Micro-galvanic corrosion during formation of epoxy coating
By Feng, Zhenliang; Song, Guang-Ling; Xu, Yuqing; Zheng, Dajiang; Chen, Xiaodong
Published in Progress in Organic Coatings
2020
Abstract
The effect of substrate micro-galvanic corrosion on the curing of an epoxy coating was investigated through analyzing the potentiodynamic polarization curves, electrochemical impedance spectra and galvanic current densities of metallic substrates with various galvanic cells exposed in epoxy, curing agent and their mixture. This corrosion of the substrate during curing proved to be able to significantly influence both the adhesion and permeability of the cured coating. The finding was further interpreted by electrochemical reactions of the substrate metal with water absorbed in the curing agent.