Influence of interfacial reaction rates on the wetting driving force in metal/ceramic systems

The wetting of copper-silicon alloys of various compositions on vitreous carbon substrates at 1423 K was studied by the sessile drop method. The morphology and chemistry of products of interfacial reactions between silicon and carbon were characterized by scanning electron microscopy (SEM), electron probe microanalysis, and high-resolution optical profilometry. In addition to measurements of contact angles and spreading kinetics in the reactive Cu-Si/Cv system, similar measurements were performed for the nonreactive Cu-Si/SiC system. It was found that the reaction rate has no effect on the final contact angle, which is nearly equal to the thermodynamic contact angle of the alloy on the reaction product. These findings appear to be valid for a wide range of interfacial reaction rates and for different types of interfacial reactions.