2D simulations of the dynamics and fracture of metals in the energy absorption zone of the high-current electron beam

Abstract

Abstract. The metal behavior under the action of high-current electron irradiation is an example of a complex problem with a large number of involved physical processes. In this paper, we develop a continuum model of dynamic fracture of a metal melt in the energy absorption zone of a high-current electron beam and present a two-dimensional version of this model. The 2D model is necessary for the description of the action of a narrow-focused electron beam on matter. Fracture of copper and aluminum in the molten state in the energy absorption zone of the electron beam is numerically simulated, and the spatial distribution of the droplet size is investigated. Action of a high-current electron beam with the electron energy of about 1 MeV leads to the formation and subsequent breakup of the melt to droplets with diameters from 0.5 µm to several tens of micrometers. The finest droplets (0.5-5 µm) are generated in the center of the energy absorption zone, while the droplet sizes increase up to several tens of micrometer at the edge of the energy absorption zone, where matter is colder. Keeping the melt in a metastable (expanded and overheated) state provides a tension wave with an amplitude of about 3-4 GPa following the shock wave and propagating deep into the target.