Formation of a protective outer layer on magnesium alloys containing aluminum

摘要

A process is disclosed for the protection of magnesium based alloys containing aluminum by treatment with eutectic mixtures of fused salts to provide a corrosion resistant outer layer on the magnesium based alloy. A suitable fused salt mixture comprises urea and at least one of ammonium nitrate or ammonium nitrite. A magnesium based alloy is also disclosed comprising magnesium and aluminum having a corrosion resistant outer layer comprising magnesium oxide and aluminum oxide; the proportion of aluminum present in the outer layer being enriched in proportion to the amount present in the magnesium based alloy.