Study of the coating/substrate interface by scanning acoustic microscopy Cathodic disbonding of epoxy-polyamide lacquer from mild steel

Abstract

The scanning acoustic microscope (SAM) has been used to examine changes at the interface during cathodic disbonding of an epoxy-polyamide coating from mild steel exposed to NaCl solution. The disbonding at a linear scribe is seen to stop after about 50 min, with subsequent development of microblistering in a widening zone alongside the disbond. Time-of-flight measurements allow blister heights to be measured.