Corrosion Behavior of Copper-Nickel Alloys Protected by BTA in Simulated Urban Atmosphere
HUANG Songpeng1,2, PENG Can1,2, CAO Gongwang1,2, WANG Zhenyao1,2()
1.School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China 2.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Cite this article:
HUANG Songpeng, PENG Can, CAO Gongwang, WANG Zhenyao. Corrosion Behavior of Copper-Nickel Alloys Protected by BTA in Simulated Urban Atmosphere. Acta Metall Sin, 2021, 57(3): 317-326.
Copper-nickel alloys are extensively used in precision instruments, ship building, building decorations, and currency manufacturing because of their excellent mechanical properties, good corrosion resistance, and silvery metallic luster. However, they are likely to suffer from discoloration owing to corrosion in the polluted atmosphere containing SO2. HSO and H+ exhibit ionization when SO2 is adsorbed and dissolved in the thin liquid film on the surface of white copper. These sulfide-containing media will accelerate the corrosion process and affect the surface gloss. Benzotriazole (C6H5N3, BTA) is a corrosion inhibitor commonly used in Cu and its alloys that forms a chemical conversion film. It mainly protects the copper-nickel alloys in solutions containing Cl- or seawater polluted by sulfides. However, some studies have investigated the chemical conversion films of BTA that are affected by atmospheric pollution in the medium, especially focusing on analyzing their failure mode. This experiment was conceptualized based on the aforementioned problem. The corrosion behavior of the copper-nickel alloys protected by BTA in a simulated urban atmospheric environment was analyzed through SEM/EDS, XRD, and electrochemical tests. The laboratory experiments were accelerated by salt deposition. Results showed the presence of prismatic salt crystals on the surface of the copper-nickel alloy treated using BTA during the early stage of corrosion, indicating that the corrosion medium could not completely penetrate the substrate. The corrosion current density of the alloy protected by BTA will decrease first and then increase with the increasing corrosion time. This can be attributed to the oxidation and the presence of BTA chemical conversion films on the surface of the alloy; corrosion was delayed because of the combined action of these two factors. When the BTA film was damaged because of continuous consumption in the local area, the corrosion area expanded, increasing the corrosion current density. Be similar to the samples without BTA treatment, the final corrosion products of the samples treated with BTA were also loose and porous, and the main components were ZnSO4·6H2O and Cu4(SO4)(OH)6. However, the degree of corrosion of the alloy protected by BTA was more slight according to the cross-section morphology observation and mass dynamic curve analysis.
Fig.1 Pre-treatment process of benzotriazole (C6H5N3, BTA) chemical conversion membrane
Fig.2 Contact angles of copper-nickel alloy surface before (a1-a3) and after (b1-b3) BTA treatment
Fig.3 Corrosion rate curves and surface morphologies (insets) of copper-nickel alloys before and after BTA treatment in different corrosion time (t)
Fig.4 Polarization curves of copper-nickel alloys before (a) and after (b) BTA treatment as function of corrosion time (E—corrosion potential, i—corrosion current density)
Sample
t / h
Ecorr / mV
icorr / (μA·cm-2)
Before BTA treatment
0
-133.63
1.32
48
-104.93
3.04
144
-131.51
4.76
240
-110.57
7.91
336
-121.45
7.50
After BTA treatment
0
-71.36
8.88 × 10-2
48
-180.29
4.59 × 10-2
144
-117.18
3.89 × 10-2
240
-156.45
1.36 × 10-1
336
-171.84
2.23 × 10-1
Table 1 Electrochemical kinetic parameters obtained from polarization curves fitted
Fig.5 XRD spectra of copper-nickel alloy surface before (a) and after (b) BTA treatment in different corrosion time
Fig.6 SEM images (a1-d1, a2-d2) and corresponding EDS results of square areas in Figs.6a2-d2 (a3-d3) of copper-nickel alloys before BTA treatment
Fig.7 SEM images (a1-d1, a2-d2) and corresponding EDS results of square areas in Figs.7a2-d2 (a3-d3) of copper-nickel alloys after BTA treatment
Fig.8 Cross section SEM images of copper-nickel alloys before (a1-a4) and after (b1-b4) BTA treatment in different corrosion time
Fig.9 High magnified cross section SEM images of copper-nickel alloys before (a) and after (b) BTA treatment after 336 h corrosion
Point
Cu
Ni
Zn
S
O
1
17.42
3.98
3.28
15.37
59.95
2
24.19
6.24
4.68
12.43
52.46
3
17.87
2.95
2.53
8.02
68.62
4
20.39
3.68
3.24
9.70
62.99
Table 2 EDS analyses of points 1-4 marked in Fig.9
Fig.10 Corrosion process schematic of copper-nickel alloys protected by BTA in simulated urban atmospheric environment
1
Yan C W, He Y F, Lin H C, et al. Atmospheric corrosion of copper at initial stage in air containing sulfur dioxide [J]. Chin. J. Nonferrous Met., 2000, 10: 645
Yang M, Wang Z Y. Review of atmospheric corrosion of copper [J]. Equip. Environ. Eng., 2006, 3(4): 38
杨 敏, 王振尧. 铜的大气腐蚀研究 [J]. 装备环境工程, 2006, 3(4): 38
5
Badawy W A, Ismail K M, Fathi A M. Corrosion control of Cu-Ni alloys in neutral chloride solutions by amino acids [J]. Electrochim. Acta, 2006, 51: 4182
6
Bureš R, Klajmon M, Fojt J, et al. Artificial patination of copper and copper alloys in wet atmosphere with increased content of SO2 [J]. Coatings, 2019, 9: 837
7
Boutillara Y, Tombeur J L, De Weireld G, et al. In-situ copper impregnation by chemical activation with CuCl2 and its application to SO2 and H2S capture by activated carbons [J]. Chem. Eng. J., 2019, 372: 631
8
Zhao H R, Xu Y L, Chen C K, et al. New aspects of copper corrosion in a neutral NaCl solution in the presence of benzotriazole [J]. Corrosion, 2018, 74: 613
9
Yi C X, Zhu B F, Chen Y, et al. Adsorption and protective behavior of BTAH on the initial atmospheric corrosion process of copper under thin film of chloride solutions [J]. Sci. Rep., 2018, 8: 5606
10
Xie W Z, Li H S, Li Z L, et al. Research progress of inhibition mechanism of benzotriazole as corrosion inhibitor of copper [J]. Mater. Prot., 2013, 46(3): 45
Fateh A, Aliofkhazraei M, Rezvanian A R. Review of corrosive environments for copper and its corrosion inhibitors [J]. Arab. J. Chem., 2020, 13: 481
12
Wang Y Q, Shao Y W, Meng G Z, et al. Study on passivating treatment of Cu-Ni alloy in compound passivant containing benzotriazole [J]. Acta Metall. Sin., 2012, 48: 744
Chang T R, Leygraf C, Wallinder I O, et al. Understanding the barrier layer formed via adding BTAH in copper film electrodeposition [J]. J. Electrochem. Soc., 2019, 166: D10
14
Cho B J, Shima S, Hamada S, et al. Investigation of Cu-BTA complex formation during Cu chemical mechanical planarization process [J]. Appl. Surf. Sci., 2016, 384: 505
15
Finšgar M, Milošev I. Inhibition of copper corrosion by 1,2,3-benzotriazole: A review [J]. Corros. Sci., 2010, 52: 2737
16
Dugdale I, Cotton J B. An electrochemical investigation on the prevention of staining of copper by benzotriazole [J]. Corros. Sci., 1963, 3: 69
17
Kokalj A, Peljhan S, Finšgar M, et al. What determines the inhibition effectiveness of ATA, BTAH, and BTAOH corrosion inhibitors on copper? [J]. J. Am. Chem. Soc., 2010, 132: 16657
18
Chen Z Y, Huang L, Zhang G A, et al. Benzotriazole as a volatile corrosion inhibitor during the early stage of copper corrosion under adsorbed thin electrolyte layers [J]. Corros. Sci., 2012, 65: 214
19
Finšgar M, Merl D K. An electrochemical, long-term immersion, and XPS study of 2-mercaptobenzothiazole as a copper corrosion inhibitor in chloride solution [J]. Corros. Sci., 2014, 83: 164
20
Chen W J, Hao L, Dong J H, et al. Effect of SO2 on corrosion evolution of Q235B steel in simulated coastal-industrial atmosphere [J]. Acta Metall. Sin., 2014, 50: 802
Yuan X J, Zhang J X, Ji X W, et al. Corrosion behavior of galvanized steel for power transmission tower in polluted environment [J]. Corros. Sci. Prot. Technol., 2013, 25: 13
Zheng Y F. Bright pickling and passivation of copper and copper alloy [J]. Electroplat. Pollut. Control, 1998, 18(2): 25
郑永峰. 铜及铜合金光亮酸洗及钝化工艺 [J]. 电镀与环保, 1998, 18(2): 25
23
Zhou Y, Xu S Y, Guo L, et al. Evaluating two new Schiff bases synthesized on the inhibition of corrosion of copper in NaCl solutions [J]. RSC Adv., 2015, 5: 14804
24
Žerjav G, Milošev I. Protection of copper against corrosion in simulated urban rain by the combined action of benzotriazole, 2-mercaptobenzimidazole and stearic acid [J]. Corros. Sci., 2015, 98: 180
25
Chen W J, Hao L, Dong J H, et al. Effect of sulphur dioxide on the corrosion of a low alloy steel in simulated coastal industrial atmosphere [J]. Corros. Sci., 2014, 83: 155
26
Chen Z Y. Atmospheric Corrosion of Copper and Research Methods [M]. Beijing: Science Press, 2011: 156
陈卓元. 铜的大气腐蚀及其研究方法 [M]. 北京: 科学出版社, 2011: 156
27
Singh D D N, Pandya A. Role of self-assembled monolayer of 1,2,3-benzotriazole in protecting copper artifacts covered with sulfide film [J]. Corrosion, 2010, 66: 115002
28
Hong S, Chen W, Luo H Q, et al. Inhibition effect of 4-amino-antipyrine on the corrosion of copper in 3 wt. % NaCl solution [J]. Corros. Sci., 2012, 57: 270
29
Wu J, Zhou X L, Dong C F, et al. Research progress on atmospheric corrosion of copper and its alloys [J]. Corros. Sci. Prot. Technol., 2010, 22: 464
Allam N K, Nazeer A A, Ashour E A. A review of the effects of benzotriazole on the corrosion of copper and copper alloys in clean and polluted environments [J]. J. Appl. Electrochem., 2009, 39: 961
32
Al-Kharafi F M, Abdullah A M, Ateya B G. An extraordinary effect of benzotriazole and sulfide ions on the corrosion of copper [J]. Electrochem. Solid-State Lett., 2006, 9: B19
