Cerium and Silane Conversion Coatings on AZ91 Magnesium Alloy

Abstract

With different means of soaking treatment, simple cerium conversion coating, KH560 silane conversion coating, cerium silane conversion coating and silane cerium conversion coating are formulated. SEM, EDS, Tafel and EIS measurements were adopted as the analysis approaches, and organic resin is coated on the conversion coating surface for the salt spray test, so as to check mainly how much the corrosion resistant capabilities could be improved if conversion coating is applied to the magnesium alloy. The result shows that the cerium silane conversion coating and silane cerium conversion coating have a higher self-corrosion potential, lower corrosion current density, improve the binding force between the organic coating and magnesium alloy matrix more effectively, thus enhance dramatically the corrosion resistant protection capabilities for the whole coating applied on the magnesium alloy matrix.