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

Cu(x)Ni(85-x)Ye(15) (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 degrees C is parabolic for all compositions and increases drastically for x > similar to 30. A stable anode for aluminium electrolysis in low-temperature (700 degrees 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. (C) 2010 Elsevier Ltd. All rights reserved.