Precision casting process in which the runner bar is kept molten - by making it the sec. winding of a transformer

摘要

Precision casting process uses a runner system leading to mould cavities. The novelty is the use of a transformer yoke with a prim. winding on one end connected to a power supply, the yoke being arranged so that the runner system forms the sec. winding in which current is induced in order to retard the solidification of the molten metal in the runner system. The transformer yoke pref. possesses a hinge so it can be located round the runner system in which heat is generated to control the cooling rate of the melt, esp. where the runner system and patters are surrounded by a ceramic shell, for casting clusters of objects. Used, e.g. when using a lost pattern made of wax or plastic. After the castings have solidified, the molten metal in the runner system can be poured back into a furnace or other vessel. There is thus a substantial energy saving as there is no need to cut off and remelt solidified runners and risers normally present on a cluster of lost wax castings.