| 摘要 |
A feeder consisting of exothermic heating composition keeps the cast material disposed in the feeder liquid until completion of the shrinkage feed of the casting. To avoid contamination of the moulding sand (2) on separation of the casting (1) due to burnt feeder disintegrating into irregular fragments, the make-up of the heating composition is so chosen that the heating composition during the shrinkage feed sinters together and the burnt feeder is given such a high strength that it can be detached as a whole or in large pieces capable of being sieved out. Various ways in which the constitution of the heating composition is adjusted to achieve sintering at the temperature reached are described with examples of constituents. <IMAGE> |
