402 消失模型鋳造法による薄肉アルミニウム合金鋳物の湯流れに及ぼす模型発泡倍率の影響(OS4-(1),OS4 オーガナイズドセッション≪材料・組織と加工≫)

Abstract

The effects of the pattern expansion ratio and the pouring temperature on the mold filling for a thin wall aluminum alloy casting in the expendable pattern casting (EPC) process was investigated experimentally. An aluminum alloy plate was cast by the EPC process, and the fluid lengths of the molten metal were measured for two expendable polystyrene (EPS) pattern with different expansion ratios. When the thin EPS pattern is used, the fluid length of the melt is shorter, because of the increase of the heat release area per unit volume of the melt. When the coat permeability is less than approximately 2, the fluid length of the melt increases with increasing of the coat permeability. When the coat permeability is greater than approximately 2, because the melt velocity hardly increases even if the coat permeability increases, the increase of the fluid length of the melt is small. The use of the EPS pattern with a high expansion ratio led to the long fluid length of the molten metal. The reason for this may be the decrease of the temperature drop at the melt surface due to the increase of the melt velocity.