Mécanismes de dégradation des matériaux métalliques protégés par peinture

Degradation mechanisms of metals protected by paints

Laboratoire de Physique du Solide, Institut de Physique, Université de Constantine (Algérie)

Abstract

Painted metals degradation is due to the interaction between several parmeters : permeability to water, oxygene and ions across paint films, utra-violet effects, decrease of adherence, pigments effects, surface pretreatements,...This degradation, in the acqueous meduim, is owed to electochemical reactions, which take place at metal/paint film interface, in addition of natural degradation of organic films. In this paper, we present bibliographical study where we want to put in exergue the facteurs which can arise at three levels : metallic support, organic film and metal/film interface. Despite divergences which exist concerning mecanisms of degradation, we present principal models proposed by searchers who are an authority in this field.