Jamieson, T.; Apel, D.; Yasinskiy, A.; Düssel, R.; Decker, P.; Gudmundur, G.; Singh, K.; Magnusson, J.; Adam, B.; Busch, R.; Firedrich, B.; Gallino, I.: On the long-term oxidation behaviour of homogeneous Ni-Fe-Cu alloys for CO2-free aluminium electrowinning applications at 800°C. Journal of Materials Science 60 (2025), p. 18455-18472
10.1007/s10853-025-11313-7
Open Accesn Version
Abstract:
The oxidation behaviour of homogeneous Ni29Fe56Cu15 wt.%, Ni42Fe38Cu20 wt.% and Ni60Fe30Cu10 wt.% is investigated under 1 atm flux of high-purity O 2 gas— using thermogravimetry—with respect to application as oxygen-evolving anodes for aluminium electrolysis. Stable cubic oxidation behaviour was observed in Ni42Fe38Cu20 wt.% and Ni60Fe30Cu10 wt.% after 30 h and 264 h, respectively, with the former showing particular promise for electrowinning applications due to a tendency to form a well-adhered scale consisting of approximately 70% NiFe2 O4 by thickness, as measured from EDX line scans. NiO dominated the scale of Ni60Fe30Cu10 wt.% up to 272 h, showing worse scale adhesion and prominent intergranular oxidation of iron. Partially blistered regions of the scale locally increased NiO/CuO formation in Ni42Fe38Cu20 wt.%, evolved to become (Cu/Ni, Fe)O spinel oxides over time.