| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an Al-Si based casting alloy that can miniaturize a primary crystal Si and an eutectic crystal at low cost in a cooling stage of a molten metal.SOLUTION: A method for manufacturing an Al-Si based casting alloy includes at least a step of vibrating a molten metal during a cooling process of the molten metal comprising the Al-Si based alloy. The step of vibrating the molten metal includes: a first vibration step of miniaturizing a primary crystal Si by giving an ultrasonic vibration to the molten metal, for a period including at least the time when the primary crystal Si begins to crystallize in the molten metal during the cooling periods from the time when the primary crystal Si begins to crystallize in the molten metal melting the Al-Si based alloy until the molten metal arrives at an eutectic temperature; and a second vibration step of making the molten metal precipitate the eutectic crystal and also miniaturizing the eutectic crystal, by vibrating the molten metal at the temperature higher than the eutectic temperature, when pouring the molten metal after the first vibration step in the casting mold. |
