In a high-speed fabrication process for producing highly uniform metallic microspheres,
a molten metal is passed through a small orifice, producing a stream of molten
metal therefrom. A series of molten metal droplets forms from the break up of the
capillary stream. To achieve high uniformity of the spheres and avoid defects,
the droplets are cooled before being captured. Separating the droplets, by causing
them to travel in different paths than their adjacent droplets, helps to facilitate
the cooling of the droplets. The droplets can be separated by electrostatically
charging them as they break off from the capillary stream. The droplets are then
passed through an electric field, which can be produced by a pair of deflection
plates. The droplets are dispersed by varying the electric field—e.g., by
rotating the plates or by varying the voltage applied thereto—or by varying
the electrostatic charge of the droplets. Advantageously, the droplets can be actively
cooled in flight by passing them through a cryogenic gas chamber.