Power balance equation in electron beam evaporation process

摘要

In the electron beam evaporation process, the total power P of the gun is used, for a part P(vap) to generate the vapor stream and for the rest to cover three main power losses P(conv), P(ebs), and P(rad) due, respectively, to three parasite phenomena: turbulent thermal convection in the molten pool, electron back scattering, and heat radiation from the vapor emitting surface. It results in a four component power balance equation and the aim of this paper is to solve this equation. The various scaling laws governing each of the four terms are used and the equation is solved by the standard iteration method. Results are given for evaporation of alumina with a 5 kW electron beam. The influence of an applied magnetic field on the evaporation rate is then studied. 3 figs., 5 refs. (Atomindex citation 27:011735)