Mercury Contacts-Bridging and Sticking Phenomena

The flow behavior of a viscous substance between two parallel circular contacts, assuming that one of the contacts moves slowly relative to the other, has been analyzed. It has been shown that if the force of separation is less than a certain minimum calculated value, the contacts will stick. The shape of the moving liquid column between the contact surfaces depends upon surface-tension and viscosity. The equilibrium bridge shape, which is defined as the shape of the liquid meniscus between the contacts after the moving contact has stopped, depends on surface-tension and the pressure difference between the fluid and external pressure. This analysis may be useful in the analysis of the flow characteristics of molten metal bridges in electrical contacts and in explaining the behavior of mercury wetted contacts.