| 摘要 |
PURPOSE:To maintain the high purity of a molten metal and to increase the output thereof by using a water-cooled divided copper crucible as a melting crucible provided with a high-frequency induction heating coil on the outer periphery thereof. CONSTITUTION:A metallic material is charged into the water-cooled divided copper crucible 63, the inside wall of which is formed by connecting water- cooled copper segments 81 divided in the longitudinal direction via insulating refratories 82. After a prescribed inert atmosphere is maintained in a hermetic chamber 60, the above-mentioned heating coil 64 for the crucible 63 is energized. The induction current hardly flows in the crucible 63 at this time and efficiently heats and melts the metallic material in the crucible 63 so that a thin solidified shell 74 of the molten metal 72 itself is formed and the inside wall of the crucible 63 is protected by the self-coating. The molten metal 72 is then dropped from a nozzle 65 heated by the induction heating coil 66 for the nozzle 65 onto a disk 69 rotating at a high speed and is splashed by centrifugal force, by which the fine powder is produced.
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