| 摘要 |
A method of casting utilizing an evaporable foam system with a hypereutectic aluminum silicon alloy. The alloy is composed by weight of 16% to 19% silicon, 0.4% to 0.7% magnesium, up to 1.4% iron, up to 0.3% manganese, up to 0.37% copper and the balance aluminum. The molten alloy is introduced into a mold in contact with an evaporable foam pattern formed of polystyrene, or the like. The heat of the molten alloy will decompose and vaporize the pattern and the vapor will enter the interstices of the surrounding sand, while the molten alloy will fill the void caused by the vaporization of the pattern. The heat of crystallization caused by precipitation of the silicon on solidification of the allow will temporarily slow the solidification rate of the alloy, thus increasing the time for elimination of pattern residue vapors from the molten alloy. |
