An overview of interphase’s formation and participation on water diffusion in epoxy/metal bonded assemblies

This overview aims at gathering the various existing works on interphases within epoxy/metal bonded assemblies. Indeed, this particular area plays an important role on the adhesion but also on the behavior in wet environment. Polymeric materials being hydrophilic, water diffusion occurs when they are in a humid environment. The water molecules then have an important impact on the mechanical and physical properties. The effect of water on the interfacial properties of adhesive joints is large discussed in literature. In this article, a complete interphase formation model is be proposed. This two-scenario model explain all the experimental results observed in the literature on the interfaces of a bonded joint. Moreover, hypotheses is made on the water diffusion mechanisms and the diffusive properties of the interface. This is allow explaining the change of the fracture surface observed during the wet aging of a bonded joint. A large number of studies have observed the transition from cohesive to adhesive failure.