PROCESS FOR MANUFACTURING A CASTING WITH A UNIDIRECTIONALLY SOLIDIFIED METALLIC ALLOY

摘要

The present invention provides in a process for manufacturing a casting with a unidirectionally solidified metallic alloy which comprises solidifying an alloy mass, initially in the molten liquid state, in a mould of the required shape, the improvement in which the alloy in the mould is gradually cooled down and in an entire manner; while a unidirectional thermal gradient is maintained parallel to a given direction for the alloy mass to set the whole of the alloy in a superfused metastable equilibrium in the form of an homogenous liquid and superfusion equilibrium is upset to cause solidification of the alloy in the form of a material with a dendritic crystallization structure comprising dendrites the main axis of which are parallel to the direction of the thermal gradient. The present invention also provides a device for manufacturing a casting with a unidirectionally solidified metallic alloy, said device comprising at least one mould located in an enclosure provided with an adjustable heating system and with means to establish within the mould a thermal gradient which is initiated and increases from a section of the mould wall.