Composition of Oxide formed on Copper and Copper–Manganese Alloys (5–40% Mn) in Oxygen at 150°–600°c

Abstract

The proportions of CuO and Cu₂O in films formed on copper and copper-manganese alloys in oxygen at temperatures of 150–400°c (600°c for higher Mn alloys) were estimated by coulometric reduction. Only Cu₂O was observed at 150°c. The proportion of CuO increased as the temperature was raised, reaching 82% for copper at 300°c and somewhat lower values for the alloys containing Mn. At temperatures of 350–400°c, the proportion of CuO declined. The oxide remained adherent above 400°c only for alloys with 20% and 40% Mn. From 400° to 600°c the proportion of CuO increased for the 20% alloy but neither CuO nor Cu₂O was found on the 40% alloy.