Technical Note: Divergent Effects of N-Acyl Glutamates on Corrosion of Aluminum and Magnesium Alloys

N-acyl glutamates as a class of amido acid compounds were discovered to inhibit the corrosion of aluminum but accelerate the corrosion of magnesium. Assuming that the carboxylate moiety is the group affecting corrosion, this behavior is consistent with previous results for aluminum that showed corrosion inhibition by straight-chain α,ω dicarboxylates. But these findings deviate from previous results for magnesium that showed corrosion inhibition by straight-chain monocarboxylates. This acceleration has been tentatively attributed to the acyl glutamates being able to form stable, soluble complexes with magnesium ions.