消失模型鋳造法におけるアルミニウム合金溶湯の簡易湯流れモデル

抄録

  In the expandable pattern casting (EPC) process, molten metal is poured into the cavity by the thermal decomposition of the expandable polystyrene pattern (EPS). Decomposition gas escapes into the dry sand through the coat layer, making the mold filling mechanism in the EPC process very complicated. In the present study, a simple simulation of the mold filling of molten aluminum alloy in the EPC process was carried out, considering the thermal decomposition of EPS pattern and discharge of decomposition gas through the coat. When there was no reduced pressure in the flask, the thickness of thermal decomposition gas layer decreased with increasing the coat permeability, but the effect on the melt velocity was not so significant. Under reduced pressure, the thickness of the gas layer was smaller and the melt velocity was lager than the case without reduced pressure, and the effect of coat permeability on the melt velocity was remarkable. The analytical values of the filling time of molten aluminum alloy were compared with the experimental values using the plate EPS pattern and were in relatively good agreement with the experimental values.