Method and device for reducing the contraction (shrink) cavity during solidification of electromelted metals, alloys, refractories and other ceramics obtained by melting

摘要

The invention relates to a method and a device making it possible to reduce the contraction (shrink) cavity during solidification of electromelted metals and refractories. To this end, by injecting inert gas by means of tubes 1 passing through the walls or the base of the mould 2, a vigorous agitation of the liquid is generated in order to obtain, as a consequence of its cooling, the appearance of numerous crystals. Simultaneously, solidification from the walls of the mould is slowed by limiting, if possible by heat-insulating them, the heat losses through the said walls. The treatment is continued until a mixture of liquid and crystals, which is as rich as possible in crystals, is obtained. When treatment is halted, there is only a small amount of contraction (shrinkage), hence a small or non-existent contraction (shrink) cavity located at the head end of the solidified block. During treatment, it is possible to add solid particles in order to accelerate crystallisation. IMAGE