METHOD AND APPARATUS FOR PRODUCING METALLIC GRAIN

摘要

PURPOSE:To continuously produce metallic grains which are relatively small in size and are uniform in shape and size by heating and melting small leaves of a metallic material on a rotating disk and cooling and solidifying the molten drops thereof while forming the same to a spherical shape. CONSTITUTION:The disk 1 formed of a material such as copper having high heat conductivity is fixed to the upper part of a revolving shaft 2. Plural lines of annular holding grooves 3 having a continuous V-shaped section are concentrically provided atop the disk 1 and the preheated small leaves of the metal are supplied into the grooves 3. Arcs are struck with a tungsten bar 7a of a TIG torch 7 as one electrode and the disk 1 as the other electrode and the small leaves of the metal are melted by utilizing the arc heat in the envelope of an inert gas. The molten small leaves flocculate to a piece of the molten drop which is formed to the spherical shape or the analogous shape by its own surface tension. The liquid drop emitted from the arc is deprived of heat by the disk 1 and the ambient atmosphere and solidifies in the form of the spherical shape. The solidified metallic grains are wiped by the rotating force of a wiper 8 and are collected.