Effects of alloying concentration on the aqueous corrosion and passivation of aluminum-manganese-molybdenum concentrated alloys

The effects of alloying concentration on the aqueous corrosion behavior of aluminum-manganese-molybdenum (Al-Mn-Mo) alloys with 8–20 at% Mn and 0–30 at% Mo were investigated by experiments and atomistic simulations. The pitting potential of Al-Mn-Mo increased with Mo% from − 0.16–0.49 V. The passive film thickness depended on the total alloy concentration, while its compactness and defect density on the individual ones. Specifically, Al80Mn8Mo12 exhibited higher corrosion resistance than Al80Mn20 due to the formation of a more compact and less defective passive film, as explained by the roles Mo played in both the substrate and the passive film.