Electrodeposition of Al-Zn on Magnesium Alloy from ZnCl2-Containing Ionic Liquids

Al-Zn codeposition on an AZ91D magnesium alloy from a Lewis acidic aluminum chloride-1-ethyl-3-methykimidazolium chloride (-EMIC) ionic liquid containing various contents of has been successfully established. The experimental results showed that the amount of Zn in the deposit increased with increasing concentration of in the electrolyte but decreased with increasing magnitude of cathodic potential. The presence of Zn in the deposit could cause a decrease in surface roughness as compared with that of plain Al deposit. The results of polarization curve measurement showed that Al and Al-Zn coatings could improve the passivation behavior of the AZ91D magnesium alloy in 3.5 wt % NaCl solutions.