METHOD AND APPARATUS FOR PRODUCING PULVEROUS POWDER OF METAL OR ALLOY OR THE LIKE

摘要

PURPOSE:To produce pulverous powder of a metal or alloy which has the narrow range of a grain size distribution and is stable in grain shape by dispersing uniformly an inert gas or reducing gas fed into the melt of the metal or alloy into a fine foam state by making use of ultrasonic oscillation. CONSTITUTION:A wire-shaped melting material 11 made of the metal or alloy fed by feed rollers 12 is heated and melted by a heater 2. The melt thereof is stored in a channel part 4 in a crucible 3. The inert gas or reducing gas such as Ar or H2 is then supplied from a gas supply part 10a of a gas flow passage 10 to pouring basin part 5. A horn 8 is vertically oscillated by an ultrasonic oscillation device 7 at the same instant. Then the above-mentioned gas is sheared to fine foam in the stage of passing through a space 9. The foam disperses and rises in the channel part 4. Cavitation is induced in the foam by the ultrasonic oscillation at the focus of the recessed surface 8a of the horn 8, by which the melt is atomized. The mist thereof is sucked by a water cooled impeller 15 rotating at a high speed, by which the mist is solidified. The solidified metal is recovered as the pulverous powder into a casing 16.