Structure and high-temperature oxidation behaviour of Cu–Ni–Fe alloys prepared by high-energy ball milling for application as inert anodes in aluminium electrolysis

CuxNi85−xFe15 (0 ⩽ x ⩽ 85 wt.%) compounds were prepared by mechanical alloying. Monophased face centered cubic (fcc) Cu–Ni–Fe alloys were obtained after 10 h of milling for x varying from 0 to 50, whereas bi-phased compounds fcc Cu–Ni–Fe + body centered cubic (bcc) Fe were formed with richer-Cu compounds. Their oxidation kinetics in air at 750 °C is parabolic for all compositions and increases drastically for x > ∼30. A stable anode for aluminium electrolysis in low-temperature (700 °C) KF–AlF3 electrolyte was obtained for 65 ⩽ x ⩽ 85. However, a substantial increase of the Cu contamination in produced aluminium was observed for x > 70.