Method for casting magnet bodies

Claim 1

THE METHOD OF CASTING UNIDIRECTIONAL GRAINED MAGNET BODIES OF AN ANISOTROPIC FERROUS MAGNET ALLOY COMPRISING: PROVIDING A CHILL MEMBER AND A REFRACTORY MOLD DISPOSED THEREON HAVING A MOLD PORTION WITH A PLURALITY OF MOLD CHAMBERS THEREIN EXTENDING VERTICALLY UPWARDLY FROM SAID CHILL MEMBER AND A PORTION PROVIDING A SUBSTANTIALLY CLOSED RESERVOIR CHAMBER SPANNING THE AREA ABOVE THE COMMUNICATING THROUGH RESTRICTED OPENINGS IN THE UPPER ENDS OF SAID MOLD CHAMBERS WITH SAID MOLD CHAMBERS, SAID MOLD PORTION HAVING A MOLD PATTERN PORTION DEFINED BY THE PERIPHERY OF THE OUTERMOST MOLD CHAMBERS AND A REINFORCING PORTION EXTENDING THEREABOUT WITH A RATIO OF MOLD CHAMBER CROSS-SECTIONAL AREA TO THE AREA OF MOLD PATTERN PORTION OF GREATER THAN ABOUT 1:3 PREHEATING THE ASSEMBLED MOLD AND RESERVOIR TO A TEMPERATURE OF ABOUT 1200 TO 2700*F.; POURING THRU SAID RESERVOIR INTO SAID MOLD ASSEMBLY ANISOTROPIC FERROUS MAGNET ALLOY SUPERHEATED TO A TEMPERATURE AT LEAST 200* F. ABOVE THE LIQUIDUS POINT BUT BELOW THE POINT AT WHICH TWIN GRAIN FORMATION OCCURS IN AN AMOUNT SUFFICIENT TO FILL SAID MOLD CHAMBERS AND PROVIDE A RESERVOIR OF SUPERHEATED ALLOY ABOVE SAID MOLD CHAMBERS SUBSTANTIALLY CLOSED TO ATMOSPHERIC HEAT LOSSES, SAID MOLD AND METAL TEMPERATURES BEING SELECTED TO PROVIDE A STEEP THERMAL GRADIENT DURING EXTRACTION OF THE SUPERHEAT AND HEAT OF SOLIDIFICATION OF THE ALLOY IN SAID MOLD CHAMBERS WHILE MINIMIZING TRANSVERSE HEAT LOSS THEREFROM, SAID RESERVOIR OF SUPERHEATED ALLOY IN SAID RESERVOIR CHAMBER PROVIDING A RESERVOIR OF HEAT FOR THE METAL IN SAID MOLD CAVITIES TO AVOID PREMATURE CHILLING THEREOF AND TO ENABLE SOLIDIFICATION TO OCCUR THROUGH EXTRACTION OF THE HEAT FROM THE MOLTEN METAL IN SAID MOLD CHAMBERS THROUGH SAID CHILL MEMBER; AND ALLOWING SAID ALLOY TO SOLIDIFY IN SAID MOLD CHAMBERS WITH THE HEAT THEREOF BEING SUBSTANTIALLY ENTIRELY EXTRACTED FROM THE BOTTOM OF SAID CHAMBERS BY SAID CHILL MEMBER TO PRODUCE A SUBSTANTIALLY UNIDIRECTIONALLY GRAINED STRUCTURE.

Claim 2

THE METHOD OF CASTING UNIDIRECTIONAL GRAINED MAGNET BODIES OF AN ANISOTROPIC FERROUS MAGNET ALLOY COMPRISING: PROVIDING A CHILL MEMBER AND A REFRACTORY MOLD DISPOSED THEREON HAVING A MOLD PORTION WITH A PLURALITY OF MOLD CHAMBERS THEREIN EXTENDING VERTICALLY UPWARDLY FROM SAID CHILL MEMBER AND A PORTION PROVIDING A SUBSTANTIALLY CLOSED RESERVOIR CHAMBER SPANNING THE AREA ABOVE THE COMMUNICATING THROUGH RESTRICTED OPENINGS IN THE UPPER ENDS OF SAID MOLD CHAMBERS WITH SAID MOLD CHAMBERS, SAID MOLD PORTION HAVING A MOLD PATTERN PORTION DEFINED BY THE PERIPHERY OF THE OUTERMOST MOLD CHAMBERS AND A REINFORCING PORTION EXTENDING THEREABOUT WITH A RATIO OF MOLD CHAMBER CROSS-SECTIONAL AREA TO THE AREA OF MOLD PATTERN PORTION OF GREATER THAN ABOUT 1:3 PREHEATING THE ASSEMBLED MOLD AND RESERVOIR TO A TEMPERATURE OF ABOUT 1200 TO 2700*F.; POURING THRU SAID RESERVOIR INTO SAID MOLD ASSEMBLY ANISOTROPIC FERROUS MAGNET ALLOY SUPERHEATED TO A TEMPERATURE AT LEAST 200* F. ABOVE THE LIQUIDUS POINT BUT BELOW THE POINT AT WHICH TWIN GRAIN FORMATION OCCURS IN AN AMOUNT SUFFICIENT TO FILL SAID MOLD CHAMBERS AND PROVIDE A RESERVOIR OF SUPERHEATED ALLOY ABOVE SAID MOLD CHAMBERS SUBSTANTIALLY CLOSED TO ATMOSPHERIC HEAT LOSSES, SAID MOLD AND METAL TEMPERATURES BEING SELECTED TO PROVIDE A STEEP THERMAL GRADIENT DURING EXTRACTION OF THE SUPERHEAT AND HEAT OF SOLIDIFICATION OF THE ALLOY IN SAID MOLD CHAMBERS WHILE MINIMIZING TRANSVERSE HEAT LOSS THEREFROM, SAID RESERVOIR OF SUPERHEATED ALLOY IN SAID RESERVOIR CHAMBER PROVIDING A RESERVOIR OF HEAT FOR THE METAL IN SAID MOLD CAVITIES TO AVOID PREMATURE CHILLING THEREOF AND TO ENABLE SOLIDIFICATION TO OCCUR THROUGH EXTRACTION OF THE HEAT FROM THE MOLTEN METAL IN SAID MOLD CHAMBERS THROUGH SAID CHILL MEMBER; AND ALLOWING SAID ALLOY TO SOLIDIFY IN SAID MOLD CHAMBERS WITH THE HEAT THEREOF BEING SUBSTANTIALLY ENTIRELY EXTRACTED FROM THE BOTTOM OF SAID CHAMBERS BY SAID CHILL MEMBER TO PRODUCE A SUBSTANTIALLY UNIDIRECTIONALLY GRAINED STRUCTURE.