Electrodeposition of Al-Mo-Mn ternary alloys from the Lewis acidic AlCl3-EtMeImCl molten salt

The electrodeposition of Al-Mo-Mn ternary alloys was examined in the Lewis acidic 66.7-33.3% mole fraction (mol%) aluminum chloride-1-ethyl-3-methylimidazolium chloride (AlCl3-EtMeImCl) molten salt containing Mo(II) and Mn(II). By adjusting the CMn(II)/CMo(II) concentration ratio in the plating solution and employing different current densities, it was possible to prepare alloys with widely varying compositions and surface morphologies. All Al-Mo-Mn alloys were dense, compact, and adhered well to the copper substrate surface. The addition of small amounts of Mn to the Al-Mo alloy resulted in an improvement in the chloride pitting corrosion resistance and metallic brightness. For example, Al90.1Mo9.9Mn0 and Al89.5Mo9.1Mn1.4 displayed pitting potentials that were 725 and 837 mV more positive than that for Al, respectively. Al-Mo-Mn alloys that contained more than about 10 atom % Mo + Mn exhibited a metallic glass structure. (c) 2005 The Electrochemical Society.