [65] and AHE occurs in strong acids [66].
(2) Uni-positive Mg⁺ ion	Mg electrochemically anodized into univalent Mg⁺ ion and then immediately reacted chemically with water, converting into Mg²⁺ and producing hydrogen.	The calculated valence of dissolved Mg was in the range from 1.33 to 1.66 [67]. Gas phase studies have indicated that Mg⁺ reacts in milliseconds with water [68,69,70,71,72,73,74,75]. Simultaneous transfer of two electron in a single step forbidden by quantum mechanics [76]. First principle calculations, the loss of one electron much easier than two [77].	Uni-positive Mg⁺ ion not experimentally observed by disk-ring electrode [46] or oxidized by a strong oxidant [78].
(3) Magnesium hydride (MgH₂)	Mg electrochemically or chemically reduced to the hydride and reacted chemically with water to release hydrogen.	MgH₂ detected by X-ray diffraction [51].	MgH₂ more difficult to form under stronger anodic polarization, and thus failure to interpret the NDE [12].
(4) Particle undermining	Particles undermined by corrosion of the surrounding matrix and falling out, resulting in more mass loss than electrochemical dissolution.	A SEM photomicrograph showing a particle partially undermined [53].	Hydrogen evolution rate not increased by anodic polarization [46].
(5) Incomplete film univalent Mg⁺ ion	Analyzed/discussed in detail in the following sections.
(6) Self-corrosion	A self-corrosion process within a crevice (or crack-like feature) isolated by hydrogen bubbles involved in the dissolution of Mg.	Hydrogen bubbles trapped on the surface of corroding Mg [31].	The self-corrosion independent from polarization, and thus not responsible for NDE.
(7) Cathodic catalytic activity	Analyzed/discussed in detail in following sections.

Table 1 Proposed Mg corrosion and NDE mechanisms.

Mechanism	Key points	Supporting experiments	Opposing observations
(1) Partially protective surface film	The surface film increasingly disrupted with increasing current density or potential.	The Mg(OH)₂ and MgO on the Mg surface detected [64].	The corrosion potential too positive in a neutral or acidic solution [65] and AHE occurs in strong acids [66].
(2) Uni-positive Mg⁺ ion	Mg electrochemically anodized into univalent Mg⁺ ion and then immediately reacted chemically with water, converting into Mg²⁺ and producing hydrogen.	The calculated valence of dissolved Mg was in the range from 1.33 to 1.66 [67]. Gas phase studies have indicated that Mg⁺ reacts in milliseconds with water [68,69,70,71,72,73,74,75]. Simultaneous transfer of two electron in a single step forbidden by quantum mechanics [76]. First principle calculations, the loss of one electron much easier than two [77].	Uni-positive Mg⁺ ion not experimentally observed by disk-ring electrode [46] or oxidized by a strong oxidant [78].
(3) Magnesium hydride (MgH₂)	Mg electrochemically or chemically reduced to the hydride and reacted chemically with water to release hydrogen.	MgH₂ detected by X-ray diffraction [51].	MgH₂ more difficult to form under stronger anodic polarization, and thus failure to interpret the NDE [12].
(4) Particle undermining	Particles undermined by corrosion of the surrounding matrix and falling out, resulting in more mass loss than electrochemical dissolution.	A SEM photomicrograph showing a particle partially undermined [53].	Hydrogen evolution rate not increased by anodic polarization [46].
(5) Incomplete film univalent Mg⁺ ion	Analyzed/discussed in detail in the following sections.
(6) Self-corrosion	A self-corrosion process within a crevice (or crack-like feature) isolated by hydrogen bubbles involved in the dissolution of Mg.	Hydrogen bubbles trapped on the surface of corroding Mg [31].	The self-corrosion independent from polarization, and thus not responsible for NDE.
(7) Cathodic catalytic activity	Analyzed/discussed in detail in following sections.

Fig. 3. Schematic illustration of anodic and cathodic reactions involved in the self-corrosion and under anodic polarization of Mg [63].

Fig. 4. Schematic Evans diagram explaining the NDE behavior by the exchange of current density for HER [42]. The bold line represents the HE current density as a function of potential.

Table 2 Values of the standard Gibbs energy of formation of species [63].

Species	Oxidation state	State	μ₀ (kcal/mol)
Mg	0	Solid	0
Mg⁺	+1	Ion	-61
Mg²⁺	+2	Ion	-109
Mg(OH)₂	+2	Solid	-199
MgH	+1	Gas	+34
MgH₂	+2	Solid	-8
MgO	+2	Solid	-136

Fig. 5. Electrochemical impedance diagrams of Mg in a 0.1 mol/L Na2SO4 solution: (a) after different immersion times at Ecorr, (b) at Ecorr and for two anodic over potentials [55].

Fig. 6. Polarization curves and hydrogen evolution results for Mg in saturated Mg(OH)2 solution: (a) experimental and IR-corrected potentiostatic polarization curves, (b) average hydrogen evolution rates at different potentials, and (c) hydrogen evolution volume versus time at different potentials [81].

Fig. 7. Hydrogen evolution and corrosion morphologies of a polarized Mg alloy MEZU under different polarization conditions, in which (a)-(e) show the cloudy “trails’’ of hydrogen bubbles and trapped hydrogen bubbles associated with cathodic hydrogen evolution, and (d) and (e) show the cloudy zones along the edges of the dark (corroding) areas associated with anodic hydrogen evolution: (a) the alloy at the cathodic potential -1.8 V/SCE; (b) MEZU at a cathodic potential -1.7 V/SCE in the same area as (a); (c) MEZU at anodic potential -1.4 V/SCE in the same area as (a); (d) MEZU at anodic potential -1.4 V/SCE in another area; (e) MEZU at cathodic potential -2 V/SCE in the same area as (d) after anodically polarized at -1.4 V/SCE [17,39].

Fig. 8. Corrosion development on an MEZU specimen during immersion in a 5 % NaCl solution (the faint cloudy “trails” from some small sites in these micrographs are evolving hydrogen bubbles. The cloud “trails” are designated as “cathodic hydrogen evolution”, and denoted as “cathodic” in Fig. 8(a). Some cloudy zones along the edge of the black areas in these figures also involving hydrogen bubbles, and the areas that are black in color are corroded or corroding sites. The hydrogen evolution from these corroding areas is designated “anodic hydrogen evolution” and denoted as “anodic” in Fig. 8(a) [39].

Fig. 9. Hydrogen evolution rates of a pure Mg specimen in 0.1 M HCl galvanostatically polarized at an anodic current density for 10 min., and immediately potentiostatically polarized at cathodic potential -2.2 V vs. Ag/AgCl for 10 min., then the anodic-cathodic step polarization repeated at a more positive anodic current density until 60 mA/cm2 (the anodic hydrogen evolution rate in each the anodic polarization step decreases first and then increases with increase anodic current density, while the cathodic hydrogen evolution rate in the cathodic potentostatic potential -2.2 V (Ag/AgCl) step immediately after the anodic polarization decreases as the anodic current density in the anodic polarization step increases) [These experimental results were recently obtained in the lab].

References 147

[1]	W.J. Joost, P.E. Krajewski, Scr. Mater. 128(2017) 107-112. DOI URL
[2]	T.T.T. Trang, J.H. Zhang, J.H. Kim, A. Zargaran, J.H. Hwang, B.C. Suh, N.J. Kim, Nat. Commun. 9(2018) 2522-2527. DOI URL PMID
[3]	T.M. Pollock, Science 328 (2010) 986-987. DOI URL PMID
[4]	N. Wang, R. Wang, Y. Feng, W. Xiong, J. Zhang, M. Deng, Corros. Sci. 112 (2016) 13-24.
[5]	H.D. Yoo, I. Shterenberg, Y. Gofer, G. Gershinsky, N. Pour, D. Aurbach, Energy Environ. Sci. 6(2013) 2265-2279. DOI URL
[6]	W. Frank, H. Norbert, V. Carla, C. Smadar, K.U. Kainer, W. Regine, F. Frank, Curr. Opin. Solid State Mat. Sci. 12(2008) 63-72. DOI URL
[7]	A.P.M. Saad, A. Syahrom, Corros. Sci. 131(2018) 45-56. DOI URL
[8]	S. Johnston, C. Lau, M.S. Dargusch, A. Atrens, J. Mech. Behav. Biomed. Mater. 97(2019) 321-329. DOI URL PMID
[9]	S. Johnston, Z. Shi, J. Venezuela, C. Wen, M.S. Dargusch, A. Atrens, JOM 71 (2019) 1406-1413.
[10]	M. Grimm, A. Lohmüller, R.F. Singer, S. Virtanen, Corros. Sci. 155(2019) 195-208.
[11]	A. Atrens, G.L. Song, M. Liu, Z. Shi, F. Cao, M.S. Dargusch, Adv. Eng. Mater. 17(2015) 400-453.
[12]	G.L. Song, A. Atrens, Adv. Eng. Mater. 1(1999) 11-33.
[13]	A. Atrens, S. Johnston, Z. Shi, M.S. Dargusch, Scr. Mater. 154(2018) 92-100.
[14]	G.-L. Song, Z. Xu, Corros. Sci. 63(2012) 100-112.
[15]	G. Song, A. Atrens, X. Wu, B. Zhang, Corros. Sci. 40(1998) 1769-1791.
[16]	G. Song, A. Atrens, Adv. Eng. Mater. 5(2003) 837-858.
[17]	G. Song, Adv. Eng. Mater. 7(2005) 563-586.
[18]	M. Esmaily, J. Svensson, S. Fajardo, N. Birbilis, G. Frankel, S. Virtanen, R. Arrabal, S. Thomas, L. Johansson, Prog. Mater. Sci. 89(2017) 92-193.
[19]	W. Zhang, Q. Liu, Y. Chen, G. Wan, Mater. Lett. 232(2018) 54-57.
[20]	L. Rossrucker, A. Samaniego, J.-P. Grote, A.M. Mingers, C.A. Laska, N. Birbilis, G.S. Frankel, K.J.J. Mayrhofer, J. Electrochem. Soc. 162(2015) C333-C339.
[21]	F. Cao, Z. Shi, J. Hofstetter, P.J. Uggowitzer, G. Song, M. Liu, A. Atrens, Corros. Sci. 75(2013) 78-99.
[22]	R.L. Liu, J.R. Scully, G. Williams, N. Birbilis, Electrochim. Acta 260 (2018) 184-195.
[23]	N. Birbilis, G. Williams, K. Gusieva, A. Samaniego, M.A. Gibson, H.N. McMurray, Electrochem.commun. 34(2013) 295-298.
[24]	S. Fajardo, C.F. Glover, G. Williams, G.S. Frankel, Electrochim. Acta 212 (2016) 510-521.
[25]	A.D. Sudholz, K. Gusieva, X.B. Chen, B.C. Muddle, M.A. Gibson, N. Birbilis, Corros. Sci. 53(2011) 2277-2282.
[26]	F. Cao, Z. Shi, G.L. Song, M. Liu, M.S. Dargusch, A. Atrens, Corros. Sci. 90 (2015) 176-191.
[27]	F. Cao, Z. Shi, G.L. Song, M. Liu, A. Atrens, Corros. Sci. 76(2013) 60-97.
[28]	A. Atrens, G.L. Song, M. Liu, Z. Shi, F. Cao, M.S. Dargusch, Adv. Eng. Mater. 17(2015) 400-453.
[29]	F. Cao, G.-L. Song, A. Atrens, Corros. Sci. 111(2016) 835-845.
[30]	S. Thomas, N.V. Medhekar, G.S. Frankel, N. Birbilis, Curr. Opin. Solid State Mater.Sci. 19(2015) 85-94.
[31]	A. Atrens, G.L. Song, F. Cao, Z. Shi, P.K. Bowen, J. Magn. Alloy. 1(2013) 177-200.
[32]	W. Beetz, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science 32 (1866) 269-278.
[33]	J. Turrentine, J. Phys. Chem. 12(1908) 448-467.
[34]	R.L. Petty, A.W. Davidson, J. Kleinberg, J. Am. Soc. 76(1954) 363-366.
[35]	M. Straumanis, B. Bhatia, J. Electrochem. Soc. 110(1963) 357-360.
[36]	D.A. Vermilyea, C.F. Kirk, J. Electrochem. Soc. 116(1969) 1487-1492.
[37]	G.G. Perrault, J. Electroanal. Chem. Int. Electrochem. 27(1970) 47-58.
[38]	R. Tunold, H. Holtan, M.-B. Berge, A. Lasson R. Steen-Hansen, Corros. Sci. 17(1977) 353-365.
[39]	G. Song, D. StJohn, J. Light Met. 2(2002) 1-16.
[40]	G. Baril, G. Galicia, C. Deslouis, N. Pébère, B. Tribollet, V. Vivier, J. Electrochem. Soc. 154(2007) C108-C113.
[41]	A. Atrens, W. Dietzel, Adv. Eng. Mater. 9(2007) 292-297.
[42]	G. Frankel, A. Samaniego, N. Birbilis, Corros. Sci. 70(2013) 104-111.
[43]	M. Taheri, J. Kish, N. Birbilis, M. Danaie, E. McNally, J. McDermid, Electrochim. Acta 116 (2014) 396-403.
[44]	C.D. Taylor, J. Electrochem. Soc. 163(2016) C602-C608.
[45]	T. Thomaz, C. Weber, T. Pelegrini Jr, L. Dick, G. Knörnschild, Corros. Sci. 52(2010) 2235-2243.
[46]	G. Song, A. Atrens, D. Stjohn, J. Nairn, Y. Li, Corros. Sci. 39(1997) 855-875.
[47]	C. Do Lee, C.S. Kang, K.S. Shin, Met. Mater. Int. 7(2001) 385-391.
[48]	E. Gulbrandsen, J. Taftø, A. Olsen, Corros. Sci. 34(1993) 1423-1440.
[49]	W.-D. Mueller, H. Hornberger, Int. J. Mol. Sci. 15(2014) 11456-11472. URL PMID
[50]	J. Chen, J. Dong, J. Wang, E. Han, W. Ke, Corros. Sci. 50(2008) 3610-3614.
[51]	C. Brun, J. Pagetti, J. Talbot, Mem. Sci. Rev. Metall. 73(1976) 659-668.
[52]	M. Cohen, G. Hoey, J. Electrochem. Soc. 105(1958) 245-250.
[53]	G.L. Makar, J. Kruger, J. Electrochem. Soc. 137(1990) 414-421. DOI URL
[54]	S. Fajardo, G. Frankel, Electrochim. Acta 165 (2015) 255-267.
[55]	M.P. Gomes, I. Costa, N. Pébère, J.L. Rossi, B. Tribollet, V. Vivier, Electrochim. Acta 306 (2019) 61-70.
[56]	Z. Shi, J.X. Jia, A. Atrens, Corros. Sci. 60(2012) 296-308.
[57]	Z. Shi, J.X. Jia, A. Atrens, Adv. Eng. Mater. 14(2012) 324-334.
[58]	J. Jia, A. Atrens, G. Song, T. Muster, Mater. Corros. 56(2005) 468-474.
[59]	D. Lysne, S. Thomas, M. Hurley, N. Birbilis, J. Electrochem. Soc. 162(2015) C396-C402.
[60]	J.A. Yuwono, C.D. Taylor, G.S. Frankel, N. Birbilis, S. Fajardo, Electrochem. commun. 104(2019), 106482.
[61]	S.H. Salleh, S. Thomas, J.A. Yuwono, K. Venkatesan, N. Birbilis, Electrochim. Acta 161 (2015) 144-152.
[62]	G. Williams, N. Birbilis, H. McMurray, Electrochem. commun. 36(2013) 1-5.
[63]	G.-L. Song, Corrosion Electrochemistry of Magnesium (Mg) and Its Alloys, in: Corrosion of Magnesium Alloys, Woodhead, 2011, pp. 3-65.
[64]	O. Fruhwirth, G. Herzog, I. Hollerer, A. Rachetti, Subsurf. Sens. Technol. Appl. 24(1985) 301-317.
[65]	G. Perrault, Encyclopedia of Electrochemistry of the Elements, Marcel Dekker, New York and Basel, 1978.
[66]	G. Song, A. Atrens, D. St John, X. Wu, J. Nairn, Corros. Sci. 39(1997) 1981-2004.
[67]	Z. Shi, F. Cao, G.-L. Song, A.Atrens, Corros. Sci. 88(2014) 434-443.
[68]	A. Harms, S. Khanna, B. Chen, A. Castleman Jr, J. Chem. Phys. 100(1994) 3540-3544.
[69]	F. Misaizu, M. Sanekata, K. Tsukamoto, K. Fuke, S. Iwata, J. Phys. Chem. 96(1992) 8259-8264.
[70]	E.H. Alsharaeh, Int. J. Mol. Sci. 12(2011) 9095-9107. DOI URL PMID
[71]	C. Berg, M. Beyer, U. Achatz, S. Joos, G. Niedner-Schatteburg, V.E. Bondybey, Chem. Phys. 239(1998) 379-392.
[72]	M.K. Beyer, Mass Spectrom. Rev. 26(2007) 517-541. URL PMID
[73]	M. Ončák, T. Taxer, E. Barwa, C. van der Linde, M.K. Beyer, J. Chem. Phys. 149(2018), 044309. URL PMID
[74]	T.W. Lam, C. van der Linde, A. Akhgarnusch, Q. Hao, M.K. Beyer, C.K. Siu, Chem. Plus. Chem. 78(2013) 1040-1048. DOI URL PMID
[75]	C. Van Der Linde, A. Akhgarnusch, C.K. Siu, M.K. Beyer, J. Phys. Chem. A 115 (2011) 10174-10180. DOI URL PMID
[76]	J. Bockris, A. Reddy, Modern Electrochemistry, 6th Printing, Plenum Press, New York, 1977.
[77]	H. Ma, M. Liu, W. Chen, C. Wang, X.Q. Chen, J. Dong, W. Ke, Phys. Rev. B Condens. Matter Mater. Phys. 3(2019), 053806.
[78]	A. Samaniego, B.L. Hurley, G.S. Frankel, J. Electroanal. Chem. 737(2015) 123-128.
[79]	G. Song, A. Atrens, Y. Li, B. Zhang, Negative Difference Effect of Magnesium, Proc. Corrosion and Prevention-97, Australasian Corrosion Association, Inc, 1997.
[80]	Z. Shi, M. Liu, A. Atrens, Corros. Sci. 52(2010) 579-588.
[81]	G.-L. Song, K.A. Unocic, Corros. Sci. 98(2015) 758-765.
[82]	H. Ma, X.-Q. Chen, R. Li, S. Wang, J. Dong, W. Ke, Acta Mater. 130(2017) 137-146.
[83]	M.N. Hull, J. Electroanal, Chem. Int. Electrochem. 38(1972) 143-157.
[84]	F. Cao, C. Zhao, G.-L. Song, D. Zheng, Corros. Sci. 150(2019) 161-174.
[85]	J. Nordlien, S. Ono, N. Masuko, K. Nisancioglu, Corros. Sci. 39(1997) 1397-1414. DOI URL
[86]	M. Santamaria, F. Di Quarto, S. Zanna, P. Marcus, Electrochim. Acta 53 (2007) 1314-1324.
[87]	A. Seyeux, M. Liu, P. Schmutz, G. Song, A. Atrens, P. Marcus, Corros. Sci. 51(2009) 1883-1886.
[88]	M.P. Brady, M. Fayek, D.N. Leonard, H.M. Meyer, J.K. Thomson, L.M. Anovitz, G. Rother, G.-L. Song, B. Davis, J. Electrochem. Soc. 164(2017) C367-C375.
[89]	M.P. Brady, D.N. Leonard, H.M. Meyer, J.K. Thomson, K.A. Unocic, H.H. Elsentriecy, G.L. Song, K. Kitchen, B. Davis, Surf. Coat. Technol. 294(2016) 164-176.
[90]	G.-L. Song, K.A. Unocic, H. Meyer, E. Cakmak, M.P. Brady, P.E. Gannon, P. Himmer, Q. Andrews, Corros. Sci. 104(2016) 36-46.
[91]	M.P. Brady, M. Fayek, H.M. Meyer, D.N. Leonard, H.H. Elsentriecy, K.A. Unocic, L.M. Anovitz, E. Cakmak, J.R. Keiser, G.L. Song, B. Davis, Scr. Mater. 106(2015) 38-41. DOI URL
[92]	M.P. Brady, G. Rother, L.M. Anovitz, K.C. Littrell, K.A. Unocic, H.H. Elsentriecy, G. L. Song, J.K. Thomson, N.C. Gallego, B. Davis, J. Electrochem. Soc. 162(2015) C140-C149. DOI URL
[93]	K.A. Unocic, H.H. Elsentriecy, M.P. Brady, H.M. Meyer, G.L. Song, M. Fayek, R.A. Meisner, B. Davis, J. Electrochem. Soc. 161(2014) C302-C311. DOI URL
[94]	M.P. Brady, M. Fayek, H.H. Elsentriecy, K.A. Unocic, L.M. Anovitz, J.R. Keiser, G. L. Song, B. Davis, J. Electrochem. Soc. 161(2014) C395-C404. DOI URL
[95]	N. Hara, Y. Kobayashi, D. Kagaya, N. Akao, Corros. Sci. 49(2007) 166-175. DOI URL
[96]	L. Yang, G. Liu, L. Ma, E. Zhang, X. Zhou, G. Thompson, Corros. Sci. 139(2018) 421-429. DOI URL
[97]	N. Birbilis, T. Cain, J. Laird, X. Xia, J. Scully, A. Hughes, ECS Electrochem. Lett. 4(2015) C34-C37. DOI URL
[98]	T. Cain, S. Madden, N. Birbilis, J. Scully, J. Electrochem. Soc. 162(2015) C228-C237. DOI URL
[99]	D. Höche, C. Blawert, S.V. Lamaka, N. Scharnagl, C. Mendis, M.L. Zheludkevich, Phys. Chem. Chem. Phys. 18(2016) 1279-1291. DOI URL PMID
[100]	R. Liu, S. Thomas, J. Scully, G. Williams, N. Birbilis, Corrosion 73 (2016) 494-505. DOI URL
[101]	S. Thomas, O. Gharbi, S. Salleh, P. Volovitch, K. Ogle, N. Birbilis, Electrochim. Acta 210 (2016) 271-284. DOI URL
[102]	S. Fajardo, O. Gharbi, N. Birbilis, G.S. Frankel, J. Electrochem. Soc. 165(2018) C916-C925. DOI URL
[103]	H. Wang, Y. Song, J. Yu, D. Shan, H. Han, J. Electrochem. Soc. 164(2017) C574-C580. DOI URL
[104]	M. Curioni, F. Scenini, T. Monetta, F. Bellucci, Electrochim. Acta 166 (2015) 372-384. DOI URL
[105]	G. Williams, R. Grace, Electrochim. Acta 56 (2011) 1894-1903. DOI URL
[106]	G. Williams, H.N. McMurray, J.Electrochem. Soc. 155(2008) C340-C349.
[107]	N. Birbilis, A. King, S. Thomas, G. Frankel, J. Scully, Electrochim. Acta 132 (2014) 277-283. DOI URL
[108]	M. Curioni, Electrochim. Acta 120 (2014) 284-292. DOI URL
[109]	T. Cain, I. Gonzalez-Afanador, N. Birbilis, J. Scully, J. Electrochem. Soc. 164(2017) C300-C311. DOI URL
[110]	J. Yang, C.D. Yim, B.S. You, J. Electrochem. Soc. 163(2016) C839-C844. DOI URL
[111]	M. Shahabi-Navid, M. Esmaily, J.-E. Svensson, M. Halvarsson, L. Nyborg, Y. Cao, L.-G. Johansson, J. Electrochem. Soc. 161(2014) C277-C287. DOI URL
[112]	C.W. Bale, P. Chartrand, S. Degterov, G. Eriksson, K. Hack, R.B. Mahfoud, J. Melançon, A. Pelton, S. Petersen, Calphad 26 (2002) 189-228. DOI URL
[113]	C. Bale, E. Bélisle, P. Chartrand, S. Decterov, G. Eriksson, K. Hack, I.H. Jung, Y.B. Kang, J. Melançon, A. Pelton, Calphad 33 (2009) 295-311. DOI URL
[114]	A.D. Atrens, I. Gentle, A. Atrens, Corros. Sci. 92(2015) 173-181. DOI URL
[115]	K.S. Williams, J.P. Labukas, V. Rodriguez-Santiago, J.W. Andzelm, Corrosion 71 (2014) 209-223. DOI URL
[116]	J.A. Yuwono, N. Birbilis, C.D. Taylor, K.S. Williams, A.J. Samin, N.V. Medhekar, Corros. Sci. 147(2019) 53-68. DOI URL
[117]	G. Baril, N. Pébère, Corros. Sci. 43(2001) 471-484. DOI URL
[118]	G. Baril, C. Blanc, M. Keddam, N. Pébère, J. Electrochem. Soc. 150(2003) B488-B493. DOI URL
[119]	N. Jadhav, V.J. Gelling, J. Electrochem. Soc. 166(2019) C3461-C3476. DOI URL
[120]	A.C. Bastos, M.C. Quevedo, O.V. Karavai, M.G.S. Ferreira, J. Electrochem. Soc. 164(2017) C973-C990. DOI URL
[121]	E. Mena, L. Veleva, R. Souto, Int. J. Electrochem. Sci. 11(2016) 5256-5266.
[122]	R. Walter, M.B. Kannan, Mater. Design 32 (2011) 2350-2354. DOI URL
[123]	S. Fajardo, J. Bosch, G.S. Frankel, Corros. Sci. 146(2019) 163-171. DOI URL
[124]	S. Fajardo, G. Frankel, Electrochem. commun. 84(2017) 36-39. DOI URL
[125]	J. Światowska, P. Volovitch, K. Ogle, Corros. Sci. 52(2010) 2372-2378. DOI URL
[126]	S. Lebouil, A. Duboin, F. Monti, P. Tabeling, P. Volovitch, K. Ogle, Electrochim. Acta 124 (2014) 176-182. DOI URL
[127]	L. Rossrucker, K.J.J. Mayrhofer, G.S. Frankel, N. Birbilis, J. Electrochem. Soc. 161(2014) C115-C119. DOI URL
[128]	J. Rodriguez, L. Chenoy, A. Roobroeck, S. Godet, M.G. Olivier, Corros. Sci. 108(2016) 47-59. DOI URL
[129]	K.-C. Lau, T.J. Seguin, E.V. Carino, N.T. Hahn, J.G. Connell, B.J. Ingram, K.A. Persson, K.R. Zavadil, C. Liao, J. Electrochem. Soc. 166(2019) A1510-A1519. DOI URL
[130]	G.P.M. van Klink, H.J.R. de Boer, G. Schat, O.S. Akkerman, F. Bickelhaupt, A.L. Spek, Organometallics 21 (2002) 2119-2135. DOI URL
[131]	P. Bernath, J. Black, J. Brault, Astrophys. J. 298(1985) 375-381. DOI URL
[132]	G.L. Song, Mater. Sci. Forum 488 (2005) 649-652.
[133]	P. Gore, V.S. Raja, N. Birbilis, J. Electrochem. Soc. 165(2018) C849-C859. DOI URL
[134]	G. Song, A. Atrens, D. StJohn, Magnes. Technol. 2001 (2001) 255-262.
[135]	G.-L. Song, Z. Xu, Electrochim. Acta 55 (2010) 4148-4161. DOI URL
[136]	Z. Pu, G.L. Song, S. Yang, J.C. Outeiro, O.W. Dillon, D.A. Puleo, I.S. Jawahir, Corros. Sci. 57(2012) 192-201. DOI URL
[137]	G.-L. Song, Z. Xu, Corros. Sci. 54(2012) 97-105. DOI URL
[138]	M. Liu, G.-L. Song, Corros.Sci. 77(2013) 143-150.
[139]	G.-L. Song, N.J. Dudney, J. Li, R.L. Sacci, J.K. Thomson, Corros. Sci. 87(2014) 11-14. DOI URL
[140]	Y.J. Wu, X.B. Chen, G. Williams, J. Scully, T. Gengenbach, N. Birbilis, RSC Adv. 6(2016) 43408-43417. DOI URL
[141]	F. Cao, C. Zhao, J. You, J. Hu, D. Zheng, G.L. Song, Adv. Eng. Mater. (2019), 1900363.
[142]	L. Yan, G.L. Song, D. Zheng, Corros. Sci. 155(2019) 13-28. DOI URL
[143]	G.-L. Song, M. Liu, Corros. Sci. 62(2012) 61-72. DOI URL
[144]	G.-L. Song, M. Liu, Corros. Sci. 53(2011) 3500-3508. DOI URL
[145]	G.-L. Song, Prog.Org. Coat. 70(2011) 252-258. DOI URL
[146]	G.-L. Song, Electrochim. Acta 55 (2010) 2258-2268. DOI URL
[147]	G.-L. Song, Electrochem.Solid-State Lett. 12(2009) D77-D79.