Interface structures of high velocity oxy-fuel sprayed WC-Co coating on a copper substrate

Microstructures developing at the interface of a high velocity oxy-fuel (HVOF) sprayed WC-Co coating onto a copper substrate, have been studied by preparing thin foils from the interfacial region and examining them using transmission electron microscopy. Two types of substrate surfaces have been considered: smooth and grit blasted. Modelling of the development of the interface structure has also been undertaken. Both experimental and theoretical results, which agree well, show that the interface structure depends significantly on the morphology of the substrate surface. The results obtained enable new views to be put forward on the factors leading to the adhesion between a coating and a substrate material.