Enhancement of the adhesion and anticorrosive properties of an epoxy coating by the application of a cerium based film

Abstract

The formation of an epoxy coating on die-cast AZ91D magnesium alloy was studied. In order to improve the adhesion of the epoxy resin, a cerium-based film was previously synthesized on the alloy surface. The influence of the surface substrate on the adhesive and anticorrosive properties of the generated coatings was evaluated. The corrosion performance of the coated samples was studied by open circuit potential test, potentiodynamic polarization and electrochemical impedance spectroscopy in a chloride containing solution. The composition and morphology of all the samples were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). In order to determine the surface free energy, contact angle measurements for the treated and untreated alloy surface were performed. An improvement in the adhesion and anticorrosive properties was obtained by applying epoxy coating onto a cerium-based film previously synthesized on Mg alloy.