Corrosion behavior of monophasic and multiphasic Al50Au50 ribbons in AlCl3 + HCl solution

[Display omitted] •Monophasic Al50Au50 ribbon has a wide passivation region in HCl solution.•The passive film of monophasic ribbon has a double-layer structure.•Monophasic ribbon has a higher corrosion resistance than multiphasic one.•Al2Au phase in multiphasic ribbon promotes corrosion in HCl solution. Monophasic Al50Au50 ribbons (labelled as S2ann) were obtained by melt spinning and annealing. The corrosion properties of S2ann were investigated in AlCl3 + HCl solution with as-spun multiphasic ribbons (labelled as S2sp) for comparison. S2ann is self-passivated and has a wide passivation region, while S2sp tends to undergo Al2Au-induced selective dissolution under anodic polarization. Besides, S2ann has a fluctuant open-circuit potential and a passive film with p-type semiconductor feature, which are not found in S2sp. The passive film of S2ann is examined to be Au-contained Al2O3 with a double-layer structure.