An ionic liquid surface treatment for corrosion protection of magnesium alloy AZ31

We describe here the development of protective surface films on a Mg alloy in ionic liquids (ILs) based on the bis(trifluoromethanesulfonyl)amide (TFSA) anion. The film is shown to provide improved corrosion resistance to the alloy against humid environments as well as in the presence of chloride. Film formation is the result of the extreme reactivity of the metal in the IL, which provides a unique, concentrated medium of the desired reactive species, in this case the TFSA anion. The duration of the treatment is shown to influence the thickness and morphology of the resulting film and hence its protectiveness. (c) 2006 The Electrochemical Society.