In this paper, the effect of surface oxidation on corrosion behaviour of Co–20·8Ni–6Al–10Cu–11Fe alloy in molten cryolite is investigated. The samples were produced by casting and then were oxidised at 1000°C for 10, 30 and 70 h respectively. The oxide layers were studied by scanning electron microscope (SEM) and X-ray diffraction (XRD). To determine the corrosion behaviour of the oxidised samples, they were exposed to molten cryolite at 930°C for 20 h. After corrosion, the samples were studied by SEM. The results showed that all the samples corroded, but the sample oxidised for 70 h, was more stable than the other and the other one that oxidised for 10 h, corroded severely.
TottenGE and Mackenzie (eds.)DS: ‘Handbook of aluminum’ Vol. 21–47; 2003New YorkMarcel Dekker.
2.
PawlekRP: ‘Inert anodes: an update’in ‘Light metals 2008’1039–1045; 2008Warrendale, PATMS.
3.
JangCKimDSahIRyuW and YooY: ‘Oxidation behaviors of wrought nickel-based superalloys in various high temperature environments’Trans. Nonferrous Met. Soc.2011211524–1531.
4.
KvandeH and HaupinW: ‘Inert anodes for Al smelters: energy balances and environmental impact’JOM20015329–33.
5.
CassyreLUtigardTA and BouvetS: ‘Visualizing gas evolution on graphite and oxygen evolving anodes’JOM200254(5)41–45.
6.
LaCameraAF and SibaSP: ‘Electrolysis in a cell having a solid oxide ion conductor’US Patent 6,187,168, 6 October 1998.
7.
ShiZXuJQiuZWangZ and GaoB: ‘300 A bench scale aluminium electrolysis cell with Fe–Ni–Al2O3 composite anode’in ‘Light metals 2005’1219–1223; 2005Warrendale, PATMS.
8.
QiuZShiZ and XuJ: ‘Metal-alumina cermet inert anode in a 100 A bench scale cell for aluminium electrolysis’Aluminium200480(3)219–222.
9.
LyakishevNPLainerYALevashovENSamoilovENSenatulinBRVetchinkinaTN and RozhkovDY: ‘Synthesis and testing of uniform and gradient materials for inert anodes used in the electrolysis of cryolite–alumina melts’Theor. Found. Chem. Eng.200741706–717.
10.
de NoraV: ‘Inert anodes are ready for the use in aluminium production cells’Aluminium200581(1-2)67–70.
11.
ChapmanVWelchBJ and Skyllas-KazacosM: ‘Anodic behavior of Ni–Fe alloys in cryolite–alumina melts’Electrochim. Acta200156(3)1227–1238.
12.
SadowayDr: ‘Inert anodes for the Hall–Heroult cell: the ultimate materials challenge’JOM200153(5)34–35.
13.
OlsenE and ThonstadJ: ‘Nickel ferrite as inert anodes in aluminium electrolysis: Part I: Material fabrication and preliminary testing’Appl. Electrochem.199929(3)293–299.
XiaoH. HovlandRRolsethS and ThonstadJ: ‘Studies on the corrosion and the behavior of inert anodes in aluminum electrolysis’Metall. Mater. Trans. B199627B185–193.
16.
CassayreLChamelotPAruraultLMassotL and TaxilP: ‘Oxidation of stoichiometric nickel ferrites used as inert anodes for aluminium electrolysis in molten cryolite mixtures’Mater. Sci. Forum2008595-598593–600.
17.
PiscitelliRARheeSK and BradleyFN: ‘Oxidation of a Fe–29Ni–17Co alloy’Electrochim. Soc.1976123929–933.
18.
DeYoungDH: ‘Solubilities of oxides for inert anodes in cryolite-based melts’in ‘Light metals 1986’299–307; 1986Warrendale, PATMS.
19.
WelchBJ: ‘Inert anodes – the status of the materials science, the opportunities they present and the challenges that need resolving before commercial implementation’in ‘Light metals 2009’971–978; 2009Warrendale PATMS.
20.
de NoraV: ‘New technologies for aluminium production’Electrochem. Soc. Interface20021120–24.
21.
ShiZXuJQuiZ and GaoB: ‘Copper–nickel superalloys as inert alloy anodes for aluminium electrolysis’JOM20035563–65.
22.
KovrovVAShurovNIKhramovAP and ZaikovYuP: ‘Character of the corrosion destruction of inert anodes during electrolysis of cryolite alumina melt and the reasons for it’Russ. J. Nonferrous Met.200950492–499.
23.
FrytE: ‘Defect structure in CoO’Oxid. Met.197610311–327.
24.
CoxMGMcEnaneyB and ScottVD: ‘Chemical diffusion model for partitioning of transition elements in oxide scales on alloys’Philos. Mag.197226839–851.
25.
KamalSJayaganthanR and PrakashS: ‘High temperature cyclic oxidation and hot corrosion behaviors of superalloys at 900°C’Bull. Mater. Sci.201033(3)299–306.
26.
ChapmanVWelchBJ and Skyllas-KazacosM: ‘High temperature oxidation behavior of Ni–Fe–Co anodes for aluminium electrolysis’Corros. Sci.201153(9)2815–2825.
27.
ShiZNXuJL and QiuZX: ‘An iron–nickel metal anodes for aluminium electrolysis’in ‘Light metals 2004’333–337; 2004Warrendale, PATMS.
28.
SingletonVWelchBJ and Skyllas-KazacosM: ‘Influence of cobalt additions on electrochemical behavior of Ni–Fe-based anodes for aluminium electrowinning’in ‘Light metals 2011’1123–1128; 2011Warrendale, PATMS.
