Publisher : The Korean Institute of Surface Engineering
DOI : 10.5695/JKISE.2010.43.2.073
Title & Authors
Characteristics Evaluation of Conversion Coating of Acid Pickling AZ31 Magnesium Alloy by a Chromium-Free Phosphate-Permanganate Solution Kim, Myung-Hwan; Kwag, Sam-Tag; Moon, Myung-Jun;
A chromium-free conversion coating for AZ31 magnesium alloy has been obtained by using a permanganatephosphate solution, which has been developed with acid pickling. Examination have been carried out on the conversion coatings for morphology, composition and corrosion resistance. The morphology of the conversion-coated layer was observed using optical microscope and SEM. It was shown that the conversion coatings are relatively uniform and continuous, with thickness 1.8 to 2.7 . The chemical composition of conversion coating was mainly consisted of Mg, O, P, K, Al and Mn by EDS analysis. It was found that the corrosion resistance of the AZ31 magnesium alloy has been improved by the permanganate-phosphate conversion treatment from electrochemical polarization.