| 摘要 |
PROBLEM TO BE SOLVED: To allow internal defects to be unevenly distributed on the inner circumferential wall side when a cylindrical body is provided by centrifugal casting. SOLUTION: A molten metal pouring tube 24 feeding the molten metal L of an Al-Si based alloy to the inside of a cylindrical die 12 is surrounded by four bar-shaped heaters 26. When the molten metal L forms a cylindrical body 60, the cylindrical body 60 is warmed by the bar-shaped heaters 26 from the inner circumferential wall side. Thus, the cooling velocity on the inner circumferential wall side is made low, and, even in the case bubbles are generated in the molten metal L, the bubbles move to the inner circumferential wall side by centrifugal force before the cylindrical body 60 is solidified. As the phenomenon is progressed, the cylindrical body 60 is cooled and solidified. Thereafter, grinding is performed from the inner circumferential wall side, and the parts in which defects caused by the bubbles are present are removed. COPYRIGHT: (C)2008,JPO&INPIT
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