The invention discloses a low tension
fine grain casting device and a method thereof. The device comprises an upper chamber, a lower chamber, a top cover, a
casting mold, a melt device, a liquid lift tube, a refiner memorizer, an air pressure regulating device, a pressure bearing plate. The refiner memorizer is placed between the liquid lift tube and the
casting mold gate, and the liquid lift tube is fixed on the pressure bearing plate; the
casting mold is placed in the upper chamber within the furnace, the periphery being filled with fine grains; the melt device is placed underneath the liquid lift tube, being concentric with the liquid lift tube; the air regulating device is circumscribed with a
vacuum pump, a pressure tank and a connection valve by the
flange plates in the upper chamber and the lower chamber so as to regulate the air pressure in the upper chamber and the lower chamber. The invention is reasonable in structure, advanced in technology and easy to operate. By arranging the refiner memorizer between the liquid lift tube and the
casting mold gate, and utilizing the melt and flow of
metal liquid, the refiner is carried into the casing mold, and meanwhile, the
melt temperature while being carried into the
casting mold is reasonably lowered so as to achieve the purposes of grain refining and shrinking looseness reduction.