The true area of contact at a liquid metal-solid interface

The properties of a liquid-solid interface are usually understood under the assumption that contact is continuous over the entire interface, regardless of the surface roughness of the solid. This letter presents results of an analysis which suggest that this assumption is not valid when the liquid is a metal characterized by weak adhesion to the solid. Under these conditions the true area of contact at the interface depends on the surface microtopology of the solid and may differ considerably from the area of nominal contact. Experimental evidence in support of these conclusions is presented.