EVAPORATION OF METALS BY HIGH-DENSITY (10(7)A-CENTER-DOT-CM(-2)) ELECTRICAL CURRENTS

In the present work, the problem of time evolution of pressure and tem perature profiles across a wire through which an electrical current wi th a density of the order of 10(7) A . cm(-2) flows is solved. The cor rect boundary conditions for a metal surface are obtained for the case when this metal is rapidly evaporated as a result of high-power Joule heating. The pressure profile appears under these conditions due to p inch-effect and inertia of thermal expansion of the metal; the tempera ture profile arises because of intensive evaporation from the surface of the wire. The conditions under which a liquid metal is superheated are formulated. On the basis of the analysis of the experimental resul ts on exploding wires, the conclusion is drawn that decay of the metas table state takes place near the binodal. It is shown that the distrib ution of fine dispersed vapor bubbles is strongly nonuniform across th e wire and the process of expansion of the two-phase mixture is very s imilar to the motion of a wave.