COATING AGENT FOR LOST FOAM PATTERN CASTING

摘要

PURPOSE: To promote the removal of gas and to suppress the development of defect by making an aggregate in a coating agent coated on the surface of a foamed resin-made lost foam pattern into grains having fine pores absorbing thermal decomposition gas produced from the pattern at the time of casting. ;CONSTITUTION: The foamed resin in the lost foam pattern 21 is thermally decomposed and lost with molten metal 22. The part 23 near the lost foam pattern 21 brought into contact with molten metal 22 is thermally decomposed in order. A part of the thermal decomposition gas produced at this time, flows into sand through gaps 26 among the aggregate 25 in the coating layer 24 and further, flows to the atmosphere from the sand layer. A part in the other part flows into fine pores 27 in the aggregate 25 and absorbed. Therefore, the absorbed part in the fine holes 27 in the aggregate 25 is promoted to remove the thermal decomposition gas. Then the material of the aggregate 25 is used to the compound of one or more kinds of the ceramics of alumina, silica, zirconia, cordierite, etc.;COPYRIGHT: (C)1995,JPO