| 摘要 |
A method for casting dental metals with a casting apparatus including a hermetically sealed casting chamber in which an arc electrode is located above, a crucible made of an electrically conductive material is positioned below the arc electrode, and a mold provided with a closed vent is disposed below the crucible, the method including by positioning a dental metal ingot on the crucible, evacuating the casting chamber to vacuum, feeding a small amount of an inert gas at such a pressure as to induce arc discharge all over the upper surface of the ingot, thereby melting the ingot placed on the crucible by arc discharge from the arc electrode, pouring the thus obtained molten metal into a mold through its inlet, and immediately feeding an additional amount of the inert gas into the casting chamber to increase its internal pressure to a level suitable for casting. Also the additional amount of the inert gas is rapidly fed into the casting chamber through a gas tank in the vicinity of the casting chamber.
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