PURPOSE: To produce the ingot which is fine in crystal grains and has a uniform a granular crystalline structure having fine crystal grains by imparting ultrasonic vibrations to metal at the time of melting the metal by irradiation with an electron beam and pulling the molten metal as the ingot.
CONSTITUTION: The ingot 9 of the metal to be melted is first arranged in a water-cooled crucible 1 of a bottomless type and a raw material electrode 7 consisting of the metal to be melted on its surface is heated and melted by irradiation with the electron beam 10 from an electron gun 2 to form a molten metal pool 11 in the upper part of the ingot 9. The ingot 9 is made successively longer by the solidification thereof and is pulled gradually from the crucible 1 by a pulling device 8. The ultrasonic vibrator transducer 4 as a raw material is mounted on the metallic electrode 7 in such a case and ≥0.1kHz ultrasonic vibrations are applied to the molten metal layer 11, by which the ingot 9 having the fine and uniform granular crystals and excellent plastic workability is obtd. without forming the coarse and large columnar crystals at the time of solidifying the molten metal pool 11.
CHIBA YASUNORI
NIKKO KINZOKU KK