Melting Thresholds of the Film-Substrate System Irradiated with a Low-Energy High-Current Electron Beam

The effect of film material thermal conductivity on the melting threshold of the film-substrate system depending on the film thickness during a low-energy high-current electron beam (LEHCEB) irradiation is analyzed based on the numerical solution of the one-dimensional nonstationary heat equation with a volumetric thermal source. The experimentally obtained waveforms of the beam current at the collector and the accelerating voltage are used to simulate the heating source. The film thermal conductivity is numerically varied in a wide range, overlapping the entire range for real materials. The dependence of the melting threshold of a homogeneous material on the thermal conductivity is determined. The general behavior regularities of the film and substrate melting thresholds in dependence of the film thickness are established.