Experimental and numerical study of E-beam evaporation of titanium

An experimental and numerical study is performed for the electron- beam evaporation of pure titanium from a bottom fed vapor source. In the experiments, an electron beam operating in the nominal range of 30-40 [kW] was used to evaporate metal from the top of a 3 inch diameter rod. Variations were made in the e-beam power, sweep pattern, and sweep frequency, and the total evaporation rate was measured from feed consumption and laser absorption. The solid-pool interface was obtained from metallographic cross sections of the metal rod. A two-dimensional finite element model was developed for the melt which includes the effect of fluid flow and energy transport in the pool and conduction in the solid. The deformation of the liquid-vapor and solid-liquid interfaces are tracked using a mesh which stretches along spines parallel to the axis of the rod. For the cases considered, high evaporative fluxes and vapor pressures generate significant depressions in the top surface of the pool. Predicted and measured evaporation rates are in good agreement for moderate evaporation fluxes, but discrepancies are larger for the case involving the highest flux and deepest depression.