| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a long-length ingot of high melting point metal whose height is 1.5 times the diameter thereof. SOLUTION: In the method for producing a long-length ingot of an active high melting point metal-containing alloy whose length is≥1.5 times the diameter thereof using a water cooling type copper crucible in which the bottom can be driven up and down in a vacuum or an inert gas atmosphere and by high frequency induction heating, the three operations of a melting/holding operation where an alloy raw material is charged inside the copper crucible and is melted, and further, the produced molten metal bath is held in the crucible for≥1 min, a crucible bottom lowering operation of lowering the bottom of the crucible by a fixed length at a rate of≤30 mm per minute, and a lowering stop operation of stopping the crucible bottom lowering operation at the point of the time in which the lowering by the fixed length is finished in the crucible lowering operation are regarded as one unit operation, and the unit operation is performed stepwise for a plurality of times. COPYRIGHT: (C)2006,JPO&NCIPI
|
