Electrohydrodynamic phenomena in exploding tungsten electrical contacts

The process of shaping of the surface of liquid tungsten in an electric field appearing between tungsten contacts exploded in air or in some gas or in vacuum was investigated. It has found that the surface tension of liquid tungsten in an oxygen-containing medium has an abnormally low value which is several orders of magnitude lower than not only the surface tension of liquid tungsten in a vacuum, but than that of liquid tungsten oxide as well. This is the reason for the development of electrohydrodynamic instabilities having the form of Taylor cones on the surface of liquid tungsten at abnormally low electric fields. These instabilities make possible the formation of secondary electric contacts between two liquid cones. These contacts are subsequently destroyed and the molten tungsten regenerates. This process may occur in a cyclic manner. The tungsten surface solidifies to take form of a contact bridge or drops with Taylor cones on their tops. Similar experiments either with contacts of other metals, refractory metals included, or with tungsten contacts exploded in oxygen-free medium failed to yield like results.