| 摘要 |
PURPOSE:To improve quality of a casting by coating facing material losing with heat of molten metal on outer face of a pattern composing of foaming resin and in case of need, coating non-lost facing material and/or refractory grain on the above coating. CONSTITUTION:The pattern 1 is formed with foaming grain 14 of foaming polystyrene, etc., and also on the outer face, the facing material 2 of combustible organic substance, etc., losing with heat of the molten metal is coated. Further, in case of need, on this coating, the facing material 3 not losing with heat and/or the refractory grain 4 are in order coated and stuck. The molten metal 16 is poured in the part of the pattern 1 and the pattern 1 is lost with this heat, to cast the casting 17. Then, the facing material 2 is hydrolyzed and the facing material 3 and the refractory grain 4 improve flatness and strength at boundary face between the casting sand 11 and the pattern 1. By this method, development of defect on the surface of the casting 17 is prevented and the quality of the casting 1 is improved. |
