Metal casting process and elements and compositions employed in same

Claim 1

IN THE ART OF METAL CASTING WHEREIN USE IS MADE OF A SHELL INTO WHICH THE MOLTEN METAL IS POURED, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF FORMING THE SHELL SOLELY BY THE APPLICATION OF PRESSURE BY COMPRESSING A DRY COMPOSITION IN M OLDING RELATION IN A DIE PATTERN HAVING A MOLD SURFACE CORRESPONDING TO A PART OF THE PRODUCT TO BE CAST AND WHEREIN THE MOLDING COMPOSITION IS FORMED OF THE COMBINATION OF A REFRACTORY MATERIAL IN FINELY DIVIDED FORM, A PRESSURE-SENSITIVE BINDER WHICH OPERATES AS AN INTERIM BINDER TO IMPART SHAPE AND INTEGRITY TGO THE DRY MOLDED PRODUCT, AND A REFRACTORY BINDER WHICH BECOMES EFFECTIVE WHEN HEATED TO A TEMPERATURE WITHIN THE RANGE OF 800-2400* F., REMOVING THE DRY MOLDED PRODUCT FROM THE DIE, AND THEN HEATING THE MOLDED SHELL PART TO A TEMPERATURE WITHIN THE RANGE OF 800-2400* F. TO DRIVE OFF THE INTERIM BINDER AND OTHER VOLATILIZABLE MATERIAL FROM THE MOLDED PRODUCT AND TO ACTIVATE THE REFRACTORY BINDER TO PRODUCE A BONDED SHELL PART FORMED OF INORGANIC MATERIALS HAVING GOOD HEAT SHOCK RESISTANCE